Funding for this research was provided by:
National Natural Science Foundation of China (31800553)
Text and Data Mining valid from 2019-11-18
Received: 2 July 2019
Accepted: 6 November 2019
First Online: 18 November 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.