Funding for this research was provided by:
National Natural Science Foundation of China (81370869)
Text and Data Mining valid from 2019-11-21
Received: 13 May 2019
Accepted: 31 October 2019
First Online: 21 November 2019
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University, and conferred to Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.