Funding for this research was provided by:
National Natural Science Foundation of China (81501557)
Text and Data Mining valid from 2019-10-25
Received: 31 May 2019
Accepted: 16 October 2019
First Online: 25 October 2019
Ethics approval and consent to participate
: Not applicable.
: We consent for the publication of this work.
: The authors declare that they have no competing of interests.