Wang, Yan
Wang, Mingjuan
Li, Jin
Yao, Shangchen
Xue, Jing
Zou, Wenbo
Hu, Changqin
Article History
Received: 3 December 2013
Revised: 9 February 2014
Accepted: 17 February 2014
First Online: 16 April 2014
Competing interests
: The authors declare no conflict of interest.