Feng, Shu
Wang, Zhonghao
Zhao, Yanhua
Tao, Chuanmin
Funding for this research was provided by:
Health and Family Planning Commission of Sichuan Province (Sichuan Health Office issued [2017] 70)
Article History
Received: 18 December 2019
Accepted: 4 June 2020
First Online: 29 June 2020
Competing interests
: The authors declare no competing interests.