Funding for this research was provided by:
National Natural Science Foundation of China (81271867)
National Natural Science Foundation of China (91431104)
International Science and Technology Cooperation Program of China (2014DFA31130)
Shanghai Municipal Commission of Health and Family Planning Grant (20174Y0089)
Article History
Received: 10 January 2018
Accepted: 4 April 2018
First Online: 12 April 2018