Liu, Qiuli
Zheng, Haiqing
Chen, Xiaoyong
Peng, Yanwen
Huang, Weijun
Li, Xiaobo
Li, Gang
Xia, Wenjie
Sun, Qiquan
Xiang, Andy Peng
Article History
Received: 1 June 2014
Revised: 21 October 2014
Accepted: 6 November 2014
First Online: 8 December 2014
Competing interests
: The authors declare that no conflict of interest exists.