Funding for this research was provided by:
Youth Fund of the Second Hospital of Shandong University (Y2014010028)
Key Research And Development Plan of Shandong Provence (No. 2015GSF118107)
Text and Data Mining valid from 2018-07-20
Received: 8 April 2018
Accepted: 13 July 2018
First Online: 20 July 2018
Ethics approval and consent to participate
: This study was approved by the ethics committee of The Second Hospital of Shandong University, and followed the ethical guidelines laid down in the 1975 Declaration of Helsinki. All participants have given informed and written consent.
: All participants have given consent for publication.
: The authors declare that they have no competing interests.
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