New Research In
Physical Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
PNAS commits to immediately and freely sharing research data and findings relevant to the novel coronavirus (COVID-19) outbreak.
See the free collection of PNAS coronavirus papers and learn more about our response to COVID-19.
See the free collection of PNAS coronavirus papers and learn more about our response to COVID-19.
Front Matter
Saltwater is far more abundant on Earth, yet about half of the known fish species live in freshwater. The longstanding question is why.
Image credit: Florian Moser (photographer).
To effectively track and measure emissions reductions, we need a Greenhouse Gas Information System.
Image credit: Shutterstock/Tatiana Grozetskaya.
How a small group of researchers has taken on the painstaking and daunting task of trying to restore two of the Bay’s most important keystone species.
In the News
A study examines how agriculture influences mortality due to poor air quality in the United States.
Image credit: Jason D. Hill.
Researchers report a unique quasicrystal discovered in the remnants of the first nuclear bomb detonation.
Image credit: Luca Bindi and Paul J. Steinhardt.
A study estimates that there are 50 billion birds in the world, with the majority in palearctic and nearctic realms.
Image credit: Corey T. Callaghan.
Sign up for Article Alerts
Science Sessions Podcasts
Maggie Wagner and Manuel Kleiner report that the interaction between maize and soil microbes influences hybrid vigor.
Featured QnAs
QnAs with NAS member and stem cell biologist Andrew P. McMahon
Image credit: Jill McMahon (photographer).