Every winter, as the air sharpens and scarves return to shoulders, an old visitor also makes a reappearance: the flu. It ...

Scientists have finally watched influenza viruses break into living human cells in real time, catching the microscopic ...

Using a tiny, spherical glass lens sandwiched between two brass plates, the 17th-century Dutch microscopist Antonie van Leeuwenhoek was the first to officially describe red blood cells and sperm cells ...