Funding for this research was provided by:
National Natural Science Foundation of China (71373058)
Received: 22 August 2020
Accepted: 26 November 2020
First Online: 14 December 2020
Ethics approval and consent to participate
: The study protocol and the informed consent form were approved by the IRB (institutional review board) of Kunming Medical University (30860248). The respondents were voluntary and provided written consent for participation.
: The authors understand and agree to publish.
: The authors declare that they have no competing interests.