ƽÌØÎå²»ÖÐ

The National Library of Medicine has announced . These changes have been introduced to optimize retrieval and to lead searchers to additional information. Automatic Term Mapping (ATM)
The ATM feature enables PubMed to search author names, journal titles, and MeSH vocabulary terms without the user having to type in individual search tags. In the past, if an author name or journal title was the same as a medical subject heading (MeSH) term, ATM performed a subject search only. This caused certain types searches to fail – especially those looking for a specific article. For example, a search using the following citation data: Lung 2005 183 225, where Lung is the journal title, failed with old ATM because "lung" would map to MeSH and therefore searched as a subject heading ot text word only. To address this problem, Automatic Term Mapping now has been modified to make it more inclusive. While ATM still maps to and searches MeSH, it now searches the search term(s) in All Fields, that is, author name, journal title, abstract, or any other searchable field. Sample search for art therapy. Old PubMed ATM:
"art therapy"[MeSH Terms] OR art therapy[Text Word] New PubMed ATM:
"art therapy"[MeSH Terms] OR ("art"[All Fields] AND "therapy"[All Fields]) OR "art therapy"[All Fields] Impact on PubMed searches:
The new ATM feature generally means larger retrieval (higher recall), but also less relevant results (lower precision). Citation Sensor
Citation Sensor matches searches with citations. It recognizes combinations of search terms that are characteristic of citation searching such as volume/issue numbers, pagination, author names, journal titles, and publication dates. The search "Chin Neurology 1995" would have failed in the previous version of PubMed. Pubmed now retrieves nine articles, two of which are displayed before the others in an area highlighted in yellow. That is, the Citation Censor has determined that the search is for specific articles and displays possible matches in this highlighted section. Advanced Search
Finally, the is developing an Advanced Search option for PubMed. A beta version is now available for user reaction and comment. To try out this iption, look for the "Advanced Search" link next to the main search window. PubMed's Advanced Search page has a search box at the top, and displays the last search if a search was previously conducted. Beneath the search box are four sections: PubMed Search History; Search by Author, Journal, and Publication Date. This is followed by a limit section including Limit by Topics, Languages, and Journal Groups; and Index of Fields and Field Values. All sections are open by default. Click the plus/minus box next to each feature to close or open a section. For more information or additional explanations concerning these new features contact angella.lambrou [at] mcgill.ca"">Angella Lambrou.