Shao, Hong
Ma, Qianli
Dong, Xiangting
Yu, Wensheng
Yang, Ming
Yang, Ying
Wang, Jinxian
Liu, Guixia
Article History
Received: 16 June 2015
Accepted: 17 August 2015
First Online: 16 September 2015
Competing interests
: The authors declare no competing financial interests.