Phát âm chuẩn cùng VOA - Anh ngữ đặc biệt: Sleep Brain (VOA)

Học tiếng Anh hiệu quả, nhanh chóng:   / hoctienganhvoa  , http://www.voatiengviet.com/section/h.... Nếu không vào được VOA, xin hãy vào http://vn3000.com để vượt tường lửa. Các chương trình học tiếng Anh miễn phí của VOA (VOA Learning English for Vietnamese) có thể giúp bạn cải tiến kỹ năng nghe và phát âm, hiểu rõ cấu trúc ngữ pháp, và sử dụng Anh ngữ một cách chính xác. Xem thêm:   / voatiengviet  

Luyện nghe nói và học từ vựng tiếng Anh qua video. Xem các bài học kế tiếp:    • Phát âm chuẩn cùng VOA - Special Engl...  

Health: 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/h... để xem các bài kế tiếp.

Why do we need sleep? Do our brains turn off for the night? Scientists recently discovered that our brains may be just as busy at night as they are during the day. While we sleep, our brains are doing much more than getting ready for the next day. Researchers at the University of Rochester found that the brain may be busy cleaning out harmful waste materials. The researchers studied mice that had colored dye injected into their brains. They observed the brains of the mice as they slept and when they were awake. The researchers say they saw that the brains of sleeping mice were hard at work. Dr. Maiken Nedergaard led the study. He says our brains perform two very different jobs. He says, when we are awake, our brain is hard at work processing information about our surroundings. But at night, our brain works to remove all the waste that builds up during waking hours. The researchers say the waste material includes poisons, or toxins, responsible for brain disorders such as Alzheimer’s disease. They also found that during sleep, the brain’s cells shrink. This shrinking permits waste to be removed more effectively. The brain’s cleaning system could only be studied with new imaging technologies. And test animals must be alive in order to see the brain process as it happen. Dr. Nedergaard says the next step is to look for the process in human brains. She says the results show just how important sleep is to health and fighting disease. The research may also lead to treatments that prevent or help fight neurological disorders.