Funding for this research was provided by:
The Beijing Municipal Administration of Hospital Clinical Medicine Development of Special Funding (ZYLX201708)
Received: 17 April 2017
Accepted: 3 January 2018
First Online: 2 February 2018
Ethics approval and consent to participate
: The trial will be conducted by the ethical principles outlined in the Declaration of Helsinki, 1996 [CitationRef removed]; National Ethics Review for Biomedical Research Involving Humans (Trial), 2007 [CitationRef removed]; and International Ethical Guidelines for Biomedical Research Involving Human Subjects, 2002 [CitationRef removed]. Approval was obtained from the Ethics Committee of Beijing Tiantan Hospital on 18 October 2014 (reference number KY-2014-031-02).
: Not applicable
: The authors declare that they have no competing interests.
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