Cao, Xiaohui
Liu, Ming
Zhai, Fushan
Li, Nan
Bao, Chaoen
Liu, Yinliang
Chen, Gang
Article History
Received: 3 August 2018
Accepted: 24 May 2019
First Online: 31 May 2019
Ethics approval and consent to participate
: The study was approved by the ethics committee of the Third Hospital of Hebei Medical University. The need for individual consent was waived by the committee.
: Not applicable.
: The authors declare that they have no competing interests.