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Near-infrared penetrates very well. The same intensity is much safer, up till you get to the levels of radiation that are dangerous regardless of how they're di
by hansvm 3y ago
Near-infrared penetrates very well. The same intensity is much safer, up till you get to the levels of radiation that are dangerous regardless of how they're distributed in your tissues.
That's one of the things that makes it suitable for thermal nano cancer therapies. You
(1) Create a nanoparticle with a gold core of the right size that it excites when exposed to near-infrared radiation (the far end of "near" is ideal),
(2) Coat it with something that's hopefully less toxic than the cancer because the gold nanoparticles are pretty reactive (silica was popular last I checked, though I'm not convinced that's actually safe, and there hasn't been much testing on it),
(3) Coat that in something that binds to the right antigens,
(4) Inject that into the patient so that you'll eventually have a tumor rich in these nanoparticles while the rest of the body has a very low concentration,
(5) Shine an intense near-infrared beam at the nanoparticles. It safely penetrates body and causes minimal heating, instead depositing all its energy at the tumor, selectively cooking just the bits of tissue you don't want anymore.
It's yet another way to make mice immortal, but human testing is a long ways off. The hard parts are (2) and (3), along with the (4a) I didn't mention where most of these things don't want to stay "nano" in most chemical environments, and the solution they're suspended in is usually also not ideally suited to being injected into living mammals who would like to retain that "living" property.
- hollerith 3y ago>Near-infrared penetrates very well. The same intensity is much safer Glowing-hot steel produces enough IR that the workers that work with it have 7 times the rate of cataracts as the general population.
- hansvm 3y agoSure, enough of almost anything is dangerous. NIR is much safer than the visible spectrum at the same power levels. The threshold for a few minutes of high-intensity NIR increasing your chance of eventual cataracts is staring at an NIR source 10x brighter (w/cm^-1) than the sun integrated across all its wavelengths. The threshold for sun-colored wavelengths causing eventual cataracts above the baseline from a few minutes of staring is under 1x. Also worth noting, very very near IR (basically red, though we can't see it) doesn't quite enjoy those same properties, and during their time working with hot metal you'd expect a lot of energy in that band. Also worth noting, many steel workers are exposed to dangerous amounts of visible light too. I absolutely believe that they can get enough NIR to cause problems, but if I wanted to try to prove that NIR specifically causes their problems to somebody else then I'd want to try to account for that fact (and for incidental welder exposure, ...).