*BioMed Central is an independent publishing house committed to providing immediate open access to peer-reviewed biomedical research* "All original research articles published by BioMed Central are freely available and permanently accessible online immediately upon publication. BioMed Central views open access to research as essential in order to ensure the rapid and efficient communication of research findings in biological sciences". For more details see http://www.biomedcentral.com/info/about/whatis List of *Journals currently covered by Thomson Scientific (ISI)* http://www.biomedcentral.com/info/about/faq?name=impactfactor *Unofficial Impact Factors* for other BioMed Central Journals* http://www.biomedcentral.com/info/about/faq?name=impactfactor BioMed Central is an independent publishing house committed to providing immediate open access to peer-reviewed biomedical research "All original research articles published by BioMed Central are freely available and permanently accessible online immediately upon publication. BioMed Central views open access to research as essential in order to ensure the rapid and efficient communication of research findings in biological sciences". For more details see http://www.biomedcentral.com/info/about/whatis http://www.biomedcentral.com/info/about/whatis List of Journals currently covered by Thomson Scientific (ISI) http://www.biomedcentral.com/info/about/faq?name=impactfactor http://www.biomedcentral.com/info/about/faq?name=impactfactor Unofficial Impact Factors* for other BioMed Central Journals http://www.biomedcentral.com/info/about/faq?name=impactfactor http://www.biomedcentral.com/info/about/faq?name=impactfactor