Funding for this research was provided by:
Chinese National Science and Technology Project of Olympic Winter Games (2018YFF0301103)
Received: 11 February 2020
Accepted: 1 July 2020
First Online: 9 July 2020
Ethics approval and consent to participate
: This study was approved by the Peking University Research Ethics Committee of our hospital. All procedures performed in studies involving human participants were in accordance with the ethics standards of the institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethics standards. Written informed consent was obtained from all individual participants included in this study.
: All data published here are under the consent for publication.
: The authors declare that they have no competing interests.