Funding for this research was provided by:
National Natural Science Foundation of China (81471349)
Natural Science Foundation of Henan Province (162300410224)
Xinxiang Medical University Educational Reform Program Foundation (2017-XYJG-26)
Text and Data Mining valid from 2018-11-20
Received: 23 March 2018
Accepted: 2 November 2018
First Online: 20 November 2018
Ethics approval and consent to participate
: The study protocol was approved by Research Ethics Committee of the Second Affiliated Hospital of Xinxiang Medical University. All the participants informed the purpose of the study and gave their oral consent before the investigation.
: Not applicable.
: The authors declare that they have no competing interests.
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