Funding for this research was provided by:
The National Science and Technology Ministry of China (Award number 2017YFD0400200)
Text and Data Mining valid from 2019-01-19
Received: 8 September 2018
Revised: 17 December 2018
Accepted: 22 December 2018
First Online: 19 January 2019
Compliance with ethical standards
: We declare no conflicts of interest exist in the submission of this manuscript.
: This article does not contain any studies with human or animal subjects.