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Dimethyl Phthalate
Dimethyl phthalate (DMP) is an organic compound and phthalate ester. it is a colourless and oily liquid that is soluble in organic solvents, but which is only poorly soluble in water (~4 g/L). It is used in a variety of products and is most commonly used as insect repellent such as ectoparasiticide for mosquitoes and flies for animal livestock. The short-chain or low molecular weight phthalate is also frequently used in consumer products such as cosmetics, ink, soap, household cleaning supplies, etc. Other uses of DMP include solid rocket propellants (as a stabilizer) and plastics. The U.S Environmental Protection Agency has classified Dimethyl phthalate as not classifiable for human carcinogenicity. Its oral LD50 is 4390 to 8200 mg/kg bw/d in rats and the dermal LD50 is 38000 mg/kg bw in rats and more than 4800 mg/kg bw in guinea pigs. Synthesis Dimethyl phthalate is manufactured commercially via the esterification of phthalic anhydride with methanol. The react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-containing compounds such as alkanes (e.g. methane ) and its derivatives are universally considered organic, but many others are sometimes considered inorganic, such as certain compounds of carbon with nitrogen and oxygen (e.g. cyanide ion , hydrogen cyanide , chloroformic acid , carbon dioxide , and carbonate ion ). Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, and even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulose Acetate Butyrate
Cellulose acetate butyrate (CAB) is a mixed ester thermoplastic derivative of cellulose acetate that contains both acetate and butyrate functional groups. It has improved weathering resistance and lower moisture absorption compared to cellulose acetate. The exact properties of a CAB compound is determined by the composition of butyrate vs acetate functional groups. CAB is commonly used as a binder or additive in coatings. CAB is widely used for tool handles, due to its toughness and resistance to oil and gasoline. Tools with CAB handles can begin to outgas unpleasant butyric acid Butyric acid (; from , meaning "butter"), also known under the systematic name butanoic acid, is a straight-chain alkyl carboxylic acid with the chemical formula . It is an oily, colorless liquid with an unpleasant odor. Isobutyric acid (2-met ... odors with age, which one manufacturer combats by adding vanilla scent to the plastic. Another usage of CAB is the production of rigid gas-permeable conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phthalic Acid
In organic chemistry, phthalic acid is an aromatic dicarboxylic acid, with formula and structure . Although phthalic acid is of modest commercial importance, the closely related derivative phthalic anhydride is a commodity chemical produced on a large scale. Phthalic acid is one of three isomers of benzenedicarboxylic acid, the others being isophthalic acid and terephthalic acid. Production Phthalic acid is produced by the catalytic oxidation of naphthalene or ''ortho-''xylene directly to phthalic anhydride and a subsequent hydrolysis of the anhydride. Phthalic acid was first obtained by French chemist Auguste Laurent in 1836 by oxidizing naphthalene tetrachloride. Believing the resulting substance to be a naphthalene derivative, he named it "naphthalic acid". After the Swiss chemist Jean Charles Galissard de Marignac determined its correct formula, Laurent gave it its present name. Manufacturing methods in the nineteenth century included oxidation of naphthalene tetrach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biotransformation
Biotransformation is the biochemical modification of one chemical compound or a mixture of chemical compounds. Biotransformations can be conducted with whole cells, their lysates, or purified enzymes. Increasingly, biotransformations are effected with purified enzymes. Major industries and life-saving technologies depend on biotransformations. Advantages and disadvantages Compared to the conventional production of chemicals, biotransformations are often attractive because their selectivities can be high, limiting the coproduction of undesirable coproducts. Generally operating under mild temperatures and pressures in aqueous solutions, many biotransformations are "green". The catalysts, i.e. the enzymes, are amenable to improvement by genetic manipulation. Biotechnology usually is restrained by substrate scope. Petrochemicals for example are often not amenable to biotransformations, especially on the scale required for some applications, e.g. fuels. Biotransformations can be slow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aedes Aegypti
''Aedes aegypti'' ( or from Greek 'hateful' and from Latin, meaning 'of Egypt'), sometimes called the Egyptian mosquito, dengue mosquito or yellow fever mosquito, is a mosquito that spreads diseases like dengue fever, yellow fever, malaria, and chikungunya. The mosquito can be recognized by black and white markings on its legs and a marking in the form of a lyre on the upper surface of its thorax. This mosquito originated in Africa, but is now a common invasive species that has spread to tropical, subtropical, and temperate regions throughout the world. Biology ''Aedes aegypti'' is a , dark mosquito which can be recognized by white markings on its legs and a marking in the form of a lyre on the upper surface of its thorax. Females are larger than males. Microscopically females possess small palps tipped with silver or white scales, and their antennae have sparse short hairs, whereas those of males are feathery. ''Aedes aegypti'' can be confused with ''Aedes albopic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Culex Pipiens
''Culex pipiens'' is a species of mosquito commonly referred to as the common house mosquito or northern house mosquito. Native to Africa, Asia and Europe, it is now widely distributed in temperate regions on every continent except Antarctica and is one of the most common mosquitoes found in human habitats in temperate parts of the northern hemisphere. A major vector of some viruses, it can be abundant in cities, especially those with poor wastewater management. It is the most common mosquito to the northern regions of the US. ''Culex pipiens'' is the type species for the genus ''Culex''. ''Culex pipiens'' includes two morphologically indistinguishable forms, ''Culex pipiens'' form ''pipiens'' and ''Culex pipiens'' form ''molestus'.'' Despite their morphological similarity, the two forms exhibit striking ecological and behavioral differences. Form ''pipiens'' lives above ground and primarily feeds on birds. Form ''molestus,'' also known as the London Underground mosquito, can li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anopheles Stephensi
''Anopheles stephensi'' is a primary mosquito vector of malaria in urban India and is included in the same subgenus as ''Anopheles gambiae'', the primary malaria vector in Africa. ''A. gambiae'' consists of a complex of morphologically identical species of mosquitoes, along with all other major malaria vectors; however, ''A. stephensi'' has not yet been included in any of these complexes. Nevertheless, two races of ''A. stephensi'' exist based on differences in egg dimensions and the number of ridges on the eggs; ''A. s. stephensi'' ''sensu stricto'', the type form, is a competent malaria vector that is found in urban areas, and ''A. s. mysorensis'', the variety form, exists in rural areas and exhibits considerable zoophilic behaviour, making it a poor malaria vector. However, ''A. s. mysorensis'' is a detrimental vector in Iran.Sinka, M.E., Bangs, M.J., Manguin, S., Chareonviriyaphap, T., Patil, A.P., Temperley, W.H., Gething, P. W., Elyazar, I.R.F., Kabaria, C.W., Harbach, R.E., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyme Disease
Lyme disease, also known as Lyme borreliosis, is a tick-borne disease caused by species of ''Borrelia'' bacteria, Disease vector, transmitted by blood-feeding ticks in the genus ''Ixodes''. It is the most common disease spread by ticks in the Northern Hemisphere. Infections are most common in the spring and early summer. The most common sign of infection is an expanding red rash, known as erythema migrans (EM), which appears at the site of the tick bite about a week afterwards. The rash is typically neither itchy nor painful. Approximately 70–80% of infected people develop a rash. Other early symptoms may include fever, headaches and fatigue (medical), tiredness. If untreated, symptoms may include Facial nerve paralysis, loss of the ability to move one or both sides of the face, arthritis, joint pains, Meningitis, severe headaches with neck stiffness or heart palpitations. Months to years later, repeated episodes of joint pain and swelling may occur. Occasionally, shootin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ixodidae
The Ixodidae are the family of hard ticks or scale ticks, one of the three families of ticks, consisting of 771 species, . They are known as 'hard ticks' because they have a scutum or hard shield, which the other major family of ticks, the 'soft ticks' (Argasidae), lack. They are ectoparasites of a wide range of host species, and some are vectors of pathogens that can cause human disease. Description They are distinguished from the Argasidae by the presence of a scutum. In both the nymph and the adult, a prominent gnathosoma (or capitulum, mouth and feeding parts) projects forward from the animal's body; in the Argasidae, conversely, the gnathosoma is concealed beneath the body. They differ, too, in their lifecycle; Ixodidae that attach to a host bite painlessly and are generally unnoticed, and they remain in place until they engorge and are ready to change their skin; this process may take days or weeks. Some species drop off the host to moult in a safe place, whereas others ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrocellulose
Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and sulfuric acid. One of its first major uses was as guncotton, a replacement for gunpowder as propellant in firearms. It was also used to replace gunpowder as a low-order explosive in mining and other applications. In the form of collodion, it was also a critical component in an early photographic emulsion, the use of which revolutionized photography in the 1860s. In the 20th century, it was adapted to automobile lacquer and adhesives. Production The process uses a mixture of nitric acid and sulfuric acid to convert cellulose into nitrocellulose. The quality of the cellulose is important. Hemicellulose, lignin, pentosans, and mineral salts give inferior nitrocelluloses. In organic chemistry, nitrocellulose is a nitrate ester, not a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethyl Phthalate
Diethyl phthalate (DEP) is a phthalate ester. It is a colourless liquid without significant odour but with a bitter disagreeable taste. Synthesis and applications Diethyl phthalate is produced by the reaction of ethanol with phthalic anhydride, in the presence of a strong acid catalyst: It finds some use as a specialist plasticiser in PVC, it has also been used as a blender and fixative in perfume. Biodegradation Biodegradation by microorganisms Biodegradation of DEP in soil occurs by sequential hydrolysis of the two diethyl chains of the phthalate to produce monoethyl phthalate, followed by phthalic acid. This reaction occurs very slowly in an abiotic environment. Thus there exists an alternative pathway of biodegradation which includes transesterification or demethylation by microorganisms, if the soil is also contaminated with methanol, that would produce another three intermediate compounds, ethyl methyl phthalate, dimethyl phthalate and monomethyl phthalate. This bio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enteric Coating
An enteric coating is a polymer barrier applied to oral medication that prevents its dissolution or disintegration in the gastric environment. This helps by either protecting drugs from the acidity of the stomach, the stomach from the detrimental effects of the drug, or to release the drug after the stomach (usually in the upper tract of the intestine). Some drugs are unstable at the pH of gastric acid and need to be protected from degradation. Enteric coating is also an effective method to obtain drug targeting (such as gastro-resistant drugs). Other drugs such as some anthelmintics may need to reach a high concentration in a specific part of the intestine. Enteric coating may also be used during studies as a research tool to determine drug absorption. Enteric-coated medications pertain to the "delayed action" dosage form category. Tablets, mini-tablets, pellets and granules (usually filled into capsule shells) are the most common enteric-coated dosage forms. Description Most e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
