Funding for this research was provided by:
Hebei Science and Technology Science and Technology Support Program (1123038ZD)
Text and Data Mining valid from 2018-08-20
Received: 4 October 2017
Accepted: 3 August 2018
First Online: 20 August 2018
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: Ethical approval was approved by the Ethics Committee of Cangzhou Central Hospital.
: Informed consent was obtained from all individual participants included in the study.