英语听力精选进阶版 13905

Frog antibiotics¹

Summary

30 August 2010

Scientists trying to develop a new range of drugs are starting to study a creature which has been around for over 200 million years. They're working on a new research project which will try to replicate² the natural defences of frogs.

Reporter:

Pallab Ghosh

Report

Frogs protect themselves by secreting³ chemicals that kill germs on their skin. So the theory is that some of these chemicals could be used as antibiotics.

To find out, researchers in the United Arab Emirates asked colleagues across the world to swab any frogs they found and send them their secretions⁴. They received samples from more than six thousand different species and identified more than a hundred germ-killing chemicals.

Because they've not been used to combat human diseases before, it's hoped that they might be able to kill bacteria that had become drug-resistant.

One problem though is that many of these newly-identified chemicals are toxic⁵. So the next step will be to adapt them to make them benign⁶ to patients but lethal⁷ to bacteria.

The researchers point out that their work highlights the importance of preserving frog diversity. They say that many species whose skin might contain potentially valuable medicinal substances may become extinct soon because of a loss of habitat and water pollution.

Pallab Ghosh, BBC science correspondent

1 antibiotics   

n.（用作复数）抗生素；（用作单数）抗生物质的研究；抗生素，抗菌素( antibiotic的名词复数 )

参考例句：

• the discovery of antibiotics in the 20th century 20世纪抗生素的发现
• The doctor gave me a prescription for antibiotics. 医生给我开了抗生素。

2 replicate   

v.折叠，复制，模写；n.同样的样品；adj.转折的

参考例句：

• The DNA of chromatin must replicate before cell division.染色质DNA在细胞分裂之前必须复制。
• It is also easy to replicate,as the next subsection explains.就像下一个小节详细说明的那样，它还可以被轻易的复制。

3 secreting   

v.（尤指动物或植物器官）分泌( secrete的现在分词 )；隐匿，隐藏

参考例句：

• It is also an endocrine gland secreting at least two important hormones. 它也是一种内分泌腺，至少分泌二种重要的激素。 来自辞典例句
• And some calcite-secreting organisms also add magnesium to the mix. 有些分泌方解石的生物，会在分泌物中加入镁。 来自互联网

4 secretions   

n.分泌（物）( secretion的名词复数 )

参考例句：

• Lysozyme is an enzyme found in egg white, tears, and other secretions. 溶菌酶是存在于卵白、泪和其他分泌物中的一种酶。 来自辞典例句
• Chest percussion and vibration are used with postural drainage to help dislodge secretions. 在做体位引流时要敲击和振动胸部帮助分泌物松动排出。 来自辞典例句

5 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

6 benign   

adj.善良的，慈祥的；良性的，无危险的

参考例句：

• The benign weather brought North America a bumper crop.温和的气候给北美带来大丰收。
• Martha is a benign old lady.玛莎是个仁慈的老妇人。

7 lethal   

adj.致死的；毁灭性的

参考例句：

• A hammer can be a lethal weapon.铁锤可以是致命的武器。
• She took a lethal amount of poison and died.她服了致命剂量的毒药死了。