Funding for this research was provided by:
National Natural Science Foundation of China (91647211, 51878008)
Text and Data Mining valid from 2019-09-03
Received: 11 December 2018
Revised: 21 June 2019
Accepted: 23 July 2019
First Online: 3 September 2019
Compliance with ethical standards
: The authors declare that they have no conflicts of interest.
: This article does not contain any studies involving human participants or animals performed by any of the authors.