Funding for this research was provided by:
Natural Science Foundation of Guangxi Province (2013GXNSFGA019002)
National Natural Science Foundation of China (81272983)
Program for New Century Excellent Talents in University (NCET-12-0654)
Received: 7 August 2017
Accepted: 8 February 2018
First Online: 14 February 2018
Ethics approval and consent to participate
: This study was approved by the Ethics Review Committee of First Affiliated Hospital of Guangxi Medical University. Written informed consent was obtained from all participants.
: Not applicable.
: The authors declare that they have no competing interests.
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