Funding for this research was provided by:
National Natural Science Foundation of China (81572719, 81471685, 81471687, 81771858, 81601520)
National Natural Science Foundation of China (81530053)
Text and Data Mining valid from 2018-05-12
Received: 10 December 2017
Accepted: 27 April 2018
First Online: 12 May 2018
: The authors declare that they have no competing interests.
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