Zhao, Yan-Rui
Wang, Dong
Liu, Yang
Shan, Lei
Zhou, Jun-Lin
Funding for this research was provided by:
Natural Science Foundation of Beijing Municipality (7152061)
Article History
Received: 18 August 2015
Accepted: 7 October 2015
First Online: 5 November 2015
Compliance with ethical standards
:
: The authors declare that they have no competing interests.
: The Natural Science Foundation of Beijing has no role in this study.