关注微信领¥50

百门课程¥0元


50万+已关注

科学美国人60秒:水熊顽强生命力-托福听力下载

2016-11-30 10:25:38来源:科学美国人60秒

点击查看>>科学美国人60秒音频:水熊顽强生命力

  科学美国人60秒中英文翻译:水熊顽强生命力

  科学美国人60秒英文文本

  This is Scientific American — 60-Second Science. I'm Lee Billings.

  Go a minute?

  Forget cockroaches. Forget Superman. Forget any other tough-as-nails creatures you've ever heard of. The most indestructible multicellular organisms on Earth are undoubtedly tardigrades—microscopic eight-legged aquatic invertebrates also known as water bears.

  These wee beasties can withstand severe dehydration, extreme temperatures and pressures, several days in Earth orbit exposed to the vacuum of space, and whopping doses of radiation that would kill most anything else. And, being Earthlings, there's no reason to think they'd be vulnerable to kryptonite.

  Scientists are beginning to understand the genetic basis of tardigrades' death-defying superpowers. And what they're learning may have profound implications for human health.

  The genome for a species of tardigrade was first sequenced last year. The analysis suggested that about one-sixth of the DNA was imported from notoriously hard-to-kill bacteria—but that conclusion was soon disputed, with all that bacterial DNA blamed on laboratory contamination.

  水熊.jpg

  Now, a new genome has been published of an exceptionally hardy tardigrade species. And it finds that almost all of the DNA is homegrown—and chock-full of sequences responsible for cellular protection and repair. The study is in the journal Nature Communications.

  In particular, the researchers discovered the gene for a protein apparently unique to water bears that shields their DNA from radiation damage. Called "DSup" for "damage suppressor", the protein binds to tardigrade DNA to keep it from snapping apart when bombarded by x-rays and other harsh radiation. The protein's protective effects against radiation may be a by-product of the tardigrades' resistance to dehydration, which causes similar damage to cells.

  The most remarkable thing about the Dsup protein, though, is that it also seems to work in other organisms—including humans. When the researchers inserted Dsup into cultured human kidney cells, the protein boosted the cells' tolerance to x-ray damage by about 40 percent.

  In theory, Dsup or something much like it could protect workers at nuclear power plants, cancer patients receiving radiation therapy or astronauts on interplanetary voyages. For now, the ethics and practicality of genetic engineering make such applications highly speculative. But, just maybe, if human beings someday stand on the surface of Mars, they could have water bear DNA to thank for helping them survive.

  Thanks for the minute for Scientific American — 60-Second Science Science. I'm Lee Billings.

  中文翻译请点击下一页

为你特别匹配的托福超值课程,快速提分先人一步!
  • 新东方托福公益课(第8期)

    新东方托福公益课(第8期)

    1元10节直播干货,新东方明星教师团,每日社群打卡带练

    课时:10小时

    查看详情
  •  托福口语训练营

    托福口语训练营

    9次托福口语满分大神 带你学透托福6大题型

    课时:3.5小时

    查看详情
  • 大学生旗舰直达班 (冲110分)

    【知心托福】大学生旗舰直达班 (冲110分)

    适合人群:托福目标分数110分!

    课时:343

    查看详情
  • 大学生旗舰直达班 (冲100分)

    【知心托福】大学生旗舰直达班 (冲110分)

    适合人群:托福目标分数100分!

    课时:331

    查看详情
  • 大学生旗舰直达班 (冲90分)

    【知心托福】大学生旗舰直达班 (冲90分)

    适合人群:托福目标分数90分!

    课时:310

    查看详情
全部课程>>
单项突破
直播课堂

更多托福课程
新东方25年教学经验沉淀
托福考生必修课
托福考生,高效提分,安心之选

查看详情>>
更多>>
更多课程>>
更多>>
更多内容
更多>>
更多公开课>>
更多>>
更多课程>>