627 resultados para NGNitroarginina Metil Éster


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Tese de Doutoramento, Química, Especialização em Química Orgânica, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016

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As most current studies, reinforced plastics have been, in recent years, a viable alternative in building structural elements of medium and large, since the lightness accompanied by high performance possible. The design of hybrid polymer composites (combination of different types of reinforcements) may enable structural applications thereof, facing the most severe service conditions. Within this class of composite materials, reinforced the underlying tissues hybrid high performance are taking space when your application requires high load bearing and high rigidity. The objective of this research work is to study the challenges in designing these fabrics bring these materials as to its mechanical characterization and fracture mechanisms involved. Some parameters associated with the process and / or form of hybridization stand out as influential factors in the final performance of the material such as the presence of anisotropy, so the fabric weave, the process of making the same, normative geometry of the specimens, among others. This sense, four laminates were developed based hybrid reinforcement fabrics involving AS4 carbon fiber, kevlar and glass 49-E as the matrix epoxy vinyl ester resin (DERAKANE 411-350). All laminates were formed each with four layers of reinforcements. Depending on the hybrid fabric, all the influencing factors mentioned above have been studied for laminates. All laminates were manufactured industrially used being the lamination process manual (hand-lay-up). All mechanical characterization and study of the mechanism of fracture (fracture mechanics) was developed for laminates subjected to uniaxial tensile test, bending in three and uniaxial compression. The analysis of fracture mechanisms were held involving the macroscopic, optical microscopy and scanning electron microscopy

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Biodiesel is an alternative fuel, renewable, biodegradable and nontoxic. The transesterification of vegetable oils or animal fat with alcohol is most common form of production of this fuel. The procedure for production of biodiesel occurs most commonly through the transesterification reaction in which catalysts are used to accelerate and increase their income and may be basic, acid or enzyme. The use of homogeneous catalysis requires specific conditions and purification steps of the reaction products (alkyl ester and glycerol) and removal of the catalyst at the end of the reaction. As an alternative to improve the yield of the transesterification reaction, minimize the cost of production is that many studies are being conducted with the application of heterogeneous catalysis. The use of nano-structured materials as catalysts in the production of biodiesel is a biofuel alternative for a similar to mineral diesel. Although slower, can esterify transesterified triglycerides and free fatty acids and suffer little influence of water, which may be present in the raw material. This study aimed at the synthesis, characterization and application of nano-structured materials as catalysts in the transesterification reaction of soybean oil to produce biodiesel by ethylic route. The type material containing SBA-15 mesoporous lanthanum embedded within rightly Si / La = 50 was used catalyst. Solid samples were characterized by X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, nitrogen adsorption and desorption. For the transesterification process, we used a molar ratio of 20:1 alcohol and oil with 0.250 g of catalyst at 60°C and times of 6 hours of reaction. It was determined the content of ethyl esters by H-NMR analysis and gas chromatography. It was found that the variable of conversion obtained was 80%, showing a good catalytic activity LaSBA-15 in the transesterification of vegetable oils via ethylic route

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Tese (doutorado)—Universidade de Brasília, Instituto de Química, Curso de Pós-Graduação em Química, 2016.

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In this work, biodiesel was produced from castor oil that was a byproduct glycerin. The molar ratio between oil and alcohol, as well as the use of (KOH) catalyst to provide the chemical reaction is based on literature. The best results were obtained using 1 mol of castor oil (260g) to 3 moles of methyl alcohol (138g), using 1.0% KOH as catalyst at a temperature of 260 ° C and shaken at 120 rpm. The oil used was commercially available, the process involves the reaction of transesterification of a vegetable oil with methyl alcohol. The product of this reaction is an ester, biodiesel being the main product and the glycerin by-product which has undergone treatment for use as raw material for the production of allyl alcohol. The great advantage of the use of glycerin to obtain allyl alcohol is that its use eliminates the large amount of waste of the biodiesel and various forms of insult to the environment. The reactions for the formation of allyl alcohol was conducted from formic acid and glycerin in a ratio 1/1, at a temperature of 260oC in a heater blanket, being sprayed by a spiral condenser for a period of 2 hours and the product obtained contains mostly the allylic alcohol .. The monitoring of reactions was performed by UV-Visible Spectrophotometer: FTIR Fourier transform, the analysis showed that these changes occur spectrometer indicating the formation of the product allylic alcohol (prop-2-en-1-ol) in the presence of water, This alcohol was appointed Alcohol GL. The absorption bands confirms that the reaction was observed in (υ C = C) 1470 -1600 cm -1 and (υ CO), 3610-3670 attributed to C = C groups and OH respectively. The thermal analysis was carried out in a thermogravimetric analyzer SDT Q600, where the mass and temperature are displayed against time, that allows checking the approximate rate of heating. The innovative methodology developed in the laboratory (LABTAM, UFRN), was able to treat the glycerine produced by transesterification of castor oil and used as raw material for production of allyl alcohol, with a yield of 80%, of alcohol, the same is of great importance in the manufacture of polymers, pharmaceuticals, organic compounds, herbicides, pesticides and other chemicals

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Tese de doutoramento, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2015

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La hiperalgesia secundaria a la administración de remifentanil se ha documentado tanto en estudios animales como en estudios experimentales en humanos y ha aumentado su incidencia dado su uso cada vez más frecuente para el mantenimiento durante diferentes procedimientos anestésicos, anestesia general balanceada, anestesia total intravenosa y sedaciones. La hiperalgesia secundaria al uso de remifentanil es un proceso pro-nociceptivo relacionado pero que difiere de la tolerancia aguda, en el que los neurotransmisores excitatorios de N- metil D aspartato (NMDA) juegan un rol central. Por tanto la ketamina se ha utilizado en diferentes dosis para la prevención de dicha hiperalgesia sin que se haya establecido su efectividad para la prevención y tratamiento de esta condición. Se encontraron 8 estudios publicados en los últimos 10 años que proponen a la ketamina como una estrategia útil y efectiva el tratamiento de la hiperalgesia inducida por el uso de remifentanil. Los resultados demuestran que la ketamina es un tratamiento costo efectivo para el tratamiento de la hiperalgesia en diferentes poblaciones sometidas a diversos procedimientos quirúrgicos y anestésicos que incluyan la administración de remifentanil tanto en la inducción como en el mantenimiento anestésico sin generar efectos secundarios adicionales, así como que logra disminuir el consumo de opioides y la EVA en el posoperatorio.

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Introducción: La diverticulosis es la condición más frecuentemente encontrada en la colonoscopia, condición asintomática, con un alto costo para el sistema de salud. Diversos factores han demostrado estar en relación con la aparición de la enfermedad. En nuestra población, esta información se desconoce; el objetivo del estudio es la caracterización de la población con diverticulosis y su relación con la frecuencia de la ingesta de fibra. Materiales y Métodos: Estudio observacional prospectivo de corte transversal con componente analítico. Realizado a todas las personas que asistieron al HUS a realización de colonoscopia entre Noviembre de 2015 y Abril de 2016. Se recolectaron datos de la frecuencia de fibra ingerida a través de entrevistas basadas. Resultados: Se estudiaron 278 personas, 55.7% mujeres. La prevalencia de diverticulosis fue de 21.58%, siendo más frecuente en mujeres ( 66,7%), 31% entre los 71-80 años, 2,16% tenían antecedente familiar de diverticulosis; principal sitio de afectación fue colon sigmoide en las mujeres y el colon descendente en los hombres. En las personas con diverticulosis el consumo de harina de trigo fue mayor (91,67% vs 86,7%), mientras el consumo de frutas fue mayor en las personas que no presentaron diverticulosis (83,49% vs 78,33%). Conclusiones: La prevalencia de diverticulosis es similar a lo reportado en la literatura. Así mismo se encontró un mayor consumo de fibra en la población sin divertículos lo que hace pensar que a pesar de que esta condición es multifactorial , el consumo de mayores cantidades de fibra puede prevenir la aparición de la misma

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O fungo lignocelulebtico, agente causal de podridão branca em madeira, Phonerochacte chrysosperium resistente a benomil, tem se mostrado eficiente como degradador do fungicida carbendazim. O fungo foi cultivado em BD complementado com 100,9 ug/ml de metil benzimidazol-2-ylcarbamato (Carbendazim ou MBC) por 22 dias, sob agitação. A determinação dos resíduos, realizada a partir do segundo dia e quantificada por cromatografia liquida de alta eficiência demonstrou que o carbendazim e rapidamente degradado por P.chrysosperium, sendo que aproximadamente 76% ocorre nos primeiros 6 dias de incubação.

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Este trabalho teve por objetivo detectar efeitos de fertilizantes organominerais e do indutor acilbenzolar-S-metil(ASM) na preferência hospedeira de mosca-branca devido à indução de resistência por antixenose no tomateiro.

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Traditional winegrowing areas are located in temperate climate zones and allow to produce grapes only once per year. Tropical wines have been elaborated in India, Thailand, Venezuela and Brazil and present another kind of viticulture, as compared with countries located in temperate climate zones. Northeast of Brazil started wine production twenty six years ago. This region vines can produce two or three crops per year, depending of the cycle of different cultivars. Harvests can be scaled throughout the year, mainly between May and December, corresponding to the dry season. Red, white, rosé and sparkling wines are being elaborated in the region. The objective of this work was to determine the physico-chemical and aromatic characteristics of some tropical wines elaborated in Northeast of Brazil, with grapes harvested in November 2008. Wines were elaborated using traditional method with control of the alcoholic and malolactic fermentation temperatures, at 25 and 18ºC for red wines, respectively, and at 18ºC for alcoholic fermentation of the white wines. After stabilization and bottling and wines were analyzed to determine physico-chemical characteristics, like alcohol degree, pH, total and volatile acidities, dry extract, sulfur dioxide, total anthocyanin and total phenol index. Aromatic profile was determined by gas chromatography, while 19 esters and 6 superior alcohols were identified. Wines presented different chemical and aromatic characteristics according to different grape cultivars.