Funding for this research was provided by:
National Natural Science Foundation of China (81660334)
Natural Science Foundation of Guangxi Province (2018GXNSFAA050099, 2017GXNSFAA198190)
National Key Science and Technology Project of China (2018ZX10101002-001-006)
Guangxi Collaborative Innovation Center for Biomedicine (GCICB-IE-2018010)
Text and Data Mining valid from 2020-02-07
Received: 6 July 2019
Accepted: 21 January 2020
First Online: 7 February 2020
Ethics approval and consent to participate
: The study was reviewed and approved by the Human Research Ethics Committee of Guangxi Medical University (Ethical review No. 2013-130). Written informed consent was signed by each participant before initiation of the survey.
: Not applicable.
: The authors declare that they have no competing interests.