Received: 29 August 2020
Accepted: 20 April 2021
First Online: 3 May 2021
: All human participants signed a written informed consent. Consent for participation in the study was obtained where participants are children (under 16 years old) from their parent or guardian. Ethics Committee of scientific research review of 307th Hospital of PLA (KY-2019-3-11).
: Not applicable.
: The authors declare no conflicts of interest.