Median lethal dose
In toxicology, the median lethal dose, LD50 (abbreviation for "lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a measure of the lethal dose of a toxin, radiation, or pathogen. The value of LD50 for a substance is the dose required to kill half the members of a tested population after a specified test duration. LD50 figures are frequently used as a general indicator of a substance's acute toxicity. A lower LD50 is indicative of increased toxicity.
The test was created by J.W. Trevan in 1927. The term semilethal dose is occasionally used with the same meaning, in particular in translations from non-English-language texts, but can also refer to a sublethal dose; because of this ambiguity, it is usually avoided. LD50 is usually determined by tests on animals such as laboratory mice. In 2011 the US Food and Drug Administration approved alternative methods to LD50 for testing the cosmetic drug BOTOX without animal tests.
Conventions
The LD50 is usually expressed as the mass of substance administered per unit mass of test subject, typically as milligrams of substance per kilogram of body mass, sometimes also stated as nanograms (suitable for botulinum), micrograms, or grams (suitable for paracetamol) per kilogram. Stating it this way allows the relative toxicity of different substances to be compared, and normalizes for the variation in the size of the animals exposed (although toxicity does not always scale simply with body mass).
Podcasts:
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by Lucky Gaucho
Make It Good
by: Lucky GauchoDoes it take you by surprise
This time's gone for real?
Does it make you realize
This time's gone for real?
Alright Alright
No deal...
Gotta take a little time
And make her smile a little
Get the moon and make it shine
Move up and down to please her
Alright Alright
No teasers...
Alright Alright
No No teasers...
And she's real gone...
When you're feelin' kinda wild,
Alone, unsatisfied,
It's time to make it good to yourself...
Be yourself
After five the field's alive,
C'mon it's a free ride.
Tonite she'll be a lady...
But... This time you should make it good
(C'mon Little Joe...)
Make your move before the dawn
And rid your mind of riddles...
Keep on rollin' till you're done
And shake your bones a little...
Showdown Showdown
No needles...
Showdown Showdown
No No needles...
Are you comin' back for more?
When you're feelin' kinda wild,
Alone, unsatisfied,
It's time to make it good to yourself...
After five the field's alive,
C'mon it's a free ride.
Tonite she'll be a lady...
But... This time you should make it good
When you're feeling kinda wild,
Alone, unsatisfied,
Spend a little time on yourself...
Be yourself
When a little ain't enough,
Who's gonna take it off
When you're feelin' kinda wild,
Alone, unsatisfied,
Ain't nothing like having a good time, yeah
After five the field's alive,
C'mon it's a free ride.
Tonite she'll be a lady...
C'mon it's a free ride!
But... This time you should make it good
Dream on...
We're gonna have a good time...