Funding for this research was provided by:
the science and technology department’s major program of Henan, China (161100311100)
the national health and family planning commission in China (201601010)
The education department’s Project of Henan, China (19A320052)
Text and Data Mining valid from 2019-11-21
Received: 29 July 2019
Accepted: 11 November 2019
First Online: 21 November 2019
Ethics approval and consent to participate
: This study was reviewed and approved by the Ethics Committee of The Third Affiliated Hospital of Zhengzhou University.
: Informed consent was obtained from all individual participants included in the study.
: The authors declare that they have no competing interests.