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Article History

Received: 1 June 2018

Accepted: 31 August 2018

First Online: 10 September 2018

Ethics approval and consent to participate

: All subjects signed the written informed consents and agreed to participate in this case control study. The study was separately approved by the ethics committee of Tianjin Medical University General Hospital and Tianjin Binjiang Hospital.

: Not applicable.

: The author declares that she has no competing interests.

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