Text and Data Mining valid from 2019-09-30
Received: 28 May 2019
Accepted: 18 August 2019
First Online: 30 September 2019
Ethics approval and consent to participate
: The study protocol was designed and approved by the ethical committee of the First Affiliated Hospital of Zhengzhou University.
: Informed consent was obtained from all patients.
: The authors declare that they have no competing interests.