Funding for this research was provided by:
Health and Family Planning Commission of Guangdong Province (SZXJ2018023)
Sanming Project of Medicine in Shenzhen (SYLY201725)
Shenzhen Health and Family Planning System Research Project (JCYJ20160422143333572)
Received: 14 March 2019
Accepted: 27 May 2019
First Online: 11 June 2019
Ethics approval and consent to participate
: All experiments were approved by the Ethics Committee of the Second Clinical Medical College (Shenzhen People’s Hospital).
: Not applicable.
: The authors declare that they have no competing interests.