Funding for this research was provided by:
National Natural Science Foundation of China (31601757)
Text and Data Mining valid from 2019-11-19
Received: 10 August 2019
Accepted: 7 November 2019
First Online: 19 November 2019
Compliance with ethical standards
: All the authors declare that there is no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.