Lin, L
Huang, H
Liao, W
Ma, H
Liu, J
Wang, L
Huang, N
Liao, Y
Liao, W
Article History
Received: 13 April 2014
Revised: 30 May 2014
Accepted: 6 June 2014
First Online: 21 July 2014
Competing interests
: The authors declare no conflict of interest.