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Vertisols have a high content of expansive clay minerals, many of them belonging to the montmorillonites that form deep cracks in drier seasons or years. In a phenomenon known as argillipedoturbation, alternate shrinking and swelling causes self-ploughing, where the soil material consistently mixes itself, causing some vertisols to have an extremely deep A horizon and no B horizon.
Batrachotoxin was discovered by Fritz Märki and Bernhard Witkop, at the National Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda, Maryland, U.S.A. Märki and Witkop separated the potent toxic alkaloids fraction from Phyllobates bicolor and determined its chemical properties in 1963. [4]
Trilostane was withdrawn from human use in the United States market in April 1994. [22] [23] [10] It continued to be available in the United Kingdom for use in humans under the brand name Modrenal for the treatment of Cushing's disease and breast cancer in humans, but was eventually discontinued in this country as well. [10] [24] [25] [26]
Age and origin of the source material determine the chemical structure of humic substances. In general, humic substances derived from soil and peat (which takes hundreds to thousands of years to form) have higher molecular weight, higher amounts of O and N, more carbohydrate units, and fewer polyaromatic units than humic substances derived from ...
In humans, cypermethrin is deactivated by enzymatic hydrolysis to several carboxylic acid metabolites, which are eliminated in the urine. Worker exposure to the chemical can be monitored by measurement of the urinary metabolites, while severe overdosage may be confirmed by quantitation of cypermethrin in blood or plasma.
T-2 mycotoxin is a trichothecene mycotoxin.It is a naturally occurring mold byproduct of Fusarium spp. fungus which is toxic to humans and other animals. The clinical condition it causes is alimentary toxic aleukia and a host of symptoms related to organs as diverse as the skin, airway, and stomach.
Treatment with 1% sodium hypochlorite (NaOCl) in 0.1M sodium hydroxide (NaOH) for 4–5 hours has been shown to inhibit the biological activity of T-2 toxin. [70] Incubation with aqueous ozone at approximately 25 ppm has also been shown to degrade a variety of trichothecenes through a mechanism involving oxidation of the 9, 10 carbon double ...
Chlorothalonil-containing products are sold under the names Bravo, Echo, and Daconil. It was first registered for use in the US in 1966. In 1997, it was the third most used fungicide in the US, behind only sulfur and copper , with 12 million pounds (5.4 million kilograms) used in agriculture that year. [ 3 ]