Funding for this research was provided by:
National Natural Science Foundation of China (81470054)
Text and Data Mining valid from 2019-11-18
Received: 17 May 2019
Accepted: 30 October 2019
First Online: 18 November 2019
Ethics approval and consent to participate
: The study was approved by the Medical Ethics Committee of Hebei Medical Center (No: F-KY-0022-20170930-01). The study was conducted in accordance with standard clinical practice guidelines. Each participant in the study obtained written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.