Funding for this research was provided by:
National Natural Science Foundation of China (81102057)
Text and Data Mining valid from 2018-04-04
Received: 13 September 2016
Accepted: 15 March 2018
First Online: 4 April 2018
Ethics approval and consent to participate
: All analyses were based on previous published studies, thus no ethical approval and patient consent are required.
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.