1 They do their best work at 55ÂºF, but can carry on right down to 0ÂºF. As they eat away at organic materials, they give off a small amount of heat.  Mesophilic - Second wave of microbial activity. Most of the decomposition in a compost pile is mesophilic.
In general, it is thought that implants last approximately 10 years or should be replaced every eight to 10 years. A ruptured saline implant is clinically obvious as the breast will deflate and there will be great asymmetry. A ruptured silicone implant is more difficult to determine and is referred as a silent rupture.
While the average tissue valve (porcine, bovine, equine) is estimated to last between 10-15 years, reports suggest that mechanical valves can last 30 years or more after implant. That said, for some younger patients, a mechanical heart valve can be a suitable replacement for the diseased valve.