. 2013 Jul 24;6:214. doi: 10.1186/1756-3305-6-214
Copyright © 2013 Hu et al.; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.