We considered the possibility of a ball design for the valve ... had two previous closed mitral commissurotomies for calcific mitral stenosis. Ralph Berg, who started open-heart surgery in ...

the valves can open and close. Interference engines allow the piston to go further into the combustion chamber to increase compression, and the valves to go deeper so they open wider and for longer.

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 ...

The risk of thrombosis of mechanical valves is higher in the mitral position compared with aortic position and in older generation valves (ball and cage valves). There is a wide spectrum of ...

At just the right moment, the right and left atria empty their accumulated blood into the right and left ventricles. The four heart valves (tricuspid, pulmonary, mitral and aortic) open and close at ...

you may see a ball valve with a lever that moves 90 degrees or a gate valve with a handle that rotates to open and close the valve. Push the handle to align with the water pipe to open a ball valve.

The Dallas Open is in full swing at The Star in Frisco, and one of its ball boys is proving that passion has no age limit. At 66 years old, Tony Downer volunteers at tennis tournaments nationwide ...

Once you have made the decision to have heart valve replacement surgery, you, along with your surgeon, will need to decide what type of replacement valve is best for you. There are several types of ...

The Chicago Bulls and veteran point guard Lonzo Ball have agreed to a two-year, $20 million contract extension, according to Shams Charania. Ball was set to be an unrestricted free agent this ...