Funding for this research was provided by:
National Natural Science Foundation of China (2016GXNSFAA380306)
Guangxi Zhuang Region Health Department (Z20170816)
Received: 20 May 2020
Accepted: 12 October 2020
First Online: 28 October 2020
Ethics approval and consent to participate
: All data were downloaded from public databases and therefore did not require approval and review by the ethics committee.
: Not applicable
: The authors declare that they have no competing interests.