Zhang, Qing
Li, Guangyuan
Liu, Xinfeng
Qian, Fang
Li, Yat
Sum, Tze Chien
Lieber, Charles M.
Xiong, Qihua
Article History
Received: 28 December 2013
Accepted: 11 August 2014
First Online: 23 September 2014
Competing interests
: The authors declare no competing financial interests.