在线英语听力室_免费在线英语听力学习网站

Ah yes.The ol' fluoride rinse¹ at the dentist. Not pleasant. But hey, good for your teeth, right?

没错，这是牙医洗牙用的含氟漱口水。确实够闹心的。但毕竟对你的牙齿有益不是吗?

Well now materials scientists have been able to figure out why—by mapping the nanostructure of tooth enamel². If you zoom³ way in, tooth enamel looks almost like the weave of a basket."Where each thread is made from thousands of nanowires."Derk Joester, of Northwestern University.

现在材料科学家们通过绘制牙釉质的纳米结构已经知晓其中的原因。如果放大牙釉质，它与篮子的纹理非常相近。每条线都由成千上万的纳米线条组成。西北大学德克·乔斯特尔说道。

And in between those crystalline nanowires,Joester and his colleagues discovered a sort of amorphous⁴ glue.And that's where the fluoride hangs out, helping⁵ to stave off an acid attack of the enamel—in other words, a cavity.But the researchers found something that works even better than fluoride: iron.And they found it in beaver⁶ teeth.

而在这些晶状纳米线中，乔斯特尔和同事们发现了一种非固定形状的胶质。而氟化物就在这里聚集，帮忙延缓阻挡牙釉质的酸蚀—换句话说抑制蛀牙。但研究人员发现了一样比氟化物效果更好的物质：那就是铁。他们是在海狸的牙齿中发现了它。

"Beavers⁷ don't get caries. Chewing through wood is a very good way to clean your teeth."But another reason, they say, is the iron-enriched glue in beaver enamel—which was even more acid-resistant than fluoride-treated enamel.

海狸不会患上龋齿。咀嚼木头是一种很好的清洁牙齿的方式。但他们称另一个原因则是海狸牙釉质中富含铁的胶质—相比氟这种牙釉质在耐酸性上更胜一筹。

The findings are in the journal Science.

这项研究已经在《科学》杂志上发表。

Of course iron-rich enamel comes with an unfortunate side effect: reddish-brown teeth But Joester says future human dental treatments that employ iron might find a way around that.

当然富含铁的牙釉质有着副作用：那就是会使牙齿变成红褐色。但乔斯特尔表示未来牙齿治疗方面会采用铁进行，应该可以找到相关解决办法。

"We have the entire periodic table to play with minus a few things that are not too healthy. So I'm sure we can come up with a way to do what the beaver does but do it better and do it in a way that still maintains a nice smile."

我们有整个周期可以解决那些并不健康的治疗手段。所以我相信我们能想出办法像海狸那样，而且在继续保持洁白笑容这方面会做得更好。