Funding for this research was provided by:
National Natural Science Foundation of China (81370981)
General Project for Scientific Research of Liaoning Provincial Education Department (L2015572)
Article History
Received: 7 May 2018
Accepted: 4 July 2018
First Online: 14 July 2018
Compliance with Ethical Standards
:
: Ran Guo, Lang Wu, and Qin Fu declare that they have no conflict of interest.
: This article does not contain any studies with human or animal subjects performed by any of the authors.