Cold sores, or fever blisters, are sores that form around the outside of your mouth, usually on or around your lips. They’re caused by herpes simplex virus and are highly contagious. Cold sores ...

† BK21 Physics Division, Department of Energy Science, and Center for Nanotubes and Nanostructured Composites, Sungkyunkwan Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon 440-746 ...