字幕表 動画を再生する 英語字幕をプリント [Music] there's an enzyme important to stem cells that also goes wrong in cancer but new research this week published in the journal PNAS has shown that this enzyme called telomerase has a role in healthy cell aging to our DNA is arranged into chromosomes which are capped on both ends by telomeres which protect the genome from damage but each time a cell divides the telomere gets a little bit shorter and once that cap wears away the cell basically can't divide anymore without risking serious genetic damage now telomerase can lengthen telomeres granting some cells like stem cells a kind of pseudo immortality but cancer cells can co-opt telomerase for their nefarious purposes allowing them to keep dividing indefinitely so until now researchers have assumed that healthy cells switch off their telomerase as a way to protect themselves from turning cancerous however the researchers in this study noticed that in previous studies of lab mice bred to be unable to express telomerase in their cells those telomerase 'less mice showed some unexpected side effects like higher rates of cancer and shorter lifespans this made the scientists curious about whether that missing telomerase had a more nuanced role in cellular health than had been suspected to investigate they looked at skin cells from two lineages of lab mice the ones that had no telomerase and ones that still had it they let the cells go through their natural life cycle while monitoring how they were growing and aging and watching for signals of cellular processes like DNA damage and they found that the cells without telomerase seemed to approach senescence more quickly the technical term for cellular old-age and they were more likely to develop more cancerous characteristics than ones with the enzyme restoring the cell's ability to produce telomerase reduce to these effects which kind of seems backwards because remember cancer cells use telomerase to help make themselves immortal so by conventional thinking no telomerase should mean less cancer later experiments in the study found similar changes in proteins within human skin cells when their telomerase genes expression is reduced suggesting human cells use the same mechanism conventionally it's been thought that normal cells produce very little telomerase or none at all but essentially the only reason it would turn on is if the cell is moving towards cancer but the researchers actually detected a burst of telomerase production in response to DNA during the aging process even in normal cells so altogether telomerase may protect ourselves by tapping the brakes just a bit on the aging process the researchers don't know the exact mechanism but think it may indeed extend those telomeres and might help direct the cell's response to DNA damage this could in turn reduce the effects of stress from aging and help prevent those cells from eventually giving rise to tumors the researchers say the next step is to figure out how telomerase is turned on in healthy aging cells and speaking of ways to get things to stick around for an unusually long time late last week researchers announced in the journal Science advances that they found a way to capture and release mechanical waves basically vibrations when a wave hits another object it's usually either reflected and scattered like when a sound wave echoes off a wall or is absorbed into the material and dissipated as heat but there might be another option theoretically by hitting a particular object with two waves tailored to resonate with that object and tightly controlling how the wave varies over time they could store the waves energy inside the object as if it had been absorbed but without losing it this phenomenon is called coherent virtual absorption and this is weird because it circumvents what we think waves should do but it's also potentially exciting because it could open up new mechanical designs for engineering or products monitoring minut vibrations can help tell us if structures like buildings and bridges are in danger of collapse for instance back in 2017 the scientists published work showing this might theoretically be possible with light waves but this time around the researchers wanted to see if they could not only extend this concept to other types of waves but actually take it from the theoretical into the real world to put this to the test the scientists performed a proof of principle experiment they built a device with a carbon steel rod with vibrating actuators attached to each end in the center of the bar it was a cavity where the wave would be stored the actuators when turned on sent waves down the device like a plucked guitar string by tweaking the waves in certain ways to interact with both each other and the cavity in the middle the scientists could find a set up where the waves energy was captured and stored and as long as the scientists maintained the correct configuration the waves energy didn't scatter or dissipate into heat it was contained and then by tweaking the signals again the scientists could release it in a controllable way this is noteworthy not just because cool when something someone worked out on paper can be turned into a real-world object but because the scientists think this new idea could eventually lead to new ways to control vibrations and that can be used to do things like monitor bridge safety or create better speakers and expanding it to other types of waves could even improve things like wireless charging and quantum computing so there's a lot of places that this technology could go even if the waves themselves are stuck in one place thanks for watching this episode of scishow news but before you go we have a new dftba pin of the month to show you I mean we don't have it physically here because we haven't had them made yet but it's this super fun super retro Viking Lander and it's available for pre-order throughout the month of September so if you like old-school robotic space exploration or if you just like orange rainbows this is your chance to show it off I just love how this Lander always looks like it's kind of waving at you these pins will ship in October at which point they will never be available again but next month spin will be just as cool you can check them out and order one for yourself in the merch shelf below the video or over at dftba.com slash scishow [Music] you [Music]
B1 中級 癌遺伝子は我々が思っていたよりも親しみやすいかもしれない|SciShow News (A Cancer Gene May Be More Friendly Than We Thought | SciShow News) 8 0 林宜悉 に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語