Funding for this research was provided by:
National Natural Science Foundation of China ((No.81571773, 81781771943))
Text and Data Mining valid from 2019-08-14
Received: 27 February 2019
Accepted: 25 July 2019
First Online: 14 August 2019
Compliance with ethical standards
: We declare that we have no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.
: Informed consent was obtained from all individual participants included in the study.