Long, Yue
Liu, Chuanyong
Zhao, Bin
Song, Kai
Yang, Guoqiang
Tung, Chen-Ho
Article History
Received: 25 September 2014
Revised: 1 November 2014
Accepted: 4 November 2014
First Online: 9 January 2015
Competing interests
: The authors declare no conflict of interest.