Acknowledgements
The authors thank Professor Teng-jiao Wang and Long Qing (Naval Medical University, China) for data analysis.
Authors’ contributions : Study design: Hua Yang and Jin-Chao Song. Data collection: Hai-yan Chen, Shu-heng Tang, and Fang Deng. Statistical analysis: Hai-yan Chen. Manuscript drafting: Fang Deng and Wen Liu. Supervision: Jin-Chao Song. Project administration: Jin-Chao Song.