体味一场不愉快遭遇.docVIP

体味一场不愉快遭遇 　　Even though shouts of “You’ve got B.O. (short for body odor) !” at a school playground might cause the scientifically minded to reply, “Of course, we all do!” The fact remains that when people talk about body odor they’re speaking of the unpleasant, sometimes eye-watering kind found in a football team’s locker room at game’s end. Or at far too many convention halls. 　　So what is it that causes the body to smell like an unwashed elephant from time to time? The answer that immediately springs to mind3 is, of course, sweat. But that’s only a part of the story. Sweat, on its own, is odorless. The smell that betrays us on first dates and job interviews is actually a product of digestion. And it’s not from our stomachs. 　　虽然在听到学校操场上的喊声“你有体味（B.O. 是英语“体味”的缩写）！”时，稍有科学常识的人都会回答：“当然了，每个人都有！”但是当人们谈及体味时，他们指的是类似于一场比赛结束后足球队更衣室里那种令人不快的、有时熏得人直掉泪的味道。许多会议厅里也会有这种气味。 　　那么，是什么使得人体会时不时地散发出闻起来像没洗过澡的大象的气味呢？我们脑海中立即涌现的答案是：当然是汗液了。但这只是部分原因。汗液本身是没有味道的。那些在我们初次约会和工作面试中背叛我们的气味实际上是“消化”的产物。然而这种“消化”并非来自我们的胃。 　　Sweat is produced by two different glands4. Eccrine glands cover most of the body and produce sweat consisting mainly of electrolytes and water, which cools the body when it evaporates from the skin.5 　　Apocrine glands are found in the groin, hands, feet and underarms.6 These glands produce sweat that contains proteins and fatty acids, which makes the perspiration thicker and milky or yellowish in color.7 This is where the sweat stains you see on light-colored shirts come from. While eccrine glands are activated8 as part of the body’s cooling system, apocrine glands can produce sweat when the body is experiencing anxiety, nervousness or stress. 　　When it first appears on our skin, sweat is just a fluid without an odor. But the bacteria on our bodies are particularly attracted to the proteins in apocrine sweat which they eat, digest and expel as highly-aromatic fatty acids.9 These include the notorious (and notoriously named) (E)-3-methyl-2-hexenoic acid. The process typically