Lethal Dose 50% (LD50) · 半数致死剂量
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| LD50/ˌel diː ˈfɪfti/ | 半数致死剂量 | bàn shù zhì sǐ jì liàng |
| dose/dəʊs/ | 剂量 | jì liàng |
Measuring how poisonous
- How do we say one chemical is more toxic than another?
- We need a fair, standard number.
- The most common one is the LD50 半数致死剂量.
- It stands for "lethal dose, 50%".
衡量有多毒
- 我们怎么说一种化学物质比另一种更毒?
- 我们需要一个公平、标准的数字。
- 最常见的是半数致死剂量(LD50)。
- 它代表"半数致死剂量"。
What LD50 means
- LD50 is the dose 剂量 that kills half a test population.
- It is measured per kilogram of body weight.
- That way it is fair across animals of different sizes.
- A lower number means a smaller dose is deadly.
LD50是什么意思
- LD50是杀死一半试验群体的剂量(dose)。
- 它按每千克体重测量。
- 那样它在不同大小的动物之间公平。
- 更低的数字意味着更小的剂量就致命。
LD50 is the dose of a substance that… · 半数致死剂量是一种物质的剂量,它……
LD50 (lethal dose, 50%) is the dose that kills half of a test group — a standard measure of toxicity. · 半数致死剂量(LD50)是杀死试验组一半的剂量——毒性的标准衡量。
The inverse rule
- Here is the tricky part: low LD50 means high toxicity.
- A tiny lethal dose (low LD50) is a very dangerous poison.
- A huge lethal dose (high LD50) is fairly safe.
- So the number and the danger run in opposite directions.
反向规则
- 这里是棘手的部分:低LD50意味着高毒性。
- 微小的致死剂量(低LD50)是非常危险的毒药。
- 巨大的致死剂量(高LD50)相当安全。
- 所以数字和危险朝相反的方向。
More toxic or less toxic? · 毒性更大还是更小?
Sort each substance by its LD50 - remember, a lower LD50 means more toxic. · 按照每种物质的LD50给它们分类——记住,LD50越低意味着毒性越大。
A substance with a lower · 更低 LD50 is… · LD50更低的物质是……
Lower LD50 = more toxic: it takes only a tiny dose to kill. The relationship is inverse. · 更低的LD50=毒性更大:只需微小的剂量就能杀死。这个关系是反的。
LD50 is given per kilogram of body weight, so it works for animals of different ____. · LD50是按每千克体重给出的,所以它适用于不同____的动物。
By measuring dose per kg of body weight, LD50 compares fairly across animals of different sizes. · 通过测量每千克体重的剂量,LD50在不同大小的动物之间公平比较。
Comparing chemicals
- LD50 lets scientists rank chemicals by toxicity.
- A nerve toxin might have an LD50 of about 1 mg/kg.
- Table salt has an LD50 of thousands of mg/kg.
- The salt is far safer, and its high LD50 shows it.
比较化学物质
- LD50让科学家按毒性给化学物质排序。
- 一种神经毒素的LD50可能约为1毫克/千克。
- 食盐的LD50是数千毫克/千克。
- 盐安全得多,它高的LD50显示了这一点。
LD50 lets scientists compare how toxic different chemicals are. · LD50让科学家比较不同化学物质的毒性有多大。
LD50 is a standard number, so chemicals can be ranked from most to least toxic. · LD50是一个标准数字,所以化学物质能从毒性最大到最小排序。
Select all · 所有 true statements about LD50. · 选出关于LD50的所有正确说法。
LD50 measures toxicity; lower means more toxic. The last option reverses the relationship. · LD50衡量毒性;更低意味着毒性更大。最后一项颠倒了这个关系。
The one thing to get right: lower LD50 = more toxic. It feels backwards, so read it carefully. LD50 is the amount needed to kill — if only a tiny amount is needed (a low number), the substance is deadly; if a huge amount is needed (a high number), it's relatively safe. Number down, danger up.
需要弄对的一件事:更低的LD50=毒性更大。它感觉是反的,所以仔细读。LD50是杀死所需的量——如果只需要微小的量(低数字),这种物质就致命;如果需要巨大的量(高数字),它相对安全。数字下降,危险上升。
Two substances compared:
- A nerve agent has an LD50 of about 1 mg/kg — a pinprick's worth can kill. Its low number screams "extremely toxic".
- Table salt has an LD50 of roughly 3000 mg/kg — you'd have to eat huge amounts to be poisoned. Its high number says "relatively safe".
- Same measure, opposite meaning: the smaller LD50 is the deadlier chemical.
比较两种物质:
- 一种神经毒剂的LD50约为1毫克/千克——针尖大小的量就能杀死。它低的数字尖叫着"极毒"。
- 食盐的LD50大约3000毫克/千克——你得吃巨量才会中毒。它高的数字说"相对安全"。
- 同样的衡量,相反的含义:更小的LD50是更致命的化学物质。
LD50 (lethal dose, 50%) is the dose that kills half of a test population, measured per kg of body weight so it is fair across sizes. The key rule is inverse: a lower LD50 means a substance is more toxic (a tiny dose kills), and a higher LD50 means it is safer. It lets scientists rank chemicals by toxicity.
半数致死剂量(LD50)是杀死一半试验群体的剂量,按每千克体重测量,所以它在不同大小之间公平。关键规则是反向的:更低的LD50意味着一种物质毒性更大(微小的剂量就能杀死),而更高的LD50意味着它更安全。它让科学家按毒性给化学物质排序。