Funding for this research was provided by:
Heilongjiang Provincial Health and Family Planning Commission approved a scientific research project (2018-222)
Article History
Received: 13 August 2020
Accepted: 31 October 2020
First Online: 10 November 2020
Compliance with ethical standards
:
: The Authors declare that they have no conflict of interest to disclose.
: This study was approved by the ethics committee of The First Affiliated Hospital of Jiamusi University. Written informed consent was obtained from all subjects.