Text and Data Mining valid from 2019-04-19
Received: 28 August 2018
Accepted: 7 December 2018
First Online: 19 April 2019
Ethics approval and consent to participate
: This study was approved by the Ethical Committee of Cangzhou Central Hospital (2016021621) and complied with the guidelines and principles of the Declaration of Helsinki. All participants signed written informed consent.
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