手机APP下载

您现在的位置: 首页 > 英语听力 > 品牌英语听力 > 逆向法巧学英语 > 正文

逆向法巧学英语 第20课:Mayapple Anti

来源:可可英语 编辑:cherry   可可英语APP下载 |  可可官方微信:ikekenet
 下载MP3到电脑  批量下载MP3和LRC到手机
加载中..

American research scientists have found a new use for a wild plant commonly found in the United States.
The researchers say the mayapple plant produes a substance used for making a drug to fight cancer.
They say it can produce more of the cancer-fighting substance than anything else known to scientists.
The mayapple grows in the forests of the southern and central United States.
Many Americans consider the plant undesirable.
However,scientists have found that the mayapple produces a substance called podophyllotoxin.
Podophyllotoxin is used to produce the cancer drug etoposide.
Etoposide is used to treat lung cancer and cancer of the testicles.
It has been shown to restrict the activity of an enzyme necessary for the reproduction of cancer cells.
This prevents the spread of the disease.
Traditionally,podophyllotoxin has been collected from the roots of podophyllum emodi.
It is a wild plant that grows only in the Himalayan Mountains.
However,the plant has been declared endangered
Because too much of it has been collected in India.
Attempts to make copies of the cancer-fighting substance have proven costly.
Now,researchers from the United States Agriculture Department and the University of Mississippi have developed a way to get podophyllotoxin from the mayapple plant.
The researchers believe that both the mayapple and podophyllum emodi produce the substance as a form of protection against insects and other plant-eating creatures.
The plants store the substance until they are attacked.
The American researchers say their method is successful because it makes the mayapple think it is being attacked.
This results in the release of large amounts of podophyllotoxin.
They say their system to remove podophyllotoxin from the mayapple is fast,effective and low cost.
The researchers say the mayapple plant provides a plentiful and renewable supply of the substance.
And they add there may be increased demand for the mayapple plant as a crop if the method becomes widely used.

重点单词   查看全部解释    
remove [ri'mu:v]

想一想再看

v. 消除,除去,脱掉,搬迁
n. 去除

联想记忆
reproduction [.ri:prə'dʌkʃən]

想一想再看

n. 再现,复制,生殖,幼树

 
effective [i'fektiv]

想一想再看

adj. 有效的,有影响的

联想记忆
produce [prə'dju:s]

想一想再看

n. 产品,农作物
vt. 生产,提出,引起,

联想记忆
supply [sə'plai]

想一想再看

n. 补给,供给,供应,贮备
vt. 补给,供

联想记忆
costly ['kɔstli]

想一想再看

adj. 昂贵的,代价高的

联想记忆
plentiful ['plentifəl]

想一想再看

adj. 丰富的,多的,充裕的

 
spread [spred]

想一想再看

v. 伸展,展开,传播,散布,铺开,涂撒
n.

 
release [ri'li:s]

想一想再看

n. 释放,让渡,发行
vt. 释放,让与,准

联想记忆
restrict [ri'strikt]

想一想再看

vt. 限制,约束

 


关键字: 学英语 逆向

发布评论我来说2句

    最新文章

    可可英语官方微信(微信号:ikekenet)

    每天向大家推送短小精悍的英语学习资料.

    添加方式1.扫描上方可可官方微信二维码。
    添加方式2.搜索微信号ikekenet添加即可。