PMC Home

<!DOCTYPE html> <html lang="en" > <head > <meta charset="UTF-8" /> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta name="HandheldFriendly" content="True" /> <meta name="MobileOptimized" content="320" /> <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <meta name="ncbi_page" content="home"> <meta name="ncbi_op" content="page_view"> <meta name="robots" content="INDEX,FOLLOW,NOARCHIVE"> <meta name="description" content="PMC is a free full-text archive of biomedical and life sciences journal literature at the U.S. National Institutes of Health's National Library of Medicine (NIH/NLM)."> <meta name="og:title" content="PubMed Central (PMC)"> <meta name="og:type" content="website"> <meta name="og:site_name" content="PubMed Central (PMC)"> <meta name="og:description" content="PMC is a free full-text archive of biomedical and life sciences journal literature at the U.S. National Institutes of Health's National Library of Medicine (NIH/NLM)."> <meta name="og:url" content="https://pmc.ncbi.nlm.nih.gov/"> <meta name="og:image" content="https://cdn.ncbi.nlm.nih.gov/pmc/cms/images/pmc-card-share.jpg?_=0"> <meta name="twitter:card" content="summary_large_image"> <meta name="twitter:site" content="@ncbi"> <link rel="stylesheet" href="/static/assets/style-70b9163a.css" /> <script type="module" crossorigin="" src="/static/assets/base_style-ec2bc71e.js"></script> <link rel="stylesheet" href="/static/assets/style-a416b081.css" /> <script type="module" crossorigin="" src="/static/assets/home_style-d197328d.js"></script> <link rel="apple-touch-icon" sizes="180x180" href="/static/img/favicons/apple-touch-icon.png" /> <link rel="icon" type="image/png" sizes="48x48" href="/static/img/favicons/favicon-48x48.png" /> <link rel="icon" type="image/png" sizes="32x32" href="/static/img/favicons/favicon-32x32.png" /> <link rel="icon" type="image/png" sizes="16x16" href="/static/img/favicons/favicon-16x16.png" /> <link rel="manifest" href="/static/img/favicons/site.webmanifest" /> <link rel="mask-icon" href="/static/img/favicons/safari-pinned-tab.svg" color="#0071bc" /> <meta name="msapplication-config" content="/static/img/favicons/browserconfig.xml" /> <meta name="theme-color" content="#ffffff" /> <title> PMC Home </title>  <meta name="ncbi_app" content="cloudpmc-viewer" /> <meta name="ncbi_db" content="pmc" /> <meta name="ncbi_phid" content="76C1B55E74217B6303B55E0000035255.m_5" />  <meta name="ncbi_pdid" content="home" /> <link rel="preconnect" href="https://www.google-analytics.com" /> <link rel="dns-prefetch" href="https://cdn.ncbi.nlm.nih.gov" /> </head> <body > <a class="usa-skipnav " href="#main-content"> Skip to main content </a> <section class="usa-banner " aria-label="Official website of the United States government" > <div class="usa-accordion"> <header class="usa-banner__header"> <div class="usa-banner__inner"> <div class="grid-col-auto"> <img aria-hidden="true" class="usa-banner__header-flag" src="/static/img/us_flag.svg" alt="" /> </div> <div class="grid-col-fill tablet:grid-col-auto" aria-hidden="true"> <p class="usa-banner__header-text"> An official website of the United States government </p> <span class="usa-banner__header-action">Here's how you know</span> </div> <button type="button" class="usa-accordion__button usa-banner__button " aria-expanded="false" aria-controls="gov-banner-default" data-testid="storybook-django-banner" > <span class="usa-banner__button-text">Here's how you know</span> </button> </div> </header> <div class="usa-banner__content usa-accordion__content" id="gov-banner-default" hidden> <div class="grid-row grid-gap-lg"> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/static/img/icon-dot-gov.svg" alt="" aria-hidden="true" /> <div class="usa-media-block__body"> <p> <strong>Official websites use .gov</strong> <br /> A <strong>.gov</strong> website belongs to an official government organization in the United States. </p> </div> </div> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/static/img/icon-https.svg" alt="" aria-hidden="true" /> <div class="usa-media-block__body"> <p> <strong>Secure .gov websites use HTTPS</strong> <br /> A <strong>lock</strong> ( <span class="icon-lock"> <svg xmlns="http://www.w3.org/2000/svg" width="52" height="64" viewBox="0 0 52 64" class="usa-banner__lock-image" role="graphics-symbol" aria-labelledby="banner-lock-description" focusable="false"> <title id="banner-lock-title">Lock</title> <desc id="banner-lock-description"> Locked padlock icon </desc> <path fill="#000000" fill-rule="evenodd" d="M26 0c10.493 0 19 8.507 19 19v9h3a4 4 0 0 1 4 4v28a4 4 0 0 1-4 4H4a4 4 0 0 1-4-4V32a4 4 0 0 1 4-4h3v-9C7 8.507 15.507 0 26 0zm0 8c-5.979 0-10.843 4.77-10.996 10.712L15 19v9h22v-9c0-6.075-4.925-11-11-11z" /> </svg> </span>) or <strong>https://</strong> means you've safely connected to the .gov website. Share sensitive information only on official, secure websites. </p> </div> </div> </div> </div> </div> </section> <div class="usa-overlay"> </div> <header class="usa-header usa-header--extended usa-header--wide" data-testid="header" data-header > <div class="ncbi-header"> <div class="ncbi-header__container"> <a class="ncbi-header__logo-container" href="/"> <img alt=" PMC home page " class="ncbi-header__logo-image" src="/static/img/ncbi-logos/nih-nlm-ncbi--white.svg" /> </a>  <button type="button" class="usa-menu-btn ncbi-header__hamburger-button " aria-label="Show menu" data-testid="navMenuButton" > <svg aria-hidden="true" class="ncbi-hamburger-icon" fill="none" focusable="false" height="21" viewBox="0 0 31 21" width="31" xmlns="http://www.w3.org/2000/svg"> <path clip-rule="evenodd" d="M0.125 20.75H30.875V17.3333H0.125V20.75ZM0.125 12.2083H30.875V8.79167H0.125V12.2083ZM0.125 0.25V3.66667H30.875V0.25H0.125Z" fill="#F1F1F1" fill-rule="evenodd" /> </svg> </button>  <div class="ncbi-header__desktop-buttons">  <button type="button" class="usa-button usa-button--unstyled ncbi-header__desktop-button " aria-expanded="false" aria-controls="search-field-desktop-navigation" aria-label="Show search overlay" data-testid="toggleSearchPanelButton" data-toggle-search-panel-button > <svg class="usa-icon " role="graphics-symbol" aria-hidden="true" > <use xlink:href="/static/img/sprite.svg#search" /> </svg> Search </button>  <div class="ncbi-header__login-dropdown"> <button type="button" class="usa-button usa-button--unstyled ncbi-header__desktop-button ncbi-header__login-dropdown-button " aria-expanded="false" aria-controls="login-dropdown-menu" aria-label="Show login menu" data-testid="toggleLoginMenuDropdown" data-desktop-login-button > <svg class="usa-icon " role="graphics-symbol" aria-hidden="true" > <use xlink:href="/static/img/sprite.svg#person" /> </svg> <span data-login-dropdown-text>Log in</span>  <svg class="usa-icon ncbi-header__login-dropdown-icon ncbi-header__login-dropdown-icon--expand-less ncbi-header__login-dropdown-icon--hidden" role="graphics-symbol" aria-hidden="true" data-login-dropdown-up-arrow> <use xlink:href="/static/img/sprite.svg#expand_less" /> </svg>  <svg class="usa-icon ncbi-header__login-dropdown-icon ncbi-header__login-dropdown-icon--expand-more ncbi-header__login-dropdown-icon--hidden" role="graphics-symbol" aria-hidden="true" data-login-dropdown-down-arrow> <use xlink:href="/static/img/sprite.svg#expand_more" /> </svg> </button>  <ul class="usa-nav__submenu ncbi-header__login-dropdown-menu" id="login-dropdown-menu" data-desktop-login-menu-dropdown hidden> <li class="usa-nav__submenu-item">  <a href="https://www.ncbi.nlm.nih.gov/myncbi/" class="usa-link " > Dashboard </a> </li> <li class="usa-nav__submenu-item">  <a href="https://www.ncbi.nlm.nih.gov/myncbi/collections/bibliography/" class="usa-link " > Publications </a> </li> <li class="usa-nav__submenu-item">  <a href="https://www.ncbi.nlm.nih.gov/account/settings/" class="usa-link " > Account settings </a> </li> <li class="usa-nav__submenu-item"> <button type="button" class="usa-button usa-button--outline ncbi-header__login-dropdown-logout-button " data-testid="desktopLogoutButton" data-desktop-logout-button > Log out </button> </li> </ul> </div> </div> </div> </div>  <div class="ncbi-search-panel ncbi--show-only-at-desktop" data-testid="searchPanel" data-header-search-panel hidden> <div class="ncbi-search-panel__container"> <form action="https://www.ncbi.nlm.nih.gov/search/all/" aria-describedby="search-field-desktop-navigation-help-text" autocomplete="off" class="usa-search usa-search--big ncbi-search-panel__form" data-testid="form" method="GET" role="search"> <label class="usa-sr-only" data-testid="label" for="search-field-desktop-navigation"> Search… </label> <input class="usa-input" data-testid="textInput" id="search-field-desktop-navigation" name="term" placeholder="Search NCBI" type="search" value="" /> <button type="submit" class="usa-button " data-testid="button" > <span class="usa-search__submit-text"> Search NCBI </span> </button> </form> </div> </div> <nav aria-label="Primary navigation" class="usa-nav"> <p class="usa-sr-only" id="primary-navigation-sr-only-title"> Primary site navigation </p>  <button type="button" class="usa-nav__close ncbi-nav__close-button " aria-label="Close navigation menu" data-testid="navCloseButton" > <img src="/static/img/usa-icons/close.svg" alt="Close" /> </button>  <form class="usa-search usa-search--small ncbi--hide-at-desktop margin-top-6" role="search"> <label class="usa-sr-only" for="search-field"> Search </label> <input class="usa-input" id="search-field-mobile-navigation" type="search" placeholder="Search NCBI" name="search" /> <button type="submit" class="usa-button " >  <img src="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIGhlaWdodD0iMjQiIHZpZXdCb3g9IjAgMCAyNCAyNCIgd2lkdGg9IjI0Ij48cGF0aCBkPSJNMCAwaDI0djI0SDB6IiBmaWxsPSJub25lIi8+PHBhdGggZmlsbD0iI2ZmZiIgZD0iTTE1LjUgMTRoLS43OWwtLjI4LS4yN0E2LjQ3MSA2LjQ3MSAwIDAgMCAxNiA5LjUgNi41IDYuNSAwIDEgMCA5LjUgMTZjMS42MSAwIDMuMDktLjU5IDQuMjMtMS41N2wuMjcuMjh2Ljc5bDUgNC45OUwyMC40OSAxOWwtNC45OS01em0tNiAwQzcuMDEgMTQgNSAxMS45OSA1IDkuNVM3LjAxIDUgOS41IDUgMTQgNy4wMSAxNCA5LjUgMTEuOTkgMTQgOS41IDE0eiIvPjwvc3ZnPg==" class="usa-search__submit-icon" alt="Search" /> </button> </form>   <div class="ncbi-nav__mobile-login-menu ncbi--hide-at-desktop" data-mobile-login-menu hidden> <p class="ncbi-nav__mobile-login-menu-status"> Logged in as: <strong class="ncbi-nav__mobile-login-menu-email" data-mobile-login-email-text></strong> </p> <ul class="usa-nav__primary usa-accordion"> <li class="usa-nav__primary-item"> <a href="https://www.ncbi.nlm.nih.gov/myncbi/" class="usa-link " > Dashboard </a> </li> <li class="usa-nav__primary-item"> <a href="https://www.ncbi.nlm.nih.gov/myncbi/collections/bibliography/" class="usa-link " > Publications </a> </li> <li class="usa-nav__primary-item"> <a href="https://www.ncbi.nlm.nih.gov/account/settings/" class="usa-link " > Account settings </a> </li> </ul> </div> <button type="button" class="usa-button ncbi-nav__mobile-login-button ncbi--hide-at-desktop " data-testid="mobileLoginButton" data-mobile-login-button > Log in </button> </nav> </header> <main id="main-content"> <section class="usa-hero" aria-label="Introduction"> <div class="grid-container"> <div class="grid-row"> <div class="grid-col-fill"> <h1 class="usa-sr-only">PubMed Central (PMC) Home Page</h1> <div class="pmc-hero__logo"> <a href="/" title="Home" aria-label="Home" ></a> </div> <div class="pmc-hero__search margin-top-3 tablet:margin-top-5"> <form class="usa-search usa-search--extra" autocomplete="off" role="search"> <label class="usa-sr-only" for="pmc-search">Search PMC Full-Text Archive</label> <span class="autoComplete_wrapper flex-1"> <input class="usa-input width-full maxw-none" required="required" placeholder="Search PMC Full-Text Archive" id="pmc-search" type="search" name="term" data-autocomplete-url="/search/autocomplete/"/> </span> <button class="usa-button" type="submit" formaction="https://www.ncbi.nlm.nih.gov/pmc/" data-ga-category="search" data-ga-action="PMC" data-ga-label="PMC_search_button" > <span class="usa-search__submit-text">Search in PMC</span> <img src="/static/img/usa-icons-bg/search--white.svg" class="usa-search__submit-icon" alt="Search" /> </button> </form> </div> <div class="pmc-hero__links margin-top-1"> <ul class="usa-list usa-list--unstyled"> <li> <a class="usa-link" href="https://www.ncbi.nlm.nih.gov/pmc/advanced/" data-ga-action="featured_link" data-ga-label="advanced_search" > Advanced </a> </li> <li> <a class="usa-link" href="/journals/" data-ga-action="featured_link" data-ga-label="journal list" > Journal List </a> </li> </ul> </div> <div class="pmc-hero__text margin-top-2 tablet:margin-top-4"> <p class="margin-0"> PubMed Central<sup>®</sup> (PMC) is a free full-text archive of biomedical and life sciences journal literature at the U.S. National Institutes of Health's National Library of Medicine (NIH/NLM) </p> </div> </div> </div> </div> </section> <section class="usa-section padding-bottom-0" aria-label="Menu"> <div class="grid-container"> <ul class="usa-card-group"> <li class="usa-card usa-card--home tablet:grid-col-6 desktop:grid-col-4"> <div class="usa-card__container"> <div class="usa-card__header"> <h2 class="usa-card__heading"> <a href="/about/intro/" data-ga-action="featured_link" data-ga-label="about" > About PMC </a> </h2> </div> <div class="usa-card__media"> <div class="usa-card__img"> <img src="/static/img/icon-about.png" alt="" aria-hidden="true" /> </div> </div> <div class="usa-card__body"> <p> Discover a digital archive of scholarly articles, spanning centuries of scientific research. </p> </div> </div> </li> <li class="usa-card usa-card--home tablet:grid-col-6 desktop:grid-col-4"> <div class="usa-card__container"> <div class="usa-card__header"> <h2 class="usa-card__heading"> <a href="/about/userguide/" data-ga-action="featured_link" data-ga-label="about" > User Guide </a> </h2> </div> <div class="usa-card__media"> <div class="usa-card__img"> <img src="/static/img/icon-guide.png" alt="" aria-hidden="true" /> </div> </div> <div class="usa-card__body"> <p> Learn how to find and read articles of interest to you. </p> </div> </div> </li> <li class="usa-card usa-card--home tablet:grid-col-6 desktop:grid-col-4"> <div class="usa-card__container"> <div class="usa-card__header"> <h2 class="usa-card__heading"> <a href="/about/collections/" data-ga-action="featured_link" data-ga-label="about" > Collections </a> </h2> </div> <div class="usa-card__media"> <div class="usa-card__img"> <img src="/static/img/icon-collections.png" alt="" aria-hidden="true" /> </div> </div> <div class="usa-card__body"> <p> Browse the PMC Journal List or learn about some of PMC's unique collections. </p> </div> </div> </li> <li class="usa-card usa-card--home tablet:grid-col-6 desktop:grid-col-4"> <div class="usa-card__container"> <div class="usa-card__header"> <h2 class="usa-card__heading"> <a href="/about/submission-methods/" data-ga-action="featured_link" data-ga-label="about" > For Authors </a> </h2> </div> <div class="usa-card__media"> <div class="usa-card__img"> <img src="/static/img/icon-authors.png" alt="" aria-hidden="true" /> </div> </div> <div class="usa-card__body"> <p> Navigate the PMC submission methods to comply with a funder mandate, expand access, and ensure preservation. </p> </div> </div> </li> <li class="usa-card usa-card--home tablet:grid-col-6 desktop:grid-col-4"> <div class="usa-card__container"> <div class="usa-card__header"> <h2 class="usa-card__heading"> <a href="/pub/pubinfo/" data-ga-action="featured_link" data-ga-label="about" > For Publishers </a> </h2> </div> <div class="usa-card__media"> <div class="usa-card__img"> <img src="/static/img/icon-publishers.png" alt="" aria-hidden="true" /> </div> </div> <div class="usa-card__body"> <p> Learn about deposit options for journals and publishers and the PMC selection process. </p> </div> </div> </li> <li class="usa-card usa-card--home tablet:grid-col-6 desktop:grid-col-4"> <div class="usa-card__container"> <div class="usa-card__header"> <h2 class="usa-card__heading"> <a href="/tools/developers/" data-ga-action="featured_link" data-ga-label="about" > For Developers </a> </h2> </div> <div class="usa-card__media"> <div class="usa-card__img"> <img src="/static/img/icon-developers.png" alt="" aria-hidden="true" /> </div> </div> <div class="usa-card__body"> <p> Find tools for bulk download, text mining, and other machine analysis. </p> </div> </div> </li> </ul> </div> </section> <section class="usa-section usa-section--boundary padding-top-0 padding-bottom-0" id="achievement"> <div class="grid-container"> <div class="grid-row"> <div class="grid-col-12"> <h2 class="font-body-xl"><span class="text-uppercase">10.4 million</span> articles are archived in PMC.</h2> <div class="text-uppercase font-body-2xs">Content provided in part by:</div> </div> <div class="grid-col-12"> <ul class="usa-card-group flex-justify-center"> <li class="usa-card usa-card--home tablet:grid-col-6 desktop:grid-col-4"> <div class="usa-card__container"> <div class="usa-card__header"> <h3 class="font-sans-lg text-normal margin-bottom-1">2935</h3> <h3 class="font-sans-lg text-normal margin-top-0">Full Participation Journals</h3> </div> <div class="usa-card__body"> <p>Journals deposit the complete contents of each issue or volume.</p> </div> </div> </li> <li class="usa-card usa-card--home tablet:grid-col-6 desktop:grid-col-4"> <div class="usa-card__container"> <div class="usa-card__header"> <h3 class="font-sans-lg text-normal margin-bottom-1">277</h3> <h3 class="font-sans-lg text-normal margin-top-0">NIH Portfolio Journals</h3> </div> <div class="usa-card__body"> <p>Journals deposit all NIH-funded articles as defined by the NIH Public Access Policy.</p> </div> </div> </li> <li class="usa-card usa-card--home tablet:grid-col-6 desktop:grid-col-4"> <div class="usa-card__container"> <div class="usa-card__header"> <h3 class="font-sans-lg text-normal margin-bottom-1">43</h3> <h3 class="font-sans-lg text-normal margin-top-0">Selective Deposit Programs</h3> </div> <div class="usa-card__body"> <p>Publisher deposits a subset of articles from a collection of journals.</p> </div> </div> </li> </ul> </div> </div> </div> </section> <section class="usa-section usa-section--boundary padding-top-0 padding-bottom-0" id="new-in-pmc"> <div class="grid-container"> <div class="grid-row"> <div class="grid-col-12"> <h2 class="font-body-xl">New in PMC</h2> </div> </div> <div class="grid-row"> <div class="order-1 grid-col-12 tablet:grid-col-7 tablet:order-0 margin-top-3 tablet:margin-top-0"> <div> <div class="text-uppercase font-sans-2xs text-light text-base-darkest"> Oct. 21, 2024 </div> <h3 class="line-height-sans-4 font-sans-lg text-normal margin-top-1 margin-bottom-0"> <a class="usa-link text-no-underline" href="/about/new-in-pmc/#2024-10-21"> PMC Transitions to Updated Website</a> </h3> <div><p class="font-sans-sm line-height-sans-5"> On October 16, 2024, NLM's NCBI transitioned to an updated PubMed Central (PMC) website, representing the next step in ongo…</p></div> </div> <div> <div class="text-uppercase font-sans-2xs text-light text-base-darkest"> Oct. 17, 2024 </div> <h3 class="line-height-sans-4 font-sans-lg text-normal margin-top-1 margin-bottom-0"> <a class="usa-link text-no-underline" href="/about/new-in-pmc/#2024-10-17">PMC Tagging Guidelines Accessibility Updates</a> </h3> <div><p class="font-sans-sm line-height-sans-5"> The PMC Tagging Guidelines (TG) were updated on October 7, 2024, to provide new guidance for PMC data providers on how to de…</p></div> </div> </div> <div class="order-0 tablet:order-1 grid-col-12 tablet:grid-col-4 tablet:grid-offset-1 pmc-home__highlight"> <div class="pmc-home__highlight__container usa-prose"> <div class="pmc__home__news__item"> <label>highlights</label> <h2>PMC Transitions to Updated Website</h2> <a href="https://pmc.ncbi.nlm.nih.gov/about/new-in-pmc/#2024-10-21"><img alt="Graphic of the updated PMC Journal List and an article" src="https://cdn.ncbi.nlm.nih.gov/pmc/cms/images/pmc_website_updates_oct2024.png" style="max-width: 300px; height: auto"/></a> <p>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.</p>  <a class="usa-button usa-button" href="https://pmc.ncbi.nlm.nih.gov/about/new-in-pmc/#2024-10-21">Read More</a>  </div> </div> </div> </div> </div> </section> </main> <footer class="ncbi-footer ncbi-dark-background " > <div class="ncbi-footer__icon-section"> <div class="ncbi-footer__social-header"> Follow NCBI </div> <div class="grid-container ncbi-footer__ncbi-social-icons-container"> <a href="https://twitter.com/ncbi" class="ncbi-footer__social-icon ncbi-footer__social-icon--gray" target="_blank" rel="noreferrer noopener"> <svg width="40" height="40" viewBox="0 0 40 40" fill="none" xmlns="http://www.w3.org/2000/svg" focusable="false" aria-hidden="true"> <path d="m6.067 8 10.81 13.9L6 33.2h4.2l8.4-9.1 7.068 9.1H34L22.8 18.5 31.9 8h-3.5l-7.7 8.4L14.401 8H6.067Zm3.6 1.734h3.266l16.8 21.732H26.57L9.668 9.734Z"> </path> </svg> <span class="usa-sr-only">NCBI on X (formerly known as Twitter)</span> </a> <a href="https://www.facebook.com/ncbi.nlm" class="ncbi-footer__social-icon ncbi-footer__social-icon--gray" target="_blank" rel="noreferrer noopener"> <svg width="16" height="29" focusable="false" aria-hidden="true" viewBox="0 0 16 29" fill="none" xmlns="http://www.w3.org/2000/svg"> <path d="M3.8809 21.4002C3.8809 19.0932 3.8809 16.7876 3.8809 14.478C3.8809 14.2117 3.80103 14.1452 3.54278 14.1492C2.53372 14.1638 1.52334 14.1492 0.514288 14.1598C0.302626 14.1598 0.248047 14.0972 0.248047 13.8936C0.256034 12.4585 0.256034 11.0239 0.248047 9.58978C0.248047 9.37013 0.302626 9.30224 0.528931 9.3049C1.53798 9.31688 2.54837 9.3049 3.55742 9.31555C3.80103 9.31555 3.8809 9.26097 3.87957 9.00272C3.87158 8.00565 3.85428 7.00592 3.90753 6.00884C3.97142 4.83339 4.31487 3.73115 5.04437 2.78467C5.93095 1.63318 7.15699 1.09005 8.56141 0.967577C10.5582 0.79319 12.555 0.982221 14.5518 0.927641C14.7102 0.927641 14.7462 0.99287 14.7449 1.13664C14.7449 2.581 14.7449 4.02668 14.7449 5.47104C14.7449 5.67604 14.6517 5.68669 14.4946 5.68669C13.4523 5.68669 12.4113 5.68669 11.3703 5.68669C10.3506 5.68669 9.92057 6.10868 9.90593 7.13904C9.89661 7.7647 9.91525 8.39303 9.89794 9.01869C9.88995 9.26364 9.96583 9.31822 10.2015 9.31688C11.7204 9.30623 13.2393 9.31688 14.7595 9.3049C15.0257 9.3049 15.0723 9.3728 15.0444 9.62439C14.89 10.9849 14.7515 12.3467 14.6144 13.7085C14.5691 14.1571 14.5785 14.1585 14.1458 14.1585C12.8386 14.1585 11.5313 14.1665 10.2254 14.1518C9.95119 14.1518 9.89794 14.2317 9.89794 14.4899C9.90593 19.0799 9.89794 23.6752 9.91125 28.2612C9.91125 28.5674 9.8407 28.646 9.53186 28.6433C7.77866 28.6273 6.02414 28.6366 4.27094 28.634C3.82499 28.634 3.87158 28.6992 3.87158 28.22C3.87602 25.9472 3.87913 23.6739 3.8809 21.4002Z"> </path> </svg> <span class="usa-sr-only">NCBI on Facebook</span> </a> <a href="https://www.linkedin.com/company/ncbinlm" class="ncbi-footer__social-icon ncbi-footer__social-icon--gray" target="_blank" rel="noreferrer noopener"> <svg width="25" height="23" viewBox="0 0 26 24" fill="none" xmlns="http://www.w3.org/2000/svg" focusable="false" aria-hidden="true"> <path d="M14.6983 9.98423C15.6302 9.24808 16.5926 8.74754 17.6762 8.51991C19.673 8.09126 21.554 8.30824 23.1262 9.7526C24.2351 10.7723 24.7529 12.1115 25.0165 13.5612C25.1486 14.3363 25.2105 15.1218 25.2015 15.9081C25.2015 18.3043 25.2015 20.6898 25.2082 23.0806C25.2082 23.3468 25.1549 23.444 24.8621 23.4414C23.1297 23.4272 21.3992 23.4272 19.6704 23.4414C19.4041 23.4414 19.3429 23.3588 19.3442 23.1019C19.3535 20.5194 19.3442 17.9368 19.3442 15.3543C19.3442 14.0005 18.3258 12.9448 17.0266 12.9488C15.7273 12.9528 14.6983 14.0071 14.6983 15.361C14.6983 17.9328 14.6917 20.5047 14.6983 23.0753C14.6983 23.3708 14.6198 23.444 14.3296 23.4427C12.6185 23.4294 10.9079 23.4294 9.19779 23.4427C8.93155 23.4427 8.86099 23.3735 8.86232 23.1086C8.8783 19.7619 8.88628 16.4144 8.88628 13.066C8.88628 11.5688 8.87874 10.0708 8.86365 8.57182C8.86365 8.3575 8.90758 8.27896 9.14054 8.28029C10.9048 8.29094 12.6687 8.29094 14.4321 8.28029C14.6464 8.28029 14.6983 8.34818 14.6983 8.54653C14.6903 9.00047 14.6983 9.45441 14.6983 9.98423Z"> </path> <path d="M6.55316 15.8443C6.55316 18.2564 6.55316 20.6699 6.55316 23.082C6.55316 23.3629 6.48127 23.4388 6.19906 23.4374C4.47737 23.4241 2.75568 23.4241 1.03399 23.4374C0.767751 23.4374 0.69986 23.3629 0.701191 23.1006C0.709178 18.2648 0.709178 13.4281 0.701191 8.59053C0.701191 8.34026 0.765089 8.27237 1.01669 8.2737C2.74991 8.28435 4.48048 8.28435 6.20838 8.2737C6.47462 8.2737 6.5465 8.33627 6.54517 8.6065C6.54783 11.0186 6.55316 13.4308 6.55316 15.8443Z"> </path> <path d="M3.65878 0.243898C5.36804 0.243898 6.58743 1.45529 6.58743 3.1406C6.58743 4.75801 5.32145 5.95742 3.60819 5.96807C3.22177 5.97614 2.83768 5.90639 2.47877 5.76299C2.11985 5.61959 1.79344 5.40546 1.51897 5.13334C1.24449 4.86123 1.02755 4.53668 0.881058 4.17902C0.734563 3.82136 0.661505 3.43788 0.666231 3.05141C0.67555 1.42601 1.9362 0.242566 3.65878 0.243898Z"> </path> </svg> <span class="usa-sr-only">NCBI on LinkedIn</span> </a> <a href="https://github.com/ncbi" class="ncbi-footer__social-icon ncbi-footer__social-icon--gray" target="_blank" rel="noreferrer noopener"> <svg width="28" height="27" viewBox="0 0 28 28" fill="none" xmlns="http://www.w3.org/2000/svg" focusable="false" aria-hidden="true"> <path d="M16.7228 20.6334C17.5057 20.5527 18.2786 20.3944 19.0301 20.1608C21.3108 19.4193 22.5822 17.8259 22.963 15.4909C23.1228 14.5112 23.1814 13.5287 22.9883 12.5437C22.8106 11.6423 22.4013 10.8028 21.8007 10.1076C21.7526 10.0605 21.7197 10 21.7064 9.934C21.6931 9.86799 21.7 9.79952 21.7262 9.73748C22.0856 8.6206 21.9711 7.51969 21.601 6.42677C21.582 6.3497 21.5345 6.2827 21.468 6.23923C21.4016 6.19577 21.3211 6.17906 21.2429 6.19248C20.7329 6.21649 20.2313 6.33051 19.7611 6.52928C19.1103 6.7908 18.4899 7.12198 17.9104 7.51703C17.84 7.56996 17.7581 7.60551 17.6713 7.62078C17.5846 7.63605 17.4954 7.6306 17.4112 7.60489C15.2596 7.05882 13.0054 7.06203 10.8554 7.61421C10.7806 7.63586 10.7018 7.63967 10.6253 7.62534C10.5487 7.611 10.4766 7.57892 10.4148 7.53167C9.64788 7.03247 8.85171 6.58918 7.96368 6.33359C7.65781 6.24338 7.34123 6.19458 7.02239 6.18849C6.94879 6.17986 6.87462 6.19893 6.81432 6.242C6.75402 6.28507 6.71191 6.34904 6.69621 6.42145C6.32342 7.51437 6.2209 8.61527 6.56307 9.73348C6.59635 9.84264 6.64694 9.93316 6.54177 10.0516C5.47666 11.2604 5.09988 12.6834 5.19574 14.2676C5.2663 15.4244 5.46201 16.5466 6.01454 17.5769C6.84399 19.1171 8.21664 19.9119 9.85158 20.3352C10.3938 20.4706 10.9444 20.5698 11.4998 20.632C11.5384 20.7492 11.4506 20.7798 11.408 20.8291C11.1734 21.1179 10.9894 21.4441 10.8634 21.7942C10.7622 22.0458 10.8315 22.4039 10.6065 22.5516C10.263 22.7766 9.83827 22.8485 9.42421 22.8871C8.17936 23.0056 7.26471 22.4877 6.6283 21.4348C6.25552 20.8184 5.76956 20.3325 5.08523 20.0663C4.76981 19.9325 4.42139 19.8967 4.08537 19.9638C3.7898 20.029 3.73788 20.1901 3.93891 20.4111C4.03639 20.5234 4.14989 20.6207 4.27575 20.6999C4.9796 21.1318 5.51717 21.7884 5.80152 22.5636C6.37002 23.9973 7.48039 24.5697 8.93825 24.6323C9.43741 24.6575 9.93768 24.615 10.4254 24.5058C10.5892 24.4672 10.6531 24.4872 10.6517 24.6762C10.6451 25.4936 10.6637 26.3123 10.6517 27.131C10.6517 27.6635 10.1684 27.9297 9.58663 27.7393C8.17396 27.2671 6.84977 26.5631 5.66838 25.656C2.59555 23.2891 0.720966 20.1861 0.217704 16.3376C-0.357453 11.9127 0.911353 8.00824 3.98551 4.73881C6.11909 2.42656 8.99932 0.939975 12.1203 0.540191C16.5351 -0.0601815 20.4347 1.14323 23.7232 4.16373C26.2449 6.47869 27.724 9.37672 28.1048 12.7726C28.5828 17.0325 27.3686 20.7945 24.4768 23.9827C22.9762 25.6323 21.0956 26.8908 18.9982 27.6488C18.8783 27.6927 18.7585 27.738 18.636 27.7726C18.0356 27.9404 17.6189 27.6395 17.6189 27.0098C17.6189 25.7452 17.6308 24.4806 17.6295 23.2159C17.6329 22.9506 17.6128 22.6856 17.5696 22.4238C17.4325 21.6664 17.3419 21.484 16.7228 20.6334Z"> </path> </svg> <span class="usa-sr-only">NCBI on GitHub</span> </a> <a href="https://ncbiinsights.ncbi.nlm.nih.gov/" class="ncbi-footer__social-icon ncbi-footer__social-icon--gray" target="_blank" rel="noreferrer noopener"> <svg width="26" height="26" viewBox="0 0 27 27" fill="none" xmlns="http://www.w3.org/2000/svg" focusable="false" aria-hidden="true"> <path d="M23.7778 26.4574C23.1354 26.3913 22.0856 26.8024 21.636 26.3087C21.212 25.8444 21.4359 24.8111 21.324 24.0347C19.9933 14.8323 14.8727 8.80132 6.09057 5.85008C4.37689 5.28406 2.58381 4.99533 0.779072 4.99481C0.202773 4.99481 -0.0229751 4.83146 0.00455514 4.21479C0.0660406 3.08627 0.0660406 1.95525 0.00455514 0.826734C-0.0413285 0.0815827 0.259669 -0.0193618 0.896534 0.00266238C6.96236 0.222904 12.3693 2.24179 16.9889 6.16209C22.9794 11.2478 26.1271 17.7688 26.4372 25.648C26.4629 26.294 26.3179 26.5271 25.6609 26.4684C25.0827 26.417 24.4991 26.4574 23.7778 26.4574Z"> </path> <path d="M14.8265 26.441C14.0924 26.441 13.2371 26.6795 12.6626 26.3786C12.0092 26.0372 12.3781 25.0644 12.246 24.378C11.1154 18.5324 6.6849 14.5497 0.74755 14.1001C0.217135 14.0615 -0.0104482 13.9422 0.0134113 13.3659C0.0519536 12.1454 0.0482829 10.9213 0.0134113 9.69524C-0.00127145 9.14464 0.196946 9.03268 0.703502 9.04736C9.21217 9.27128 16.5994 16.2511 17.2804 24.7231C17.418 26.4446 17.418 26.4446 15.6579 26.4446H14.832L14.8265 26.441Z"> </path> <path d="M3.58928 26.4555C2.64447 26.4618 1.73584 26.0925 1.06329 25.4289C0.39073 24.7653 0.00933763 23.8617 0.0030097 22.9169C-0.00331824 21.9721 0.365937 21.0635 1.02954 20.3909C1.69315 19.7184 2.59675 19.337 3.54156 19.3306C4.48637 19.3243 5.39499 19.6936 6.06755 20.3572C6.7401 21.0208 7.1215 21.9244 7.12782 22.8692C7.13415 23.814 6.7649 24.7226 6.10129 25.3952C5.43768 26.0677 4.53409 26.4491 3.58928 26.4555Z"> </path> </svg> <span class="usa-sr-only">NCBI RSS feed</span> </a> </div> </div> <div data-testid="gridContainer" class="grid-container ncbi-footer__container"> <div class="grid-row ncbi-footer__main-content-container" data-testid="grid"> <div class="ncbi-footer__column"> <p class="ncbi-footer__circled-icons-heading"> Connect with NLM </p> <div class="ncbi-footer__circled-icons-list"> <a href=https://twitter.com/nlm_nih class="ncbi-footer__social-icon ncbi-footer__social-icon--circled" target="_blank" rel="noreferrer noopener"> <svg width="32" height="32" viewBox="0 0 40 40" fill="none" xmlns="http://www.w3.org/2000/svg" focusable="false" aria-hidden="true"> <path d="m6.067 8 10.81 13.9L6 33.2h4.2l8.4-9.1 7.068 9.1H34L22.8 18.5 31.9 8h-3.5l-7.7 8.4L14.401 8H6.067Zm3.6 1.734h3.266l16.8 21.732H26.57L9.668 9.734Z"> </path> </svg> <span class="usa-sr-only">NLM on X (formerly known as Twitter)</span> </a> <a href=https://www.facebook.com/nationallibraryofmedicine class="ncbi-footer__social-icon ncbi-footer__social-icon--circled" target="_blank" rel="noreferrer noopener"> <svg width="13" height="24" viewBox="0 0 13 24" fill="none" xmlns="http://www.w3.org/2000/svg" focusable="false" aria-hidden="true"> <path d="M4.11371 23.1369C4.11371 23.082 4.11371 23.0294 4.11371 22.9745V12.9411H0.817305C0.6709 12.9411 0.670898 12.9411 0.670898 12.8016C0.670898 11.564 0.670898 10.3287 0.670898 9.09341C0.670898 8.97903 0.705213 8.95158 0.815017 8.95158C1.8673 8.95158 2.91959 8.95158 3.97417 8.95158H4.12057V8.83263C4.12057 7.8055 4.12057 6.7738 4.12057 5.74897C4.1264 4.92595 4.31387 4.11437 4.66959 3.37217C5.12916 2.38246 5.94651 1.60353 6.95717 1.1921C7.64827 0.905008 8.3913 0.764035 9.13953 0.778051C10.0019 0.791777 10.8644 0.830666 11.7268 0.860404C11.8869 0.860404 12.047 0.894717 12.2072 0.90158C12.2964 0.90158 12.3261 0.940469 12.3261 1.02968C12.3261 1.5421 12.3261 2.05452 12.3261 2.56465C12.3261 3.16857 12.3261 3.7725 12.3261 4.37642C12.3261 4.48165 12.2964 4.51367 12.1912 4.51138C11.5369 4.51138 10.8804 4.51138 10.2261 4.51138C9.92772 4.51814 9.63058 4.5526 9.33855 4.61433C9.08125 4.6617 8.84537 4.78881 8.66431 4.97766C8.48326 5.16652 8.3662 5.40755 8.32972 5.66661C8.28476 5.89271 8.26027 6.1224 8.25652 6.35289C8.25652 7.19014 8.25652 8.02969 8.25652 8.86923C8.25652 8.89439 8.25652 8.91955 8.25652 8.95615H12.0219C12.1797 8.95615 12.182 8.95616 12.1614 9.10714C12.0768 9.76596 11.9876 10.4248 11.9029 11.0813C11.8312 11.6319 11.7626 12.1824 11.697 12.733C11.6719 12.9434 11.6787 12.9434 11.4683 12.9434H8.26338V22.899C8.26338 22.979 8.26338 23.0591 8.26338 23.1392L4.11371 23.1369Z"> </path> </svg> <span class="usa-sr-only">NLM on Facebook</span> </a> <a href=https://www.youtube.com/user/NLMNIH class="ncbi-footer__social-icon ncbi-footer__social-icon--circled" target="_blank" rel="noreferrer noopener"> <svg width="21" height="15" viewBox="0 0 21 15" fill="none" xmlns="http://www.w3.org/2000/svg" focusable="false" aria-hidden="true"> <path d="M19.2561 1.47914C18.9016 1.15888 18.5699 0.957569 17.2271 0.834039C15.5503 0.678484 13.2787 0.655608 11.563 0.65332H9.43556C7.71987 0.65332 5.4483 0.678484 3.77151 0.834039C2.43098 0.957569 2.097 1.15888 1.74242 1.47914C0.813665 2.32097 0.619221 4.62685 0.598633 6.89384C0.598633 7.31781 0.598633 7.74101 0.598633 8.16345C0.626084 10.4121 0.827391 12.686 1.74242 13.521C2.097 13.8412 2.4287 14.0425 3.77151 14.1661C5.4483 14.3216 7.71987 14.3445 9.43556 14.3468H11.563C13.2787 14.3468 15.5503 14.3216 17.2271 14.1661C18.5676 14.0425 18.9016 13.8412 19.2561 13.521C20.1712 12.6929 20.3725 10.451 20.3999 8.22064C20.3999 7.74025 20.3999 7.25986 20.3999 6.77946C20.3725 4.54907 20.1689 2.30724 19.2561 1.47914ZM8.55942 10.5311V4.65201L13.5601 7.50005L8.55942 10.5311Z" fill="white" /> </svg> <span class="usa-sr-only">NLM on YouTube</span> </a> </div> </div> <address class="ncbi-footer__address ncbi-footer__column"> <p> <a class="usa-link usa-link--external" href="https://www.google.com/maps/place/8600+Rockville+Pike,+Bethesda,+MD+20894/%4038.9959508, -77.101021,17z/data%3D!3m1!4b1!4m5!3m4!1s0x89b7c95e25765ddb%3A0x19156f88b27635b8!8m2!3d38.9959508! 4d-77.0988323" rel="noopener noreferrer" target="_blank">National Library of Medicine <br/> 8600 Rockville Pike<br/> Bethesda, MD 20894</a> </p> </address> <ul class="usa-list usa-list--unstyled ncbi-footer__vertical-list ncbi-footer__column"> <li class="ncbi-footer__vertical-list-item"> <a href="https://www.nlm.nih.gov/web_policies.html" class="usa-link usa-link--alt ncbi-footer__link" > Web Policies </a> </li> <li class="ncbi-footer__vertical-list-item"> <a href="https://www.nih.gov/institutes-nih/nih-office-director/office-communications-public-liaison/freedom-information-act-office" class="usa-link usa-link--alt ncbi-footer__link" > FOIA </a> </li> <li class="ncbi-footer__vertical-list-item"> <a href="https://www.hhs.gov/vulnerability-disclosure-policy/index.html" class="usa-link usa-link--external usa-link--alt ncbi-footer__link" rel="noreferrer noopener" target='_blank' > HHS Vulnerability Disclosure </a> </li> </ul> <ul class="usa-list usa-list--unstyled ncbi-footer__vertical-list ncbi-footer__column"> <li class="ncbi-footer__vertical-list-item"> <a href="https://support.nlm.nih.gov/" class="usa-link usa-link--alt ncbi-footer__link" > Help </a> </li> <li class="ncbi-footer__vertical-list-item"> <a href="https://www.nlm.nih.gov/accessibility.html" class="usa-link usa-link--alt ncbi-footer__link" > Accessibility </a> </li> <li class="ncbi-footer__vertical-list-item"> <a href="https://www.nlm.nih.gov/careers/careers.html" class="usa-link usa-link--alt ncbi-footer__link" > Careers </a> </li> </ul> </div> <div class="grid-row grid-col-12" data-testid="grid"> <ul class="ncbi-footer__bottom-links-list"> <li class="ncbi-footer__bottom-list-item"> <a href="https://www.nlm.nih.gov/" class="usa-link usa-link--alt ncbi-footer__link" > NLM </a> </li> <li class="ncbi-footer__bottom-list-item"> <a href="https://www.nih.gov/" class="usa-link usa-link--alt ncbi-footer__link" > NIH </a> </li> <li class="ncbi-footer__bottom-list-item"> <a href="https://www.hhs.gov/" class="usa-link usa-link--external usa-link--alt ncbi-footer__link" rel="noreferrer noopener" target='_blank' > HHS </a> </li> <li class="ncbi-footer__bottom-list-item"> <a href="https://www.usa.gov/" class="usa-link usa-link--external usa-link--alt ncbi-footer__link" rel="noreferrer noopener" target='_blank' > USA.gov </a> </li> </ul> </div> </div> </footer> <script type="text/javascript" src="https://cdn.ncbi.nlm.nih.gov/core/pinger/pinger.js"> </script> <script type="application/javascript"> window.ncbi = window.ncbi || {}; window.ncbi.pmc = window.ncbi.pmc || {}; window.ncbi.pmc.options = { logLevel: 'INFO', staticEndpoint: '/static/', citeCookieName: 'pmc-cf', }; </script> <script type="module" crossorigin="" src="/static/assets/base-9bea7450.js"></script> <script type="module" crossorigin="" src="/static/assets/home-4ed993c7.js"></script> </body> </html>

CINXE.COM

PMC Home