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The modern decimal position system was the invention of the Hindus (around 800 AD), involving the placing of numerals to indicate their value (units, tens, hundreds, and so on).
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.
Barbituric acid, the base material of barbiturates, was first synthesized in 1863 by Adolph von Bayer. His company later went on to synthesize aspirin for the first time, and Bayer aspirin is still a popular brand today.
Serum cholesterol testing in adults is recommended every 1 to 5 years. People with diabetes and a family history of high cholesterol should be tested even more frequently.
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