Received: 28 May 2020
Accepted: 20 July 2020
First Online: 29 July 2020
Ethics approval and consent to participate
: This study was approved by the biomedical research ethics committee of Peking University First Hospital (approval No. 2018, scientific research 242), and the need for informed consent was waived.
: Not applicable.
: The authors declare that they have no competing interests.