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From VOA Learning English, this is the Health & Lifestyle report.
这里是美国之音慢速英语健康与生活方式报道。
A rare look inside the human brain might help to explain how it clears away waste.
对人类大脑内部的罕见观察可能有助于解释它是如何清除废物的。
Scientists say the failure to clear away such waste can lead to Alzheimer’s disease and other brain disorders.
科学家表示，如果废物未能清除，可能导致阿尔茨海默病和其他脑部疾病。
Brain cells use a lot of nutrients. This means they produce a lot of waste.
脑细胞会消耗大量的营养物质。这也意味着他们产生了大量的废物。
Scientists believe the brain has special structures to take out this “cellular trash,” especially during sleep.
科学家们认为，大脑具有特殊的结构来清除这种“细胞垃圾”，尤其是在睡眠期间。
They have reported observing this process happening in mice. But they had no clear evidence that this happens in humans.
科学家已经报告，在老鼠身上确实有这种现象。但他们没有明确证据表明人类也是如此。
Recently published research appears to have identified a system, or network, of very small waste-clearing channels in the brains of living humans.
最近发表的研究似乎已经确定了一个在活体人类大脑中由非常小的废物清除通道组成的系统，或者说是网络。
The researchers used a special kind of imaging technology to study the network.
研究人员使用了一种特殊的成像技术来研究该网络。
One of the researchers was Dr. Juan Piantino of Oregon Health & Science University.
其中一位研究人员是俄勒冈健康与科学大学的胡安·皮安迪诺博士。
Piantino said the new research was important evidence.
皮安迪诺说，这项新研究是重要的证据。
“We needed this piece to say this happens in humans, too,” he said.
“我们需要这部分内容来证明这种情况也发生在人类身上，”他说。
His team recently published its findings in Proceedings of the National Academy of Sciences.
他的团队最近在《美国国家科学院院刊》上发表了他们的研究结果。
The brain is very active during sleep. During sleeping hours, the brain appears to clean itself.
大脑在睡眠期间非常活跃。在睡眠期间，大脑似乎会自我清洁。
That idea has gotten the attention of researchers. Losing a good night’s sleep can cause people’s thinking to be unclear.
这种想法已经引起了研究人员的注意。如果一晚上没睡好，会让人们思维不清晰。
But a continuous lack of sleep is believed to increase the risk of the brain disorder dementia.
但是，持续缺乏睡眠可能会增加大脑紊乱痴呆症的风险。
How does the brain clean itself?
大脑是如何进行自我清洁的？
Over 12 years ago, scientists at the University of Rochester first reported finding a network they named the “glymphatic system.”
12多年前，罗切斯特大学的科学家首次报告发现了一个他们命名为“胶状淋巴系统”的网络。
Fluid from the brain, called cerebrospinal fluid, travels through channels surrounding blood vessels to carry waste out of the brain.
来自大脑的液体，称为脑脊液，会流过环绕血管的通道，将废物带出大脑。
Beta-amyloids are substances linked to problems in the brain including Alzheimer’s disease.
β-淀粉样蛋白与大脑问题有关，包括阿尔茨海默病。
When scientists injected mice with beta-amyloids, the substance left the brain faster when the animals were sleeping.
当科学家给小鼠注射β-淀粉样蛋白时，小鼠睡着后，这种物质离开大脑的速度会更快。
It is not clear exactly how the system works.
目前尚不清楚该系统究竟是如何工作的。
However, some research has shown that the movement of blood vessels might help move the waste-clearing fluid where it needs to go.
然而，一些研究表明，血管的运动可能有助于将清除废物的液体移动到需要去的地方。
Finding the system in humans is not easy. Regular MRI scans can show some of the fluid-filled channels.
在人类身上找到这个系统并不容易。定期的核磁共振成像扫描显示出有一些充满液体的通道。
But Piantino said the scans do not show their purpose.
但是皮安迪诺说，扫描结果并没有显示出它们的目的。
To find out more, his team at Oregon Health & Science University injected a substance called a tracer into five patients.
为了了解更多信息，他在俄勒冈健康与科学大学的团队向五名患者注射了一种叫做示踪剂的物质。
The tracer “lit up” during MRI scans.
示踪剂在磁共振成像扫描期间“亮了起来”。
Twenty-four to 48 hours later, the tracer material was seen moving through the brain using the channels as in the earlier research on mice.
24到48小时后，示踪物质通过这些通道在大脑中移动，就像早期在老鼠身上做的研究一样。
Rochester’s Dr. Maiken Nedergaard predicts that the study will increase interest in how brain waste clearance connects to people’s health.
罗切斯特的迈肯·内德加德博士预测，这项研究会让人们更有兴趣将大脑废物清除与人们的健康联系起来。
But to test if better sleep or other treatments might really increase waste clearance and improve health, researchers "have to be able to measure glymphatic function in people,” said Dr. Jeff Iliff.
但是，为了测试更好的睡眠或其他治疗方法是否真的能增加废物清除并改善健康，研究人员“必须能够测量人们的胶状淋巴功能”，杰夫·伊利夫博士说。
He is with the University of Washington and has helped lead waste-clearance research.
他就职于华盛顿大学，并帮助领导了废物清理研究。
The question is whether the new study might point to ways of measuring the process.
问题是，这项新研究是否能指出衡量这一过程的方法。
Sleep is not the only question.
睡眠不是唯一的问题。
For example, animal studies show that a blood pressure drug now used to treat the stress disorder called PTSD might improve glymphatic clearing.
例如，动物研究表明，一种目前用于治疗被称为创伤后应激障碍（PTSD）的血压药可能会改善胶状淋巴系统的清除功能。
Iliff and Dr. Elaine Peskind plan to study this drug in a group of patients.
伊利夫和伊莱恩·佩斯金博士计划在一组患者中研究这种药物。
Larger studies in healthy people are also needed.
还需要在健康人群中进行更大规模的研究。
In addition, Piantino, who used tracer chemicals in people, wants to find an easier, noninvasive test to follow the waste clearance.
此外，曾在人体中使用示踪剂的皮安迪诺希望找到一种更简单、无创的测试方法来跟踪废物清除情况。
“We cannot study all the questions by injecting people,” he said.
“我们不能通过给人注射来研究所有问题，”他说。
And that’s the Health & Lifestyle report. I’m Anna Matteo.
以上就是健康与生活方式报道。我是安娜·马特奥。
