Dai, Yunxiang
Yan, Tingguo
Gao, Yuming
Article History
Received: 21 November 2019
Accepted: 26 February 2020
First Online: 3 March 2020
Ethics approval and consent to participate
: The experimental procedures of this study were approved by the Ethics Committee of Qingdao Jiaozhou Central Hospital, and an informed consent was received from each participant.
: Written informed consent for publication was obtained from each participant.
: The authors declare that they have no competing interests.