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VOA慢速英语2012 SCIENCE IN THE NEWS - Six Researchers Who Gave All to Their Work

时间:2012-05-08 06:05来源:互联网 提供网友:nan   字体: [ ]
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SCIENCE IN THE NEWS - Six Researchers Who Gave All to Their Work

SHIRLEY GRIFFITH: This is SCIENCE IN THE NEWS, in VOA Special English. I'm Shirley Griffith.

CHRISTOPHER CRUISE: And I'm Christopher Cruise. Today, we tell the stories of some medical heroes.

(MUSIC)

SHIRLEY GRIFFITH: At the start of the twentieth century, the United States Army had a Yellow Fever Commission. The Army wanted medical experts to study yellow fever and find a way to stop the disease. One team went to Cuba to test the idea that mosquitoes spread yellow fever. The team was led by Walter Reed, the Army doctor and scientist noted1 for his work on infectious diseases.

In August of nineteen hundred, the researchers began to raise mosquitoes and infect them with the virus. Nine of the Americans let the infected insects bite them. Nothing happened. Then two more let the mosquitoes bite them. Both men developed yellow fever.

CHRISTOPHER CRUISE: A doctor named Jesse William Lazear recognized that the mosquitoes that bit the last two men had been older than the others. Doctor Lazear proved that mosquitoes did carry yellow fever.

Doctor Lazear himself was also bitten. No one is sure how it happened. He said it happened accidentally as he treated others. But some people said he placed the mosquito on his arm as part of the experiment. Medical historians say he may have reported the bite as an accident so his family would not be denied money from his life insurance policy.

SHIRLEY GRIFFITH: Jesse Lazear died of yellow fever. His death shocked the others on the team in Cuba. But they continued their work.

More people let themselves be bitten by mosquitoes. Others were injected with blood from the victims of yellow fever. Some people in this test group developed the disease, but all recovered to full health.

Members of the team praised the work by Jesse Lazear. They called it a sacrifice to research that led the way to one of the greatest medical discoveries of the century.

CHRISTOPHER CRUISE: The research answered the question of how yellow fever was spread. Now the question was how to protect people. The researchers had a theory. They thought that people who were bitten by infected mosquitoes, but recovered, were protected in the future.

To test this idea, the team in Cuba offered one hundred dollars to anyone who would agree to be bitten by infected mosquitoes. Nineteen people agreed. The only American was Clara Maass. She was a nurse who worked with yellow fever patients in Cuba.

Clara Maass was bitten by infected mosquitoes seven times between March and August of nineteen-oh-one. Only one of the nineteen people developed the disease -- until that August. Then seven people got yellow fever. Clara Maass died six days after she was bitten for the seventh time.

SHIRLEY GRIFFITH: The experiment showed that the bite of an infected mosquito was not a safe way to protect people from yellow fever. Medical historians say the death of Clara Maass also created a public protest over the use of humans in yellow fever research. Such experiments ended.

Cuba and the United States both honored Clara Maass on postage stamps. And today a hospital in her home state of New Jersey2 is known as the Clara Maass Medical Center.

(MUSIC)

CHRISTOPHER CRUISE: Joseph Goldberger was a doctor for the United States Public Health Service. In nineteen twelve, he began to study a skin disease that was killing3 thousands of people in the South. The disease was pellagra.

Doctor Goldberger traveled to the state of Mississippi where many people suffered from pellagra. He studied the victims and their families. Most of the people were poor. The doctor came to believe that the disease was not infectious, but instead related to diet.

He received permission from the state governor to test this idea at a prison. Prisoners were offered pardons if they took part. One group of prisoners received their usual foods, mostly corn products. A second group ate meat, fresh vegetables and milk.

Members of the first group developed pellagra. The second group did not.

SHIRLEY GRIFFITH: But some medical researchers refused to accept that a poor diet caused pellagra. For the South, pellagra was more than simply a medical problem. There were other issues involved, including Southern pride.

So Doctor Goldberger had himself injected with blood from a person with pellagra. He also took liquid from the nose and throat of a pellagra patient and put them into his own nose and throat. He even swallowed pills that contained skin from pellagra patients.

An assistant also took part in the experiments. So did Doctor Goldberger's wife. None of them got sick. Later, the doctor discovered that a small amount of dried brewer's yeast4 each day could prevent pellagra.

Joseph Goldberger died of cancer in nineteen twenty-nine. He was fifty-five years old. Several years later, researchers discovered the exact cause of pellagra: a lack of the B vitamin known as niacin.

(MUSIC)

CHRISTOPHER CRUISE: Matthew Lukwiya was the medical administrator5 of Saint Mary’s Hospital in the Gulu District of northern Uganda. In two thousand, the hospital was the center of treatment for an outbreak of Ebola. The virus causes severe bleeding. No cure is known. Doctors can only hope that victims are strong enough to survive.

Doctor Lukwiya acted quickly to control the spread of infection. He kept the people with Ebola separate from the other patients. He ordered hospital workers to wear protective clothing and follow other safety measures.

One day he had to deal with a patient who was dying of Ebola. The man had been acting6 out of control. The doctor knew him well. The patient was a nurse who worked at the hospital. The man was coughing and bleeding. Doctor Lukwiya violated one of his own rules. He wore no protection over his eyes.

Matthew Lukwiya died from the virus in December of two thousand. He was only forty-two years old. Ugandans mourned his death. He was an important influence in the community. Experts say his work during the outbreak helped stop the Ebola virus from spreading out of control.

(MUSIC)

SHIRLEY GRIFFITH: On February twenty-eighth, two thousand three, the Vietnam-France Hospital in Hanoi asked Carlo Urbani for help. The Italian doctor was an expert on communicable diseases. He was based in Vietnam for the World Health Organization.

The hospital asked Doctor Urbani to help identify an unusual infection. He recognized it as a new threat. He made sure other hospitals increased their infection-control measures.

On March eleventh, Doctor Urbani developed signs of severe acute respiratory syndrome7. Four days later, the World Health Organization declared it a worldwide health threat.

Carlo Urbani was the first doctor to warn the world of the disease that became known as SARS. He died of it on March twenty-ninth, two thousand three. He was forty-six years old.

(MUSIC)

CHRISTOPHER CRUISE: Our final medical hero is an American: molecular8 biologist Anita Roberts. She was widely recognized by other researchers for her work with a protein called transforming growth factor-beta. TGF-beta can both heal wounds and make healthy cells cancerous.

In nineteen seventy-six, Anita Roberts joined the National Cancer Institute, part of the National Institutes of Health. She worked for many years with another researcher, Michael Sporn.

They found that TGF-beta helps to heal wounds and is important in the body’s defense9 system against disease. At the same time, though, the two scientists found that the protein can also support the growth of cancer in some cells.

SHIRLEY GRIFFITH: Between nineteen eighty-three and two thousand two, Anita Roberts published more than three hundred forty research papers. Many other scientists gave credit to her published work. In fact, the publication Science Watch listed her as the forty-ninth most-cited researcher in the world during that twenty-year period. She was the third most-cited female scientist.

But in two thousand four, after years of studying cancer, Anita Roberts learned that she herself had the disease. She died of gastric10 cancer in May of two thousand six. She was sixty-four years old.

(MUSIC)

CHRISTOPHER CRUISE: Our program was written by Nancy Steinbach and George Grow. June Simms was our producer. I'm Christopher Cruise.

SHIRLEY GRIFFITH: And I'm Shirley Griffith. You can find transcripts11, MP3s and podcasts of our programs at www.voanews.cn. And you can find us on Twitter and YouTube at VOA Learning English. We hope you join us again next week for more news about science, in Special English, on the Voice of America.


点击收听单词发音收听单词发音  

1 noted 5n4zXc     
adj.著名的,知名的
参考例句:
  • The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
  • Jim is noted for arriving late for work.吉姆上班迟到出了名。
2 jersey Lp5zzo     
n.运动衫
参考例句:
  • He wears a cotton jersey when he plays football.他穿运动衫踢足球。
  • They were dressed alike in blue jersey and knickers.他们穿着一致,都是蓝色的运动衫和灯笼短裤。
3 killing kpBziQ     
n.巨额利润;突然赚大钱,发大财
参考例句:
  • Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
  • Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。
4 yeast 7VIzu     
n.酵母;酵母片;泡沫;v.发酵;起泡沫
参考例句:
  • Yeast can be used in making beer and bread.酵母可用于酿啤酒和发面包。
  • The yeast began to work.酵母开始发酵。
5 administrator SJeyZ     
n.经营管理者,行政官员
参考例句:
  • The role of administrator absorbed much of Ben's energy.行政职务耗掉本很多精力。
  • He has proved himself capable as administrator.他表现出管理才能。
6 acting czRzoc     
n.演戏,行为,假装;adj.代理的,临时的,演出用的
参考例句:
  • Ignore her,she's just acting.别理她,她只是假装的。
  • During the seventies,her acting career was in eclipse.在七十年代,她的表演生涯黯然失色。
7 syndrome uqBwu     
n.综合病症;并存特性
参考例句:
  • The Institute says that an unidentified virus is to blame for the syndrome. 该研究所表示,引起这种综合症的是一种尚未确认的病毒。
  • Results indicated that 11 fetuses had Down syndrome. 结果表明有11个胎儿患有唐氏综合征。
8 molecular mE9xh     
adj.分子的;克分子的
参考例句:
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时,分子的碰撞就停止了。
9 defense AxbxB     
n.防御,保卫;[pl.]防务工事;辩护,答辩
参考例句:
  • The accused has the right to defense.被告人有权获得辩护。
  • The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。
10 gastric MhnxW     
adj.胃的
参考例句:
  • Miners are a high risk group for certain types of gastric cancer.矿工是极易患某几种胃癌的高风险人群。
  • That was how I got my gastric trouble.我的胃病就是这么得的。
11 transcripts 525c0b10bb61e5ddfdd47d7faa92db26     
n.抄本( transcript的名词复数 );转写本;文字本;副本
参考例句:
  • Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样,都是染色体DNA的转录产物。 来自辞典例句
  • You can't take the transfer students'exam without your transcripts. 没有成绩证明书,你就不能参加转学考试。 来自辞典例句
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TAG标签:   VOA慢速英语  Six  Researcher
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