Funding for this research was provided by:
National Natural Science Foundation of China (81600312)
Text and Data Mining valid from 2018-02-08
Received: 24 November 2017
Accepted: 19 January 2018
First Online: 8 February 2018
Compliance with ethical standards
: This article does not contain any studies with human or animal subjects performed by the any of the authors.
: All of the eligible articles included in the meta-analysis stated that they had obtained informed consent from participants.