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Article History

Received: 25 January 2019

Accepted: 8 May 2019

First Online: 13 June 2019

Ethics approval and consent to participate

: The study was approved by the Ethics Board of Guangxi Medical University. All the subjects were given the detailed information of this study and had signed in the written consent before enrollment.

: Not applicable.

: The authors declare that they have no competing interests.

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