Funding for this research was provided by:
National Natural Science Foundation of China (81573005, 81602724, 81803101)
Natural Science Foundation of Tianjin City (18JCQNJC83100, 18JCZDJC33400)
Text and Data Mining valid from 2019-10-17
Received: 30 July 2019
Accepted: 9 October 2019
First Online: 17 October 2019
: The authors declare that they have no competing interests.