Liu, Juan
Wang, Quanzhen
Karagić, Đura
Liu, Xv
Cui, Jian
Gui, Jing
Gu, Muyu
Gao, Wei
Article History
Received: 21 August 2015
Accepted: 12 February 2016
First Online: 1 March 2016
Competing interests
: The authors declare no competing financial interests.