美国科学60秒 SSS 2012-12-10
时间：2013-06-25 08:11:14
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（单词翻译）
Porcupines sport some 30,000 quills3, which easily penetrate4 flesh—and then stay stuck in it. Now, scientists have analyzed5 the shape of individual quills to discover what makes them so effective—and how we can harness their power for medical devices. The study is in the Proceedings6 of the National Academy of Sciences.
The black tip of each
quill2 features backward-facing
barbs7. These barbs are tiny: a row of two hundred of them would be short of an inch long. The barbs help a quill penetrate flesh more easily than a hypodermic needle of about the same diameter, and using only half the force required to push a barb-free quill through tissue. Once the quill is in, the barbs then greatly increase what force would be needed to pull it back out again.
The researchers think understanding
porcupine1 quill properties can help them make less painful needles, because of the lower force needed for
penetration8. Also stickier
adhesives9, because of the greater force needed for removal. And the study reminds us that you really, really don't want to mess with a porcupine.
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