Funding for this research was provided by:
National Natural Science Foundation of China (31571291, 31771417)
Text and Data Mining valid from 2019-11-23
Received: 13 May 2019
Accepted: 24 September 2019
First Online: 23 November 2019
Ethics approval and consent to participate
: Ethics approval was obtained from local institutional review boards of all institutions, and all participants gave written informed consent before being recruited into the study.
: Not applicable.
: The authors declare that they have no competing interests.