Li, Linglong
Lu, Lu
Wang, Zhiguang
Li, Yanxi
Yao, Yonggang
Zhang, Dawei
Yang, Guang
Yao, Jianjun
Viehland, Dwight
Yang, Yaodong
Article History
Received: 10 December 2014
Accepted: 24 February 2015
First Online: 18 March 2015
Competing interests
: The authors declare no competing financial interests.