The impact factor of rheumatology journals: an analysis of 2008 and the recent 10 years
ABSTRACT Despite various weaknesses, the impact factor (IF) is still used as an important indictor for scientific quality in specific subject categories. In the current study, the IFs of rheumatology journals over the past 10 years were serially analyzed and compared with that from other fields. For the past 10 years (1999-2008), the IFs published by the Institute for Scientific Information in the Science Citation Index-Journal Citation Report were analyzed. For the majority of rheumatology journals, the IF shows a gradually increasing trend. The mean and median level of increase of IF from 1999 to 2008 is 233.9 and 66.5%, respectively. The increase in IF from 1999 or the first year with IF documentation to that in 2008 was higher for European journals than for the USA journals. The aggregate IF and the median IF of rheumatology journals remained within the top 30% and top 15% in clinical medical and all the scientific categories, respectively. Over the past 10 years, rheumatology journals showed a general increase in IF and rheumatology remained a leading discipline. For journals in the English language, those from Europe had an even higher increase than those from USA.
Full-textDOI: · Available from: Cees G M Kallenberg, Jun 26, 2015
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ABSTRACT: In the first part of this study we analysed the temporal stability of Garfield's Impact Factor (IF) over the last decade (2001-2010). The analyses were performed for two Web of Science (WoS) categories of the JCR Science Edition ("Polymer Science" and "Nanoscience & Nano-technology") and two of the Social Sciences Edition ("Political Science" and "Information Science & Library Science") at journal category level. Furthermore, we tried to identify the most characteristic patterns of IF timelines at journal level and analysed the reasons for strong IF fluctuations. Additionally, we checked if alternative journal impact measures like the Article Influence Score, SJR or SNIP are as sensitive to short-term fluctuations in the citation frequencies as Garfield's Impact Factor. In the second part, we explored if one often mentioned weakness of the IF, its short citation window, can be used to identify hot papers, i.e. papers that are cited clearly above-average in the first two years after publication, by means of IF fluctuations. By analysing the citation distributions at article level we show that abrupt and large short-term variations of the IF can, in principle, offer a very simple and intuitive method to identify "unexpected" hot papers and hot topics at journal level. Background and introduction Apart from simplicity one of the key strengths of Garfield's impact factor (IF) is its assumed relative temporal stability (Glanzel & Moed, 2002, 174). However, as exemplified by the journal "Acta Crystallographica A" there might at least be a few exceptions. The impact factor of this journal increased from approximately 2 to 50 and beyond within only 2 years simply because of one single extremely highly-cited paper. This paper also provoked considerable changes in other bibliometric indicators that are based on arithmetic means like the crown indicator.
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ABSTRACT: A challenge in nanofabrication is to overcome the limitations of various fabrication methods, including defects, line-edge roughness and the minimum size for the feature linewidth. Here we demonstrate a new approach that can remove fabrication defects and improve nanostructures post-fabrication. This method, which we call self-perfection by liquefaction, can significantly reduce the line-edge roughness and, by using a flat plate to guide the process, increase the sidewall slope, flatten the top surface and narrow the width while increasing the height. The technique involves selectively melting nanostructures for a short period of time (hundreds of nanoseconds) while applying a set of boundary conditions to guide the flow of the molten material into the desired geometry before solidification. Using this method we reduced the 3σ line-edge roughness of 70-nm-wide chromium grating lines from 8.4 nm to less than 1.5 nm, which is well below the ‘red-zone limit’ of 3 nm discussed in the International Technology Roadmap for Semiconductors. We also reduced the width of a silicon line from 285 nm to 175 nm, while increasing its height from 50 nm to 90 nm. Self-perfection by liquefaction can also be extended to other metals and semiconductors, dielectrics and large-area wafers.Nature Nanotechnology 06/2008; DOI:10.1038/nnano.2008.156 · 33.27 Impact Factor
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ABSTRACT: The impact factor (IF) is a common citation metric used for evaluating and comparing scientific journals within a certain field. Previous studies have shown that IFs are increasing. However, rates may depend on journal publication language. The aim of this study was to determine IF values and trends for general medical journals, comparing non-English-language with English-language journals. For all journals categorised as "medicine, general and internal" (n = 150) in the Journal Citation Reports (JCR), publication language, country of origin and IFs for the last 10 years were recorded (2001-2010). Data were classified, analysed descriptively and compared using non-parametric tests. From 2001 to 2010, IFs increased for English-language and non-English-language journals (p <0.001). During the 10-year study period, IFs were higher for English-language than for non-English-language journals (p <0.001). The proportion of non-English-language journals included in the JCR was 12.2% in 2001 and 18.0% in 2010 (p = 0.28). From 2001 to 2010, IFs increased significantly for English-language and non-English-language journals. When comparing IF values year-by-year (2001-2010), IFs were significantly higher for English-language than for non-English-language journals. In an international scientific community with English as the universal language of science, non-English-language journals should consider changing publication language, and adopt either a bi- or a monolingual approach. Publishing in English will increase citation counts and thus IFs, but, more importantly, scientific findings will be accessible to a much wider audience.Schweizerische medizinische Wochenschrift 01/2012; 142. DOI:10.4414/smw.2012.13572 · 1.88 Impact Factor