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托福听力练习-科学美国人60秒:碳纳米管

2017-04-20 08:38:00来源：科学美国人60秒

点击查看>>科学美国人60秒音频：碳纳米管

　　科学美国人60秒听力练习：碳纳米管

　　科学美国人60秒英文文本

　　碳纳米管的圆形端部欺骗细胞吞噬而导致细胞死亡，粗糙的端部可解决该问题。该技术具备潜在的医疗应用价值。

　　Asbestos increases the risk for certain cancers. The fibers are thought to do so by skewering cells, setting off chemical reactions that lead to inflammation, DNA damage and cell death. Some studies have suggested carbon nanotubes might have similar effects—because they're long and spiky, like asbestos. But why would a cell draw in a nanotube, essentially impaling itself on a microscopic lance?

　　To find out, researchers exposed mouse and human cells to carbon nanotubes. They saw that the cells frequently engulfed the tubes—almost always tip-first. They then simulated that sword-swallowing maneuver on a computer. And they concluded that the round tips of nanotubes feel like bite-sized spheres, which cells commonly ingest. But once the cell senses the nanotube isn’t bite-size? It's too late. It can't stop sucking it in. The finding is in the journal Nature Nanotechnology. [Xinghua Shi et al., "Cell entry of one-dimensional nanomaterials occurs by tip recognition and rotation"]

　　As nanotubes may have medical applications, making them safe is key. And there may be a way to keep cells from biting off more than they can swallow—snip off the nanotubes' rounded tips. In one such simulation, the cells left the tubes alone—meaning we may get to have our nanotubes, without eating them, too.

　　—Christopher Intagliata

　　中文翻译请点击下一页

本文关键字: 托福听力 科学美国人 科学60秒sss

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