X-Message-Number: 564 Date: Mon, 2 Dec 91 14:40:57 EST From: (Mark Kaminsky (Contractor)) Subject: #554 - Cryonics Debate > Keith: > > Radiation damages the DNA/RNA of the cells. A nanotech might be > developed that would repair the structure of a cell, but a nanotech > could not be made small enough to repair the DNA/RNA of the cell. What > causes the cell to die from radiation is the damage to its DNA/RNA. > If a cell can repair its DNA (which it does), then a nanotech "virus" can repair DNA. The minimum of what its possible to do with nanotech is what natural-nanotech (nature) can do already. We will likely be able to do more. My understanding (correct me if I'm wrong) is that radiation does most of its damage by setting off free-radical reactions. In other words, a high energy particle or photon comes along and knocks an electron or atom off a molecule (damaging it) creating one or more free-radicals which then react with other molecules (damaging them) and so on. The whole process continues until a free- radical meets up with a de-oxident molecule like Vitamin E or beta carotine which quenches the reaction. The cell's self-repair mechanism then takes over to fix the damage. Thus radiation can damage the DNA even if it didn't get a direct hit. I would guess that the damage to DNA from direct radiation hits is orders of magnitudes less than from radiation induced free-radical chain reactions. Now to the point: since free-radical reactions are chemical reactions they vary with temperature (millions of times slower at liquid Nitrogen temperatures???), and thus a suspended body should be able to take much greater one time dose before becomming unrepairable. On the other hand, a suspended body is not doing any self-repair so all radiation (even low-level) over the storage time should be added together. Mark B. Kaminsky - Computervision/Prime Computer, Bedford, Massachusetts, USA My goal is a simple one: To live forever - or die trying. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=564