Funding for this research was provided by:
Project of Hebei Health Commission (No.20191713)
Article History
Received: 10 September 2020
Accepted: 21 October 2020
First Online: 6 November 2020
Compliance with ethical standards
:
: The authors declare that they have no competing interests.
: This study was approved by Institutional Review Board of our hospital, and all guardians of participants provided written informed consents before enrollment.