Author Contributions
Conception and design: XY, CJZ
Analysis and interpretation: XY, HYP
Data collection: HYP
Writing the article: XY
Critical revision of the article: CJZ
Final approval of the article: CJZ
Statistical analysis: XY
Conflict of interest: No conflicts of interest
Funding: The Talent Research Starting Foundation (2016QDJZR09), Hubei University of Medicine (2016).