Receive emails about upcoming NOVA programs and related content, as well as featured reporting about current events through a science lens. Our first question was about the concept of molecular ...

Students learn how to predict the shape of a molecule based on the electron dot diagram. Covalent Bonds: Students learn how to predict the shape of a molecule based on the electron dot diagram and to ...

Permeation of active drugs across the vascular brain endothelium into the central nervous system (CNS) is controlled by the blood-brain barrier (BBB). The BBB separates the bloodstream from the brain.

This is a preview. Log in through your library . PNAS is the world's most-cited multidisciplinary scientific serial. It publishes high-impact research reports, commentaries, perspectives, reviews, ...