Funding for this research was provided by:
National Natural Science Foundation of China (31501037, 31870072, 21506245, 21472234)
Text and Data Mining valid from 2019-02-15
Received: 20 November 2018
Revised: 30 January 2019
Accepted: 2 February 2019
First Online: 15 February 2019
Compliance with ethical standards
: This article does not contain any studies with human participants or animals performed by any of the authors.
: The authors declare that they have no conflict of interest.