Funding for this research was provided by:
National Natural Science Foundation of Liaoning Province (NO.:20170540239)
Text and Data Mining valid from 2018-11-01
Received: 28 June 2018
Accepted: 11 October 2018
First Online: 1 November 2018
Ethics approval and consent to participate
: This study was approved by the Medical Ethics Research Board of The Second Hospital of Dalian Medical University (No.IRB29). Written consent was obtained from the participants before the study began.
: Not applicable
: The authors declare that they have no competing interests.
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