An, Shuoming
Zhang, Jing-Ning
Um, Mark
Lv, Dingshun
Lu, Yao
Zhang, Junhua
Yin, Zhang-Qi
Quan, H. T.
Kim, Kihwan
Article History
Received: 16 April 2014
Accepted: 14 November 2014
First Online: 22 December 2014
Competing interests
: The authors declare no competing financial interests.