''Superfluid helium-4 is the superfluid form of helium-4, an isotope of the element helium. A superfluid is a state of matter in which the matter behaves like a fluid with zero viscosity. ...'
''College Park, MD (February 28, 2008) -- Many of the greatest inventions in modern medicine were developed by physicists who imported technologies such as X rays, nuclear magnetic resonance, ultrasound, particle accelerators and radioisotope tagging and ...'