Guo, G
Kang, Q
Zhu, X
Chen, Q
Wang, X
Chen, Y
Ouyang, J
Zhang, L
Tan, H
Chen, R
Huang, S
Chen, J-L
Article History
Received: 16 October 2013
Revised: 25 March 2014
Accepted: 26 March 2014
First Online: 19 May 2014
Competing interests
: The authors declare no conflict of interest.