Funding for this research was provided by:
Beijing Municipal Commission of Science and Technology (Z161100000216124)
Strategic Priority Research Program of the Chinese Academy of Sciences (XDB02060007)
Text and Data Mining valid from 2017-09-25
Received: 9 April 2017
Accepted: 13 September 2017
First Online: 25 September 2017
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.
: This article does not contain any studies with human participants performed by any of the authors.