Liu, Chao
Che, Yanxu
Article History
Received: 23 April 2018
Revised: 24 June 2018
Accepted: 11 July 2018
First Online: 20 July 2018
Compliance with Ethical Standards
:
: The content has not been published or submitted for publication elsewhere.
: The authors declare that they have no conflicts of interest.
: The present study has been approved by the ethics committee of the Cangzhou Central Hospital. All participants or their relatives were informed of the study protocol and their written informed consents were obtained.