Funding for this research was provided by:
National Natural Science Foundation of China (81703322, 81960592, 81660545)
Guangdong Medical Research Foundation (A2019438)
joint special fund project of applied basic research of Kunming Medical University, department of science and technology of Yunnan province (2017FE468 (-013))
Received: 18 June 2020
Accepted: 21 December 2020
First Online: 14 January 2021
Ethics approval and consent to participate
: Ethics approval for the study was granted by the Medical Ethics Committee of Yunnan Provincial Population and Family Planning Research Institute (reference number 2017101702). Informed consent was written by study participants.
: Not applicable.
: The authors declare that they have no conflict of interest.