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Article History

Received: 2 July 2018

Accepted: 30 October 2018

First Online: 13 November 2018

Ethics approval and consent to participate

: Written consent was obtained from all subjects and individual patient data was not available. This study protocol was approved by the ethics committee of the Second Affiliated Hospital of Dalian Medical University (20180504007).

: Not applicable.

: The authors declare that they have no competing interests.

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