The first detailed images of an elusive drug target on the outer wall of bacteria may provide scientists with enough new information to aid design of novel antibiotics. The drugs are much needed to treat deadly infections initiated by Staphylococcus aureus and other bacterial pathogens.

When a virus infects a person, it triggers a series of biochemical reactions in immune-system cells that literally may have life or death consequences.

New scientific research may close a major loophole in the RNA world hypothesis, the idea that ribonucleic acid -- not the fabled DNA that makes up genes in people and other animals -- was the key to life's emergence on Earth 4.6 billion years ago.