Mu, Haiyan
Zheng, Qingqing
Hao, Lihai
Article History
Received: 22 January 2021
Accepted: 6 May 2021
First Online: 5 June 2021
Declarations
:
: All participating subjects undersigned informed consent. The Ethics Committee of Weifang People’s hospital approved the conduction of this retrospective study. This study was in line with the Helsinki declaration.
: Not applicable.
: The authors declare that they have no competing interests.