Qin, Qingquan
Yin, Sheng
Cheng, Guangming
Li, Xiaoyan
Chang, Tzu-Hsuan
Richter, Gunther
Zhu, Yong
Gao, Huajian
Article History
Received: 19 June 2014
Accepted: 28 November 2014
First Online: 13 January 2015
Competing interests
: The authors declare no competing financial interests.