Funding for this research was provided by:
Natural Science Foundation of Beijing Municipality (6192011)
National Natural Science Foundation of China (31770280)
Text and Data Mining valid from 2020-03-19
Received: 1 November 2019
Accepted: 2 March 2020
First Online: 19 March 2020
Ethics approval and consent to participate
: Not applicable.
: All authors consent for publication.
: The authors declare that they have no conflict of interests.