Funding for this research was provided by:
National Natural Science Foundation of China (61272036)
Natural Science Foundation of Anhui Province (KJ2017A414, 1908085MF191)
Text and Data Mining valid from 2019-07-04
Received: 23 January 2019
Accepted: 22 June 2019
First Online: 4 July 2019
: The authors declare that they have no competing interests.