Text and Data Mining valid from 2019-01-24
Received: 2 April 2018
Accepted: 13 December 2018
First Online: 24 January 2019
Ethics approval and consent to participate
: Written informed consent for research was obtained from each patient. This retrospective study was approved by the Institutional Human Experiment and Ethics Committee of the First Affiliated Hospital of Zhengzhou University.
: Not applicable.
: The authors declare that they have no competing interest.
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