Zhang, Lei
Pan, Zhiming
Kang, Xilong
Yang, Yun
Kang, Heekap
Zhang, Na
Rosati, James M
Jiao, Xinan
Article History
Received: 26 December 2013
Revised: 19 July 2014
Accepted: 22 July 2014
First Online: 8 September 2014
Competing interests
: The authors declare no financial or commercial conflicts of interest.