Article History
Received: 18 July 2019
Accepted: 30 March 2020
First Online: 15 April 2020
Ethics approval and consent to participate
: Ethical approval was given by the medical ethics committee of Daping Hospital of Army Medical University with the following reference number: ME (2014), No. fifty-one. Informed consent was waived because this research did not involve individual data.
: Not applicable
: The authors declare that they have no competing interests.