Funding for this research was provided by:
the 2017 Education and Teaching Reform Project of Peking Union Medical College (No. 2017zlgc0122)
Received: 14 February 2020
Accepted: 19 November 2020
First Online: 26 November 2020
Ethics approval and consent to participate
: The study protocol was approved by the Ethics Committees of the Peking Union Medical College Hospital, Beijing, and all participants provided written informed consent.
: Not Applicable.
: All authors declare that they have no any Competing interests.