Vapor-compression refrigeration replaced, such as sulfur dioxide. Haloalkanes are also an order(s) of magnitude more expensive than petroleum derived flammable alkanes of similar or better cooling performance. Unfortunately, chlorine- and fluorine-bearing refrigerants reach the upper atmosphere when they escape. In the stratosphere, CFCs break up due to UV radiation, releasing their chlorine free radicals. These chlorine free radicals act as catalysts in the breakdown of ozone through chain reactions. One CFC molecule can cause thousands of ozone molecules to break down. This causes severe damage to the ozone layer that shields the Earth's surface from the Sun's strong UV radiation, and has
Protein S (Myxococcus xanthus) Protein S (Myxococcus xanthus) Protein S is a protein found in "Myxococcus xanthus". Its name derives from being the "S" band in an alphabetical ordering of proteins run from Myxococcus xanthus cell contents on a SDS-denaturing gel. Its study was initially prompted by the huge increase in Protein S production during sporulation of Myxococcus xanthus. Though it has been purported as recently as 1994 that Protein S enables myxospores of Myxococcus xanthus higher resistance to endure heating, desiccation, UV radiation and sonication no such evidence exists. The work that cites claims no such evidence: and there are other studies that