Li, Tian-gang
Ma, Bin
Qi, Ping-an
Funding for this research was provided by:
Natural Science Foundation of Gansu Province (21JR1RA048, 21JR1RA048, 21JR1RA048)
Article History
Received: 20 April 2022
Accepted: 20 June 2022
First Online: 28 June 2022
Declarations
:
: This study has been granted an exemption from the Medical Ethics Committee of Gansu Provincial Maternity and Child-care Hospital.
: Not applicable.
: The authors declare that they have no competing interests.