Wang, Jun
Zheng, Changcheng
Ning, Jiqiang
Zhang, Lixia
Li, Wei
Ni, Zhenhua
Chen, Yan
Wang, Jiannong
Xu, Shijie
Article History
Received: 22 August 2014
Accepted: 24 November 2014
First Online: 8 January 2015
Competing interests
: The authors declare no competing financial interests.