Funding for this research was provided by:
the fund of Ningxia Hui Autonomous Region (2018AAC03145)
Article History
Received: 28 September 2020
Accepted: 12 January 2021
First Online: 29 January 2021
Compliance with ethical standards
:
: The authors declare no conflict of interest.
: This study was approved by the ethics committee of the General Hospital of Ningxia Medical University. Prior to participating in the study, each participant signed a written informed consent form. The study was conducted according to the principles of the Declaration of Helsinki.