An, Ning
Lin, Ji Sheng
Fei, Qi
Article History
Received: 9 May 2021
Accepted: 15 June 2021
First Online: 28 June 2021
Declarations
:
: This cross sectional study was approved by the Ethics Committee of Beijing Friendship Hospital, Capital Medical University, and all subjects provided signed informed consent. All participants provided informed consent prior to commencing study involvement.
: Not applicable.
: The authors declare that they have no competing interests.