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Adult head lice are gray, about ? inch long, and often have a tiny dot on their backs. A female can lay between 50 and 150 eggs within the several weeks that she is alive. They feed on human blood.
Most strokes are caused when blood clots move to a blood vessel in the brain and block blood flow to that area. Thrombolytic therapy can be used to dissolve the clot quickly. If given within 3 hours of the first stroke symptoms, this therapy can help limit stroke damage and disability.
About 100 new prescription or over-the-counter drugs come into the U.S. market every year.
In 1844, Charles Goodyear obtained the first patent for a rubber condom.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.