Characteristics and Features of PubMed
- PubMed is a free search engine accessing the MEDLINE database.
- Maintained by the United States National Library of Medicine (NLM).
- PubMed was released in January 1996.
- PubMed offers access to over 35 million citations and abstracts.
- PubMed has links to full-text versions of articles.
- PubMed's interface was updated in October 2009.
- The website design and domain were updated in January 2020.
- Researchers had a critical reaction to the site changes.
- The results on PubMed can be sorted by various criteria.
- A mobile-friendly version of PubMed is available.

Search and Retrieval Options in PubMed
- Simple searches on PubMed can be done by entering key aspects of a subject.
- PubMed automatically adds relevant terms, synonyms, and Boolean operators to enhance the search.
- PubMed offers comprehensive search options using MeSH terms.
- Reference librarians and search specialists can assist with complex searches.
- The use of MeSH terms provides more accurate and relevant results.
- PubMed supports Boolean operators (AND, OR, NOT) for combining search terms.
- MeSH (Medical Subject Headings) can be used to improve search precision.
- Truncation and wildcard symbols can be used to expand search terms.
- Filters and limits can be applied to narrow down search results.
- PubMed offers tools for advanced searching and topic searching.

Journal Article Parameters in PubMed
- PubMed extracts and stores structured information about journal articles.
- Parameters include article type, secondary identifiers, language, and publication history.
- Publication type parameter allows searching by the type of publication.
- Secondary identifiers include accession numbers and trial IDs.
- PubMed extracts trial IDs from ClinicalTrials.gov and other trial registries.

Related Features and Resources in PubMed
- PubMed has a 'related articles' feature to identify relevant articles.
- Related articles are listed based on their relatedness to the selected article.
- The related articles function can be used instead of a full search.
- PubMed automatically links to MeSH terms and subheadings.
- MeSH terms help in mapping and organizing the articles in PubMed.
- My NCBI provides tools for saving searches, filtering search results, setting up automatic updates sent by e-mail, saving sets of references retrieved as part of a PubMed search, and configuring display formats or highlighting search terms.
- LinkOut is an NLM facility to link and make available full-text local journal holdings.
- Over 3,200 sites, mainly academic institutions, participate in LinkOut.
- Users at participating institutions see their institution's logo within the PubMed search result if the journal is held at that institution.
- PubMed Commons allows authors of articles indexed by PubMed to comment on articles.
- Initially tested in pilot mode since 2013 and made permanent in 2016.
- Discontinued in February 2018 due to minimal usage.

Other Tools and Resources Related to PubMed
- MEDLINE is a subset of PubMed that focuses on articles in the field of medicine.
- askMEDLINE is a free-text, natural language query tool for MEDLINE/PubMed.
- Developed by the NLM and suitable for handhelds.
- PubMed Central (PMC) is a digital archive of full-text articles.
- MedEvi is a tool for retrieving evidence of relations between biomedical concepts from Medline.
- PubCrawler is a tool for keeping up with new articles in PubMed and GenBank.
- PMID (PubMed identifier or PubMed unique identifier) is a unique integer value assigned to each PubMed record.
- PMID is not the same as PMCID (PubMed Central identifier), which is the identifier for works published in PubMed Central.
- The assignment of a PMID or PMCID does not indicate the type or quality of the content.
- PMIDs are assigned to various types of publications, including peer-reviewed papers, letters to the editor, and editorial opinions.
- Any reference in PubMed can be located using the PMID.