Received: 3 March 2021
Accepted: 25 May 2021
First Online: 10 June 2021
: This study was performed according to the Helsinki Declaration and approved by the Ethics Committee of West China Hospital (West China Hospital #2020198). Because no paper documents are allowed to be taken out of the quarantine area, the requirement for written informed consent was waived by the Ethics Committee of West China Hospital and informed consent was obtained verbally (Y.M) from all participants.
: Not applicable.
: The authors declare that they have no competing interests.