It has become a reflex action to go into PubMed when searching for scientific citations or abstracts. But PubMed is not always the best search engine. You can optimise your search by using other search interfaces.
PubMed takes its citations and abstracts from MEDLINE (Medical Literature Analysis and Retrieval System Online), which in turn is a bibliographic database created by the United States National Library of Medicine (NLM). The citations in PubMed are linked then to full-text articles in open-access archives or at various publishers. PubMed was introduced in 1996. MEDLINE was opened for others who wanted to present alternative interfaces in 2002, and several other actors have created alternative interfaces since then. The various interfaces are in general not as transparent as PubMed, since it is often commercial actors who lie behind them.
Why are different interfaces necessary? What are the advantages of using another interface than PubMed? To put it simply, the large amount of information that the United States National Library of Medicine offers to so many users makes it impossible for PubMed to offer optimised functions within various special fields.
A selection of the many interfaces available is presented below, together with some of their principal functions.
Gopubmed offers various search possibilities, such as specific MeSH descriptors, genes or proteins. The citations link back to the full-text articles through PubMed. Gopubmed also offers easy access to statistics of such parameters as the most published author in a field, and graphical presentations of the relationships between authors. www.gopubmed.com
Hubmed offers the user the possibility of presenting relationships between various articles graphically. The citations are linked to full-text articles, and it is possible to export them in several formats. The “citation finder” function makes it possible to search through a complete reference list, which can be copied in.
Ligercat creates tag clouds of MeSH descriptors based on search terms. These can then be sent to PubMed as a search. Ligercat also present statistics of how many articles are related to the search term, and these articles can be directly accessed by clicking on the graph. It is also possible to carry out similar searches for journals or for genes. http://ligercat.ubio.org
MEDSUM makes possible, among other things, graphical presentation of statistics about fields based on a timeline. It gives the user the opportunity to carry out profile searches based on author or field. MEDSUM does not link to the full-text articles from the citations. http://webtools.mf.uni-lj.si/public/medsum.html
Pubget mainly offers simple access to full-text articles. www.pubget.com
Quertle is a semantic search engine that encourages phrase-based searches of the type: “what treats measles”. Quertle offers the possibility of searching based on pre-defined concept categories such as $Diseases, which cover various fields. The citations link back to the full-text articles through PubMed. www.quertle.info/
There are several other services for obtaining information from the NLM resources, in addition to these alternative interfaces. The particular choice of tool depends on the information-retrieval needs of the user.
