Declarations
The authors have disclosed that they do not have any potential conflicts of interest.
Author contributions: Data collection was performed by Fengyuan Li, Wei-yun Zhang and Bing Liang. Statistical analysis was conducted by Fengyuan Li, Da-xiong Zeng and Qiang Guo. Analysis, interpretation and drafting of the manuscript was conducted by Jia-lin Liu, Hong-yang Xu, Qingyuan Zhan, Shanshan Wang, Chang Gao, Jian-an Huang, Bo Shen, Alpaslan Tasdogan, Jessalyn M. Ubellacker. All authors approved the manuscript before submission.