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Multiple experimental evidences have confirmed that at the molecular level, cancer is caused by lesions in cellular DNA.
When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.
The word drug comes from the Dutch word droog (meaning "dry"). For centuries, most drugs came from dried plants, hence the name.
In 1864, the first barbiturate (barbituric acid) was synthesized.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
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