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Genetic Variation of Goat Interferon Regulatory Factor 3 Gene and Its Implication in Goat Evolution
Okpeku M1,2; Esmailizadeh A1,6; Wang YZ1; Sanni TM5; Imumorin IG7; Peters SO8; Zhang JJ3; Dong Y1,4; Adeola AC1; Wang W*1; Shu LP1; Zhang YS1; wwang@mail.kiz.ac.cn
2016
发表期刊PLOS ONE
卷号11期号:9页码:e0161962.
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摘要The immune systems are fundamentally vital for evolution and survival of species; as such, selection patterns in innate immune loci are of special interest in molecular evolutionary research. The interferon regulatory factor (IRF) gene family control many different aspects of the innate and adaptive immune responses in vertebrates. Among these, IRF3 is known to take active part in very many biological processes. We assembled and evaluated 1356 base pairs of the IRF3 gene coding region in domesticated goats from Africa (Nigeria, Ethiopia and South Africa) and Asia (Iran and China) and the wild goat (Capra aegagrus). Five segregating sites with θ value of 0.0009 for this gene demonstrated a low diversity across the goats' populations. Fu and Li tests were significantly positive but Tajima's D test was significantly negative, suggesting its deviation from neutrality. Neighbor joining tree of IRF3 gene in domesticated goats, wild goat and sheep showed that all domesticated goats have a closer relationship than with the wild goat and sheep. Maximum likelihood tree of the gene showed that different domesticated goats share a common ancestor and suggest single origin. Four unique haplotypes were observed across all the sequences, of which, one was particularly common to African goats (MOCH-K14-0425, Poitou and WAD). In assessing the evolution mode of the gene, we found that the codon model dN/dS ratio for all goats was greater than one. Phylogenetic Analysis by Maximum Likelihood (PAML) gave a ω0 (dN/dS) value of 0.067 with LnL value of -6900.3 for the first Model (M1) while ω2 = 1.667 in model M2 with LnL value of -6900.3 with positive selection inferred in 3 codon sites. Mechanistic empirical combination (MEC) model for evaluating adaptive selection pressure on particular codons also confirmed adaptive selection pressure in three codons (207, 358 and 408) in IRF3 gene. Positive diversifying selection inferred with recent evolutionary changes in domesticated goat IRF3 led us to conclude that the gene evolution may have been influenced by domestication processes in goats.
资助者This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang.
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资助者This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang. ; This work was supported by the Chinese Academy of Sciences Fellowship for Postdoctoral and Visiting Scholars from Developing Countries, Grant Number Y302851081, awarded to Dr. Moses Okpeku; Education Trust Fund (TETFUND), Nigeria, Grant Number NDU/TETFUND/2013/0004, awarded to Dr. Moses Okpeku; and “973” project (Grant No. 2013CB835200) to Dr. Wen Wang.
文献类型期刊论文
条目标识符http://ir.kiz.ac.cn/handle/152453/10448
专题基因起源组
遗传资源与进化国家重点实验室
通讯作者wwang@mail.kiz.ac.cn
作者单位1.State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences (CAS), Kunming, Yunnan 650223, China
2.Department of Animal Science, Niger Delta University, Wilberforce Island, Ammassoma, Bayelsa State, Nigeria
3.School of Science and Information Engineering, Yunnan Agricultural University, Kunming 650201, China
4.Laboratory of Applied Genomics and Synthetic Biology, College of Life Science, Kunming University of Science and Technology, Kunming 650500, China
5.Department of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
6.Department of Animal Science, Shahid Bahonar University of Kerman, Kerman, PB 76169–133, Iran
7.Animal Genetics and Genomics Laboratory, Office of International Programs, College of Agriculture and Life Sciences, Cornell University, Ithaca, USA, 8 Department of Animal Science, Berry College, Mount Berry, USA
8.Department of Animal Science, Berry College, Mount Berry, USA
推荐引用方式
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Okpeku M,Esmailizadeh A,Wang YZ,et al. Genetic Variation of Goat Interferon Regulatory Factor 3 Gene and Its Implication in Goat Evolution[J]. PLOS ONE,2016,11(9):e0161962..
APA Okpeku M.,Esmailizadeh A.,Wang YZ.,Sanni TM.,Imumorin IG.,...&wwang@mail.kiz.ac.cn.(2016).Genetic Variation of Goat Interferon Regulatory Factor 3 Gene and Its Implication in Goat Evolution.PLOS ONE,11(9),e0161962..
MLA Okpeku M,et al."Genetic Variation of Goat Interferon Regulatory Factor 3 Gene and Its Implication in Goat Evolution".PLOS ONE 11.9(2016):e0161962..
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