What is MeSH? MeSH is the National Library of Medicine's controlled vocabulary thesaurus. It consists of sets of terms naming descriptors in a hierarchical structure that permits searching at various levels of specificity. MeSH descriptors are arranged in both an alphabetic and a hierarchical structure. At the most general level of the hierarchical structure are very broad headings such as "Anatomy" or "Mental Disorders." More specific headings are found at more narrow levels of the eleven-level hierarchy, such as "Ankle" and "Conduct Disorder."
There are 22,997 descriptors in MeSH. In addition to these headings, there are more than 151,000 headings called Supplementary Concept Records within a separate thesaurus. There are also thousands of cross-references that assist in finding the most appropriate MeSH Heading, for example, Vitamin C see Ascorbic Acid. These additional entries include 24,050 printed see references and 112,012 other entry points.
MeSH Applications The MeSH thesaurus is used by NLM for indexing articles from 4,800 of the world's leading biomedical journals for the MEDLINE/PubMED® database. It is also used for the NLM-produced database that includes cataloging of books, documents, and audiovisuals acquired by the Library. Each bibliographic reference is associated with a set of MeSH terms that describe the content of the item. Similarly, search queries use MeSH vocabulary to find items on a desired topic
Establishing and Updating MeSH The Medical Subject Headings Section staff continually revise and update the MeSH vocabulary. Staff subject specialists are responsible for areas of the health sciences in which they have knowledge and expertise. In addition to receiving suggestions from indexers and others, the staff collect new terms as they appear in the scientific literature or in emerging areas of research; define these terms within the context of existing vocabulary; and recommend their addition to MeSH.
Professionals in various disciplines are also consulted regarding broad organizational changes and close coordination is maintained with various specialized vocabularies.
MeSH Tree Structures In some thesauri the function cross references to broader and narrower terms is comparable to the hierarchical relationships in the MeSH Tree Structures, though hierarchies enable multiple levels of specificity, as do the MeSH Trees. These relationships are displayed graphically in the MeSH Browser and printed MeSH. The Trees data are also used by PubMed for the default behavior of inclusive searching. The Trees data in XML MeSH are to be found in the TreeNumber elementMeSH Tree Structures MeSH BrowserTreeNumber
History of MeSH The first official list of subject headings published by the National Library of Medicine appeared in 1954 under the title Subject Heading Authority List. It was based on the internal authority list that had been used for publication of Current List of Medical Literature which in turn had incorporated headings from the Library's Index-Catalogue and from the 1940 Quarterly Cumulative Index Medicus Subject Headings.
With the beginning of Index Medicus in 1960, a new and thoroughly revised Medical Subject Headings appeared. In the 1960 Medical Subject Headings, the number of subheadings was reduced to sixty-seven. They could be used under any kind of main heading if the combination was not patently foolish or impossible. These sixty-seven subheadings were applied with more generalized meanings.
In 1963, the second edition of Medical Subject Headings contained 5,700 descriptors, compared with 4,400 in the 1960 edition. Of the headings used in the 1960 list, 113 were withdrawn in favor of newer terms. In contrast, the 2007 edition of MeSH contains 24,357 descriptors.
In 1960, medical librarianship was on the cusp of a revolution. The first issue of the new Index Medicus series was published. On the horizon was a computerization project undertaken by the National Library of Medicine (NLM) to store and retrieve information. The Medical Literature Analysis and Retrieval System (MEDLARS) would speed the publication process for bibliographies such as Index Medicus, facilitate the expansion of coverage of the literature, and permit searches for individuals upon demand.
The new list of subject headings introduced in 1960 was the underpinning of the analysis and retrieval operation. MeSH was a new and thoroughly revised version of lists of subject headings compiled by NLM for its bibliographies and cataloging. Frank B. Rogers, then NLM director, announced several innovations as he introduced MeSH in 1960.
The adoption of a single subject authority list for both books and periodical articles is a departure from traditional practice. We take the view that subject cataloging and periodical indexing, as exemplified in the Index Medicus and in the NLM Catalog, are identical processes in their major dimensions. A single list can and should be used for both purposes. This has two major virtues: simplicity for users, in requiring familiarity with only a single scheme; and economy to the library in the development and maintenance of a single scheme.
There is another departure from traditional practice represented in this list. This is the adoption of standard topical subheadings for cataloging books, as well as for indexing periodical articles. The topical subheading is in effect a substitute for a phrase heading, and on the whole it is a preferable substitute. The main heading-topical subheading combination is a pre-coordination of terms, reducing the problem of term permutation, which looms large in most manual retrieval systems in book form.
From its beginning, MeSH was intended to be a dynamic list, with procedures for recommending and examining the need for new headings. The content of the vocabulary related to the usage of terms in the literature itself and evolved to meet new concepts in the field. The use of the computer made revisions more practical and systematic, despite the difficulty in updating printed indexes and card catalogs.
“cancer” as an example
Tree structure (from the top)
在 OVID Medline 之應用
OVID Medline 簡介 The Ovid MEDLINE database contains bibliographic citations and author abstracts from more than 4,600 biomedical journals published in the United States and in 70 other countries. The database contains well over 12 million citations dating back to the mid-1960's, including more than 130,000 population-related journal citations (unique to the former POPLINE® database) that were added to MEDLINE in October of Although coverage is worldwide, most records are derived from English-language sources or have English abstracts. Abstracts are included for more than 75% of the records.
Mapping to MeSH
勾選適合的概念 & 複分
在 PubMed 之應用 PubMed 簡介 PubMed, a service of the National Library of Medicine, includes over 14 million citations for biomedical articles back to the 1950's. These citations are from MEDLINE and additional life science journals. PubMed includes links to many sites providing full text articles and other related resources.
PubMed 簡介 PubMed provides access to bibliographic information which includes MEDLINE as well as: The out-of-scope citations (e.g., articles on plate tectonics or astrophysics) from certain MEDLINE journals, primarily general science and chemistry journals, for which the life sciences articles are indexed for MEDLINE. Citations that precede the date that a journal was selected for MEDLINE indexing. Some additional life science journals that submit full text to PubMedCentral and receive a qualitative review by NLM.