Funding for this research was provided by:
National Natural Science Foundation of China (31640002)
Natural Science Foundation of Shandong Province (ZR2015JL013)
Postdoctoral Research Foundation of China (2016M600551)
International Postdoctoral Exchange Fellowship, China (20170058)
Text and Data Mining valid from 2019-01-06
Received: 5 September 2018
Revised: 10 December 2018
Accepted: 12 December 2018
First Online: 6 January 2019
Compliance with ethical standards
: The authors declare that they have no competing interests.
: This article does not contain any studies with human participants or animals performed by any of the authors.