久久亚洲国产成人影院-久久亚洲国产的中文-久久亚洲国产高清-久久亚洲国产精品-亚洲图片偷拍自拍-亚洲图色视频

您現在的位置: > Language Tips > Audio & Video > Special Speed News  
 





  Genetically engineered drug to cure malaria
[ 2006-04-20 09:37 ]

This is Shep O'Neal with the VOA Special English Health Report.

Malaria infects as many as five hundred million people every year. And more than one million people die from the disease each year. Those who do not die become seriously ill.

Southern African countries have the largest number of malaria deaths, mostly among young children. The disease is also common in Asia.

Malaria is caused by a parasite. Mosquitoes carry the infection from person to person. Researchers say the parasite is becoming increasingly resistant to older drugs used to treat the disease.

Artemisinin (ar-te-MIS-in-in) is the most effective treatment for malaria and the best drug for treating resistant forms. The World Health Organization says artemisinin should always be used in combination with other drugs to prevent drug resistance.

Artemisinin is made from the sweet wormwood plant found in China and Vietnam. But supplies of the plant are limited. And it takes a lot of plant material to get enough of the drug to treat one patient. Many suppliers are unable to meet the strong demand. The drug is costly to produce. Each treatment costs more than two dollars. So many people with malaria in developing countries are unable to get the drug. Jay Keasling is a chemical and biological engineer at the University of California at Berkeley. His research team has found a possible solution to the problem. They reported their research in the publication Nature. They placed genes from the wormwood plant into a yeast organism and got it to produce large amounts of artemisinic acid. This acid can be made into the drug artemisinin in just a few chemical steps. The researchers say this would end the need for a lot of plants.

Mr. Keasling says chemical tests show that the genetically engineered artemisinin is structurally the same as the natural form. The new drug must be tested in animals and people to make sure it is safe and effective against malaria.

So the researchers say the drug is still about five to ten years away from final development. They say their findings could reduce the cost of the active substance in artemisinin by ninety percent. This could help save many lives.

This VOA Special English Health Report was written by Cynthia Kirk. Our reports are online at voaspecialenglish.com. I’m Shep O'Neal.


malaria : 瘧疾

wormwood : 苦艾

yeast : 酵母

 
 
 




主站蜘蛛池模板: 久久99爰这里有精品国产 | 女人张开腿让男人桶视频免费大全 | 免费中文字幕 | 欧美一级毛片美99毛片 | 国产欧美日韩高清专区手机版 | 本道久久综合88全国最大色 | 久久国产经典视频 | 波野多结衣在线观看 | 新版天堂中文资源8在线 | 国产精品二区页在线播放 | 国产欧美17694免费观看视频 | 国内真实愉拍系列情侣自拍 | 免费国产一区二区在免费观看 | 成人免费观看国产高清 | 毛片在线全部免费观看 | 欧美成人精品免费播放 | 欧美又粗又硬又大久久久 | 亚洲图片国产日韩欧美 | 亚洲成a人片在线观 | 亚洲精品国产福利 | 久久精品免费在线观看 | 亚洲一区二区三区国产精品 | 国产午夜三级 | 久久综合精品国产一区二区三区 | 欧美成人三级视频 | 欧美日本在线一区二区三区 | 欧美一级毛片在线看视频 | 亚洲欧美日韩在线一区二区三区 | 欧美另类视频videosbest18 | 外国成人网在线观看免费视频 | 激情欧美日韩一区二区 | 国产综合久久久久 | 在线观看欧美一区 | 欧美特黄一级高清免费的香蕉 | 香港av三级 | 伊人成人在线 | 91大神在线精品视频一区 | 欧美a一级 | a级毛片高清免费视频 | 性欧美视频a毛片在线播放 性欧美一级 | 久久久久久a亚洲欧洲aⅴ |