密码:
注册找密码我的浏览
设首页加收藏加书签 ______

首页每天学英语新概念六级音标词汇语法四级研究生大学高中初中小学少儿演讲有声圣经VOA商务雅思

您所在的位置: 大耳朵首页 > 听力资料 > 在线视听资料 >...> VOA慢速听力 > 健康报道 > 正文

站内搜索:

小提示:学单词背单词请到大耳朵免费在线背单词系统
tumour/[]/ n. 瘤, 肿块...

VOA慢速 Health Report-A Way to Make New Eggs in Women(2012-02-29)

This is the VOA Special English Health Report.

New research could raise hope for women who are having trouble getting pregnant.

For years, the thinking has been that women are born with all the eggs their bodies will ever produce. In fact, this has been the thinking not just about humans but all mammals.

Then, in two thousand four, a researcher at Massachusetts General Hospital reported a surprising discovery. Jonathan Tilly found that adult female mice could produce new eggs.

Now, Jonathan Tilly has extended his work and reported another discovery -- this time about human females.

JONATHAN TILLY: "We've isolated, essentially, the female equivalent of the stem cells that we know exist in men that actively make new sperm. So having these cells now isolated, I think, opens up a lot of opportunities to consider that we simply couldn't fathom before."

Stem cells are special kinds of cells. Starting in embryos just a few days old, they produce the many different cell types and tissues that form the body. In some adult tissues, stem cells produce replacements for damaged or worn out cells.

In his new study, Jonathan Tilly and other researchers removed cells from ovaries. Ovaries are the female reproductive organs that produce eggs. The scientists did laboratory tests to make sure they had the right cells that they were looking for. Then they used what are known as culturing methods to grow the cells so they would divide and produce more cells.

JONATHAN TILLY: "And we could start with perhaps one hundred cells, and over several months' time take those one hundred cells and make hundreds of thousands of cells. And interestingly, we noticed that these cells would spontaneously generate immature eggs, all on their own, in these cultures."

The researchers did not stop there. They wanted to further confirm the ability of these cells to make eggs. They placed some of the cells into human ovary tissue. Then they implanted the tissue under the skin of laboratory mice.

The studies found that these human cells were -- in Jonathan Tilly's words -- "more than happy to create brand-new human egg cells." He says growing eggs in the lab could improve the chances for women who are having the process known as in vitro fertilization. With IVF, an egg is fertilized with sperm in a laboratory, then placed in the woman's uterus to develop.

Jonathan Tilly says his work could also lead to fertility treatments that might improve the chances for more traditional fertilization methods.

JONATHAN TILLY: "We can also think about, perhaps, targeting these cells in the ovaries with hormones that these cells like, and thereby increasing their activity and perhaps increasing the size of the egg cell reserve in the ovary, when it would be desirable to do so."

His paper on making new human eggs from stem cells was published online this week by the journal Nature Medicine. Some experts raised questions about his earlier work with mice. Some are not so sure about this study either, until other researchers can reproduce the findings.

And that's the VOA Special English Health Report. I'm Jim Tedder.

___
您是否对这篇资料想说点什么?欢迎评论或者纠错,或者提交填空题答案! 您也可以立即
共有6人向本资料提供了听力原文,其中被采用了1篇,当前有0篇待审批,有5篇未被采用! 查看明细>>
如果您有更好的听力原文,欢迎提供给大耳朵,如果被采用,您将获得20到100金币的奖励!
健康报道
高瞻远瞩
放眼全球
推荐资源
最新社区精华帖子更多>>
  • 走遍美国教学版
    走遍美国教学版
  • 哈利学前班[英语儿歌]
    哈利学前班[英语儿歌]
  • 海绵宝宝 英文版
    海绵宝宝 英文版
  • 风中的女王第1季
    风中的女王第1季
经典学习方法更多>>
听力资料目录导航
听力测试 英语词汇 英语口语 考试英语 品牌英语 大学教材 其他教材 商务英语 广播英语 儿童英语
历年中考听力
初中中考模拟
历年高考听力
高考听力模拟
历年四级听力
历年六级听力
四级听力模拟
小学  初中
高中  四级
六级  考研
托福  GRE
星火记忆单词
用Mp3背单词
刘毅词汇记忆
情景英语口语
4+1听力口语
出国实用会话
英语口语8000句
新东方900句
美语听力与发音
ABC到流利口语
口译考试
剑桥考试
中高考考试
大学四六级考试
研究生考试
公共英语考试
英语专业考试
新概念 六人行
赖世雄 许国璋
走遍美国 越狱
疯狂英语 沛沛
语法讲座 动感
大山英语 探索
千万别学英语
大学英语听力
大学英语精读
全新版 21世纪
新视野 实用综
大学体验 新编
成人自考 step
Listen this way
广州版小学英语
广州版初中英语
剑桥少儿英语
朗文3L看听学
Goforit新目标
高中英语课本
进阶听说教程
商务英语300句
VOA商务英语
商业英语视频
中级商务英语
初级剑桥证书
新编剑桥英语
剑桥英语精华版
2007年VOA慢速
VOA中级美语
美国习惯用语
VOA流行美语
澳广播英语讲座
在线大学课堂
VOA视频节目
宝宝ABC
棒棒英语
哈哈美语
LittleFox儿歌
英语儿童故事
380英语小故事
1035个英语单词

免责声明:本站只提供资源播放平台,如果站内部分资源侵犯您的权益,请您告知,我们会立即处理。
Copyright © 2010-2017 大耳朵英语  京ICP备10010568号 | 京公网安备 11010802020324号

微信扫一扫手机学英语 关闭
微博扫一扫手机学英语 关闭
QQ扫一扫手机学英语 关闭
0.418014s