Peer-reviewed journal articles
- Leydesdorff L., Rotolo D., Rafols I. 2012. Bibliometric Perspectives on Medical Innovation Using the Medical Subject Headings of PubMed. Journal of the American Society for Information Science and Technology (in press). DOI: 10.1002/asi.22715. PDF(arXiv; SSRN)
Abstract: Multiple perspectives on the nonlinear processes of medical innovations can be distinguished and combined using the Medical Subject Headings (MeSH) of the Medline database. Focusing on three main branches—“diseases,” “drugs and chemicals,” and “techniques and equipment”—we use base maps and overlay techniques to investigate the translations and interactions and thus to gain a bibliometric perspective on the dynamics of medical innovations. To this end, we first analyze the Medline database, the MeSH index tree, and the various options for a static mapping from different perspectives and at different levels of aggregation. Following a specific innovation (RNA interference) over time, the notion of a trajectory which leaves a signature in the database is elaborated. Can the detailed index terms describing the dynamics of research be used to predict the diffusion dynamics of research results? Possibilities are specified for further integration between the Medline database, on the one hand, and the Science Citation Index and Scopus (containing citation information), on the other.
Further details at Loet Leydesdorff's website.
- Leydesdorff L., Carley S., Rafols I. 2012. Global maps of science based on the new Web-of-Science categories. Scientometrics (in press). DOI: 10.1007/s11192-012-0784-8. PDF (link)
Abstract: In August 2011, Thomson Reuters launched version 5 of the Science and Social Science Citation Index in the Web of Science (WoS). Among other things, the 222 ISI Subject Categories (SCs) for these two databases in version 4 of WoS were renamed and extended to 225 WoS Categories (WCs). A new set of 151 Subject Areas was added, but at a higher level of aggregation. Perhaps confusingly, these Subject Areas are now abbre- viated ‘‘SC’’ in the download, whereas ‘‘WC’’ is used for WoS Categories. Since we previously used the ISI SCs as the baseline for a global map in Pajek (Pajek is freely available at http://vlado.fmf.uni-lj.si/pub/networks/pajek/) (Rafols et al., Journal of the American Society for Information Science and Technology 61:1871–1887, 2010) and brought this facility online (at http://www.leydesdorff.net/overlaytoolkit), we recalibrated this map for the new WC categories using the Journal Citation Reports 2010. In the new installation, the base maps can also be made using VOSviewer (VOSviewer is freely available at http://www.VOSviewer.com/) (Van Eck and Waltman, Scientometrics 84:523–538, 2010).