1000 resultados para Di-ureasils


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Multicomponent reactions between phenols, β-diesters and benzaldehydes for the synthesis of 4-aryl-3,4-dihydrocoumarin derivatives were carried out under mild conditions (room temperature) and presented moderate yields (38-88%) and reasonable reaction times (2-4 days), using niobium pentachloride as a catalyst.

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Sol–gel derived poly(oxyethylene)/siloxane organic–inorganic di-ureasil hybrids containing different amounts (20–60% mol) of methacrylic acid (McOH) modified zirconium oxo-clusters (Zr-OMc) were processed as thin films and transparent and shape controlled monoliths. Laser direct writing was used to create channel waveguides, Bragg gratings, Fabry–Perot cavities and optical filters. The resulting Fabry–Perot optical cavity displays a free spectral range of 16.55 GHz and a fringe intensity contrast of 5.35 dB. Optical rejection values between 6.7 and 10.4 dB were obtained by varying the amount of the Zr-OMc oxo-clusters.

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Tendo em vista a problemática mundial com relação à degradação dos materiais plásticos e sua dispersão no meio ambiente, e diante de estudo realizado anteriormente onde se observou alterações histopatológicas e bioquímicas na próstata de animais expostos ao DBP (Di-N-Butil-ftalato) no período perinatal, este estudo teve por objetivo avaliar o potencial carcinogênico do DBP administrado desde o período fetal e após iniciação pelo MNU em um modelo de carcinogênese prostática. Ratas prenhes foram divididas em 4 grupos experimentais: 2 tratados: n=16/grupo (TDBP100 e TDBP500) e 2 controles: n=8/grupo (CN e CMNU). O grupo TDBP100 foi exposto ao DBP (100 mg/kg) e o TDBP500 a 500 mg/kg do 15º. dia de gestação (DG15) até a 21º. dia pósnatal (DPN21), enquanto que os animais controle receberam o veículo. Após o desmame, os machos foram separados e os grupos tratados e CMNU receberam dose única de MNU (50 mg/Kg, i.p.) na 6ª. semana pós-natal. Metade dos animais tratados (n=8/grupo) continuaram recebendo o DBP (DBP100+ e DBP500+) após o desmame em doses semanais até o dia do sacrifício (DPN180), enquanto os demais foram mantidos pelo mesmo período sem tratamento (DBP100- e DBP500-).Após a aplicação do MNU, os animais foram submetidos a injeções semanais de Cipionato de Testosterona (promotor) 2mg/aplicação. No dia do sacrifício, o sangue foi coletado, os órgãos reprodutores foram pesados e fragmentos do lobo ventral da próstata foram processados para inclusão em resina e Paraplast para as análises estruturais; e imunocitoquímicas para a detecção de AR e ER. Fragmentos de próstata ventral foram congelados e estocados a -80ºC e após extração das proteínas, estas foram destinadas à reação de Western Blot para avaliar a expressão das mesmas proteínas. Houve diminuição na distância anogenital nos animais DBP500 no DPN1 quando comparado com o grupo controle apontando para o efeito efetivo do DBP ...

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Coumarin is a natural active compound that can be found in many plants. The coumarins have many properties such as bronchodilator, anti-inflammatory, antioxidant, anticoagulant, antibiotics, immunomodulatory, antimicrobial and antiviral, thus, they are widely used in medical applications. More recently the coumarin derivatives have attracted the interest of many research groups in the field of new materials, for example the possibility of their use as sensitizers in dye-sensitized solar cells (DSSC) and lasers. The MCRs are defined as a process in which three or more reactants are combined in the same reaction pot, resulting in products with good structural complexity a single step, in addition to economy of atoms and selectivity and is a very important feature in modern synthetic methodology. In this work we investigated the use of niobium pentachloride as catalyst of the multicomponent reactions between phenolic derivatives, various aromatic aldehydes and β-diester derivatives in the synthesis of 4-aryl-3,4-dihydrocoumarin derivatives. The reactions were carried out at room temperature, under inert atmosphere (N2), using dichloromethane anhydrous (CH2 Cl2) as solvent, with a reaction time of most 120 hours. The products were isolated by column chromatography on silica gel and submitted to spectrometric and spectroscopic analysis. The results show that NbCl5 is an excellent agent for promoting the synthesis of 4-aryl-3,4-dihydrocoumarin derivatives through multicomponent reactions, obtaining yields varying from 45 to 95%

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Vasco Pratolini recreates the 1920’s and the assertion of fascism resorting to the medieval and historiographical tradition, to the social outlook and the childhood memoir. Under the effects of the intellectual movement of the Italian Resistance, within the democratic context of the parliamentary republic and pluripartyism (1946- 1948), the novel makes clear the equalitarian perspective betraying the represented moment, when hopelessness crowned the political and social life. Carlo Lizzani shoots his adaptation in the closure of horizons caused by the restoration of the conservative forces (1953), reducing the visionary focus of the narrative and representing the past from the disillusionments of the present.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In the present study, it was evaluated the susceptibility of prostatic lesions in male adult rats exposed to Di-N-butyl-phthalate during fetal and lactational periods and submitted to MNU plus testosterone carcinogenesis protocol. Pregnant females were distributed into four experimental groups: CN (negative control); CMNU (MNU control); TDBP100 (100 mg/kg of DBP); TDBP500 (500 mg/kg of DBP). Females from the TDBP groups received DBP, by gavage, from gestation day 15 (GD15) to postnatal day 21 (DPN21), while C animals received the vehicle (corn oil). CMNU, TDBP100, and TDBP500 groups received a single intraperitoneal injection of MNU (50 mg/kg) on the sixth postnatal week. After that, testosterone cypionate was administered subcutaneously two times a week (2 mg/kg) for 24 weeks. The animals were euthanized on PND220. Distal segment fragments of the ventral (VP) and dorsolateral prostate (DLP) were fixed and processed for histopathological analysis. Protein extracts from ventral prostate were obtained, and western blotting was performed to AR, ERα, MAPK (ERK1/2), and pan-AKT. Stereological analysis showed an increase in the epithelial compartment in TDBP100 and TDBP500 compared to CN. In general, there was increase in the incidence of inflammation and metaplasia/dysplasia in the DBP-treated groups, mainly in DLP, compared to CN and CMNU. Proliferation index was significant higher in TDBP500 and PIN (prostatic intraepithelial neoplasia) was more frequent in this group compared to CMNU. Western blot assays showed an increase in the expressions of AR and MAPK (ERK1/2) in the TDBP100 compared to CN, and ERα and AKT expressions were higher in the TDBP500 group compared do CN. These results showed that different doses of DBP during prostate organogenesis in Wistar rats could increase the incidence of premalignant lesions in initiated rats inducing distinct biological responses in the adulthood. © 2015 Wiley Periodicals, Inc. Environ Toxicol, 2015.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This article intends to contribute to the Brazilian design history through a study of a selection of book covers produced in 1960 decade by Vicente Di Grado (1922 - 2004), who was the main cover artist and illustrator of a publishing house named Clube do Livro. The covers were analysed considering their visual and contextual syntax and in their relations with information design.

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O resgate da história e da memória do design gráfico brasileiro ainda possui algumas lacunas, pois muitos profissionais, seus projetos e obras não são lembrados ou ainda não foram estudados e registrados, deixando uma lacuna na história gráfico-visual de nosso país. Este artigo pretende contribuir nesse sentido, resgatando as capas de livros projetadas por Vicente Di Grado. Designer gráfico, artista plástico e docente, Di Grado (1922-2005) atuou como principal capista para a Editora Clube do Livro entre as décadas de 1950 e 1970, sendo seu maior período de produção a década de 1960, justamente o objeto deste estudo. Pelo conjunto de seu trabalho, recebeu o Prêmio Jabuti em 1963. Sua obra representa uma grande fonte de elementos e referências gráficas, além de ter marcado a linguagem editorial da Editora Clube do Livro.

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Organic-inorganic hybrids containing methacrylic acid (McOH, CH(2)= C(CH(3))COOH)) modified zirconium tetrapropoxide, Zr(OPr(n))(4), classed as di-ureasil-zirconium oxo-cluster hybrids, have been prepared and structurally characterized by X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), Fourier transform infrared (FT-IR) and Raman (FT-Raman) spectroscopies, Si and C nuclear magnetic resonance (NMR), and atomic force microscopy (AFM). XRD and SAXS results have pointed out the presence of Si- and Zr-based nanobuilding blocks (NBBs) dispersed into the organic phase. Inter-NBBs correlation distances have been estimated for the pure di-ureasil and a model compound obtained. by hydrolysis/condensation of Zr(OPr(n))(4):McOH (molar ratio 1: 1): d(Si) approximate to 26 +/- 1 angstrom and d(Zr) approximate to 16 +/- 1 angstrom, respectively. In the case of the di-ureasil-zirconium oxo-cluster hybrids, these distances depend on the Zr relative molar percentage (rel. mol. Zr %) (d(Si) ranges from 18 to 25 angstrom and d(Zr) from 14 to 23 angstrom, as the rel. mol. Zr % increases from 5 to 75), suggesting that the Si- and Zr-based clusters are interconstrained. Complementary data from FT-IR, FT-Raman, (29)Si and (13)C NMR, and AFM support to a structural model where McOH-modified Zr-based NBBs (Zr-OMc) are present over the whole range of composition. At low Zr-OMc contents (rel. mol. Zr % <30) the clusters are well-dispersed within the di-ureasil host, whereas segregation occurs at the 0.1 mu m scale at high Zr-OMc concentration (rel. mol. Zr % = 50). No Zr-O-Si heterocondensation has been discerned. Monomode waveguides, diffractions gratings, and Fabry-Perot cavities have been written through the exposure of the hybrid monoliths to UV light. FT-Raman has shown that the chemical process that takes place under illumination is the polymerization of the methacrylate groups of the Zr-OMc NBBs. The guidance region in patterned channels is a Gaussian section located below the exposed surface with typical dimensions of 320 mu m wide and 88 mu m deep. The effective refractive index is 1.5162 (maximum index contrast on the order of 1 x 10(-4)) and the reflection coeficient of the Fabry-Perot cavity (formed by a grating patterned into a 0.278 cm channel) is 0.042 with a free spectral range value of 35.6 GHz.