Qu, Yuanyuan
Dai, Bo
Ye, Dingwei
Kong, Yunyi
Chang, Kun
Jia, Zhongwei
Yang, Xiaoqun
Zhang, Hailiang
Zhu, Yao
Shi, Guohai
Article History
Received: 28 September 2014
Accepted: 1 December 2014
First Online: 7 January 2015
Competing interests
: The authors declare no competing financial interests.