Proceedings of the National Academy of Sciences of the United States of America

The Proceedings of the National Academy of Sciences of the United States of America, usually referred to by the acronym PNAS, is the official journal of the United States National Academy of Sciences (NAS). PNAS is an important scientific journal that printed its first issue in 1915 and continues to publish highly cited research reports, commentaries, reviews, perspectives, feature articles, profiles, letters to the editor, and actions of the Academy. Coverage in PNAS broadly spans the biological, physical, and social sciences. Although most of the papers published in the journal are in the biomedical sciences, PNAS recruits papers and publishes special features in the physical and social sciences and in mathematics. PNAS is published weekly in print, and daily online in PNAS Early Edition.

History
PNAS was established by NAS in 1914, with its first issue published in 1915. The NAS itself had been founded in 1863 as a private institution, but chartered by the US Congress, with the goal to "investigate, examine, experiment, and report upon any subject of science or art." By 1914, the Academy was well established.

Prior to the start of the journal, NAS published three volumes of organizational transactions, consisting mostly of minutes of meetings and annual reports. In accordance with the guiding principles established by astronomer George Ellery Hale, the foreign secretary of NAS in 1914, PNAS publishes brief first announcements of Academy members' and foreign associates' more important contributions to research and of work that appears to a member to be of particular importance.

Editors

 * 1914–1918 – Arthur A. Noyes
 * 1918–1940 – Raymond Pearl
 * 1940–1949 – Robert A. Millikan
 * 1950–1955 – Linus Pauling
 * 1955–1960 – Wendell M. Stanley
 * 1960–1968 – Saunders Mac Lane
 * 1968–1972 – John T. Edsall
 * 1972–1980 – Robert Louis Sinsheimer
 * 1980–1984 – Daniel E. Koshland, Jr.
 * 1985–1988 – Maxine Singer
 * 1988–1991 – Igor B. Dawid
 * 1991–1995 – Lawrence Bogorad
 * 1995–2006 – Nicholas R. Cozzarelli
 * 2006–present – Randy Schekman

The first managing editor of the journal was mathematician Edwin Bidwell Wilson.

Peer review
All research papers published in PNAS are peer-reviewed. The standard mode is for papers to be submitted directly to PNAS rather than going through an Academy member. Members may handle the peer review process for up to 4 of their own papers per year—this is an open review process because the member selects and communicates directly with the referees. These submissions and reviews, like all for PNAS, are evaluated for publication by the PNAS Editorial Board. Until July 1, 2010, members were allowed to communicate up to 2 papers from non-members to PNAS every year. The review process for these papers was anonymous in that the identities of the referees were not revealed to the authors. Referees were selected by the NAS member. PNAS eliminated communicated submissions through NAS members as of July 1, 2010, while continuing to make the final decision on all PNAS papers.

Dual use papers and national security
In 2003, PNAS issued an editorial stating its policy on publication of sensitive material in the life sciences. PNAS stated that it would "continue to monitor submitted papers for material that may be deemed inappropriate and that could, if published, compromise the public welfare." This statement was in keeping with the efforts of several other journals. In 2005 PNAS published an article titled "Analyzing a bioterror attack on the food supply: The case of botulinum toxin in milk" despite objections raised by the U.S. Department of Health and Human Services. The paper was published with a commentary by the president of the Academy at the time, Bruce Alberts, titled "Modeling attacks on the food supply".

Impact
PNAS is widely read by researchers, particularly those involved in basic sciences, around the world. PNAS Online receives over 21 million hits per month. The journal is notable for its policy of making research articles freely available online to everyone 6 months after publication (delayed open access), or immediately if authors have chosen the "open access" option (hybrid open access). Immediately free online access (without the 6-month delay) is available to 139 developing countries and for some categories of papers such as colloquia. Abstracts, tables of contents, and online supporting information are free. Anyone can sign up to receive free tables of contents by email.

Because PNAS is self-sustaining and receives no direct funding from the government or the National Academy of Sciences, the journal charges authors publication fees and subscription fees to offset the cost of the editorial and publication process. According to the Journal Citation Reports, the journal's 2010 impact factor is 9.771. PNAS is the second most cited scientific journal with 1,338,191 citations from 1994–2004 (the Journal of Biological Chemistry is the most cited journal over this period with 1,740,902 citations in total).

PNAS has received occasional criticism for its practice (sometimes known as news embargo ) of releasing papers to science journalists as much as a week before making them available to the general public&mdash;according to critics, this allows mainstream news outlets to misrepresent or exaggerate the implications of experimental findings before the scientific community is able to respond. Science writer Ed Yong, on the other hand, has claimed that the real problem is not embargoes themselves, but the press releases issued by research institutes and universities.

PNAS Plus
Beginning in January 2011, PNAS will consider manuscripts for exclusive online publication, PNAS Plus papers. These will have a larger page number (10 rather than 6 pages). Accompanying these papers both online and in print, will be a one- to two-page summary description written for a broad readership. The introduction of PNAS Plus is part of gradual shift in PNAS content described in an editorial: "If PNAS Plus succeeds, we envision transitioning to a print edition of PNAS in a magazine format comprising special features, commentaries on important papers flagged by member editors and the Editorial Board, and summary statements of the online articles."