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Saku District, Nagano
was a district located in Shinano Province (now Nagano Prefecture). Due to land reforms, Saku District split into Minamisaku (南佐久郡) and Kitasaku (北佐久郡) Districts on January 14, 1879. The former is estimated to be located at Nagatoro in the city of Saku. Pesticide problems Cases of dermatitis caused by pesticide exposures, tabulated by the Division of Dermatology, Saku Central Hospital, Japan, from 1975 to 2000 are described. Dermatitis cases gradually decreased from 1975 to 2000, presumably accelerated by the phase-out of dermatitis-causing pesticides, including difolatan fungicide and salithion, an organophosphate insecticide. Cases of chronic and solar dermatitis gradually decreased, which may be explained by reductions in the use of allergenic or photosensitive sulfur agents and organophosphates. However, the ratios of chemical burns from irritant pesticides— calcium polysulfide, dazomet, methyl bromide, chlorpicrin, paraquat/diquat, organophosphorus, q ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Districts Of Japan
In Japan, a is composed of one or more rural municipalities (Towns of Japan, towns or Villages of Japan, villages) within a Prefectures of Japan, prefecture. Districts have no governing function, and are only used for geographic or statistical purposes such as mailing addresses. Cities of Japan, Cities are not part of districts. Historically, districts have at times functioned as an administrative unit in Japan, administrative unit. From 1878 to 1921The governing law, the district code (''gunsei'', 郡制Entry for the 1890 originalanentry for the revised 1899 ''gunsei''in the National Diet Library ''Nihon hōrei sakuin''/"Index of Japanese laws and ordinances"), was abolished in 1921, but the district assemblies (''gunkai'', 郡会) existed until 1923, the district chiefs (''gunchō'', 郡長) and district offices (''gun-yakusho'', 郡役所) until 1926. district governments were roughly equivalent to a County (United States), county of the United States, ranking below Prefectu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insecticide
Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to be a major factor behind the increase in the 20th-century's agricultural productivity. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans and/or animals; some become concentrated as they spread along the food chain. Insecticides can be classified into two major groups: systemic insecticides, which have residual or long term activity; and contact insecticides, which have no residual activity. The mode of action describes how the pesticide kills or inactivates a pest. It provides another way of classifying insecticides. Mode of action can be important in understanding whether an insecticide will be toxic to unrelated species, such as fish, birds and mammals. Insecticides may be repellent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quintozene
Pentachloronitrobenzene, typically abbreviated PCNB, is a registered fungicide formally derived from nitrobenzene. It is either an off-white or yellow solid, depending on its purity, with a musty odor. Preparation PCNB was originally synthesized in the laboratory in 1868. It was introduced to the agricultural world in the 1930s in Germany by Bayer AG as a substitute to mercurial pesticides. PCNB is prepared by chlorination of nitrobenzene at 60–70 °C in chlorosulfuric acid, with iodine as a catalyst. It can also be produced by the nitration of chlorinated benzenes. A side product of the synthesis of PCNB is hexachlorobenzene (HCB), which is considered as hazardous as PCNB. :5 Cl2 + C2H5NO2 → C6Cl5NO2 + 5 HCl Main reactions Reaction with ethanol and potassium hydroxide yields pentachlorophenetole, indicating its high reactivity: :C6Cl5NO2 + KOCH2CH3 → C6Cl5OCH2CH3 + KNO2 Although PCNB has a long shelflife, it is labile in soil, with a half life of 1.8 d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diquat
Diquat is the ISO common name for an organic dication that, as a salt with counterions such as bromide or chloride is used as a contact herbicide that produces desiccation and defoliation. Diquat is no longer approved for use in the European Union, although its registration in many other countries including the USA is still valid. Synthesis Pyridine is oxidatively coupled to form 2,2′-bipyridine over a heated Raney nickel catalyst. The ethylene bridge is formed by the reaction with 1,2-dibromoethane : History Diquat's herbicidal properties were recognized in 1955 in the Imperial Chemical Industries (ICI) laboratories at Jealott's Hill, following its first synthesis at ICI's Dyestuffs Division in Blackley, England. It was active on test plants at application rates as low as 0.1 lb/acre. It was found that only those quaternary salts which were capable of being converted by reducing agents to radical cations had herbicidal activity and another of these was paraquat, which was mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraquat
Paraquat (trivial name; ), or ''N'',''N''′-dimethyl-4,4′-bipyridinium dichloride (systematic name), also known as methyl viologen, is an organic compound with the chemical formula C6H7N)2l2. It is classified as a viologen, a family of redox-active heterocycles of similar structure. This salt is one of the most widely used herbicides. It is quick-acting and non-selective, killing green plant tissue on contact. It is also toxic (lethal) to human beings and animals due to its redox Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate (chemistry), substrate change. Oxidation is the loss of Electron, electrons or an increase in the oxidation state, while reduction ... activity, which produces superoxide anions. It has been linked to the development of Parkinson's disease and is banned in several countries. Paraquat may be in the form of salt (chemistry), salt with chloride or other anions; quantities of the substan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorpicrin
Chloropicrin, also known as PS and nitrochloroform, is a chemical compound currently used as a broad-spectrum antimicrobial, fungicide, herbicide, insecticide, and nematicide. It was used as a poison gas in World War I. Its chemical structural formula is Cl3CNO2. Synthesis Chloropicrin was discovered in 1848 by Scottish chemist John Stenhouse. He prepared it by the reaction of sodium hypochlorite with picric acid: : HOC6H2(NO2)3 + 11 NaOCl → 3 Cl3CNO2 + 3 Na2CO3 + 3 NaOH + 2 NaCl Because of the precursor used, Stenhouse named the compound chloropicrin, although the two compounds are structurally dissimilar. Today, chloropicrin is manufactured by the reaction of nitromethane with sodium hypochlorite: : H3CNO2 + 3 NaOCl → Cl3CNO2 + 3 NaOH or by the reaction of chloroform with nitric acid: : CHCl3 + HNO3 → CCl3NO2 + H2O Properties Chloropicrin's chemical formula is CCl3NO2 and its molecular weight is 164.38 grams/mole. Pure chloropicrin is a colorless liquid, with a boiling po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Bromide
Bromomethane, commonly known as methyl bromide, is an organobromine compound with formula C H3 Br. This colorless, odorless, nonflammable gas is produced both industrially and biologically. It has a tetrahedral shape and it is a recognized ozone-depleting chemical. It was used extensively as a pesticide until being phased out by most countries in the early 2000s. Occurrence and manufacture Bromomethane originates from both natural and human sources. In the ocean, marine organisms are estimated to produce 56,000 tonnes annually. It is also produced in small quantities by certain terrestrial plants, such as members of the family Brassicaceae. It is manufactured for agricultural and industrial use by treating methanol with bromine in the presence of sulfur or hydrogen sulfide: :6 CH3OH + 3 Br2 + S → 6 CH3Br + 2 H2O + H2SO4 Uses In 1999, an estimated 71,500 tonnes of synthetic methyl bromide were used annually worldwide. 97% of this estimate was used for fumigation purposes, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dazomet
Dazomet is a common soil fumigant that acts as a herbicide, fungicide, slimicide, and nematicide. Applications Dazomet is a chemical used to kill pests that inhibit plant growth through gaseous degradation. Dazomet is used as a soil sterilant on a variety of sites such as golf courses, nurseries, turf sites, and potting soils. Dazomet is used for soil sterilization as an alternative to methyl bromide. Although less effective it is still used to kill pests because of its comparatively lower toxicity. Dazomet is applied to wet soil, which causes dazomet itself to decompose into a gaseous form, which is what actively controls pests. The decomposition of dazomet releases methyl isothiocyanate (MITC) a gas toxic to pests that would prevent or kill plant growth. Dazomet has also been proven to be effective in the prevention of ''Phellinus noxius ''Phellinus noxius'' is a plant pathogen. References External links Fungal plant pathogens and diseases noxius Fungi described in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Polysulfide
In horticulture, lime sulfur (British spelling lime sulphur) is mainly a mixture of calcium polysulfides and thiosulfate (plus other reaction by-products as sulfite and sulfate) formed by reacting calcium hydroxide with elemental sulfur, used in pest control. It can be prepared by boiling in water a suspension of poorly soluble calcium hydroxide (lime) and solid sulfur together with a small amount of surfactant to facilitate the dispersion of these solids in water. After elimination of any residual solids (flocculation, decantation and filtration), it is normally used as an aqueous solution, which is reddish-yellow in colour and has a distinctive offensive odour of hydrogen sulfide (H2S, rotten eggs). Synthesis reaction The exact chemical reaction leading to the synthesis of lime sulfur is poorly known and is generally written as: : : where x = 2–8 and x value is often found around 5, calcium pentasulfide, a polysulfide as reported in a document of the US Department of Agric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allergen
An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies. In technical terms, an allergen is an antigen that is capable of stimulating a type-I hypersensitivity reaction in atopic individuals through immunoglobulin E (IgE) responses. Most humans mount significant Immunoglobulin E responses only as a defense against parasitic infections. However, some individuals may respond to many common environmental antigens. This hereditary predisposition is called atopy. In atopic individuals, non-parasitic antigens stimulate inappropriate IgE production, leading to type I hypersensitivity. Sensitivities vary widely from one person (or from one animal) to another. A very broad range of substances can be allergens to sensitive individuals. Types of allergens Allergens can be found in a variety of sources, such as dust mite e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Dermatitis
Photodermatitis, sometimes referred to as sun poisoning or photoallergy, is a form of allergic contact dermatitis in which the allergen must be activated by light to sensitize the allergic response, and to cause a rash or other systemic effects on subsequent exposure. The second and subsequent exposures produce photoallergic skin conditions which are often eczematous. It is distinct from sunburn. Signs and symptoms Photodermatitis may result in swelling, difficulty breathing, a burning sensation, a red itchy rash sometimes resembling small blisters, and peeling of the skin. Nausea may also occur. There may also be blotches where the itching may persist for long periods of time. In these areas an unsightly orange to brown tint may form, usually near or on the face. Causes Many medications and conditions can cause sun sensitivity, including: * Sulfa used in some drugs, among them some antibiotics, diuretics, COX-2 inhibitors, and diabetes drugs. * Psoralens, coal tars, photo-active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organophosphate
In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered as esters of phosphoric acid. Like most functional groups, organophosphates occur in a diverse range of forms, with important examples including key biomolecules such as DNA, RNA and ATP, as well as many insecticides, herbicides, nerve agents and flame retardants. OPEs have been widely used in various products as flame retardants, plasticizers, and performance additives to engine oil. The popularity of OPEs as flame retardants came as a substitution for the highly regulated brominated flame retardants. The low cost of production and compatibility to diverse polymers made OPEs to be widely used in industry including textile, furniture, electronics as plasticizers and flame retardants. These compounds are added to the final product physica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
