Li, Guilian
Zhang, Jingrui
Guo, Qian
Wei, Jianhao
Jiang, Yi
Zhao, Xiuqin
Zhao, Li-li
Liu, Zhiguang
Lu, Jianxin
Wan, Kanglin
Article History
Received: 27 September 2014
Revised: 28 October 2014
Accepted: 19 January 2015
First Online: 18 February 2015
Competing interests
: The authors declare no conflict of interest.