摘要：Objectives :The objective of this study was to examine the open-access publishing companies BioMed Central & Public Library of Science (PLoS), both of which receive no subscription fees from readers, and investigate what sort of influence they have on, and how thoroughly they have penetrated, the academic world. Methods : An examination was made of Impact Factor (IF), using the Science Edition database of the Thomson Journal Citation Reports (JCR) on the Web. This examination was carried out by various methods, mainly through comparison with other companies: 1) by examining JCR 2001 through to JCR 2004, and comparing average IF and increase/decrease in number of publications cited, 2) by comparisons only in the field of those over a median IF of 2.0 in JCR 2004, and 3) by comparisons of BioMed Central and PLoS, in JCR 2004 again, in the field with the most publications cited (Biochemistry & Molecular Biology). Also, in 4), a study was made on each publication's ranking within the field, focusing only on the publications of the open-access publishing companies from JCR 2001 through to JCR 2004. Results : In 1), BioMed Central increased average IF by 1.962 points, and number of cited publications increased by 14 titles. In 2), PLoS increased average IF by 13.868 points (and 1 title), where BioMed Central increased average IF by 2.833 points (and 8 titles). In 3), within the target 14 publishing companies, PLoS occupied #1 position, and BioMed Central occupied number 8. In 4), publications in nearly every field in the JCR 2004 showed a superior positioning. Conclusions : Open-access publishing companies have achieved rapid growth and undeniable prominence. It is clear that in 2004 they achieved great pervasiveness, and were highly competitive with regard to other publishers.
关键词：Open Access;Publishing;Impact Factor;BioMed Central;Public Library of Science
