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SynthOrange posted:Afaik bacteriophages are used around the former USSR and are practically unknown in the outside world where antibiotics would be used instead. There's been some speculation that this is going to change if antibiotic resistant stuff becomes the new normal. The problem at least in the US is regulatory hurdles. You need a cocktail of different phage strains for most bacteria, and then reformulate the cocktail as populations evolve. As it stands, the FDA requires at least Phase 1 (safety) and Phase 2 (efficacy) trials before letting a new drug come to market, and each cocktail formulation would count as a new drug that needs to be tested. It's a reasonable system for chemotherapies but not so much for a constantly-evolving system like phage, except with some edge cases like acne where all the known strains of bacteria are susceptible to a single strain of phage. The regulations will probably change as antibiotic resistance becomes a bigger problem though. I really hope so.
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Nov 18, 2015 05:55
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Would phages really count as a drug, though? It's a microorganism. Don't flu shots use the latest stain available? I can't imagine they have to go through that testing every year.
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Nov 18, 2015 06:08
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I was reading some of the IAEA's other accident response publications and came across one for a criticality accident in Russia in the late 90s. quote:On the basis of this work and the assumptions mentioned earlier concerning the position of the technician at the time of the initial radiation burst, the average dose to the upper part of the body was estimated to be 40 ± 1 Gy for the neutron component and 2.5 ± 0.5 Gy for the gamma component. quote:This suggested that the total dose to the hands could lie between 800 and 2000 Gy. The final estimates were 1700 ± 170 Gy and about 120 Gy for the neutron and gamma components, respectively. http://www-pub.iaea.org/MTCD/Publications/PDF/Pub1106_scr.pdf
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Nov 18, 2015 06:26
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KillHour posted:Would phages really count as a drug, though? It's a microorganism. Don't flu shots use the latest stain available? I can't imagine they have to go through that testing every year. They're treated as a biological product (basically as a drug). Flu shots are updated yearly but the update is just changing the mix of existing vaccines - new strain vaccines still have to go through regulatory approval.
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Nov 18, 2015 06:29
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GWBBQ posted:For illustration purposes (images from Oak Ridge Associated Universities Museum): poo poo. I never realized just how harmless those things could look. The bottom two especially look exactly like the kind of little connector or wire some poor bastard would just instinctively pick up and stick in their pocket or toolbox. They couldn't look any more innocuous.
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Nov 18, 2015 06:34
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Luneshot posted:I was reading some of the IAEA's other accident response publications and came across one for a criticality accident in Russia in the late 90s. quote:The technician reportedly realized that a criticality accident had happened. He Goddamn
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Nov 18, 2015 06:38
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quote:During this first few minutes after the criticality event he was fully conscious
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Nov 18, 2015 06:45
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Neutron radiation has the fun bonus of making everything else radioactive too, such as your clothing, skin, body... I read something once, might even have been in this thread. You have four sources: an alpha emitter, a beta emitter, a gamma emitter, and a neutron emitter. You have to hold one in your hand, put one in your pocket, eat one, and throw one away. What do you do? If I remember correctly, you hold the alpha, pocket the beta, eat the gamma, and throw away the neutron source.
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Nov 18, 2015 06:53
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Luneshot posted:Neutron radiation has the fun bonus of making everything else radioactive too, such as your clothing, skin, body... The idea being that the gamma emitter will f you up no matter where it is while skin/clothing will definitely stop alpha emitters and reduce beta emitters enough? I would rather the alpha emitter pocketed and the beta emitter in my hand. I don't need both hands, I do need a butt.
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Nov 18, 2015 08:34
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Alpha can only travel through air pretty much and is usually stopped even then. It can't get through skin at all, to reactive and massive. Beta being a fast moving free electron is smaller and less likely to interact, so skin won't stop it or at least the first few layers. It will be stopped by clothing though or a thin layer of metal. Gamma is a high energy EM wave instead of a physical atomic mass. It is very very hard to stop but its also not likely to interact with you. Being around gamma emissions is a bad idea but less dangerous then Alpha and Beta. Good example is that it takes meters of lead to stop Gamma rays. Now the danger comes not from casual exposure but ingestion. Alpha and beta radiation can be stopped by skin or clothing but if a source is ingested it is extremely dangerous. Beta isn't as bad but ingesting an Alpha source due to its high reactive potential can be deadly outright and cause numerous genetic defects if it doesn't kill you. Gamma source would just make you radioactive and cause increased cancer ricks. And a neutron source just wants to end you and everything around you. UCS Hellmaker has a new favorite as of 10:15 on Nov 18, 2015 |
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Nov 18, 2015 08:46
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Clothing will stop beta emitters. (Air will stop alpha emitters.)
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Nov 18, 2015 08:47
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Clothing stopping beta emitters? Maybe from an isotope with low decay energy like tritium, but tons of beta emitters penetrate and those are the ones that will harm you anyway. When my radioactive sources arrived I took a G-M pancake probe (mostly sensetive to alpha and beta) to the box and I was getting a raw count of almost 700 cpm from the 0.1 microcurie strontium-90 source. That's a good couple percent of its total activity through 20cm of packaging to a relatively small probe after accounting for its efficiency which is well under 10%, so the reading is off by over an order of magnitude from reality. In your back pocket? Yeah, you're going to be taking almost half of the source to your rear end assuming an isotropic source unless you're wearing tinfoil undies. Edit: low energy beta emitting isotopes like tritium only present an ingestion hazard though BattleMaster has a new favorite as of 17:07 on Nov 18, 2015 |
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Nov 18, 2015 14:45
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BattleMaster posted:Clothing stopping beta emitters? Maybe from an isotope with low decay energy like tritium, but tons of beta emitters penetrate and those are the ones that will harm you anyway. When my radioactive sources arrived I took a G-M pancake probe (mostly sensetive to alpha and beta) to the box and I was getting almost 700 cpm from the 0.1 microcurie strontium-90 source. That's a good full percent of its total activity through 20cm of packaging to a small probe. In your back pocket? Yeah, you're going to be taking about half of the source to your rear end assuming an isotropic source unless you're wearing tinfoil undies. You don't? 
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Nov 18, 2015 14:48
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Luneshot posted:Poor guy never had a chance, only lasted like three days even with immediate intensive medical treatment. Neutron radiation will gently caress you up hardcore. I like the slight quandary they ended up with there where they couldn't send a person in because that would be death and using heavy equipment would radically increase the activity of the assembly. It took them over a week to figure out a method and execute their plan.
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Nov 18, 2015 18:01
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Flood the room with heavy water? 
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Nov 18, 2015 19:00
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Jesus, that was a rough ride. Poor dude got his arms amputated and ended up dying from circulatory system failures, but if he had survived that he was probably going to go on and die from gastrointestinal issues instead. Dude caught such a hard burst of neutrons that one of the normal methods of estimating his radiation exposure couldn't even be used  quote:Chromosome aberration analysis, an established method for assessing mean whole body dose, uses the technician’s own biological material as a dosimeter [32]. This method takes time, since the lymphocytes need to be cultured. Currently, the minimum time period between sampling and results cannot be reduced to less than three days. Moreover, in the case of non-uniform exposure, the technique can only give some hypothetical mean dose, and the reliability of the method was limited by the too high dose. If the whole body dose exceeds about 10 Gy, it is difficult to perform the analysis because there are few if any viable cells that can be cultured. Icon Of Sin has a new favorite as of 21:04 on Nov 18, 2015 |
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Nov 18, 2015 19:41
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Icon Of Sin posted:Jesus, that was a rough ride. Poor dude got his arms amputated and ended up dying from circulatory system failures, but if he had survived that he was probably going to go on and die from gastrointestinal issues instead. Dude caught such a hard burst of neutrons that one of the normal methods of estimating his radiation exposure couldn't even be used And if his guts didn't get him then the ongoing necrosis as his various still functioning cells die off and can be replaced due to extensive damage. That's one of the things that got me about the other one. One of the guys died over a year after the initial exposure and the other one nearly did due to the lingering effects of the exposure on their tissues. And again there the vascular system seemed to be one of the core issue since patient 2 only survived after they diverted the blood supply from elsewhere to prevent the grafts from dieing off and causing further infection and necrosis (which is what got patient 1 in the end).
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Nov 18, 2015 20:06
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Are beta-+ sources considered much the same as gamma sources?
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Nov 18, 2015 21:41
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The Lone Badger posted:Are beta-+ sources considered much the same as gamma sources? It depends on the isotope. Some are pure beta emitters. Many other isotopes are left in an excited state after beta decay and will quickly de-excite, releasing one or more gammas. There's no such thing as a pure gamma emitter, but for some isotopes the gamma ray energy far exceeds that of the beta particles it emits. For example, strontium-90 is considered a pure beta emitter because it only emits gammas very rarely. (Edit: in fact it's strontium-90's daughter, yttrium-90, that rarely emits gammas; strontium-90 itself never does) Cobalt-60 undergoes beta decay and then one (rarely) or two (most of the time) gamma rays with well-defined energies. Even though cobalt-60 undergoes beta decay, it is considered a gamma emitter because the gamma rays are more numerous and far more energetic. BattleMaster has a new favorite as of 22:04 on Nov 18, 2015 |
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Nov 18, 2015 21:59
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I mean beta-plus emitters (spit out positrons).
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Nov 18, 2015 22:15
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The Lone Badger posted:I mean beta-plus emitters (spit out positrons). Oh I thought you meant "beta -/+" when you said "beta-+." It's the same deal except that you get the annihilation gammas thrown in. While it's true that positron emitters cause a lot of gammas to be emitted as the positrons they emit annihilate with electrons, they're not used as gamma emitters in the same way cobalt-60 is. (Also, to be pedantic, there's no such thing as a pure gamma emitter anyway) Unlike beta- emitters, beta+ emitters are all very short-lived. That's because having too few neutrons is even less stable than having too many neutrons like beta- emitters do. Also, they are usually made in particle accelerators by throwing protons at certain isotopes which is more difficult to do in large quantities than making beta- emitters via neutron irradiation. Both of those facts make them difficult to get a lot of a beta+ emitter in one place. On top of that, the gammas are all fairly low energy (511 keV or so, the rest mass of an electron) so that limits their use in many situations where you need gammas. There's only a narrow range of applications for positron emitters. They're useful in medical imagine though. The fact that annihilation gammas are thrown out in exactly opposite directions makes them useful since that allows the precise point of annihilation to be determined. Read up on positron-emission tomography; it's pretty cool. Edit: The short explanation is that fluorine-18 is created by bombarding water containing oxygen-18 with protons which knock out and replace neutrons. The fluorine-18 ions that are now dissolved in the water are used in some process I don't understand (I'm a nuclear engineer not a chemical one) to make fludeoxyglucose (18F) which is glucose with an OH- group replaced with the fluorine-18. The patient eats it and the body uptakes it like glucose so it quickly goes to places of high activity such as organs and more importantly tumors. A ring of photomultiplier tubes around the patient can then create a 3D picture of the organs and tumors. In the process the patient gets a decent radiation dose but it's considered less dangerous than not knowing where say a brain tumor is. BattleMaster has a new favorite as of 23:07 on Nov 18, 2015 |
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Nov 18, 2015 22:55
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poo poo, and here I thought you were just the capybara guy.  Now I'm forever going to associate them with nuclear physics.
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Nov 18, 2015 23:25
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AlphaKretin posted:poo poo, and here I thought you were just the capybara guy. They pretty much look like the nuclear mutants of the rodent world, so that's already a pretty good association to make. Just imagine how big they'll be after the nuclear apocalypse....human survivors don't stand a chance.
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Nov 19, 2015 00:01
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All your swimming pools are belong to us. 
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Nov 19, 2015 00:54
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AlphaKretin posted:poo poo, and here I thought you were just the capybara guy. Ahaha It really tickles me that this isn't the first time someone has commented on that in this thread. Though I'd give up my career if I could take care of capybaras at a zoo 
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Nov 19, 2015 02:57
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Cross-post from OSHA.JPG: What happens if you on a whim mix these two chemicals?: HF + H2NNH2 + Heat (for good measure) + violent shaking = ??? (Hydrofluoric acid plus hydrazine plus heat and shaking, because chemistry) Would this be awesome or not awesome? (Would probably want to do this under one of those fume hood things with gloves, safety goggles, and something to pull fumes out.) Three-Phase has a new favorite as of 00:26 on Nov 20, 2015 |
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Nov 20, 2015 00:19
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Three-Phase posted:Cross-post from OSHA.JPG: It should make hydrazonium fluoride, which is thermally stable as far as I know. You would definitely want to do it with maximum safety gear since HF and hydrazine are both pretty nasty. If this was done and something really bad happened, there must have been something else going on that you're not telling us. Otherwise it's just an acid/base neutralization reaction.
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Nov 20, 2015 00:34
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Like doing it in a sealed container, maybe?
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Nov 20, 2015 01:07
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Three-Phase posted:Cross-post from OSHA.JPG: Now I'm just a physicist, so I would walk away from anything that involved HF and "We don't know exactly what to expect". Then once I was outside any reasonable spilling radius, I would up my pace to a run.
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Nov 20, 2015 02:04
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I feel like any chemical reaction involving HF can only result in chemicals less scary than the HF was to begin with.
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Nov 20, 2015 02:08
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Maxwells Demon posted:Now I'm just a physicist, so I would walk away from anything that involved HF and "We don't know exactly what to expect". Then once I was outside any reasonable spilling radius, I would up my pace to a run. Chemically, HF is just a weak acid and not a big deal. It's not exceptionally reactive in most cases. It will do odd things like dissolve glass, making SiF4, so you have to be aware of its occasionally unusual behavior. Fluoride has its own unique chemistry, but it's not some shock-sensitive world destroyer. Fluorine, F2, is the stuff you have to run away from. Biologically, HF is thoroughly nasty stuff, however. That is where its hazards lie.
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Nov 20, 2015 02:14
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KillHour posted:I feel like any chemical reaction involving HF can only result in chemicals less scary than the HF was to begin with.
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Nov 20, 2015 02:17
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I'd say ClF3 (do I need to post the infamous quote from Ignition again?) but I think that's made by combining pure fluorine with pure chlorine, preferably at least 100 miles from where I live.
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Nov 20, 2015 09:27
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Zemyla posted:FOOF?
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Nov 20, 2015 09:56
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Carbon dioxide posted:I'd say ClF3 (do I need to post the infamous quote from Ignition again?) but I think that's made by combining pure fluorine with pure chlorine, preferably at least 100 miles from where I live. When it sets your wet sand on fire it'll make clouds of hot steamy HF, no big deal 
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Nov 20, 2015 16:27
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So basically with these ridiculous fluorine compounds, nobody wants to be there, but we all want somebody to be there.
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Nov 20, 2015 17:05
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Not sure whether to post this here or in the pseudoscience thread. The Doomsday Scam
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Nov 20, 2015 17:44
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Zopotantor posted:Not sure whether to post this here or in the pseudoscience thread. This is a really good read. I've heard of "red mercury" but I didn't know the story behind it.
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Nov 20, 2015 21:01
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Zopotantor posted:Not sure whether to post this here or in the pseudoscience thread. quote:There are other variants of [Red Mercury's origin] story, including one in which Washington and Moscow collaborated in circulating red-mercury stories to flush out nuclear smugglers and to waste terrorists’ time
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Nov 20, 2015 22:09
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SynthOrange posted:Afaik bacteriophages are used around the former USSR and are practically unknown in the outside world where antibiotics would be used instead. There's been some speculation that this is going to change if antibiotic resistant stuff becomes the new normal. a well timed posted this considering http://www.theguardian.com/science/2015/nov/18/antibiotic-defences-against-serious-diseases-under-threat-experts-warn
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Nov 21, 2015 00:09
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