419 resultados para 337.1


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The parasitic protozoan Leishmania (Leishmania) amazonensis alternates between mammalian and insect hosts. In the insect host, the parasites proliferate as procyclic promastigotes andthen differentiate into metacyclic infective forms. The meta 1 gene is preferentially expressed during metacyclogenesis. Meta 1 expression profile determination along parasite growth curves revealed that the meta 1 mRNA level peaked at the early stationary phase then decreased to an intermediate level. No correlation was observed between meta 1 expression and infectivity. Conversely, infectivity correlated with the increase of apoptotic cells in the late stationary phase.

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Objective: Wives of pathological gamblers tend to endure long marriages despite financial and emotional burden. Difficulties in social adjustment, personality psychopathology, and comorbidity with psychiatric disorders are pointed as reasons for remaining on such overwhelming relationships. The goal was to examine the social adjustment, personality and negative emotionality of wives of pathological gamblers. Method: The sample consisted of 25 wives of pathological gamblers, mean age 40.6, SD = 9.1 from a Gambling Outpatient Unit and at GAM-ANON, and 25 wives of non-gamblers, mean age 40.8, SD = 9.1, who answered advertisements placed at the Universidade de São Paulo hospital and medical school complex. They were selected in order to approximately match demographic characteristics of the wives of pathological gamblers. Subjects were assessed by the Social Adjustment Scale, Temperament and Character Inventory, Beck Depression Inventory and State-Trait Anxiety Inventory. Results: Three variables remained in the final Multiple Logistic Regression model, wives of pathological gamblers presented greater dissatisfaction with their marital bond, and higher scores on Reward Dependence and Persistence temperament factors. Both, Wives of pathological gamblers and wives of non-gamblers presented well-structured character factors excluding personality disorders. Conclusion: This personality profile may explain wives of pathological gamblers emotional resilience and their marriage longevity. Co-dependence and other labels previously used to describe them may work as a double edged sword, legitimating wives of pathological gamblers problems, while stigmatizing them as inapt and needy.

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The reactions of meso-1,2-bis(phenylsulfinyl)ethane (meso-bpse) with Ph2SnCl2, 2-phenyl-1,3-dithiane trans-1-trans-3-dioxide (pdtd) with n-Bu2SnCl2 and 1,2-cis-bis-(phenylsulfinyl)ethene (rac-,cis-cbpse) with Ph2SnCl2, in 1:1 molar ratio, yielded [{Ph2SnCl2(meso-bpse)}n], [{n-Bu2SnCl2(pdtd)}2] and [{Ph2SnCl2(rac,cis-cbpse)}x] (x = 2 or n), respectively. All adducts were studied by IR, Mössbauer and 119Sn NMR spectroscopic methods, elemental analysis and single crystal X-ray diffractometry. The X-ray crystal structure of [{Ph2SnCl2(meso-bpse)}n] revealed the occurrence of infinite chains in which the tin(IV) atoms appear in a distorted octahedral geometry with Cl atoms in cis and Ph groups in trans positions. The X-ray crystal structure of [{n-Bu2SnCl2(pdtd)}2] revealed discrete centrosymmetric dimeric species in which the tin(IV) atoms possess a distorted octahedral geometry with bridging disulfoxides in cis and n-butyl moieties in trans positions. The spectroscopic data indicated that the adduct containing the rac,cis-cbpse ligand can be dimeric or polymeric. The X-ray structural analysis of the free rac-,cis-cbpse sulfoxide revealed that the crystals belong to the C2/c space group.

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A practical method for the structural assignment of 3,4-O-benzylidene-D-ribono-1,5-lactones and analogues using conventional NMR techniques and NOESY measurements in solution is described. 2-O-Acyl-3,4-O-benzylidene-D-ribono-1,5-lactones were prepared in good yields by acylation of Zinner’s lactone with acyl chlorides under mildly basic conditions. Structural determination of 2-O-(4-nitrobenzoyl)-3,4-O-benzylidene-D-ribono-1,5-lactone was achieved by single crystal x-ray diffraction, which supports the results based on spectroscopic data.

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OBJETIVO: Verificar a associação entre relato de sibilância em crianças e adolescentes e o local de residência em relação à dispersão dos poluentes atmosféricos emitidos pelo Pólo Petroquímico (PPQ) de Guamaré (RN). MÉTODOS: Estudo transversal de relato de sibilância em crianças e adolescentes de 0 a 14 anos de idade, residentes no entorno do PPQ de Guamaré, em 2006. Foi utilizado o questionário padronizado do International Study of Asthma and Allergies in Childhood, acrescido de questões relativas ao tabagismo, renda, moradia e escolaridade. Concentrações diárias de PM10, PM2,5, carbono grafítico, SO2, NO2, O3, benzeno, tolueno e xilenos foram medidas em uma estação de monitoramento fixa. As comunidades residentes na área de influência das emissões do PPQ foram classificadas, segundo a direção preferencial dos ventos, em expostas e de referência. RESULTADOS: Participaram do estudo 209 crianças e adolescentes. As concentrações médias diárias dos poluentes monitorados mantiveram-se abaixo dos limites estabelecidos nos padrões de qualidade do ar. A prevalência de sibilos nos últimos 12 meses foi de 27,3%. Associações estatisticamente significantes com sibilos nos últimos 12 meses foram verificadas mesmo após ajustamentos para comunidades expostas [razão de chances (odds ratio, ORajust) = 2,01; intervalo de confiança de 95% (IC95%) 1,01-4,01], gênero masculino (ORajust = 2,50; IC95% 1,21-5,18) e idade de 0 a 6 anos (ORajust = 5,00; IC95% 2,41-10,39). CONCLUSÃO: Mesmo em baixas concentrações de poluentes atmosféricos, a ocorrência de sintomas respiratórios em crianças e adolescentes nas comunidades no entorno de um PPQ esteve associada a residência na direção preferencial dos ventos, mostrando-se mais vulnerável o grupo de pré-escolares do gênero masculino.

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The absorption spectra of DPH at fixed concentration do not change with water content in organic solvents. It exhibits monomer bands, such as those obtained in ethanol. The absorption did not change for solutions up to 54 and 46% of water in ethanol and DMSO, respectively, for [DPH] = 5.0 × 10-6 mol L-1 at 30 °C. However, at the same experimental conditions, a gradual sharp decay of the DPH fluorescence is observed. It is proposed that water molecules below these water concentration limits act as quenchers of the excited states of DPH. Stern-Volmer quenching constants by intensities measurements are 7.4 × 10-2 (water/ethanol) and 2.6 × 10-2 L mol-1 (water/DMSO). DPH lifetime measurements in the absence and presence of water resulted in 7.1 × 10-2 L mol-1 in water/ethanol, which pointed out that the process is a dynamic quenching by water molecules. For experiments using DPH as probe, this process can affect data, leading to misunderstanding interpretation.

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Neste trabalho estudou-se o desempenho mecânico e térmico de compostos de borracha natural (Hevea brasiliensis) de 4 diferentes clones (GT 1, IAN 873, PB 235 e RRIM 600) cultivados no Estado de São Paulo, assim como de uma mistura destes clones e de uma borracha comercial, GEB-1. Estas borrachas foram formuladas e vulcanizadas com tempos de 5, 7 e 9 minutos. A caracterização foi realizada por calorimetria exploratória diferencial, termogravimetria, ensaios de resistência à tração, análise dinâmico-mecânica, medidas de dureza Shore A, microscopia eletrônica de varredura e espectroscopia na região do infravermelho. Os resultados permitiram concluir que o tempo de vulcanização e o tipo de clone não influenciaram na temperatura de transição vítrea (Tg) dos compostos. Os valores de Tg obtidos por DMA foram de cerca de -62 °C, e os resultados ensaios de dureza apresentaram valores próximos de 60 para todos os compostos estudados. Os ensaios de resistência à tração mostraram que o melhor desempenho mecânico foi obtido pelo clone RRIM 600. De acordo com os resultados obtidos neste trabalho, todos os clones atingiram as propriedades reportadas na literatura, podendo ser utilizados, em princípio, nas indústrias de artefatos de borracha separadamente ou na forma de mistura.

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Five previously synthesized 4-trifluoromethyl-2-(5-aryl-3-styryl-1H-pyrazol-1yl)-pyrimidines and six 5-aryl-3-styryl-1-carboxamidino-1H-pyrazole derivatives were screened for their antioxidant proprieties. The antioxidant activities were evaluated by using the DPPH and the HRP/luminol/H2O2 chemiluminescence assay systems and for their antimicrobial activity (MIC). The results were good for those series in some concentration in comparison with the standards.

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The aqueous alkaline reaction of 1,3-bis(4-cyanopyridinium)propane dibromide, a reactant constituted of two pyridinium rings linked by a three-methylene bridge, generates a novel compound,1 -(4-cyano-2-oxo-1,2-dihydro-1-pyridyl)-3-(4-cyano-1,2-dihydro-1-pyridyl)propane. The reaction pathway is attributed to the proximity of the OH- ion inserted between two pyridinium moieties, which occurs only in bis(pyridinium) derivatives connected by short methylene spacers, where charge-conformational effects are important.

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Capillary electrophoresis has become a well-established and routine-based separation technique. It is based on the differences between charged analyte mobility in aqueous or organic electrolytes. Its major limitation is the sensitivity due to small sample injection volumes and the narrow diameter of the capillaries, especially when UV detection is used. There are a number of ways to increase the concentration sensitivity. This report shows some on-line preconcentration strategies to perform it in free solution capillary electrophoresis that are based on manipulation of the analyte electrophoretic velocity during the sample introduction (stacking, field amplification and transient isotachophoresis).

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Com base nas grandes modificações das propriedades de materiais poliméricos resultantes da inclusão de unidades organometálicas, descrevem-se neste trabalho a síntese e a caracterização de um polímero organometálico conjugado com estrutura semelhante à de poli(p-fenilenovinileno) (PPV), o qual apresenta grupos 1,1'-ferrocenileno no lugar de 1,4fenileno em sua cadeia principal. Sintetizado por meio de reação de acoplamento de McMurry de 1,1'-ferrocenodialdeído, o poli(1,1'-ferrocenilenovinileno) (PFV) se apresentou na forma de um sólido de cor laranja, amorfo e insolúvel tanto em solventes polares quanto em apolares. Para caracterização do PFV, empregaram-se os métodos de espectroscopia no infravermelho (FTIR), espectroscopia Raman e análise termogravimétrica (TGA).

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Lipase from Burkholderia cepacia immobilized on superparamagnetic nanoparticles using adsorption and chemisorption methodologies was efficiently applied as recyclable biocatalyst in the enzymatic kinetic resolution of (RS)-1-(phenyl)ethanols via transesterification reactions. (R)-Esters and the remaining (S)-alcohols were obtained with excellent enantiomeric excess (> 99%), which corresponds to a perfect process of enzymatic kinetic resolution (conversion 50%, E > 200). The transesterification reactions catalysed with B. cepacia lipase immobilized by the glutaraldehyde method showed the best results in terms of reusability, preserving the enzyme activity (conversion 50%, E > 200) for at least 8 successive cycles.

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This work describes the infrared spectroscopy characterization and the charge compensation dynamics in supramolecular film FeTPPZFeCN derived from tetra-2-pyridyl-1,4-pyrazine (TPPZ) with hexacyanoferrate, as well as the hybrid film formed by FeTPPZFeCN and polypyrrole (PPy). For supramolecular film, it was found that anion flux is greater in a K+ containing solution than in Li+ solution, which seems to be due to the larger crystalline ionic radius of K+. The electroneutralization process is discussed in terms of electrostatic interactions between cations and metallic centers in the hosting matrix. The nature of the charge compensation process differs from others modified electrodes based on Prussian blue films, where only cations such as K+ participate in the electroneutralization process. In the case of FeTPPZFeCN/PPy hybrid film, the magnitude of the anions’s flux is also dependent on the identity of the anion of the supporting electrolyte.

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A metal-free protocol was developed to synthesize indanes by ring contraction of 1, 2-dihydronaphthalenes promoted by PhI(OH)OTs (HTIB or Koser's reagent). This oxidative rearrangement can be performed in several solvents (MeOH, CH3CN, 2 , 2, 2-trifluoroethanol (TFE), 1 , 1, 1, 3, 3, 3-hexafluoroisopropanol (HFIP), and a 1:4 mixture of TFE:CH2Cl2) under mild conditions. The ring contraction diastereoselectively gives functionalized trans-1, 3-disubstituted indanes, which are difficult to obtain in synthetic organic chemistry

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The identification of the sandfly fauna and investigation of some ecological aspects of its populations in areas frequented by tourists of the PEI, an Atlantic forest reserve with many caves, were the objective of this study. Captures were undertaken monthly from January 2001 to December 2002, with automatic light traps installed in 13 ecotopes, including caves, forests, domiciliary and peridomiciliary environments, and by aspiration in armadillo burrows. Additionally, although not at regular intervals, Shannon traps were installed in forests and anthropic environments, aspirations were made on cave walls, among roots and fallen leaves, and some insects were captured while biting researchers. A total of 891 sandflies belonging to 21 species were captured. Six hundred specimens representing 19 species were captured with light traps, 215 in anthropic (2.24 insects/trap) and 385 in extra-domiciliary (1.46 insects/trap) environments. Brumptomyia troglodytes was the most abundant species (the Standardised Index of Species Abundance = 0.705). Pintomyia monticola predominated in the Shannon traps and showed anthropophilic and diurnal activity. Psathyromyia pascalei predominated in the aspirations; the largest number being in armadillo burrows. Eleven species were captured in caves; although some might be troglophiles, the majority used these ecotopes as resting places. Nyssomyia intermedia, Nyssomyia neivai and Migonemyia migonei, implicated in the transmission of cutaneous leishmaniasis in the Southeastern Brazilian region, were all found, though in such low densities as to suggest minimal risk of the disease in the PEI.