With peaks and valleys, folds and rifts,

近看之下，你的手一點也不光滑

there are plenty of hiding places for a virus to stick.

充滿溝壑起伏

If you then touch your face, the virus can infect you.

非常便於病毒隱藏

But there are two extraordinarily simple ways you can keep that from happening:

然後病毒再透過你觸摸臉時感染

soap and water, and hand sanitizer.

但有兩種非常簡單的預防方法

So which is better?

肥皂和水，以及乾洗手

The coronavirus that causes COVID-19

那麼哪種比較好呢？

is one of many viruses whose protective outer surface is made of a lipid bilayer.

冠狀病毒

These lipids are pin shaped molecules whose heads are attracted to water,

是一種由磷脂雙分子層包覆的病毒

and tails are repulsed by it.

這是一種針狀的脂質分子

So in water-rich environments, lipids naturally form a shell like this,

頭部親水，尾部厭水

with the heads outside and the tails inside.

所以在富含水分的環境中 脂質自然形成這樣的外殼

Their shared reaction to water makes the lipids stick loosely together—

頭部向外，尾部向內

this is called the hydrophobic effect.

它們對水的共同反應 使它們鬆散地黏合在一起

This outer structure helps the molecular machinery of the virus

這叫疏水反應

break through cellular membranes and hijack our cells.

這種外部結構有助於病毒分子機制

But it has thousands upon thousands of weak points

打破細胞膜

where the right molecules could pry it apart.

入侵我們的細胞

And this is where soap comes in.

但這種包覆有許多突破口

A single drop of any brand of soap contains quadrillions of molecules

特定分子能撬開

called amphiphiles, which resemble biological lipids.

這也就是肥皂能進入之處

Their tails, which are similarly repulsed by water,

無論任何品牌，一滴肥皂液

compete for space with the lipids that make up the virus's shell.

就包含了數不盡的「兩親分子」

But they're just different enough to break up the regularity of the virus's membrane,

形似生物脂質

making the whole thing come crashing down.

尾部也具有疏水性

Those amphiphiles then form bubbles of their own around particles

和組成病毒外膜的脂質爭奪空間

including the virus's RNA and proteins.

但其結構上的差異

Apply water, and you'll wash that whole bubble away.

足以打破病毒外膜分子的排列秩序

Hand sanitizers work less like a crowbar, and more like an earthquake.

致使整個病毒解體

When you surround a coronavirus with water,

然後這些兩親分子形成自己的泡泡

the hydrophobic effect gives the bonds within the membrane their strength.

圍繞病毒的核糖核酸和蛋白質

That same effect also holds the big proteins

沖水就能洗掉這些泡泡

that form coronavirus's spikes in place

如果說肥皂像撬棍

and in the shape that enables them to infect your cells.

乾洗手就更像地震

If you dry the virus out in air, it keeps its stability.

在水溶液裡

But now surround it with a high concentration of an alcohol,

冠狀病毒外膜的堅韌 得益於分子結構中的疏水共性

like the ethanol or isopropanol found in most hand-sanitizers.

同樣的疏水共性

This makes the hydrophobic effect disappear,

也讓形成冠狀病毒尖端的蛋白質固定

and gives the molecules room to move around.

並讓它維持能夠感染你細胞的形狀

The overall effect is like removing all of the nails and mortar from a house

風乾環境不會打破這種穩定性

and then hitting it with an earthquake.

但在高濃度酒精環境中

The cell's membrane collapses and those spike proteins crumble.

比如乾洗手裡的乙醇或者異丙醇

In either method, the actual process of destroying the virus

疏水共性被打散

happens in just a second or two.

使得分子有空間可以鬆動

But doctors recommend at least 20 seconds of hand-washing

總體就像拆掉房子的釘子和砂漿

because of the intricate landscape that is your hand.

然後由地震把房子震散

Soap and sanitizer need to get everywhere, including your palms, fingertips,

細胞膜瓦解

the outsides of your hands, and between your fingers,

棘蛋白散落

to protect you properly.

這兩種殺毒方式

And when it comes to a coronavirus outbreak,

都只需一兩秒就能起到殺毒作用

doctors recommend washing your hands with soap and water whenever possible.

但醫生建議洗手至少 20 秒

Even though both approaches are similarly effective at killing the virus,

因為手部表面型態複雜

soap and water has two benefits:

肥皂和乾洗手必須全面覆蓋

first it washes away any dirt which could otherwise hide virus particles.

包含手掌、指尖、手背，以及手指縫

But more importantly,

才能充分起作用

it's simply easier to fully cover your hands with soap and water

冠狀病毒疫情之下

for 20 seconds.

醫生建議儘量用肥皂和水洗手

Of course, hand sanitizer is more convenient to use on the go.

儘管兩種方式殺毒效果不相上下

In the absence of a sink, use the sanitizer as thoroughly as possible

肥皂和水有兩個優點：

and rub your hands together until they're dry.

首先，可以沖洗掉 可能潛藏病毒的塵土

Unfortunately, there are billions of people

更重要的是

who don't have access to clean drinking water,

肥皂和水便於讓你

which is a huge problem at any time but especially during an outbreak.

充分搓洗 20 秒

Researchers and aid groups are working to provide solutions for these communities.

當然，乾洗手更方便

One example is a device that uses salt, water, and a car battery

當無處可洗手時

to make chlorinated water that kills harmful pathogens

充分搓洗直至乾洗手蒸發乾

and is safe for hand-washing.

不幸的是

So wherever possible, soap and water are recommended for a coronavirus,

數十億人沒有乾淨的飲用水

but does that mean it's best for every viral outbreak?

這在任何時候都是大問題 疫情時期尤甚

Not necessarily.

研究員和支援團隊正致力於 給這些社區提供解決方案

Many common colds are caused by rhinoviruses

其中一個裝置是用鹽、水和車載電池

that have a geometric protein structure called a capsid

達到氯化消毒作用

instead of a lipid membrane.

製出能用於洗手的水

The capsid doesn't have nearly as many weak points

所以對於冠狀病毒 肥皂和水是條件允許下的首選

where soap amphiphiles can pry it apart,

但這適用於任何病毒疫情嗎？

so it takes longer for soap to be effective.

不一定

However some of its surface proteins are still vulnerable

很多引起普通感冒的鼻病毒

to the destabilizing effect of hand sanitizer.

外層包覆是一種名為 衣殼的幾合蛋白結構

In this and similar cases, hand sanitizer may be more effective,

而不是脂質膜

especially if you then wash your hands to remove residual particles.

衣殼沒有那麼多

The best way to know which to use for any given outbreak

肥皂兩親分子能撬開的突破口

is to do what's best for all things illness-related:

所以肥皂要搓洗很久才能起作用

follow the advice of accredited medical professionals.

但乾洗手的破壞作用