Funding for this research was provided by:
Beijing Municipal Science & Technology Commission (Z18110000171837)
China Postdoctoral Science Foundation (2019M650773)
National Key Research and Development Program of China (2016YFC1301500)
Hebei Provincial Health and Family Planning Commission (20181258)
Article History
Received: 5 August 2020
Revised: 22 September 2020
Accepted: 23 September 2020
First Online: 28 September 2020
Compliance with Ethical Standards
:
: The authors declare that they have no conflicts of interest.
: The study procedures were in accordance with the 1964 Helsinki declaration and its later amendments. Informed consent was obtained from all individual participants included in the study. The protocol of this study had been approved by our institutional review board. This article does not contain any studies with animals performed by any of the authors.