Funding for this research was provided by:
National Natural Science Foundation of China (72002113, 71772176)
Article History
Accepted: 9 October 2020
First Online: 12 October 2020
Compliance with Ethical Standards
:
: On behalf of all authors, the corresponding author states that there is no conflict of interest.
: The present study was carried out following the ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments or compare ethics commitment. Our study was conducted with the consent of the ethics committee of Tsinghua University and Renmin University of China.
: The corresponding author is sure that informed consent, written, was obtained from all participants and clearly state it. And written informed consent to participate was obtained from the parents/guardians of the minors included in this study.