Funding for this research was provided by:
National Natural Science Foundation of China (81802226, 81871834, 81301589)
Text and Data Mining valid from 2019-01-18
Received: 9 October 2018
Accepted: 6 January 2019
First Online: 18 January 2019
Consent for publication
: Not applicable.
: The authors declared that they no competing interests.
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