(单词翻译:单击)
Ahh, winter.
冬天啊。
The leaves have fallen, the breeze is chilly and cold season has arrived.
树叶飘落、寒风习习，寒季已经到来。
When that sticky cough and sniffly nose hits, you probably cozy up with some hot soup,
咳嗽和鼻涕来袭，可能你会需要热汤、
a box of tissues, and your favorite brand of cold medicine.
一盒纸巾以及你最爱的那个牌子的感冒药。
There are syrups, pills, and vaporizers to treat about every symptom your cold can bring,
糖浆剂、药片和雾化器能够治疗感冒所导致的各种症状，
and they all involve some pretty cool chemistry.
它们都含有一些相当酷的化学成分。
But before you down that bitter syrup,
但在你喝下这些苦苦的糖浆剂前，
it might also help to know that not every cold medicine is as effective as you’d think.
糖浆剂还能帮助了解，并不是每种感冒药都如你所想的那么有效。
Colds are some of the most common infectious diseases we can get,
感冒虽然是最常见的传染病之一，
but since they’re caused by more than 200 different viruses,
但由于感冒是由200多种不同病毒引起，
it’s been basically impossible for us to create a vaccine against them.
因此要制造出一种对抗这些病毒的疫苗基本是不可能的。
So the best we can do for now is fight the symptoms.
因此现在我们所能做到的最好的就是对抗这些症状。
Most cold symptoms are probably caused by your body's efforts to fight off the virus, not the virus itself.
大多数感冒症状可能由于你身体对抗病毒而作出的努力而并非病毒本身所导致的。
When you catch a cold, inflammatory proteins like cytokines,
当你感冒时，炎性蛋白，比如细胞因子，
get released and tell your immune cells to get to work fixing the problem.
得到释放并通知免疫细胞修复这些问题。
Mainly, they do this by dilating your blood vessels
大体上，它们是通过扩张你的血管进行修复
so that infection-fighting white blood cells can move around more easily.
所以抗感染白细胞的移动就变得更加容易。
Unfortunately, in your nose, those dilated blood vessels also lead to tissue swelling and congestion.
不幸的是，在你的鼻子中，那些扩张的血管同样导致了软组织肿胀和堵塞。
Cytokines also interact with pain receptors in your esophagus, which can cause a sore throat.
细胞因子也与食道中的痛觉感受器相互作用，这会引起咽喉痛。
And in the nervous system, they can stimulate various nerves to trigger a runny nose, sneezing and coughing.
在神经系统中，它们能够刺激各种神经触发流鼻涕、打喷嚏和咳嗽。
None of those things are especially fun -- okay, really, they kind of stink.
这些都不是特别有趣，好吧，它们真的有些讨厌。
So we've come up with all kinds of drugs to knock them down as much as possible.
所以我们会用上各种感冒药尽可能缓解这些症状。
When your nose is stuffed up, you'll probably reach for a decongestant to clear up your sinuses.
当你的鼻子被堵住，你可能使用解充血药清除你的鼻窦。
Pseudoephedrine is a popular one, found in medications like Sudafed Decongestant and Aleve D.
假麻黄碱就是常见的一种，苏达菲和非和Aleve D这些药品中就含有假麻黄碱。
It's a carbon ring attached to a complex chain of other atoms, including nitrogen and oxygen.
这是一种附在其他原子复杂链上的碳环，包括氮和氧。
It reduces congestion by binding to receptors in your nose,
它能够通过捆绑你鼻子中的感受器，减少堵塞，
which makes the muscles around your blood vessels tense up and reduces the extra blood flow caused by cytokines.
这让你肌肉周围的血管紧张起来并减少因细胞因子而导致的额外血液流动。
Unfortunately, since pseudoephedrine is a stimulant,
不幸的是，由于假麻黄碱是一种兴奋剂，
it can also can cause insomnia, nervousness, dizziness, and even affect your heart rate.
它也会引起失眠、紧张、头晕，甚至影响你的心率。
It's even been used Breaking Bad-style to make methamphetamines illegally,
《绝命毒师》中甚至用它来非法制作甲基苯丙胺，
which is why it's kept behind the pharmacy counter.
所以这种药被放在药房柜台后面。
Phenylephrine is a similar medicine, found in brands like Sudafed PE,
苯福林是一种类似的药物，Sudafed PE中就含有苯福林，
but since it can't be used to make meth, it's easier to buy.
但由于苯福林不能被用来制造甲基苯丙胺，所以更容易买到。
Unfortunately, several studies have also found that it doesn't seem to be any more effective than a placebo,
不幸的是，几项研究也发现，似乎没有比安慰剂更有效，
which means it probably doesn't do much.
这意味着安慰剂可能也并不能改善。
So, if that's your favorite decongestant…sorry.
所以，如果这是你最喜欢的解充血药...那么你要失望了。
Some colds can also cause chest congestion and coughing.
一些感冒也能引发胸闷和咳嗽。
To clear out some of that mucus, many medications contain an expectorant,
要清除黏液，许多药物都含有一种祛痰剂，
which helps you spit up those lovely green gobs of phlegm.
帮助你咳出那些绿色的痰。
The most common one is called guaifenesin,
最常见的一种就是愈创甘油醚，
which is a carbon ring attached to chains of oxygen, hydrogen, and carbon atoms.
这是一种附在氧、氢和碳原子链上的一个碳环。
It's found in medicines like Mucinex.
Mucinex等药物中就有这种愈创甘油醚。
We're not entirely sure why it works, but scientists think it suppresses the production of mucins,
我们并不确定这种成分是如何起作用的，但科学家们认为它能够压制黏蛋白的产生，
one of the main proteins in the mucus lining your lungs.
黏蛋白是肺部黏液中主要蛋白质的一种。
That makes it easier for specialized cells to move mucus up and out of your body.
从而细胞分化能够更容易的移除粘液并将它们排出体外。
Still, that's just based on research done in a lab.
这是基于实验室的研究。
In patients, scientists have found that guaifenesin does seems to help thin mucus,
在病人之中，科学家发现愈创甘油醚似乎确实能帮助稀释粘液，
but it might not be that effective at clearing it from your lungs.
但还不至于有效清除你肺部的粘液。
Some studies haven't found much of an improvement over a placebo in people with respiratory infections.
一些研究还并未发现呼吸道感染病人使用安慰剂有什么改善。
But at least we know it helps somehow.
但至少我们知道它还是有帮助的。
Now, maybe the most irritating symptom of a cold for you and everyone around you is that nasty, lasting cough.
现在，或许感冒最恼人的症状是可恶的、持续的咳嗽。
To help calm it, many medications, including Robitussin, contain a cough suppressant, like dextromethorphan.
帮助缓解咳嗽，许多药物，包括惠菲芬，都含有一种咳嗽遏抑剂，比如右美沙芬。
Dextromethorphan and molecules like it are made up of four carbon rings, along with some oxygen and nitrogen atoms.
右美沙芬和类似分子都由四种碳环以及一些氧和氮原子组成。
They're derived from morphine, a highly-addictive painkiller, but at the doses used in cold medicines,
它们从吗啡中剥离，吗啡，一种极容易上瘾的止痛药，但感冒药中的剂量，
they don't have the same potential for abuse.
还不存在滥用的迹象。
We're not 100% sure how these molecules work, but they probably work on the brain instead of the respiratory system.
我们并不完全确定这些分子如何起作用，但它们可能是对大脑起作用而不是呼吸系统。
When you take dextromethorphan, it crosses the blood-brain barrier --
服用右美沙芬时，它会穿过血脑屏障——
the tightly-woven net of cells in your brain's blood vessels that protect it from bacteria and infection.
你的大脑血管中细密的细胞网，能够保护大脑不受细菌和感染。
And once it's there, it affects a bunch of different receptors.
一旦它穿过屏障，就会影响大量不同的感受器。
Researchers think that it helps reduce coughing by binding to receptors for neurotransmitters called NMDA,
研究员认为通过绑定神经传导物质感受器（NMDA、sigma-1以及血清素），它能够帮助缓解咳嗽，
sigma-1, and serotonin, since other drugs that bind to them also seem to suppress coughing.
因为绑在上边的其他药物似乎也压制了咳嗽。
Mainly, this tricks your brain into thinking there's no tickle in your throat and that you don't really need to cough.
它骗过了你的大脑，让大脑认为你的喉咙没有痒痒的感觉并且你不需要咳嗽。
Then again, some recent studies have also found that dextromethorphan may not actually be that effective,
还有，一些近期研究也发现右美沙芬可能并没有那么有效，
at least in kids, although many studies don't seem to be that reliable.
至少对孩子没用，虽然很多研究似乎并没有那么可靠。
Outside of cold medicine, though, it does have some uses.
除了最为感冒药，还有其他用途。
Because of its effects on the nervous system,
因为其对神经系统的效果，
it's also being investigated for use in a bunch of different conditions,
右美沙芬还被用于不同情况的调查之中，
like treating anxiety and agitation in Alzheimer's disease -- which is really cool.
比如，阿尔茨海默病中的焦虑和躁动——这样真的很棒。
Still, effective or not, all of these medications only treat the symptoms of the cold.
不论有效与否，所有这些药物仅用于治疗感冒的症状。
None of them actually do anything to help kill the virus or boost your immune system except maybe by helping you sleep better.
所有这些都不能帮助杀死病毒或促进你的免疫系统，除了帮助你睡得更好。
Ultimately, the only thing that can cure a cold is time!
最后，能治愈感冒的唯一解药就是时间！
But these medicines will hopefully make things easier while you wait it out.
当你在等到的时候，这些药物能让事情变得容易些。
Thanks for watching this episode of SciShow!
感谢收看本期科学秀！
Besides over-the-counter medicines, you've probably heard how vitamin C or zinc can help stop a cold but that's not true.
除了非处方药，你可能还听说过维C或锌能够帮助阻止感冒，但这都不是真的。
And if you'd like to learn more, you can watch our episode all about it to find out why.
如果你想了解更多，可以收看相关视频，找出原因。
