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Article History

Received: 31 August 2018

Accepted: 13 November 2018

First Online: 20 November 2018

Ethics approval and consent to participate

: The study was performed in accordance with the guidelines of the Declaration of Helsinki. The study protocol and the form of consent were approved by the Ethics Committee of the Institutional Review Board of Zhenhai Lianhua Hospital, Ningbo Yinzhou Second Hospital and Affiliated Hospital of Medical School of Ningbo University. Written informed consent was obtained from all participants before our gathering of data and the study.

: Not applicable.

: The authors declare that they have no competing interests.

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