(单词翻译:单击)
Most of you probably know the name Scott Kelly.
可能你们中间有大部分人都知道斯科特·凯利这个名字了吧。
He's a retired astronaut who holds the current U.S. record for the longest ever single spaceflight,
他是一名退休宇航员，当前美国单次太空飞行时间最长的纪录就是他创下的，
clocking in at 342 consecutive days in space.
他曾在太空连续飞行了342天。
Some of you may also know that he has an identical twin who is ALSO an astronaut.
一部分人可能还知道他还有一个同卵双胞胎，而且也是个宇航员了吧。
What are the chances of that?!
还有这种操作？！
Mark and Scott Kelly were the central figures in a brand new, totally unique twin study.
马克·凯利和斯科特·凯利是一项全新而且是绝对独一无二的双胞胎研究的核心人物。
NASA just published the results that let us know, in unprecedented detail,
NASA刚刚公布了一项研究结果，这一结果以史无前例的细节告诉了我们
what happens to our bodies during long-term spaceflight—
在太空中长期飞行会给我们的身体带来怎样的变化——
and we're here to give you the rundown.
今天，我们就来为大家简答地介绍一下。
In the decades since first sending humans into space,
自人类首次进入太空以来的几十年里，
we've been monitoring spaceflight-induced physiological changes in hundreds of astronauts.
我们一直在监测太空飞行给数百名宇航员引起的生理变化。
We can compare an individual to themselves before, during, and after a mission—
我们可以就一位宇航员执行任务的前中后三个阶段进行自我比较，
allowing NASA to develop countermeasures against issues like decreased bone density and decreased muscle mass.
这样一来，NASA就能针对骨密度的下降和肌肉量的减少等问题制定相应的对策。
But so far, we're most familiar with the results of 1-4 months of spaceflight,
但目前我们最熟悉还是时长在1~4个月的太空飞行产生的结果，
and comparing an individual to themselves doesn't clearly let us know what could be caused by spaceflight
对宇航员进行自我对比并不能帮我们清楚地了解哪些变化是太空飞行造成的，
vs. something that may have happened to that individual anyway.
哪些变化属于个人情况。
If we're expecting humans to survive years for something like transport to Mars, how do we prep for that?
如果我们抱的是人类能在火星上生存数年这种预期，我们又该如何准备？
How do we know what's going to happen to our bodies?
我们怎么知道我们的身体会发生怎样的变化？
Well, Scott and Mark Kelly presented an incredibly exciting opportunity for NASA.
斯科特和马克就为NASA提供了一个异常激动人心的研究机会。
While Scott spent a year in space, Mark served as his ‘genetically matched ground control’.
斯科特到太空生活一年，马克则充当他的“基因匹配的地面对照”。
Both twins were monitored closely before, throughout, and after the mission—
这对双胞胎在执行任务的前中后起都受到了密切的监控——
physiologically, genetically, and cognitively—
包括生理、基因和认知多方面的监控——
creating a massive amount of data in the first twin study of its kind.
获取了大量开创性的首例双胞胎研究的数据。
Some things changed during spaceflight that,
太空飞行期间的有一些变化是
while SUPER interesting and important to keep measuring in future studies, don't seem to pose a significant health risk.
超级有意思，而且其测量在未来的研究中也很重要，但似乎并不会带来重大的健康风险的。
For example, body mass decreased, gut microbiome composition changed, and inflammation increased—all temporarily.
比如，体重的下降，肠道微生物组成的改变，炎症的加重——所有这些都只是暂时性的。
Plus the flu vaccine works just as well on someone in space as it does for someone on earth, which is a relief.
而且，流感疫苗对太空中的人和对地球上的人一样有效，这下我们就放心了。
Then we've got the medium-risk stuff, stuff we may need to be careful about.
接下来是属于中等风险的变化，也就是我们可能需要小心的变化。
Urine sample metabolites indicated that spaceflight could interrupt collagen regulation in the body.
尿液样本代谢表明，太空飞行可能会打断人体胶原蛋白的调节。
While we may most often hear about collagen in the context of our skin,
虽然我们可能经常听到的胶原蛋白说的都是我们皮肤里的胶原蛋白,
it's also part of all our veins and arteries and valves,
但它其实也是我们的静脉、动脉以及瓣膜的组成部分，
and disturbance in its production and incorporation could result in issues like
其产生和合成受到干扰，就可能引起
blood pooling at the bottom of our legs or issues with blood pressure regulation.
腿下部充血或者血压调节问题等。
And don't even get me started on the telomeres—
染色体端粒就更不用说了——
these are the caps on the end of your chromosomes that protect your DNA from damage and that deteriorate as we age.
它们是你染色体两头所戴的帽子，其作用是保护你的DNA免受破坏，而且，随着年龄的增长，端粒会逐渐退化。
Scott Kelly's telomeres actually lengthened during his year on the ISS—
斯科特·凯利在空间站那一年里他的端粒实际上是变长了的——
but then shortened rapidly and significantly when he returned to Earth.
但当他回到地球后，端粒又迅速而显著地缩短了。
They've since recovered to around pre-spaceflight length,
它们又基本恢复到了飞行前的长度，
but given the essential nature of telomeres in protecting genomic integrity and the role we think they play in aging,
但鉴于端粒保护基因组完整性的这一核心本质，以及我们认为它在人体衰老过程中发挥的作用，
further research into this aspect of space-induced genetic changes could be really fruitful,
进一步研究这类太空飞行诱发的基因变化可能会颇富成果,
not only for spaceflight, but for other areas of science and medicine.
不仅对航天事业是如此，对其他科学领域以及医学领域也是如此。
And now for the high-risk stuff, the stuff we really need to work on solutions for.
最后我们来说说属于高风险的变化，也就是我们真正需要想办法面对的变化。
A comprehensive suite of computerized tests indicated
一套全面的计算机测试表明，
that while some measures of cognitive function increased, especially early in the mission,
虽然太空飞行，尤其是在飞行早期，让一些认知功能的测量值增加了，
other cognitive functions—like emotion recognition and abstract matching accuracy—
其他的认知功能——比如情感识别功能和抽象匹配的准确性——
actually declined during spaceflight, along with cognitive speed.
其实是和认知速度一样都会下降的。
And these declines persisted for about 6 months after return to Earth.
这些退化在返回地球后还会持续大约6个月。
In a weightless environment, our veins and arteries can also get a little confused.
在失重的环境中，我们的静脉和动脉也会变得有些迷惑。
