Search Medical Journals & Research Articles

PMC Releases Improved Related Resources Feature

PMC has released an updated feature to make it easier to explore information related to a given article. You will now see three sections in the right-hand column of all PMC articles which can be opened to browse similar articles in PubMed, articles that cite the current article, and links to related data records in National Center for Biotechnology Information (NCBI) databases. See our post in the NLM Technical Bulletin for more details about the update, and please continue to provide feedback through the Feedback button found on the PMC website.

PMC Collaborating with Publishers in Response to Mpox Public Health Emergency

On August 4, 2022, the White House Office of Science and Technology Policy (OSTP) announced a coordinated call to action with the science and technology leaders of more than 20 countries, requesting that publishers voluntarily make mpox and other orthopox-related publications freely and immediately accessible in appropriate public repositories to support the ongoing public health emergency response efforts. The call specified that these articles be made available with broad reuse rights in both human- and machine-readable formats to allow access to full text content and metadata. Publishers have responded to the call by volunteering to make their relevant articles accessible in PMC in formats and under license terms that facilitate text mining and secondary analysis. PMC-participating publishers can email PMC at pmc-phe@ncbi.nlm.nih.gov to notify us of their interest in collaborating on this effort. For a list of current collaborators, help with querying mpox-related literature, and more information, please visit our Public Health Emergency Mpox Initiative webpage.

Next Phase of NIH Preprint Pilot Launching Soon

Last month, the National Library of Medicine (NLM) announced plans to extend its NIH Preprint Pilot in PubMed Central (PMC) and PubMed beyond COVID-19 to encompass all preprints reporting on NIH-funded research. The second phase of the pilot, launching later this month, will include preprints supported by an NIH award, contract, or intramural program and posted to an eligible preprint server on or after January 1, 2023. In preparation for the launch of this second phase, we have updated PMC and PubMed site features to help users of these databases incorporate the increased volume of preprints into their discovery workflows. See the NCBI Insights post for more information about these preprint record display and search filter updates. PMC will continue to update the NIH Preprint Pilot Overview and FAQs in the coming weeks. Please send your questions and feedback to pmc-preprints@ncbi.nlm.nih.gov.

Second Phase of the NIH Preprint Pilot Launched

Today, we are pleased to announce the launch of the second phase of the NIH Preprint Pilot with the addition of more than 700 new preprint records to PubMed Central (PMC) and PubMed. This second phase expands the scope of the Pilot to include preprints resulting from all NIH-funded research. Eligible preprints are those acknowledging direct support of an NIH award or authored by NIH staff and posted to bioRxiv, medRxiv, arXiv, or Research Square, on or after January 1, 2023. NLM will automatically include the full text of the preprint (as license terms allow) and associated citation information in PMC and PubMed, respectively. New preprint records will be added on a weekly basis. Phase 2 of the pilot is expected to run through 2023. A project of NLM, the NIH Preprint Pilot was launched in 2020 to explore new approaches to increase the discoverability of NIH-supported research results, with the first phase focusing on NIH-supported research on COVID-19 and the SARS-CoV-2 virus. To learn more, visit the NIH Preprint Pilot page.

Clarifying PMC's Role as an Archive

The role of what a library means in a digital world is evolving and expanding. PMC has a large and diverse user base that includes students and the public, as well as researchers, clinicians, and librarians. We recognize that these different audiences have varying levels of familiarity with NLM, the National Institutes of Health (NIH), and the scholarly publishing process and have recently updated how we describe, display, and share articles in PMC to provide our users with more context. Visit NCBI Insights for more information about these updates.

PMC Public Health Emergency Initiatives Update

The National Library of Medicine (NLM) recently renamed the COVID-19 and Mpox Public Health Emergency Initiatives as the PMC COVID-19 Collection and PMC Mpox Collection, respectively. NLM continues to work with publisher and scholarly society collaborators who contribute content to these collections to provide broad access and support reuse of relevant scientific literature.

Update on Access to Coronavirus-related Articles in PubMed Central (PMC) COVID-19 Collection after end of Public Health Emergency

Early in the COVID-19 pandemic, the National Library of Medicine (NLM) collaborated with publishers and scholarly societies to expand access to coronavirus-related journal articles in PubMed Central (PMC). Through this collaboration, more than 50 publishers made more than 350,000 coronavirus-tates and around the globe, so too did article-level license terms for use of some of these articles. Most of the articles deposited in the PMC COVID-19 Collection will remain available in PMC, and all citations will remain searchable in PubMed and available for bulk distribution and reuse through the PMC Open Access Subset. However, some publishers retained the right to remove their content and have requested to do so. Details on changes to the licensing status or availability of content can be found in the NLM Technical Bulletin. More information, including a list of publishers and their licensing statuses, is available in the PMC COVID-19 Collection FAQs and on the PMC COVID-19 Collection webpage.

Update on PubReader Format

The PubReader format was added to PMC in 2012 to make it easier to read full text articles on tablet, mobile, and other small screen devices. In March 2022, NCBI launched an updated PMC website. The updated website is mobile responsive, making it easy to read articles in PMC on any device. This makes some legacy features, such as the PubReader view, no longer necessary. In January 2024, we will remove the PubReader links from the PMC website. You will temporarily still be able to access the PubReader format by appending "?report=reader" to any PMC article URL (e.g., https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9825438/?report=reader ). In May 2024, we will fully remove the PubReader functionality from the PMC website. Any link to the PubReader format will redirect to the standard, mobile responsive, PMC article view. For content in Bookshelf, PubReader view will continue to be available for the majority of titles, specifically those with unrestricted navigation. PubReader view is accessed from the Views menu on the right.

Preview Upcoming Improvements to PMC

We are pleased to announce the availability of a preview of improvements planned for the PMC website. These improvements will become the default in October 2024 and include an updated article display and enhanced PMC journal list. Click on the "Try it out now" link in the banner on the top of any page on the current PMC website to preview these updates, and visit NCBI Insights for more information.

PMC website update coming October 16

On October 16, 2024, PMC will transition to a new website. This update, available for preview since March 2024 for user testing and feedback, will become the default for PMC on that date. With this update: the primary URL format for the website will change from https://www.ncbi.nlm.nih.gov/pmc/ to https://pmc.ncbi.nlm.nih.gov/ Existing links to most PMC pages with the prior format will redirect to the equivalent page using the new format. PMC search, the PMC Publisher Portal, and most of the public file validation tools will maintain the https://www.ncbi.nlm.nih.gov/pmc format. Journal "archive" pages will redirect to the new PMC Journal List record: https://www.ncbi.nlm.nih.gov/pmc/journals/2/ --> https://pmc.ncbi.nlm.nih.gov/journals/?term=Proceedings+of+the+National+Academy+of+Sciences+of+the+United+States+of+America Table of contents pages for issues will also redirect to the PMC Journal List. Visit the PMC User Guide to learn how to find articles by volume and issue. This change will NOT affect PubMed URLs ( https://pubmed.ncbi.nlm.nih.gov/ ). See our previous posts in NCBI Insights (March 2024) and in the NLM Technical Bulletin (May 2024) for more details.

PMC Tagging Guidelines Accessibility Updates

The PMC Tagging Guidelines (TG) were updated on October 7, 2024, to provide new guidance for PMC data providers on how to deposit accessible article information using Journal Article Tag Suite (JATS) XML. This guidance aligns with accessibility recommendations from JATS for Reuse, a working group under NISO. This recommendation bases its set of tagging best practices on the following definition: "Accessibility is the practice of ensuring there are minimal barriers to access and interact with websites and other electronic information for users with physical or situational disabilities." The newly added Accessibility section provides an overview summarizing these recommendations and provides links to over 30 elements and document objects throughout the TG. For ease of identification, each updated TG area has an "Accessibility" section that provides guidance. PMC's operations team will be engaging with publisher and data providers to encourage adoption of this guidance to improve the digital accessibility of articles that are deposited into PMC over the long term.

PMC Transitions to Updated Website

On October 16, 2024, NLM's NCBI transitioned to an updated PubMed Central (PMC) website, representing the next step in ongoing efforts to modernize NLM's products and services. As part of this update, the primary URL for the PMC website has changed from ncbi.nlm.nih.gov/pmc to pmc.ncbi.nlm.nih.gov. In addition, you'll notice a new look, feel, and organization of PMC article pages and the PMC Journal List. Learn more in the NLM Technical Bulletin.

Preview of Upcoming Changes to PMC's eFetch Output

In April 2025, the data formats for PMC articles available through eFetch will be updated as part of NLM's ongoing efforts to modernize its products and services. While most of the data will remain unchanged, there are several key differences in the XML and PubMed (formerly MEDLINE) data formats that we'd like to highlight for users. ( Learn more about eFetch and the rest of the NCBI Entrez Programming Utilities. ) In addition, prior to moving the new formats into production, the new PMC eFetch data formats are now available at a preview location. To use the preview version of PMC's eFetch, update the subdomain of current eFetch URLs that use db=PMC from "eutils" to "eutilspreview". For example, to retrieve the XML data format for an article in the PMC Open Access Subset, such as PMC8270360, use the following preview URL, where the subdomain "eutils" has been replaced with "eutilspreview": https:// eutilspreview.ncbi.nlm.nih.gov/entrez/eutils/efetch.cgi?db=pmc&id=PMC8270360&rettype=xml Changes and additions to the XML format Within, there are changes and additional pub-id-types values: pmcaid - replaces "pmc" as the value identifying that the value of this element is a PMCID pmcid - the unique identifier for the article in PMC pmcid-ver - the PMCID with a decimal suffix indicating the version number doi - the DOI, or Digital Object Identifier, for the article pmcaiid - the article instance identifier, used internally at PMC to distinguish between different versions of the article Within, there are additional values for article properties and statuses: pmc-status-embargo - indicates if the full text is under embargo. If yes, only the metadata is available until the release date has been reached. pmc-prop-open-access - indicates if the article is available for reuse under a Creative Commons or similar license through the PMC Open Access Subset. pmc-prop-olf - indicates if this is an Online First (OLF) version of the article. pmc-prop-manuscript - indicates if this is the accepted author manuscript version of the article. pmc-prop-has-pdf - indicates if there is a PDF available for the article in PMC. pmc-prop-has-supplement - indicates if the article has supplementary material available in PMC. pmc-prop-pdf-only - indicates if the full text of the article is only available as a PDF in PMC. pmc-prop-is-scanned-article - indicates if the article was included as part of a digitization project. pmc-prop-preprint - indicates if the article is a preprint, deposited under the NIH Preprint Pilot. names in the xlink:href attribute will include the file extension. In the current output, the file extension is not present. If additional DOIs, PMCIDs, or PMIDs are associated with a reference in an article's reference list during processing of the article by PMC, they will be added as elements to the reference with attribute values of pub-id-type="doi", pub-id-type="pmcid", and pub-id-type="pmid" respectively. Additions to the PubMed Format The updated PubMed format available when using db=pmc with eFetch will include a number of data fields previously unavailable for PMC articles, including: MESH terms when available for MEDLINE-indexed records in PubMed Grant information Preprint indicators Additional Publication History (PHST) dates Please reach out to PMC if you have questions or would like to provide feedback.

PubMed Central's Updated Full-Text Search Preview Now Available

As the next step in the ongoing modernization of the PubMed Central (PMC) website, NCBI is updating the PMC search functionality and user experience. In preparation for a planned transition to this updated search later this year, NCBI has released a beta version for you to preview and provide feedback on. Click the "Try this search in PMC Beta Search" link under the search bar on the PMC website to try out the PMC Beta Search. Visit NCBI Insights or our beta search user guide for more information.

Updates in Support of the 2024 NIH Public Access Policy

The National Center for Biotechnology Information (NCBI) at the National Library of Medicine (NLM) has made initial updates to several offerings to support NIH-funded researchers and institutions to comply with the 2024 NIH Public Access Policy, which went into effect July 1, 2025. NCBI will continue to make ongoing improvements over the coming months. These initial changes include guidance on PubMed Central for authors and related to Online First (OLF) articles, updated options in NCBI's My Bibliography tool, and new error messaging and help text within the NIH Manuscript Submission (NIHMS) System. Please note that the NIH Public Access Compliance Monitor (PACM) continues to use the 2008 NIH Public Access Policy rules and NCBI cannot ensure the reliability of compliance data in PACM in relation to the revised requirements. For more details on all these updates, visit NCBI Insights.