Received: 30 March 2020
Accepted: 16 June 2020
First Online: 23 June 2020
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study. This study was approved by Peking University Third Hospital Ethics Committee.
: Not applicable
: The authors declare that they have no competing interests.