时差N小时 梅子干皮肤

Prune¹ skin on this Moment of Science At some time, we've all probably taken a long bath or been in the pool for a while, and then notice that parts of the palms of our hands and the bottoms of our feet became wrinkled. This Moment of Science answers two questions about this. Why does it happen? And why doesn't our whole body wrinkle like that?

梅子干皮肤？对，我们这次的内容与皮肤有关。有时候，我们可能在浴池或泳池中的时间较长，然后，会发现手掌和脚底板的皮肤起了褶皱。本次内容将对这一现象做出科学的解释。为什么会发生这种情况？为什么我们的整个身体不会出现褶皱？ The answer lies in the structure of our skin, and that is not the same all over. The outer layer of skin, the epidermis², on our palms and the soles of our feet is thicker than the skin on the rest of our body. When we soak in water, the epidermis all over our body absorb some water and swells⁴. Because the skin on our palms and soles is thicker, it can absorb more water, and therefore, swells more.

答案在于，我们身体各处的皮肤结构并非完全相同。手掌或足底的外层皮肤（真皮）要比身体其它部位的皮肤较厚一点。当浸泡在水中时，外层皮肤会吸收一些水，然后膨胀。因为手掌和足底的皮肤较厚，它吸收的水分更多，因此膨胀得也就越多。

That seems simple enough. But why did ends our fingers and toes wrinkle like black prunes⁵ and not the rest of us? Most of our skins absorbs water and swells rather evenly, but there is something different about ends of our toes and fingers -- there is a nail on one side. The ends of the fingers and toes can't swell³ towards the nails, so the skin bunches up opposite nails on the palm side of our fingers and the sole side of our toes. This bunching up of the skin gives us the wrinkles, prune skin.

道理似乎很简单了。但是，为什么手指和脚趾的末端褶皱得像黑色的梅子干，但其它部位则不会如此呢？原因在于，当皮肤吸收水分时，大部分会均匀地膨胀，但手指和脚趾的末端结构有点特殊：那里生长着指甲（趾甲）。当吸收水分时，手指和脚趾末端的皮肤无法向指甲（趾甲）的方向膨胀，因此，那儿皮肤就会缩成一团。结果，我们看到，指甲（趾甲位置的皮肤会皱起来，看起来就像梅子干一样。

1 prune   

n.酶干；vt.修剪，砍掉，削减；vi.删除

参考例句：

• Will you prune away the unnecessary adjectives in the passage?把这段文字中不必要的形容词删去好吗？
• It is our job to prune the side branches of these trees.我们的工作就是修剪这些树的侧枝。

2 epidermis   

n.表皮

参考例句：

• The external layer of skin is called the epidermis.皮的外层叫表皮。
• There is a neoplasm originating in his leg's epidermis.他的腿上有个生长在表皮上的肿瘤。

3 swell   

vi.膨胀，肿胀；增长，增强

参考例句：

• The waves had taken on a deep swell.海浪汹涌。
• His injured wrist began to swell.他那受伤的手腕开始肿了。

4 swells   

增强( swell的第三人称单数 )； 肿胀； （使）凸出； 充满（激情）

参考例句：

• The waters were heaving up in great swells. 河水正在急剧上升。
• A barrel swells in the middle. 水桶中部隆起。

5 prunes   

n.西梅脯，西梅干( prune的名词复数 )v.修剪（树木等）( prune的第三人称单数 )；精简某事物，除去某事物多余的部分

参考例句：

• Dried fruits such as prunes, pears, and peaches, are stewed. 梅干、梨脯、桃脯等干果，都是炖过的。 来自辞典例句
• We had stewed prunes for breakfast. 我们早饭吃炖梅干。 来自辞典例句