Funding for this research was provided by:
National Natural Science Foundation of China (No.81660529, No. 81360420)
Natural Science Foundation of Guangxi Province (No.2015GXNSFAA139120)
Received: 21 January 2017
Accepted: 29 January 2018
First Online: 12 February 2018
Ethics approval and consent to participate
: This study was approved by the Medical Ethics Committee of Guangxi Medical University. Written informed consent was obtained from the all included subjects.
: Not applicable.
: The authors declare that they have no competing interests.
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