Học tiếng Anh: http://www.facebook.com/Words.and.Idioms hiệu quả, nhanh chóng: Các chương trình của VOA Learning English for Vietnamese (http://www.voatiengviet.com/section/hoc-tieng-anh/2693.html) có thể giúp các bạn cải tiến kỹ năng nghe, hiểu rõ cấu trúc và ngữ pháp, và sử dụng Anh ngữ một cách chính xác.
Luyện nghe nói tiếng Anh qua video: Chương trình học tiếng Anh của VOA: Special English Health Report. Xin hãy vào http://www.voatiengviet.com/section/hoc-tieng-anh/2693.html để xem các bài kế tiếp.
From VOA Learning English, this is the Health Report.
Researchers have developed a medical device which they say can recognize malaria infections in the human body. The laser beam scanner is said to be the first device to identify the disease without a blood test. The test is painless, does not require blood from the sick person, and appears to be correct every time. At present, doctors use costly equipment to test for malaria. The new test only needs a person to place a finger on the laser device. Dr. Dmitri Lopotko is with Rice University in Houston, Texas. He says the scanner works by shining a very short pulse of light through the skin. The light comes from a low-powered laser. It shines on a very small particle called the hemozoin. The malaria parasite produces hemozoin when it infects red blood cells. Hemozoin crystals are not found in blood cells that are free of the disease. As the laser heats the crystals, they create small bubbles inside infected cells. Dr. Lopotko says the bubbles explode, making a sound that scientists can hear and count. He says that in tests, the laser scanner was never wrong. It also identified the malaria infection early, when treatment is important. The device is easy to carry, and operates on battery power. It costs about $10,000 to $20,000 to make. Dr. Lopotko estimates that each laser beam scanner could test more than 200,000 people a year. He says that means the cost of testing would be less than 50 cents for each patient. An article describing the malaria testing device was published in the journal Proceedings of the National Academy of Sciences.