In This Issue:
Technical Notes - e1
NLM Classification, 5th Edition Additions and Changes List 4 - e2
PubMed: Searching Using Subsets - e3
OLDMEDLINE Database Moves Back in Time - e4
 Hands On: PubMed Update - e5
MEDLINEplus - e6
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Hands On: PubMed Update
Introduction
Welcome to the Hands On column in the NLM Technical Bulletin. This column which was previously in Gratefully Yours will now continue on in this publication. If you are a regular reader of the Hands On column, you might expect to see an article in question and answer format, focusing on specific solutions to search questions. However, the last several months of 1998 were extremely busy with updates, enhancements, and some fixes to PubMed. So, this article will focus on the changes to PubMed that occurred during the last quarter of 1998, and give a brief glimpse at future PubMed developments.
Preview 1999
For those of you who want a peek at what's in store for 1999, PubMed's [this link was removed because it is no longer valid] Overview and New/Noteworthy links (available from the PubMed home page sidebar) now contain the latest information on the additional bibliographic resources under development. Discussed are new features, such as LinkOut, a service that will provide user-customized links to outside resources; PubRef, a service that will offer full-text links to journals not covered in PubMed; and a "Cubby Service," which will allow users to set up custom profiles of stored searches, filters, and preferences. Stay tuned for more details as these services are developed.
Overview of 1998 Changes
Much of the 1998 focus was on enhancing the Author and Text Word indexes and the MeSH Translation Table to improve search retrieval accuracy. A new search field, Subset was introduced in December. See the article on Searching Using Subsets in this issue of the Technical Bulletin for detailed information on searching using this new feature.
The changes to PubMed are detailed in a chronological listing below.
September 1998
MeSH Browser
The highest level MeSH categories, i.e., MeSH Tree Categories A through Z, were added to the PubMed MeSH Browser, (e.g., Chemicals and Drugs, Diseases, Geographical Locations). To view this listing, click on the Start at the top of the tree link from the MeSH Browser page. If you click on one of the categories as shown, the MeSH Browser displays the next (narrower) levels of MeSH terms within that category.
In addition, a Check Tags (e.g., Animal, Female, Human, Male) category was also added and displays as part of the above list. Previously, it was not possible to view a listing of the Check Tags or select them using the MeSH Browser.
System Changes
Author Index
Often an article is published with an author name misspelled. These are corrected in MEDLINE after an erratum is published in the journal. The Author Index has been re-indexed to include both the incorrect author's name as well as the corrected author's name. For example, the incorrect author name, Floubeidi MA will retrieve the corrected author name Eloubeidi MA.
Previously in PubMed, once an erratum was published to correct an author's name, only the correct author name was searchable. Users unaware of such a correction searched with the incorrect author name and were unable to retrieve the citation to the article.
New Algorithm for the Source Field
The algorithm used to create the Source field, e.g., Postgrad Med. 1997 May;101(5):67-70, 73-7. has been corrected so that it properly displays the complete pagination. Previously, if a citation (such as the one shown in this paragraph), included more than one set of pages, e.g., 67-70, 73-7, in the Page field, only the first set, i.e., 67-70 was displayed in the Source field. Now the complete pagination is shown.
MeSH Terms beginning with Support,... have been added to the MeSH Translation Table
The three MeSH terms listed below, which are MeSH Check Tags, are now included in the MeSH Translation Table and are directly searchable.
- Support, Non-U.S. Gov't
- Support, U.S. Gov't, Non-P.H.S.
- Support, U.S. Gov't, P.H.S.
Text Word Index Updated with Single Word MeSH Terms
The Text Word index was re-indexed to include single word MeSH terms, such as Lung. Prior to this update, a search for lung [tw] did not include citations with the MeSH heading, Lung if the record did not have the word "lung" in either the title or the abstract or embedded in a multi-word MeSH heading.
October 1998
NLM's MEDLINEplus
NLM released a new consumer health Web page that is designed to direct the public to resources containing information that will help them research their health questions. The "Health Topics" page provides links for a variety of medical subjects. Some of the many links are for MEDLINE searches that are run in PubMed. You can link to MEDLINEplus from NLM's site http://www.nlm.nih.gov or go directly to http://medlineplus.gov/ See the article in this issue of the NLM Technical Bulletin for more information on MEDLINEplus.
November 1998
New Cancer Mappings
The MeSH Translation Table was updated to include MeSH term mapping for 105 new cancer terms. For example, the term, colon cancer, maps to the MeSH term, Colonic Neoplasms and is searched as:
("colonic neoplasms" [MeSH Terms] OR colon cancer [Text Word])
MeSH Translation Table Update
The MeSH Translation table was updated with 1999 MeSH.
December 1998
New Search Field: Subset [sb]
With the addition of this new search field, users now have the ability to limit retrieval to a predefined set of citations (e.g., PREMEDLINE citations, AIDS-related citations) within PubMed. Please note this field is not in the Search Field pull-down menu in the Advanced Search Mode. For more information, please see the article on Searching Using Subsets in this issue of the Technical Bulletin.
MeSH Translation Table Update
The MeSH translation table has been updated with a new MeSH mapping file generated from both MeSH and the Unified Medical Language System (UMLS) to include translations of searches where one concept may map to two or more MeSH headings. A good example is the word "cold". The MeSH term, "Cold" is the concept of "an absence of warmth or heat or a temperature notably below an accustomed norm." However, the word "cold" is used by many people to mean the "common cold".
For example, an unqualified search for the term cold now maps as:
((("lung diseases, obstructive"[MeSH Terms] OR "common cold' [MeSH Terms]) OR "cold"[MeSH Terms]) OR cold [Text Word])
The term cold, qualified with [mh] or unqualified, is considered a multiple concept (either a disorder or a temperature) and is, therefore, searched as that MeSH term and also mapped to Common Cold [mh] or Lung Diseases, Obstructive [mh]. The latter mapping is derived from one of the many sources contributing entry vocabulary to the UMLS.
A search for cold [mh] maps similarly, merely omitting the Text Word part:
(("lung diseases, obstructive" [MeSH] OR "common cold" [MeSH Terms]) OR "cold" [MeSH Terms])
To prevent this mapping and to search for cold only with the MeSH definition meaning you must either enclose the term in double quotes and qualify with [mh], e.g., "Cold" [mh], or select the term from the Advanced Search screen using the List Terms Mode in combination with the MeSH Terms or MeSH Major Topic search field.
Please note, however, an unqualified search for common cold maps only to the one MeSH heading as shown below:
("common cold" [MeSH Terms] OR common cold[Text Word])
Frequently Asked Questions (FAQs) Page Added to PubMed
A link to a list of FAQs was added to the PubMed sidebar menu next to the online Help link. The PubMed FAQs provide links to the answers to commonly asked questions and allow the user to find information quickly in an accessible format.
MEDLINE Citations Updated
MEDLINE 1999 class maintained citations were added to PubMed.
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