Funding for this research was provided by:
National Natural Science Foundation of China (No. 81773885, No. 31770366, No. 81703224)
Text and Data Mining valid from 2019-10-29
Received: 22 May 2019
Accepted: 16 October 2019
First Online: 29 October 2019
Ethics approval and consent to participate
: Not applicable
: Not applicable.
: The authors declare that they have no competing interests.