Help Using This Site

Need help using this site? Here are some answers to common support questions.

  1. Navigation of PLOS Content
  2. Recommended Web Browsers
  3. PLOS Journals Account
  4. Journal E-mail Alerts
  5. Printing PDFs
  6. Free Readers/Viewers
  7. Viewing and Using Multimedia Files
  8. Article Feeds
  9. XML Content
  10. Social Bookmark Links
  11. Article-Level Metrics
  12. Related Content
  13. Subject Areas
  14. Linking your ORCID Account

Navigation of PLOS Content

We have designed the site to enhance access to and assessment of article content and data as quickly as possible.

Navigate the corpus
Content discovery can be laborious without robust tools to create a refined list of relevant articles customized for your changing needs. We provide three components to assist you in this process: search filters, abstract and figure previews, and custom saved search.

  1. Search filters
  2. We offer search filters for users to drill down into preliminary results and glean a more precise selection. On the results page, you can create filters based on a set of facets and sub-facets to further refine the search. Users can toggle back and forth between results by adding and clearing filters. We currently offer the following filters:

    • Journals
      • PLOS ONE
      • PLOS Biology
      • PLOS Medicine
      • PLOS Pathogens
      • PLOS Computational Biology
      • PLOS Neglected Tropical Diseases
      • PLOS Hub for Clinical Trials
      • PLOS Collections
    • Subject Areas
      • Biology and life sciences
      • Medicine and health sciences
      • Physical sciences
      • Research and analysis methods
      • [additional taxonomic terms based on search]
    • Authors
      • [author listing based on search]
    • Where my keywords appear
      • Title
      • Abstract
      • Introduction
      • Body
      • Materials and Methods
      • Results and Discussion
      • Conclusions
      • Supporting Information
      • References
    • Article Type
      • Research Article
      • Review
      • Overview
  3. Abstract and figure previews
  4. While the default view of search results is in list form, they can also be displayed as "figures." With this setting, each article tile showcases a representative image, along with general information such as title, date published, author listing, etc. Without leaving their search results, users can immediately preview the article by screening its abstract and complete set of figures or directly download the PDF.

  5. Custom saved search
  6. Once you have created a search on exact fields of interest, stay up-to-date with automatic notifications of the latest content that matches your request: email and RSS feed. Users can directly subscribe to that particular RSS feed. Or they can log in and save the search for email notifications.

Navigate the article
We designed the layout and functionality of our articles to help users quickly navigate the article across each of its components.

  1. Metrics signposts
  2. We offer at-a-glance Metrics Signposts at the top of every article to further support content discovery. These numbers offer an up-to-date glimpse of the article’s reach since publication. This data can inform your browsing experience and enable swift navigation based on the impact profile of interest. We display a varied selection of metrics versatile to serve a variety of browsing modes, whether you are interested in a highly cited paper, highly shared paper, etc.

    • Views: the sum of PLOS and PubMed Central pageviews and downloads
    • Citations: the paper's citation count computed by Scopus
    • Academic Bookmarks: the total Mendeley, CiteULike, and Connotea bookmarks
    • Social Shares: the sum of Facebook and Twitter activity

    Metrics Signposts are made up of a sub-set of ALM data. For a more comprehensive view of article reach and impact, please use the full ALM suite of impact indicators displayed on the article Metrics tab.

  3. Enriched article information across tabs
  4. We display additional content for each article across article tabs, making it easy to see and use. Users can navigate to the article's companion information:

    • About the Authors
    • Metrics
    • Comments
    • Related Comment
  5. Persistent article navigation links
  6. As you scroll down the article page, the article navigation links to the left of the main article text float down the screen, and indicate which section of the article you’re currently viewing. Clicking these links will jump you directly to the relevant article section.

Recommended Web Browsers

This site supports modern web browsers with JavaScript enabled.

Viewing Special Characters and Symbols

We are aware of problems with the display of some special characters and symbols within the articles on some browsers. To ensure you are seeing all special characters and symbols correctly, please look at the PDF version of the article.

PLOS Journals Account

You may read PLOS journals without creating an account. However, an account is required to receive journal e-mail alerts and to comment on articles. Accounts are free.

Create Account

Create a PLOS Journals account at A confirmation will be sent to your e-mail address with the title "Please verify your PLOS registration". Use the URL in that e-mail to complete your registration.


The "Login" or "My Profile" is available near the top right corner of every journal page.

The first time you log in, you are required to create a profile with basic information, with which you will be identified whenever you rate or comment on an article. As part of your profile, you must choose a username. Your username is attached to all commentary that you make on PLOS Web sites. This means that all your commentary is credited and attributed to you. You cannot change your username. It is possible to get a new username by registering for a whole new account, but anything you have done on your original account will not transfer to the new account with the new username.

Lost Password

If you have forgotten your password, go to, enter your E-mail address, and click "Submit". An e-mail will be sent to the e-mail address you use to log in to your PLOS user account.

Journal E-mail Alerts

Sign up for a PLOS journal e-mail alert at A confirmation will be sent to your e-mail address with the title "Please verify your PLOS registration". Use the URL in that e-mail to complete your registration.

To unsubscribe from a PLOS journal e-mail alert:

  1. Login at Enter your PLOS login E-mail address and Password. Click "Go!".
  2. Please check/uncheck the boxes to subscribe/unsubscribe from a specific mailing list.
  3. Scroll to the bottom of the page and click "Save".

To update your e-mail address to which PLOS journal e-mail alerts are sent:

  1. Login at Enter your PLOS login E-mail address and Password. Click "Go!".
  2. Under "Preferences", click "Change your e-mail address".
  3. Enter the new e-mail address which you wish to use to receive alerts and click "Submit".

Printing PDFs

If you have difficulty printing PDFs, please try updating the drivers on your printer. Printer driver updates are typically available from the printer manufacturer's Web site.

Here are links to several printer manufacturers' download Web sites:

If updating your printer drivers does not resolve the problem, please contact with detailed information, including your Web browser software (e.g., Internet Explorer 6.0), version of Adobe Acrobat Reader (or other PDF reader), computer operating system (e.g., Windows XP), and the URLs of the PDFs you are trying to print.

Free Readers/Viewers

Free software is available for viewing Adobe Acrobat PDF, Microsoft Excel, Word, and PowerPoint files. Download sites for a few popular free programs are listed below.

Document Type Free Viewers/Readers
PDF Adobe Acrobat Reader (cross-platform)
Xpdf (for X Window System under UNIX, VMS, and OS/2)
DOC Microsoft Word 97/2000 Viewer (for Windows)
XLS Microsoft Excel 97/2000 Viewer (for Windows)
PPT Microsoft PowerPoint 2003 Viewer (for Windows) and PowerPoint Viewer 97/2000/2002 (for Windows) and PowerPoint 98 Viewer (for Mac OS)
All of the above offers a free cross-platform software suite for word-processing, spreadsheets, presentations, drawing, and database design. Download for Windows/Linux/Solaris, Mac OS X, and Linux PPC.

Viewing and Using Multimedia Files

If your Web browser does not already have a plug-in to play videos and use Flash, Shockwave, and SVG (Scaleable Vector Graphics) files, there are free players and viewers available for download. We list just a few popular programs below.

File Type Free Players
MOV, MPG, or AVI Windows Media Player (for Windows and Mac); QuickTime (for Mac and Windows); MPlayer and Totem (for Linux)
SWF Macromedia Flash Player (for Windows, Mac, Linux, Solaris)
DCR Macromedia Shockwave Player (for Windows and Mac)

Download the Adobe SVG Viewer (for Windows, Mac, Linux, Solaris) installer program. You must run the installer program to install the plug-in, and for some Web browsers, including Netscape, Mozilla, and Opera, you must take additional steps to complete the installation. For more help, read Adobe's installation instructions and be sure to test your SVG plug-in. Opera users should read how to get Adobe SVG Viewer to work with Opera.

Here is a list of other SVG viewers.

You may right-click or control-click on an SVG figure to save the file to your desktop.

Article Feeds

Want to keep abreast of PLOS journals content without having to regularly visit the Web sites? Our article feeds will allow you to do just that. Get more information about PLOS article feeds.

XML Content

The XML for an individual article can be downloaded directly from that article's Web page using the "Download Article XML" link in the sidebar. If you wish to download the entire corpus of a PLOS journal, please contact help [at]

Share This Article

The 'bookmarklet' icons in the right-hand column of every article allow users to save and share links to articles via a number of popular "social bookmarking" services such as Reddit, Google+, Stumble Upon, Facebook, Connotea, and CiteULike.

Article-Level Metrics

The "Metrics" tab on each article provides information on online article usage, citations to the article, and other indicators of impact. The regularly updated data fall into the following categories:

  • citations
  • article usage
  • media and blog coverage about the article
  • social tools for reference management as well as research recommendation and evaluation
  • PLOS reader evaluation

These are described in full on the journal ALM page.

Article Usage

Online "Article Usage" data, as recorded at PLOS sites, are available for all PLOS journals for all articles published from June 17, 2005 to present. The understanding of these data is not straightforward, and so we have provided detailed (technical) information and summary data tables. Newly published articles do not accumulate usage data instantaneously but require approximately 48 hours before data are shown.

PubMed Central (PMC) usage data for each article was introduced in January of 2010, and PLOS started displaying this data from Jan 2012. PMC counts the number of page views and PDF downloads of the article on their site. PMC sends their usage data to us once a month. As a result, articles may experience a lag with the display of PMC data (up to a month's time). The total article usage data is an aggregate of PLOS and PMC usage, combined.

These sources have their own limitations and in addition, results may overlap between sources. Read more detailed information about article usage data.

Article Citations

Citations to the article are gathered from several sources including PubMed Central, Scopus, ISI Web of Science, and CrossRef.

These sources have their own limitations and in addition, results may overlap between sources. Read more detailed information about article citation metrics.

Article Citations

Other indicators of the impact of the article include:

  • Social tools for reference management, recommendation, and evaluation: Twitter, Facebook, Mendeley, CiteULike, and Connotea
  • Blog coverage: ResearchBlogging and Nature Blogs
  • Non-scholarly references: Wikipedia
  • PLOS reader evaluation: Comments/Notes/Star ratings on PLOS site

More information about each of these indicators and their limitations can be found on our Article-Level Metrics Information page.

Please note that, excluding PLOS article usage and PLOS reader evaluation, the data reported is automatically generated via information supplied by each service. PLOS is not responsible (nor able to correct) any errors which originate with the third party concerned.

Related Content

The "Related Content" tab on each article provides links (and information) to additional content which may be related to this article.

The tab provides links to:

  • Related PLOS Articles: More articles by the authors.
  • Subject Areas: The Subject Areas provide access to articles that share the same assigned terms.
  • Media Coverage: Links to News, Blogs and Related Resources

Related Blog Posts

Provides links to blog posts citing each PLOS article via a number of blog aggregation services: ResearchBlogging and Nature Blogs.* A link is also provided to blog posts that have linked to the article via a trackback.

*Please note that the above information is automatically generated via information supplied by each service. PLOS is not responsible (nor able to correct) any errors which originate with the third party concerned.

Subject Areas

The "Subject Areas" panel on each article page displays a set of terms selected for that article based on its content. The Subject Areas belong to a thesaurus of over 10,000 terms initially built for us over the course of 2012 by Access Innovations (, taking into account the controlled vocabulary of classification terms that had been in use in PLOS Editorial Manager. The entire corpus of PLOS articles was analysed to ensure that the thesaurus covers the research domain comprehensively.

Specific terms are associated with articles by Machine Aided Indexing (MAI) which identifies text strings in the articles and matches them to Subject Area terms from the thesaurus. The output ranks the matches in order of frequency of hits within the text of the article and the top eight terms are selected for display. Whereas previously the eight terms were presented in alphabetical order, we are introducing weightings to the Subject Area panel, such that the order of Subject Areas will reflect the frequency of hits in the MAI process. This new presentation will be introduced progressively, beginning with the main Article tab.

The MAI process uses a Rulebase to guide Subject Area selection. Whereas identifying a phrase such as "Retinitis pigmentosa" is relatively straightforward for software, the issue is more complex for a word such as "Sodium" where the relevant Subject Area might be "Voltage-gated sodium channels", any of several sodium compounds or even just "Sodium" the element. The rule for terms such as "Sodium" are therefore compound and include conditional statements to disambiguate these different contexts. While the vast majority of terms are effectively indexed there remain ambiguities for some terms and part of our work is to continue to identify these cases and modify the Rulebase accordingly.

The Subject Area terms are related to each other with a system of broader/narrower term relationships. The thesaurus structure is a polyhierarchy, so for example the Subject Area "White blood cells" has two broader terms "Blood cells" and "Immune cells". At its deepest the hierarchy is ten tiers deep, with all terms tracking back to one or more of the top tier Subject Areas, such as "Biology and life sciences" or "Social sciences".

The Subject Area terms can be used to filter PLOS content via the Subject-specific option in Advanced Search. The MAI Rulebase accommodates synonyms, so a Subject-specific Search for "Highly active antiretroviral therapy" will retrieve articles based on MAI matches to "HAART" (a known synonym) as well as "Highly active antiretroviral therapy" in one step. Additionally, because we select the most frequently MAI-indexed Subject Areas for each article the Search returns articles where the Subject Area in question ranks highly enough to be included in the top eight MAI-retrieved terms, so is of relatively high significance, whereas a query term in an "All fields" search will return every article that contains even a single match to the query term.

The hierarchical nature of the thesaurus also enhances article retrieval in Search. Not only does Search retrieve all articles specifically indexed by MAI with the query Subject Area term in question, but it also retrieves all articles specifically indexed with any Subject Area term that sits deeper into the hierarchy than the query Subject Area term, but on the same broader/narrower term path. Thus, in the "White blood cells" example, queries for either "Blood cells" or "Immune cells" will return all articles indexed with "White blood cells".

The Subject Area terms on all article pages are hyperlinked and following the link returns a listing of all articles to which that Subject Area term applies. Subject Area terms can also be used as the basis for Saved Searches, RSS feeds and PLOS ONE customized Journal Alerts.

The content of the PLOS thesaurus and the Rulebase that governs the application of Subject Areas to the articles is constantly under review. We incorporate analysis of the Subject Area panel "feedback" clicks into this review process, and are always happy to receive specific input on Subject Area terms and their application by email. We update the thesaurus behind the PLOS sites several times each year. Files corresponding to the current version (as well as previous versions) can be downloaded here.

Questions and comments about Subject Areas and the PLOS thesaurus can be sent to

Linking your ORCID Account

By linking your ORCID digital identifier to your PLOS account you can easily be distinguished from other researchers. When you integrate your ORCiD in key research workflows such as manuscript and grant submission, automated linkages occur between you and your professional activities, ensuring that your work is recognized. For more information about ORCiD please visit

You can link your PLOS account with a new or existing ORCiD ID by visiting your preferences. If you have technical difficulties please contact