• spicy pancake@lemmy.zipEnglish
      46·
      2 days ago

      Some atoms don’t like being the way they are (mood tbh), and we call them unstable. Some unstable atoms spit out something called a positron in order to become the atom they want to be.

      A positron is an anti-electron, and when it collides with an electron (easy since those are everywhere) they annihilate each other, turning into a bunch of energy in the process, in the form of gamma radiation. The gamma radiation from annihilation is special because it always comes out as two rays going in the opposite direction from each other.

      That means, if you can detect when those two rays hit a ring that encircles the point of annihilation, you can use math to figure out where that point is in the ring. That’s because you know the speed of the rays and the difference in the times that both rays struck the ring.

      The aforementioned ring is a PET scanner’s detector array. (The machine at the bottom of this meme is a PET scanner.) So if you put a living thing in the PET scanner that has eaten or been injected with something that is undergoing positron emission, you can tell where in their body the position emission is happening.

      This is useful because you can use chemistry to attach something that emits positions to something that a body will move to specific locations based on what it is. For example, if you want to find cancer cells: they absorb way more glucose than normal cells. So you can attach unstable fluorines to glucose molecules and inject them into a cancer patient to find the cancer.

      Wherever you see way more positron emission happening than normal, that’s where the glucose is going. So if we know cancer cells are absorbing glucose at an abnormal rate, now we know where in the body the cancer is.

      (That’s more or less how I explained my previous job to my 4-year old niece, but with more drawings and smaller words.)

  • Alexander@sopuli.xyzEnglish
    128·
    3 days ago

    I remember my senior advisor student tellimg me a story how she went to industrial lab internship in a hospital with these things.

    They had their own little collider there. They made synthetic radioactive cocaine to study something in the brain.

    They didn’t measure the drug dosage, they just filled the syringe and waited holding it near a radiation counter for radiation to drop to desired level.

    Once she spilled something and dipped her hand in it. She was told to hold a hand away rfom the body for a day - on a train ride home, in shower, in sleep - to protect internal organs. Next day, radiation was gone, down to natural level.

    These things are amazing.

    • spicy pancake@lemmy.zipEnglish
      24·
      2 days ago

      That liquid must have had a hell of an ability to be absorbed into skin if she wasn’t able to remove the contamination by just washing her hand.

      The fact that they let her leave the controlled area makes me think the activity was low enough that holding her hand away from her was probably overkill. If you’re contaminated enough that it’s a risk to your organs, most radiation safety officers aren’t going to let you leave the controlled area lol

      At the radiopharm manufactory I used to work at, we had a guy accidentally inject his finger with the QC sample. Fortunately it was low enough activity that he was able to leave by the end of his shift. It was really stupid that the QC sample syringe was capped with a needle instead of a blunt syringe cap, but changing the manufacturing protocol to allow capping with a new type of device would have required FDA oversight.

      The first thing I always did during my QC testing was remove the needle and yeet it directly in the rad sharps waste container, cuz fuuuuck that.

      • Aqarius@lemmy.worldEnglish
        6·
        2 days ago

        I kinda wonder if it was a “Tell her to keep her arm raised until tomorrow, it’ll teach her to be more careful next time.” situation.

      • MehBlah@lemmy.worldEnglish
        4·
        2 days ago

        I once spent several hours stuck in decon on a reactor shutdown because I had breathed in … Its been thrity years… I think boron gas from the reactor. It had a short half life measured in seconds but I got enough dose that it took a while for it to drop down low enough for me to be passed by the machine. Nothing to do in decon but stand around. No restrooms, food or water. No chairs either. It could have been worse. One guy got a hot particle on them. A microscopic piece of fuel rod. It finally ended up his nethers and they used duct tape pull it off. Hair and all. He left in a set of scrubs with his boots and everything else taken.

        • spicy pancake@lemmy.zipEnglish
          2·
          1 day ago

          Ok that is a rough time. Every time I got contaminated I was always insanely glad it was only a 2 hour half life (and that each time, I managed to remove it by ditching clothes/shoes or washing my skin so I wouldn’t be trapped in the lab).

          We also had some very small amounts of long-lived isotopes that would end up in our waste stream and have to be found by playing hot/cold with the pancake. Oh and most of the contaminated items were needles and broken glass. I was so fuckin scared of accidentally stabbing myself with a LLRM sharp 😭

          Oh also I broke a pancake tube by letting it get stabbed and Ludlum took like 3 months to get it back to us and the other Model 3 was shitty uuuuuuuugh

          • MehBlah@lemmy.worldEnglish
            3·
            1 day ago

            I once forgot I had a contaminated sharpie from the hot shed. It had a fairly high level of contamination and probably shouldn’t have been handed out. it fell out of my anti-c’s hitting the leg of my scrubs and both of my boots at decon. They were not happy with me and I lost my scrub bottoms and boots. I did the walk of shame from the sally port back to the locker room.

            Fun times, sorta. It was good money though. I was in a union with a bunch of old timers(in their forties and early fifties) who built the unit and they were a treasure trove of knowledge about that place. I’m glad I quit because all of those guys died before they were sixty. Too many chemicals from different plants we also worked.

            Three people my age died before they were thirty when they got exposed to something at a chemical plant. All of them died from massive organ failure and tumors withing three years of each other. They were all doing some cutting in a supposedly cleared high pressure storage tank. When they cut through in one place there was a void filled with something. It covered them and they were cleaned up and laid off. They were not in a union so they had no way to complain It was not a pretty thing to witness.

            • spicy pancake@lemmy.zipEnglish
              2·
              15 hours ago

              ah the undies walk of shame. I started keeping extra large lab coats in the controlled area after that to use as emergency bathrobes but fortunately never needed one after that

              the story about the 3 guys is fucking heartbreaking. I hope to hell I can get into a union at my next position. Not that it would have reversed the death sentence, but fuck’s sake a little dignity would have been in order

      • Droggelbecher@lemmy.worldEnglish
        9·
        2 days ago

        I’m sometimes slightly radioactive for medical reasons. Most people will be fine with a certain dosis, but little kids and pregnant people (well, their foetus) won’t. So they tell you to stay away from people because you don’t know who’s pregnant. Maybe that contributes.

      • Alexander@sopuli.xyzEnglish
        6·
        2 days ago

        Oh, I forgot to mention that my story was happening in Moscow. Radiation safety rules there are… unusual. You get slapped for handling a thorium chunk in an explicitly hot environmental lab outside of fume hood, then dump ion exchange resin flush down the drain. You get strict access control in Kurchatov institute with weeks prior to entry to submit documents just to get to a meeting room, but then the same area has radioactive waste dumped between the trees in forested area (yes, it’s in center of the city with many times more people than my whole country).

        And then it’s regular ALARA. For that girl, that is, screw them those bystanders on the train. Clearly the fancy hospital with all that gear was one of those damned places where government and oligarchs get patched up and regular people are only experimental test samples, and they made no secret out of that.

        • spicy pancake@lemmy.zipEnglish
          2·
          2 days ago

          this explains a lot, lol. especially the “your hand is hot enough to worry about but sure go ahead get on a crowded train”

          As Long As Radiation AintNearMe lol

          drains always bothered the hell out of me because we were told to wash our hands in the regular sink if we got them contaminated. granted, 99% of our shit had a 2 hour half life, but still… I asked our RSO if we had a portal monitor around the building’s sewer outtake and he was like “lol no. also don’t do anything where we’d need one.”

    • ryannathans@aussie.zoneEnglish
      3·
      3 days ago

      Would love to know how many sieverts per hour, though given it was cocaine I assume it was almost entirely beta radiation from light elements?