今日导读
人类对于宇宙的探索从未止步。前不久，美国国家航空航天局 NASA 宣布，计划在未来 5 年中重新登陆月球。同时，美国计划在 2033 年将宇航员送上火星。而这些都需要宇航员能够在长时间的太空环境中保持一个健康的身体状态。为了考察长期太空飞行是否会对人体产生伤害，NASA 开展了长达 27 个月的凯利双胞胎研究，并在最近发布了研究结果。结果如何？让我们一起跟着 Roxy 老师一起来看看《华盛顿邮报》的这篇新闻。
新闻原文
NASA Kelly twins study shows harsh effects of space flight and a brutal return to Earth
The Washington Post
Astronaut Scott Kelly made himself a guinea pig for all the people who dream of human journeys to Mars and other destinations in space. In 2015, Kelly rode a rocket into space and spent nearly a year on the International Space Station in low Earth orbit, while his identical twin brother, Mark Kelly, stayed on Earth's surface for NASA's celebrated "twins study, " designed to see what spaceflight does to the human body.
The full results, published Thursday in the journal Science, showed that Scott Kelly experienced numerous physiological and chromosomal changes during his long sojourn in orbit, including changes in gene expression. His immune system went on high alert, both when he went to space and upon returning to Earth. His body acted as if it were under attack.
One of the most dramatic findings concerned epigenetics — how genes are turned on or off to produce proteins. Gene expression changed in both Kellys during the study but in significantly different ways. The study found that more than 90 percent of Scott Kelly's gene expression changes reverted to normal when he returned to the surface.
His telomeres lengthened in space. But that's no fountain of youth, the study found, because the telomeres shortened dramatically when he returned to Earth.
Months later, he still showed a slightly elevated number of cells with shortened telomeres, possibly an effect of radiation exposure. "He might be at some increased risk for cardiovascular disease or some types of cancer, " said Susan Bailey, a biologist at Colorado State University who led one of the investigations in the study.
带着问题听讲解
什么是 epigenetics？
在太空飞行后，宇航员的身体发生了什么样的变化？
这次研究中最引人注目的一点是什么？
新闻正文
NASA Kelly twins study shows harsheffects of space flight and a brutalreturn to Earth
美国航空航天局凯利双胞胎研究显示，太空飞行和直接返回地球（会对人体）产生严重影响
Astronaut Scott Kelly made himself a guinea pig for all the people who dream of human journeys to Mars and other destinations in space. In 2015, Kelly rode a rocket into space and spent nearly a year on the International Space Station in low Earth orbit, while his identical twin brother, Mark Kelly, stayed on Earth's surface for NASA's celebrated "twins study," designed to see what spaceflight does to the human body.
为了所有那些梦想前往火星或者太空中的其它目的地的人，宇航员斯科特·凯利把自己变成了试验品。2015 年，凯利乘坐火箭前往太空，并在近地轨道上的国际空间站待了近一年。与此同时，为了进行美国航空航天局著名的“双胞胎研究”，他的孪生兄弟，马克·凯利，留在了地球表面。该研究旨在了解太空飞行对人体的影响。
The full results, published Thursday in the journal Science, showed that Scott Kelly experienced numerous physiological and chromosomalchanges during his long sojourn in orbit, including changes in gene expression. His immune system went on high alert, both when he went to space and upon returning to Earth. His body acted as if it were under attack.
周四发布在《科学》期刊上的完整结果显示，斯科特·凯利在（近地）轨道长期逗留期间，经历了许多生理上的和染色体上的变化，其中包括基因表达上的变化。在他去往太空和回到地球后，他的免疫系统都处于高度戒备状态。他的身体好像是在遭受到攻击一样。
One of the most dramatic findings concerned epigenetics — how genes are turned on or off to produce proteins. Gene expression changed in both Kellys during the study but in significantly different ways. The study found that more than 90 percent of Scott Kelly's gene expression changes reverted to normal when he returned to the surface.
最引人注目的结果之一和表观遗传学有关，表观遗传学展示了基因是如何被表达或被阻遏以产生蛋白质的。在研究期间，凯利两兄弟体内的基因表达都发生了变化，但是方式大相径庭。研究显示，当斯科特回到地面时，他体内超过 90%的基因表达变化恢复到了正常状态。
His telomeres lengthened in space. But that's no fountain of youth, the study found, because the telomeres shortened dramatically when he returned to Earth.
他的（染色体）端粒在太空中变长了。但是研究发现，这并没有使他重获年轻，因为当他返回地球时，端粒又急剧缩短了。
Months later, he still showed a slightly elevated number of cells with shortened telomeres, possibly an effect of radiation exposure. "He might be at some increased risk for cardiovascular disease or some types of cancer," said Susan Bailey, a biologist at Colorado State University who led one of the investigations in the study.
几个月后，斯科特·凯利体内的端粒变短的细胞数量依旧稍有增加，这可能是因为（他）暴露在了辐射下。科罗拉多州立大学的生物学家苏珊·贝利领导了该研究中一个项目，她表示：“他患有心血管疾病或某些癌症的风险可能会有所增加。”
重点词汇
harsh
/hɑːrʃ/
adj. 刺激的；严重的；令人不快的
e.g.
搭配短语：harsh lighting（adj. 过于强烈、刺激的）
英文释义：severe, cruel or unkind
搭配短语：harsh criticism
搭配短语：harsh words
brutal
/ˈbruːtl/
adj. 残忍的；直截了当的
e.g.
搭配短语：a brutal murder
英文释义：disagreeably direct and precise
例句：She spoke to me with brutal honesty, "I don't want to see you again!"
guinea pig
豚鼠；实验对象，供做实验的人
e.g.
英文释义：a person used in experiments
例句：They're asking for students to be guinea pigs for the new teaching methods.
orbit
/ˈɔːrbɪt/
n.（天体围绕行星或恒星运行的）轨道
e.g.
搭配短语：the earth’s orbit around the sun
identical
/aɪˈdentɪkl/
adj. 完全相同的；极为相似的
e.g.
英文释义：exactly the same, or very similar
例句：He's got three identical T-shirts.
physiological
/ˌfɪziəˈlɑːdʒɪkl/
adj. 生理学的
e.g.
相关词汇：physiology（n. 生理学）
搭配短语：physiological reactions
chromosomal
/ˌkroʊməˈsoʊməl/
adj. 染色体的
e.g.
相关词汇：chromosome（n. 染色体）
例句：Humans have 23 pairs of chromosomesin their cells.
搭配短语：chromosomal abnormalities
sojourn
/ˈsoʊdʒɜːrn/
n. 逗留，停留
e.g.
英文释义：a period when a person stays in a particular place
搭配短语：a week's sojourn in Paris
go on high alert
高度戒备，高度警戒
e.g.
相关词汇：alert（n. 警戒，戒备）
相关短语：put/be on high alert
例句：With the war looming, the troops went on high alert.
epigenetics
/ˌepɪdʒəˈnetɪks/
n. 表观遗传学
e.g.
词根词缀：epi-（在...之上）
词根词缀：-tics（一般指某个科学学科）
相关词汇：genetics（n. 遗传学）
revert to
回到，恢复
e.g.
英文释义：go back to sth.
例句：After her divorce she reverted to her maiden name.
telomere
/ˈteləmɪr/
n. 端粒
e.g.
英文释义：a compound structure at the end of a chromosome
*更多讲解见今日“拓展内容”
lengthen
/ˈleŋθən/
v. 延长，拉长，加长，变长
e.g.
相关词汇：length（n. 长度）
英文释义：get longer
反义词：shorten（v. 变短）
例句：The days lengthened as summer approached.
elevated
/ˈelɪveɪtɪd/
adj. 提高的，升高的
e.g.
相关词汇：elevate（v. 升高，提高）
相关词汇：elevator（n. 升降电梯）
近义词：raised
搭配短语：keep my feet elevated
exposure
/ɪkˈspoʊʒər/
n. 接触；面临；遭受
e.g.
相关词汇：expose（v. 暴露，接触）
例句：You should limit your exposure to the sun.
cardiovascular
/ˌkɑːrdioʊˈvæskjələr/
adj. 心血管的
e.g.
相关词汇：cardio（n. 有氧运动）
词根词缀：cardio-（跟心脏有关的）
相关词汇：vascular（adj. 血管的）
补充词汇知识
NASA
美国国家航空航天局
全称：The National Aeronautics and Space Administration
space flight
太空飞行
make oneself sth.
把…变成…
destination
n. 目的地
celebrated
adj. 著名的，有名的
近义词：famous
numerous
adj. 数量多的
近义词：many
including
prep. 包括
immune system
免疫系统
upon sth.
一…就…
as if
似乎，好像
concerned
adj. 和… 相关
搭配短语：as far as I am concerned
turn on
表达，激活
turn off
阻遏
近义词：repress
gene regulation
基因调控
fountain
n. 来源
英文释义：source
相关词汇：fountain （n. 喷泉、泉水）
slightly
adv. 稍微地
at risk
处于危险之中
长难句解析
In 2015, Kelly rode a rocket into space and spent nearly a year on the International Space Station in low Earth orbit, while his identical twin brother, Mark Kelly, stayed on Earth's surface for NASA's celebrated "twins study," designed to see what spaceflight does to the human body.
2015 年，凯利乘坐火箭前往太空，并在近地轨道上的国际空间站待了近一年。与此同时，为了进行美国航空航天局著名的“双胞胎研究”，他的孪生兄弟，马克·凯利，留在了地球表面。该研究旨在了解太空飞行对人体的影响。
这句话由一系列并列句组成，第一部分是 Kelly rode a rocket into space and spent nearly a year on the International Space Station in low Earth orbit，第二部分是 while his identical twin brother, Mark Kelly, stayed on Earth's surface for NASA's celebrated "twins study," 逗号后的部分省略了定语从句的关系词和谓语 that was 或者 which was，完整的说法是 for NASA's celebrated "twins study", that/which was designed to see what sapceflight does to the human body，其中 what spaceflight does to the human body 为名词性从句。
The full results, published Thursday in the journal Science, showed that Scott Kelly experienced numerous physiological and chromosomal changes during his long sojourn in orbit, including changes in gene expression.
周四发布在《科学》期刊上的完整结果显示，斯科特·凯利在（近地）轨道长期逗留期间，经历了许多生理上的和染色体上的变化，其中包括基因表达上的变化。
句子的主干是 The full results showed sth. ，published Thursday in the journal Science 为插入语，that 引导的宾语从句that Scott Kelly experienced numerous physiological and chromosomal changes during his long sojourn in orbit 就是句子的的宾语 sth.，在这里是研究结果的具体内容，逗号后的 including changes in gene expression 作同位语，补充说明了具体的变化。
学习资源
发表在《科学》期刊上的文章链接：
NASA 双胞胎实验的官方网站：
推荐的查音标网站：
英文引号的正确用法：[图片上传失败...(image-250357-1557044942001)]
拓展阅读
染色体端粒与人体衰老
在生物的细胞核中，载有遗传信息的线状物质被称为“染色体”，主要由 DNA 和蛋白质组成，指导着生物的生长发育。而端粒就存在于染色体末端，可将其类比为鞋带两端防止磨损的塑料套，像塑料套保护鞋带一样保护染色体。它能防止染色体相互粘连，保护染色体上 DNA 的完整。
端粒被科学家们称为生命体的“分子时钟”。研究表明，染色体端粒的缩短与人体衰老有关。每次细胞分裂时端粒都会缩短，细胞分裂次数越多，端粒就缩短得越多。当它们变得太短时，细胞就无法继续分裂，并逐渐迈向死亡。
此外，有研究发现，空气污染、吸烟、压抑酗酒、运动少、睡眠不足、心情烦闷等均能加速细胞染色体端粒缩短。可见，健康的生活方式能够延缓衰老。
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