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Dimethyl Phthalate
Dimethyl phthalate 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 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 reaction can be catalysed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. 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, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Liv ... [...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 The conjugate acids are in :Carboxylic acids. {{Commons category, Carboxylate ions, Carboxylate anions Carbon compounds Oxyanions ... 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. References Thermoplastics Butyrate esters Acetate esters {{ester-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phthalic Acid
Phthalic acid is an aromatic dicarboxylic acid, with formula C6H4(CO2H)2. 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 tetrachloride with nitric acid, or, bette ... [...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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aedes Aegypti
''Aedes aegypti'', the yellow fever mosquito, is a mosquito that can spread dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents. 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 found in tropical, subtropical and temperate regions throughout the world. Biology ''Aedes aegypti'' is a long, 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 mixed up with Aedes albopictus without a magnifying glass: The latter have a white stripe on the top of the mid thorax. Males live off fruit and only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Culex Pipiens
''Culex pipiens'', commonly referred to as the common house mosquito, is a species of mosquito. House mosquitoes are some of the most common mosquitoes in the United States. More specifically, ''Culex pipiens'' is considered as the northern house mosquito, as it is the most common mosquito to the northern regions of the US. North of the 39th parallel north in the US, only ''C. pipiens'' are present, whereas south of the 36th parallel north, only '' C. quinquefasciatus'' (commonly known as the southern house mosquito) are present. Additionally, they can be found in both urban and suburban temperate and tropical regions across the world. ''Culex pipiens'' diet typically consists of vertebrate blood, as they consume human blood, but prefer bird blood of species that are nearly linked to human interaction, such as doves and pigeons. Furthermore, at the end of the summer and the start of the fall season before it is time for them to overwinter, ''C. pipiens'' subsist on nectar and o ... [...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 takes place 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyme Disease
Lyme disease, also known as Lyme borreliosis, is a vector-borne disease caused by the ''Borrelia'' bacterium, which is spread by ticks in the genus ''Ixodes''. 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. Early diagnosis can be difficult. Other early symptoms may include fever, headaches and tiredness. If untreated, symptoms may include loss of the ability to move one or both sides of the face, joint pains, severe headaches with neck stiffness or heart palpitations. Months to years later repeated episodes of joint pain and swelling may occur. Occasionally shooting pains or tingling in the arms and legs may develop. Despite appropriate treatment about 10 to 20% of those affected develop joint pains, memory problems and tiredness for at least six months. Lym ... [...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 over 700 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 other ... [...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. 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 precise chemical terms, nitrocellulose is not a nitro compound, but a nitrate ester. The glucose repeat unit (anhydroglucose) within ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethyl Phthalate
Diethyl phthalate (DEP) is a phthalate ester. It occurs as a colourless liquid without significant odour but has a bitter, disagreeable taste. It is more dense than water and insoluble in water; hence, it sinks in water. 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 comp ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
