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推荐阅读:新SAT必读演讲大全(汇总)
今日名人
Kary Mullis
Kary Mullis won the Nobel Prize in Chemistry for developing a way to copy a strand of DNA. (His technique, called PCR, jump-started the 1990s' biorevolution.) He's known for his wide-ranging interests — and strong opinions.
Why you should listen
In the early 1980s, Kary Mullis developed the polymerase chain reaction, an elegant way to make copies of a DNA strand using the enzyme polymerase and some basic DNA "building blocks." The process opened the door to more in-depth study of DNA -- like the Human Genome Project. Mullis shared the 1993 Nobel Prize in Chemistry for developing this technique.
As he tells it, after winning the Nobel Prize, his next career move was to learn how to surf. It's typical of Mullis, whose scientific method is to get deeply curious about a topic, work it out from first principles, and then imagine the next giant leap forward. As he puts it in his Nobel autobiography, revised several times since 1993, "I read a lot, and think a lot, and I can talk about almost anything. Being a Nobel laureate is a license to be an expert in lots of things as long as you do your homework."
Most recently, he's been taking a hard look at immunity; a recent patent from his company Altermune describes the redirection of an existing immune response to a new pathogen.
新SAT必读演讲:英语字幕
00:11
So it was about four years ago, five years ago, I was sitting on a stage in Philadelphia, I think it was,with a bag similar to this. And I was pulling a molecule out of this bag. And I was saying, you don't know this molecule really well, but your body knows it extremely well. And I was thinking that your body hated it, at the time, because we are very immune to this. This is called alpha-gal epitope. And the fact that pig heart valves have lots of these on them is the reason that you can't transplant a pig heart valve into a person easily.
00:43
Actually our body doesn't hate these. Our body loves these. It eats them. I mean, the cells in our immune system are always hungry. And if an antibody is stuck to one of these things on the cell, it means "that's food." Now, I was thinking about that and I said, you know, we've got this immune response to this ridiculous molecule that we don't make, and we see it a lot in other animals and stuff. But I said we can't get rid of it, because all the people who tried to transplant heart valvesfound out you can't get rid of that immunity.
01:14
And I said, why don't you use that? What if I could stick this molecule, slap it onto a bacteria that was pathogenic to me, that had just invaded my lungs? I mean I could immediately tap into an immune response that was already there, where it was not going to take five or six days to develop it -- it was going to immediately attack whatever this thing was on. It was kind of like the same thing that happens when you, like when you're getting stopped for a traffic ticket in L.A., and the cop drops a bag of marijuana in the back of your car, and then charges you for possession of marijuana.It's like this very fast, very efficient way to get people off the street.
01:51
(Laughter)
01:53
So you can take a bacteria that really doesn't make these things at all, and if you could clamp these on it really well you have it taken off the street. And for certain bacteria we don't have really efficient ways to do that anymore. Our antibiotics are running out. And, I mean, the world apparently is running out too. So probably it doesn't matter 50 years from now -- streptococcus and stuff like that will be rampant -- because we won't be here. But if we are -- (Laughter) we're going to need something to do with the bacteria.
02:22
So I started working with this thing, with a bunch of collaborators. And trying to attach this to things that were themselves attached to certain specific target zones, bacteria that we don't like. And I feel now like George Bush. It's like "mission accomplished." So I might be doing something dumb, just like he was doing at the time. But basically what I was talking about there we've now gotten to work. And it's killing bacteria. It's eating them.
02:54
This thing can be stuck, like that little green triangle up there, sort of symbolizing this right now. You can stick this to something called a DNA aptamer. And that DNA aptamer will attach specifically to a target that you have selected for it. So you can find a little feature on a bacterium that you don't like,like Staphylococcus -- I don't like it in particular, because it killed a professor friend of mine last year. It doesn't respond to antibiotics. So I don't like it. And I'm making an aptamer that will have this attached to it. That will know how to find Staph when it's in your body, and will alert your immune system to go after it.
03:30
Here's what happened. See that line on the very top with the little dots? That's a bunch of mice that had been poisoned by our scientist friends down in Texas, at Brooks Air Base, with anthrax. And they had also been treated with a drug that we made that would attack anthrax in particular, and direct your immune system to it. You'll notice they all lived, the ones on the top line -- that's a 100 percent survival rate. And they actually lived another 14 days, or 28 when we finally killed them, and took them apart and figured out what went wrong. Why did they not die? And they didn't die because they didn't have anthrax anymore. So we did it. Okay?
04:10
(Applause)
04:12
Mission accomplished!
04:14
(Applause)