英语听力精选进阶版 13687

 Do women have unlimited¹ human eggs?

Summary

28 February 2012

Doctors in America say it may become possible to create an unlimited supply of human eggs, to help fertility treatment. Researchers found that when they extracted stem cells from the ovaries of women, the cells spontaneously produced new eggs in the laboratory.

Reporter

James Gallagher

Report

A long-held theory is that women are born with all the eggs they will ever have. Researchers say they have shattered that idea by finding the stem cells which produce new eggs. 

Doctors at Massachusetts General Hospital used unique proteins on the surface of stem cells to fish them out of ovarian tissue.

The study, in Nature Medicine, showed that growing these cells in the laboratory resulted in new eggs being produced spontaneously. Legal and ethical² rules limit research on human eggs, but the same techniques repeated on mice showed the eggs could be fertilised and produce embryos³. 

The findings are a long way from being used in fertility clinics but the researchers said the cells had unprecedented⁴ potential to overcome infertility⁵. British experts said the study rewrote the rule book and opened up exciting new possibilities for women.

1 unlimited   

adj.无限的，不受控制的，无条件的

参考例句：

• They flew over the unlimited reaches of the Arctic.他们飞过了茫茫无边的北极上空。
• There is no safety in unlimited technological hubris.在技术方面自以为是会很危险。

2 ethical   

adj.伦理的，道德的，合乎道德的

参考例句：

• It is necessary to get the youth to have a high ethical concept.必须使青年具有高度的道德观念。
• It was a debate which aroused fervent ethical arguments.那是一场引发强烈的伦理道德争论的辩论。

3 embryos   

n.晶胚；胚，胚胎( embryo的名词复数 )

参考例句：

• Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段，而且其行为象胚。 来自辞典例句
• Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句

4 unprecedented   

adj.无前例的，新奇的

参考例句：

• The air crash caused an unprecedented number of deaths.这次空难的死亡人数是空前的。
• A flood of this sort is really unprecedented.这样大的洪水真是十年九不遇。

5 infertility   

n.不肥沃，不毛；不育

参考例句：

• It is the Geneva, Switzerland-based Biotech Company's second recombinant infertility drug. 它是瑞士生物技术公司在日内瓦的公司生产的第二种重组治疗不孕症的药。 来自英汉非文学 - 生命科学 - 生物技术制药疫苗
• Endometritis is a cause of infertility. 子宫内膜炎是不育的原子。 来自辞典例句