Wang, Nan
Gray, Michelle
Lu, Xiao-Hong
Cantle, Jeffrey P
Holley, Sandra M
Greiner, Erin
Gu, Xiaofeng
Shirasaki, Dyna
Cepeda, Carlos
Li, Yuqing
Dong, Hongwei
Levine, Michael S
Yang, X William
Article History
Received: 17 October 2013
Accepted: 27 February 2014
First Online: 28 April 2014
Competing interests
: The authors declare no competing financial interests.