Funding for this research was provided by:
National Natural Science Foundation of China (81260060, 81560042)
Natural Science Foundation of Hainan Province, China (20158355, 30726)
Text and Data Mining valid from 2018-07-27
Received: 24 May 2018
Accepted: 18 July 2018
First Online: 27 July 2018
Ethics approval and consent to participate
: All procedures were conducted in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008. This study was approved by the Ethics Committee of the First Affiliated Hospital of Hainan Medical University. Informed consent was obtained from all participants.
: Not applicable.
: The authors declare that they have no competing interests.
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