Luo, Huiqiang
Ren, Xiaohui
Li, Jijie
Wu, Kan
Wang, Yixi
Chen, Qing
Li, Ningxiu
Article History
Received: 22 May 2019
Accepted: 12 May 2020
First Online: 24 May 2020
Ethics approval and consent to participate
: Ethics approval for the study was granted by the Ethics Review Committee of Peking University, and all the participants provided signed informed consent at the time of participation. The study methodology was carried out in accordance with approved guidelines.
: Not applicable.
: The authors declare that there are no conflicts of interest.