Funding for this research was provided by:
National Natural Science Foundation of China (31371279)
Guangzhou Science and Technology Program key projects (201707010301)
Text and Data Mining valid from 2019-01-11
Received: 2 April 2018
Accepted: 22 November 2018
First Online: 11 January 2019
Ethics approval and consent to participate
: All procedures used in this study were approved by the Medical Ethics Committee of Nanfang Hospital, an affiliate of Southern Medical University, China.
: Not applicable.
: The authors declare that they have no competing interests.
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