For the past three years MDPI has announced the newly released impact factors for its Open Access journals by the means of an annual editorial [1,2,3]. In 2012 we are—once again—pleased to report that the growth of the impact factors of MDPI’s Open Access journals continues. This year’s edition of the Journal Citation Reports (JCR), which is published annually by Thomson Reuters, includes 10 journals published by MDPI, including three that have received their first official Impact Factors—International Journal of Environmental Research and Public Health (IJERPH), Materials and Nutrients. Table 1 reports the latest Impact Factors for 2011. Figure 1 graphically depicts the evolution of the Impact Factors for four MDPI open access journals that have received Impact Factors in the past. Table 2 reports the ranking of the MDPI journals within the subject categories of the Science Citation Index Expanded (SCIE).
Table 1.
Impact Factors of ten MDPI journals (adapted from the Journal Citation Reports (JCR), Edition 2011, Copyright 2012 by Thomson Reuters).
| 2007 | 2008 | 2009 | 2010 | 2011 | |
|---|---|---|---|---|---|
| Energies | 1.130 | 1.865 | |||
| Entropy | 1.109 | 1.183 | |||
| IJERPH | 1.605 | ||||
| IJMS | 0.750 | 0.978 | 1.387 | 2.279 | 2.598 |
| Marine Drugs | 1.103 | 1.200 | 2.863 | 3.471 | 3.854 |
| Materials | 1.677 | ||||
| Molecules | 0.940 | 1.252 | 1.738 | 1.988 | 2.386 |
| Nutrients | 0.676 | ||||
| Sensors | 1.573 | 1.870 | 1.821 | 1.771 | 1.739 |
| Viruses | 1.000 | 1.500 |
Figure 1.
Evolution of the Impact Factors for four MDPI open access journals (adapted from the Journal Citation Reports (JCR), Edition 2011, Copyright 2012 by Thomson Reuters).
Table 2.
Rankings of MDPI open access journals by subject categories (adapted from the Journal Citation Reports (JCR), Edition 2011, Copyright 2012 by Thomson Reuters).
| Journal | Rank | Category |
|---|---|---|
| Energies | 35/80 | Energy & Fuels |
| Entropy | 36/83 | Physics, Multidisciplinary |
| IJERPH | 103/204 | Environmental Sciences |
| IJMS | 44/150 | Chemistry, Multidisciplinary |
| Marine Drugs | 7/58 | Chemistry, Medicinal |
| Materials | 85/230 | Materials Science, Multidisciplinary |
| Molecules | 26/56 | Chemistry, Organic |
| Nutrients | 64/72 | Nutrition & Dietetics |
| Sensors | 14/58 | Instruments & Instrumentation |
| 18/27 | Electrochemistry | |
| 41/37 | Chemistry, Analytical | |
| Viruses | 28/32 | Virology |
The continued growth of the Impact Factors of MDPI journals provides further evidence for the citation advantage of the full Open Access publishing policy—which was instituted for all MDPI journals in early 2007 [4]—over the non-Open Access publishing policy [5].
References
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© 2012 by the authors; licensee MDPI, Basel, Switzerland. This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).