(单词翻译:单击)
听力文本
From VOA Learning English, this is the Health Report.
Researchers have developed a medical device which they say can find malaria infections in the human body. The laser beam scanner is the first device that can find the sometimes deadly disease without going inside the body. The test is painless, does not need blood from a person, and appears to be right every time it is done.
At the present time, a trained medical worker needs costly equipment, a person's blood and a lot of time to know if a person has been infected with malaria. Trained workers, equipment and time are not always available in poor parts of the world. The newly developed device only needs a person to place a finger on a laser device.
Doctor Dmitri Lopotko is a researcher at the department of biochemistry and cell biology at Rice University in Houston, Texas.
A possible rapid, non-invasive test for malaria infection detects tiny vapor nanobubbles produced by the malaria parasite when it is zapped by a short laser pulse. (Rice University)
"We shine a very short light pulse through the skin. And this light pulse is absorbed only by malaria parasites because of the wavelength we use. And in response to this short light pulse, the parasite literally explodes," he said.
The light pulse comes from a low-powered laser. It has less power than a laser point. It shines on a very tiny particle called the hemozoin which is produced by the malaria parasite once it has infected red blood cells. Hemozoin crystals are not found in red cells that are not infected with malaria.
As the crystals are heated by the laser, they create small bubbles inside infected cells. Doctor Lopotko says the bubbles exploded, and then make a sound that scientists can hear and count.
"You can detect just a few infected cells in a million normal cells," he said.
Doctor Lopotko says when researchers tested the device, it was never wrong. And it was able to find malaria infection early when treatment is very important.
The device can be carried and uses its batteries. It costs about 10,000 to 20,000 dollars to make. But Doctor Lopotko says considering the number of people it can test, that is not a lot of money.
"Each device will be capable to screen more than 200,000 people per year. So the cost of analysis for each patient will be less than 50 cents," he said.
People without medical training can use the device to discover whether people are infected with malaria. Doctor Lopotko says the light beam used by the device is safe.
Researchers will now test the device at a hospital in Houston that cares for patients infected with malaria. If those tests are successful, researchers will test the device throughout the world this year.
An article describing the malaria detection device was published in the journal Proceedings of the National Academy of Sciences.
And that's the VOA Learning English Health Report. I'm Christopher Cruise.
文本来自51voa，译文属可可原创，仅供学习交流使用，未经许可请勿转载
词汇解释
1.scanner n. [计] 扫描仪；扫描器；光电子扫描装置
This picture has been digitized by a scanner.
这幅图已由扫描仪进行了数字化。
2.parasite n. 寄生虫；食客
Kangaroos harbour a vast range of parasites.
袋鼠身上有各种各样的寄生虫。
3.low-powered adj. 低功率的
Though net book shipments are falling below manufacturers' expectations, the inexpensive, low-powered devices appear to still be selling well.
尽管便携笔记本的出货低于制造商们的期望值，这些价格低、低耗能的设备看起来依旧会卖得很好。
4.beam n. 横梁；光线；电波；船宽；[计量] 秤杆
A beam of light slices through the darkness.
一道光束划破了黑暗。
内容解析
1.And in response to this short light pulse, the parasite literally explodes
in response to 响应；回答；对…有反应
The quick recovery was truly in response to medication.
这次迅速康复确实是对药物治疗的反应。
He did it in response to an inner calling.
他受内心欲望的驱使而做了那件事。
参考译文
这里是美国之音慢速英语健康报道。
研究者开发出一种医疗设备，据悉能发现人体中的疟疾感染。这种激光束扫描器是首个无需进入人体就能识别出这种有时可能致命的疾病，这种化验无痛，无需抽血，看来每次化验的结果都是正确的。
目前，经过培训的医务人员需要昂贵的设备、人的血液和大量的时间，才能知道一个人是否感染上疟疾。在全世界一些贫困地区，经过培训的人员、设备和时间这些条件并不都能同时满足，这款新的设备只需人将手指放在激光设备上。
Dmitri Lopotko医生是德州休斯顿莱斯大学生物化学和细胞生物学院研究人员。
“我们给人体皮肤上照射一种很短的光脉冲，因为我们所用的波长的类型，这种光脉冲只能被疟疾寄生虫吸收，寄生虫在这种短光脉冲下会爆裂。”
这种脉冲来自低功率激光，比激光点的能量要少，它照射在疟疾寄生虫感染红细胞后生成的名为疟原虫色素的很微小的颗粒。未感染疟疾的红细胞中不存在疟原虫色素晶体。
这种晶体被激光加热后能在感染细胞内生成小泡泡，Lopotko医生说这种泡泡会爆裂，然后发出一种科学家能听到和计算的声音。
“你能在一百万个正常细胞内侦探到少量被感染的细胞。”
Lopotko医生说当研究者测验这种设备时，从来没有出过错，能在治疗很重要的时期提前发现疟疾感染。
这种设备能便于携带，使用电池运转，制作成本在一万到两万美元，但Lopotko医生说考虑到设备能测验的人的数量，其成本并不高。
“每台设备每年能诊断20多万人，所以每位病人的费用不到50美分。”
没有得到医疗培训的人可使用这种设备来诊断一个人是否感染上疟疾，Lopotko医生说该设备使用的光束是安全的。
研究在现在在休斯顿一家治疗疟疾感染病人的医院测试这种设备，如果测试成功，研究者今年将在全世界其他地方测验该设备。
一篇描述这款疟疾诊断设备的文章发表在《美国国家科学院院刊》上。
这就是美国之音慢速英语健康报道，我是克里斯多夫·克鲁斯。
