Funding for this research was provided by:
National Natural Science Foundation of China (30901108, 21776310)
Natural Science Foundation of Shandong Province (ZR2017MB019, ZR2009EQ007)
Fundamental Research Funds for the Central Universities (15CX02014A, 16CX02044A)
Text and Data Mining valid from 2019-03-14
Received: 10 July 2018
Accepted: 4 March 2019
First Online: 14 March 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.