An artificial valve is also known as a mechanical ... A cadaveric valve comes from a human donor. Bovine valves are recovered from cows and porcine valves come from pigs. The valve may be an ...

These curious molecules are both positively and negatively charged at the same time; the word “zwitter” in German means “hybrid” or “hermaphrodite”. Their unusual nature affords zwitterions a ...

Mechanical valves last longer, but blood can clot on them. A patient may need long-term medication that prevents blood clots developing. Biological valves are more likely to wear out.