Author contributions
MM
GL had full access to all the data in the study and took responsibility for the integrity of the data and the accuracy of the data analysis. Concept and design: HW, ZL, ZH, YG and GL. Acquisition, analysis or interpretation of data: HW, ZL, ZH, MM and WM. Drafting of the manuscript: HW, ZL and ZH. Critical revision of the manuscript for important intellectual content: HW, ZL, ZH, YG, MM, WM and GL. Statistical analysis: HW, ZL, ZH and YG. Administrative, technical or material support: GL. Supervision: GL.