Funding for this research was provided by:
National Natural Science Foundation of China (81601545)
Chongqing Health and Family Planning Commission Foundation (2016MSXM018)
Text and Data Mining valid from 2019-11-07
Received: 31 May 2019
Accepted: 18 October 2019
First Online: 7 November 2019
Ethics approval and consent to participate
: The Research Ethics Committee of The First Affiliated Hospital of Chongqing Medical University (IRB No. 2019–062) approved this study. All the participants provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.