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Author Question: Calculate the frequency of visible light having a wavelength of 686 nm. (Read 16 times) |
Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.
Despite claims by manufacturers, the supplement known as Ginkgo biloba was shown in a study of more than 3,000 participants to be ineffective in reducing development of dementia and Alzheimer’s disease in older people.
During the twentieth century, a variant of the metric system was used in Russia and France in which the base unit of mass was the tonne. Instead of kilograms, this system used millitonnes (mt).
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.
The types of cancer that alpha interferons are used to treat include hairy cell leukemia, melanoma, follicular non-Hodgkin's lymphoma, and AIDS-related Kaposi's sarcoma.