Gao, Wenxiu
Chang, Lei
Ma, He
You, Lu
Yin, Jiang
Liu, Junming
Liu, Zhiguo
Wang, Junling http://orcid.org/0000-0003-3663-7081
Yuan, Guoliang
Article History
Received: 6 February 2015
Revised: 23 April 2015
Accepted: 23 April 2015
First Online: 12 June 2015
Competing interests
: The authors declare no conflict of interest.