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What's New in MeSH

Highlights of Recent Improvements and Changes

  • We redesigned our FTP Site for easier MeSH downloads

    Our FTP download site:  now includes separate directories for each release year of MeSH. In addition, we created the folder "MESH_FILES" with the latest release files that are updated every morning Monday - Friday. The yearly release folders span from 2011 to the latest full release which occurs in November of the preceding year (for example, 2016 MeSH was released in November of 2015). A single directory is also included for earlier files from 1999-2010. We hope that making these archive copies more readily available to the public will be useful for those of us that are interested in studying the history MeSH terminology as it progressed over the years.

    Note that distributed MeSH files are freely available to the public provided that you agree to our Memorandum of Understanding.


    MeSH FTP Directory Structure:

    MeSH FTP FoldersDescription
          1999-2010 Includes all annual release files from 1999-2010
    Separate folders for MeSH years 2011 through 2016
          MESH_FILES The most recent MeSH files, updated Monday - Friday

    Subfolders included under year folder

    Folder NameDescription
    asciimesh MeSH ASCII files
    meshtrees Headings with Tree Nodes
    mtms MeSH translation files
    marc MeSH/MARC files
    newterms New MeSH terms and term changes
    xmlmesh MeSH files in XML format

    MeSH data file naming convention using 2016 MeSH year example:

    ASCII MeSH File NamesDescription
    c2016.bin Supplemental Records for year 2016
    d2016.bin Descriptor Records for year 2016
    q2016.bin Qualifier Records for year 2016
    mtrees2016.bin MeSH headings with tree nodes for 2016
    meshnew2016.txt New Descriptor preferred terms for 2016
    mnchg2016.txt Tree changes for 2016
    mshd2016.txt All Descriptor preferred terms for 2016
    replace2016.txt Deleted and replaced Descriptor headings
    XML* MeSH File NamesDescription
    desc2016.xml Descriptor Records for year 2016
    supp2016.xml Supplemental Records for year 2016
    qual2016.xml Qualifier Records for year 2016
    pa2016.xml Pharmacological Actions of MeSH chemicals
    *Note files ending with gz, and zip are compressed XML files



  • Projects Completed for 2016 MeSH

    In addition to responding to user requests for changes and additions we have completed several projects that will improve MeSH vocabulary structure and content.

    • MeSH Hierarchy (Trees) Revision: In the past MeSH headings were more loosely organized into a tree hierarchy. A heading could appear in multiple tree locations depending upon its importance and specificity. In some cases headings would appear two or more times in the same tree at higher and lower levels. This arraignment led to some headings appearing as a sibling (uncle) next to the parent heading that they were also treed under. In other cases a heading was included at a top level so it could be seen more readily in printed material. We reviewed these headings in MeSH and removed either the "Uncle" or "Nephew" depending upon the judgment of our Internal and External reviewers.

    • People and Professions: People and Professions: The M01 tree in MeSH is devoted to persons as individuals or members of a group, while the H tree contains the Disciplines and Occupations (professions). Although this premise held true for most cases we had a large number of exceptions where people were listed as an entry term under their profession. In addition the subheading manpower was used with a profession to indicate the person when a heading for them was not available. We felt this inconsistency required too much effort on the part of searchers to determine where to look and what to do. We simplified the trees by moving all people from the Professions tree and created new headings for them in the Persons tree.

    • Plants and Food Category Revision: The MeSH J-tree includes food items, while Plants and Animals are under the B-tree. For many years the fact that some plants and animals are also treed under food has been source of confusion for searchers. We received many requests to add and subtract specific plants from food that based upon conflicting sources of information. In addition the range of exotic plants being eaten has expanded over the years. To respond to these problems we made major changes to the organization of nutritional phenomena for the 2016 Medical Subject Headings. Nutritionally related headings were brought together for under the MeSH heading "Diet, Food, and Nutrition" was created in the G-7 tree. The headings "Diet" and "Nutritional Physiological Phenomena" along with their child descriptors were moved there. In addition a second tree location for "Food and Beverages" and its child descriptors were added there. Specific plant and chemical headings were removed from underneath "Food and Beverages" because many of the citations indexed with them were not about food or nutritional topics. As a result, searching "Food and Beverages" or "Diet, Food, and Nutrition" now gives a more focused retrieval of citations that are nutritionally related. Articles that discuss a specific plant or chemical in the context of food can still be found through use of coordination of topics instead finding using tree inheritance. For example, a search of "Diet, Food, and Nutrition" AND "Spinach" could be used to find specific citations about the nutritional value of spinach.

    For a full list of changes and improvements to 2016 MeSH see: NLM Tech Bull. 2015 Nov-Dec;(407):e9.