Li, Nan
Qiao, Hong
Guo, Jing-Fei
Yang, Hong-Yun
Li, Xue-Ying
Li, Shuang-Ling http://orcid.org/0000-0002-4292-8208
Wang, Dong-Xin
Yang, Li
Article History
Received: 2 April 2019
Accepted: 26 August 2019
First Online: 2 September 2019
Ethics approval and consent to participate
: The study protocol was approved by the Clinical Research Ethics Committee of Peking University First Hospital (2018–137). The ethics committee agreed to waive the written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.