Simply Spacey'S

前言：实验做累了，逛逛光华BBS的JOKE版算是我的一种“低级”消遣方式。不过最近发生的一件趣事说明——JOKE版的帖子也是有搞头的。搞什么？呵呵，当然是搞学术啦：）待我从头道来：

Monopoly网友在3月4日转载了题为“喝液氮的不死猛男zz”的文章，内容如下：

# 本文来自煎蛋(http://jandan.net/)，作者为sein。

本来我(指原作者mike)可以跟所有人一样顺利完成研究课题然后毕业的，但是两个月前的一件小事，却于我有意义，将我从既定的人生轨道拖开，使我至今忘记不得。当然你也许听说过那个所谓的谣言，主角就是在下，现在我可以亲口告诉你传说中的未删节版本。

在开学第二周，物理系组织了新生欢迎会。作为一项传统，我们用液氮来做冰激凌——当然它不是食用成分，而是作为冷凝剂。当一滴液氮落到桌子上时，它展示了奇异的舞蹈动作。于是新生们奇怪了：怎么会这样？

于是我解释道：氮气在接触到桌面时表面部分已经蒸发，形成一个气垫阻止它继续下落；并且起到隔热效果，减少了进一步的蒸发，因此它不会马上沸腾甚至不接触桌面，看起来就像在跳舞。

我又说了，同样原则可能适用于不小心用液氮洗手活当饮料喝下去的情况，原则上说喝下液氮应该不会造成伤害的。以我在低温实验室的多年经验，这在物理学上应该是可行的。

但是没有人相信我，“你会被整个儿冻成冰雕，就像《终结者2》里一样”。靠，敢蔑视师兄的权威，于是我倒了一杯液氮一饮而尽，爽！一股青烟从我鼻子冒出来，大家都呆了。

2秒后我崩溃了，瘫倒在地板上，动弹不得，感到极度的痛苦。救护车和警车一起赶到，把被终结的我送到医院。一路上没人能解释我是怎么了。

第二天我被病房里机器的滴滴响声中醒来，这时我终于承认喝下液氮是不对的，虽然这与我的信仰不符。

随后我了解到关于液氮的几件事。你能把液氮倒进嘴里然后表演喷烟，但是你不能把它吞下去。因为闭合的会厌阻止气体的逃逸，于是它们被迫进入你的体内；而且食道会压缩里面的任何东西，因此即便有稀薄的气垫保护，液氮还是与食道发生了亲密接触。

原来如此。6年前我曾经玩过这个把戏，但是没有吞下去过，昨晚上我一定是在某个环节搞错了。

结果我从会厌到胃底都被严重损坏。快速扩散的气体压迫胸腔，然后肺部都破裂了。在一整夜的手术后，医生们切掉一部分胃，用一台机器上运行我的整个消化系统，直到第二天我的肺功能开始恢复。

后来他们对我的恢复能力感到惊奇(靠！怎么说我也是大师兄)。几天后我能自己呼吸，一周后我能坐起来，两周后能走动和进食，八周后基本上都愈合了，除了一些不太好看的伤痕。

有个好消息就是，我是首个摄取低温材料的医学案例。强烈推荐你看最新的英格兰医学学报，将有三篇有关的文章。

因为这次冒险我多了一个外号叫硝基迈克(Nitro-Mike)，以及给物理系增加了一个经典玩笑，偶尔学校的文章上还会提到我。"嘿，那不是迈克最喜欢喝的饮料吗？"

以下为英文原版：

(June 1998) A letter from Michael.

My senior year of college opened with the customary research projects, grad school applications, and the like. But that all changed two months ago. Some ofyou may have heard rumors of some bizarre accident that I was involved in. Here is the truth, unabridged, for those who actually want to know.

In the second week of school, the society of physics students held a roughly annual welcome back party. As tradition dictates, we made our own ice cream with liquid nitrogen, 77� Kelvin, as a refrigerant and aerator. We spilled a little liquid nitrogen onto a table and watched the tiny little drops dance around. Someone asked, "Why does it do that?" That may have been the point of no return.

As is traditionally my role, I answered that the nitrogen evaporates at the surface of the table, which creates a cushion of air for the drop to sit on, and thermally insulates the drop, which minimizes further evaporation. That's why a drop dances around without boiling, without touching the table, and without spreading out like a pool of water.

Then I continued. I mentioned that the very same principle makes it possible to dip one's wet hand into molten lead, or drink liquid nitrogen without injury. I had done the latter several years earlier in a cryogenics lab, and remembered the physics of how it worked.

Naturally those around me were skeptical. "It will freeze your whole body. Remember Terminator 2?" But I was sure of myself. I had done it before, and I believed in the physics behind it. So I unhesitatingly poured myself a glass and took a shot. Simple. Swallow, blow smoke out my nose, impress everyone.

Within two seconds, I collapsed to the floor, unable to breathe or indeed do anything except feel intense pain. The ambulance arrived. The police arrived. The journey to the hospital. The attempt to explain to baffled ER staff how something like this could happen. Then I passed out.

I woke up the next morning connected to beeping machines. It turns out that, in accordance with popular belief, you really should not drink liquid nitrogen.

I subsequently learned a few things about liquid nitrogen. While you can safely hold it in your mouth and blow neat smoke patterns, you should never, ever swallow. The closed epiglottis prevents the gas from escaping, so expanding gas is forced into your body. And your esophagus naturally constricts around anything inside it, so even though there is a thin protective gas layer, the esophagus will manage to make contact with the liquid nitrogen.

I also learned that my memory was flawed. When I had done the trick six years ago, I put it into my mouth and didn't swallow. Over time, that fine line between parlor trick and fatal accident must have blurred.

I was badly burned from epiglottis to stomach bottom. The gas expanded to fill my chest cavity, and the pressure collapsed a lung. After what I'm told was a grueling all-night surgery, they removed part of my stomach and ran my entire digestive system on a machine. I was on a breather for a day until my lung was restored. There are a few considerably uglier details which I will spare you.

They were impressed with my recuperative skills. I could breathe on my own after a few days. I could sit up in bed after a week, and was walking and eating in two. At eight weeks, I'm virtually healed except for a number of unsightly scars.

And there's good news! I am the first documented medical case of a cryogenic ingestion. Read the New England Journal of Medicine. Three articles are in review now, and will be published soon.

My little adventure leaves me with the nickname Nitro-Mike, a tendency to tell bad physics jokes at department meetings, and an occasional blurb in the school paper. "Let's make Mikey drink it. Hey! Mikey likes it!"

而后，众光华网友就此帖展开热烈讨论。有网友提出，是否可以搜索到《新英格兰医学杂志》（以下简称NEJM）相关的论文或病例报告，供大家仔细研究用。随后有人说没有搜到相关文献。我也动手在NEJM的网站上搜索了一下，“liquid nitrogen”作为关键词想必不错，但同其他网友一样一无所获。就病例本身以及勇敢的科学献身者Mike来说，的确有被NEJM收入的理由。

这时候似乎大家都一筹莫展，也激发了我的追寻欲望。到底最后这个Mike兄发表文章了没？

我重新阅读了原帖中的英文部分，锁定了关键词“cryogenic ingestion”。Google这个关键词组合，出来的结果来自雀巢基金会（Nestlé Foundation）的一篇电子文献题录：“Frostbite of the Esophagus. Case Reports. Journal of Pediatric Gastroenterology & Nutrition. 45(3):361-362, September 2007. Shirkey, Breann L *; Markowitz, Jonathan E *,+”这个页面上提供的pdf原文是需要付费才能阅读的。

那让我们看看复旦的数据库里有没有《Journal of Pediatric Gastroenterology & Nutrition》这本杂志。登录“复旦大学图书馆学术资源门户”，在“电子期刊”的搜索中，发现复旦收录有这本杂志，位于Ovid数据库。



直接用“学术资源门户”获取这份文献发生了登录问题，于是我手动登录了Ovid数据库。直接搜索“Frostbite of the Esophagus”，立刻获取到Shirkey等人撰写的论文原文（点击下载）。这篇文章主要报道了一个15岁小男孩在高中化学课实验中，用干冰和水做“汽水”，但不慎在干冰没有完全融解的情况下，吞下了“汽水”。他立刻感到喉疼、吞咽困难等。医生们使用静脉点滴、广谱抗生素、静脉滴注的H₂受体阻断剂（抑制胃酸分泌），并静脉滴注皮质激素皮质酮。24小时后，病人症状缓解；3周后的钡餐吞咽试验结果正常。小男孩最终痊愈。

问题是，该文中的小男孩吞咽的干冰，正常情况下温度为零下79摄氏度左右，而且他实际吞下的是温度更高的干冰-水混合物，这比Mike兄吞下的零下195摄氏度的液氮要“温和”多了。

于是我开始扫视该文的参考文献部分，第二篇入了我的法眼：

该文题目正合吾意。老办法，通过“学术资源门户”连接到EBSCOHOST Academic Source Premier，第二篇原文现身啦（点击下载）。可惜的是，该文提到的显然不是Mike兄：13岁的小男孩在化学课上不慎吞入液氮，立刻感到喉后强烈的灼烧感和腹部剧痛。实验室检查结果为良性呼吸性酸中毒；同时腹部剧烈胀大。后来医生们在病孩腹中线处切开腹部，释放出大量气体（氮气==）。术后10天，孩子回家。4个月后的随访未发现任何问题。

难道Mike兄的病例就这样悄无声息地消失了？要知道就转载的英文原文来看，医生们是通过一系列大手术才把他救回来的。

“天无绝人之路”。我顺手继续浏览这篇文献，在讨论部分出现了这段文字（注意年份也为1998年）：

好吧。Mike同学，原来你终于还是没有能够被登上NEJM，只是通过“私人通讯报告”的方式出现在了《Pediatrics》杂志的一篇论文的讨论文字中。严重momo。

后记：这个帖子我搞到这儿就罢手了。JOKE版上的小小讨论也告一段落。如果要再追问下去，也不是不可以：俺们可以写信给NEJM的编辑们——“请问1998年给你们投稿的那个小伙子吞液氮的病例报告你们最后为啥拒收了？”