Authors’ contributions
Conception and design: Yan-Tao Ma, Qiang-Min Huang, Yong-Jun Zheng; Acquisition of data: Bo Wang, Wen-Pin Xie; Analysis and interpretation of the data: Yu-Lin Dong; Drafting of the article: Yan-Tao Ma, Yu-Lin Dong; Critical revision of the article for important intellectual content: Qiang-Min Huang. All authors contributed to and approved the final manuscript.