THE thermionic valve has long been recognized as a useful tool in many branches of science and engineering; but few, with the exception of experimenters, have realized that it can be usefully applied ...

There are three types of bicuspid aortic valves — types 0, 1, and 2. Experts classify these types based on whether the leaflets of the valve have fused to form a ridge. A bicuspid aortic valve is a ...

(Reuters Health) - People who need a heart valve replaced often face a dilemma: should they have a mechanical valve made of graphite or a biological valve derived from a cow or pig? A new study ...

The question, “Presta or Schrader?”, may seem confusing when you’re new to cycling and head to a bike shop to buy a replacement inner tube. For the vast majority of bikes, there are two types of valve ...