Funding for this research was provided by:
Jiangsu Provincial Department of Education (2018SJA0960)
Text and Data Mining valid from 2019-11-21
Received: 14 March 2019
Accepted: 29 October 2019
First Online: 21 November 2019
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of Xuzhou Medical University.
: All participants gave consent for publication of their data.
: The authors declare that they have no competing interests.