Received: 20 January 2021
Accepted: 13 July 2021
First Online: 23 July 2021
: This study was approved by the ethics committee of the People's Hospital of Shouguang. Written informed consent was obtained from all subjects as well as parental consent for subjects aged less than 18 years. The study was carried out in compliance with the ARRIVE guidelines.
: Not applicable.
: The authors declare that they have no conflicts of interest to disclose.