Li, S
Jiang, C
Pan, J
Wang, X
Jin, J
Zhao, L
Pan, W
Liao, G
Cai, X
Li, X
Xiao, J
Jiang, J
Wang, P
Article History
Received: 7 May 2014
Revised: 9 October 2014
Accepted: 14 October 2014
First Online: 21 November 2014
Competing interests
: The authors declare no conflict of interest.