1000 resultados para 4-Quinolones


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A series of novel 1-(substituted phenyl)-3-(2-oxo-1,3,4-oxadiazol-5-yl) β-carbolines (4a-e) and the corresponding Mannich bases 5-9(a-c) were synthesized and evaluated for their in vitro antitumor activity against seven human cancer cell lines. Compounds of 4a-e series showed a broad spectrum of antitumor activity, with GI50 values lower than 15μM for five cell lines. The derivative 4b, having the N,N-dimethylaminophenyl group at C-1, displayed the highest activity with GI50 in the range of 0.67-3.20μM. A high selectivity and potent activity were observed for some Mannich bases, particularly towards resistant ovarian (NCI-ADR/RES) cell lines (5a, 5b, 6a, 6c and 9b), and ovarian (OVCAR-03) cell lines (5b, 6a, 6c, 9a, 9b and 9c). In addition, the interaction of compound 4b with DNA was investigated by using UV and fluorescence spectroscopic analysis. These studies indicated that 4b interact with ctDNA by intercalation binding.

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The aim of this study was to evaluate the degree of conversion (DC) and the cytotoxicity of photo-cured experimental resin composites containing 4-(N,N-dimethylamino)phenethyl alcohol (DMPOH) combined to the camphorquinone (CQ) compared with ethylamine benzoate (EDAB). The resin composites were mechanically blended using 35 wt% of an organic matrix and 65 wt% of filler loading. To this matrix was added 0.2 wt% of CQ and 0.2 wt% of one of the reducing agents tested. 5x1 mm samples (n=5) were previously submitted to DC measurement and then pre-immersed in complete culture medium without 10% (v/v) bovine serum for 1 h or 24 h at 37 °C in a humidifier incubator with 5% CO2 and 95% humidity to evaluate the cytotoxic effects of experimental resin composites using the MTT assay on immortalized human keratinocytes cells. As a result of absence of normal distribution, the statistical analysis was performed using the nonparametric Kruskal-Wallis to evaluate the cytotoxicity and one-way analysis of variance to evaluate the DC. For multiple comparisons, cytotoxicity statistical analyses were submitted to Student-Newman-Keuls and DC analysis to Tukey's HSD post-hoc test (=0.05). No significant differences were found between the DC of DMPOH (49.9%) and EDAB (50.7%). 1 h outcomes showed no significant difference of the cell viability between EDAB (99.26%), DMPOH (94.85%) and the control group (100%). After 24 h no significant difference were found between EDAB (48.44%) and DMPOH (38.06%), but significant difference was found compared with the control group (p>0.05). DMPOH presented similar DC and cytotoxicity compared with EDAB when associated with CQ.

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The local anesthetic effects on neuromuscular junction and its influence on blockade produced by nondepolarizing neuromuscular blockers are still under-investigated; however, this interaction has been described in experimental studies and in humans. The aim of this study was to evaluate in vitro the interaction between ropivacaine and pancuronium, the influence on transmission and neuromuscular blockade, and the effectiveness of neostigmine and 4-aminopyridine to reverse the blockade. Rats were divided into groups (n=5) according to the study drug: ropivacaine (5μgmL(-1)); pancuronium (2μg.mL(-1)); ropivacaine+pancuronium. Neostigmine and 4-aminopyridine were used at concentrations of 2μgmL(-1) and 20μgmL(-1), respectively. The effects of ropivacaine on membrane potential and miniature end-plate potential, the amplitude of diaphragm responses before and 60minutes after the addition of ropivacaine (degree of neuromuscular blockade with pancuronium and with the association of pancuronium-ropivacaine), and the effectiveness of neostigmine and 4-aminopyridine on neuromuscular block reversal were evaluated. Ropivacaine did not alter the amplitude of muscle response (the membrane potential), but decreased the frequency and amplitude of the miniature end-plate potential. Pancuronium blockade was potentiated by ropivacaine, and partially and fully reversed by neostigmine and 4-aminopyridine, respectively. Ropivacaine increased the neuromuscular block produced by pancuronium. The complete antagonism with 4-aminopyridine suggests presynaptic action of ropivacaine.

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This reaserch analysed the developmental stage of fourth grade (primary school) children in ability of writting argumentative texts joint with their context. The reason of this reaserch is the lack of new studies in linguistical area and high ratio of unable students to make this kind of text. It will be showed the analysis of making text by public schools children for three months. These data were analysed trying identify argumentative operators, the kinds of arguments used and the stage of the argumentative ability of these children. The study showed that the introduction of argumentative text in first grades give them more chances of succeed, preparing these pupils in their finishing high school. This fact obviously will make easier the development of their critical point of view, helping the students to think about their living social reality.

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OBJETIVO: investigar o conhecimento dos professores de 1ª a 4ª série quanto ao distúrbio da leitura e escrita, pesquisando quais dificuldades referentes a esse distúrbio, foram apresentadas por estes professores. MÉTODOS: esses dados foram obtidos, por meio de um questionário informativo de 10 questões, aplicados a 50 professores de 1ª a 4ª série, da cidade de Bauru. Os questionários foram analisados e tabulados, e receberam tratamento estatístico pertinente. RESULTADOS: os resultados obtidos revelaram que os professores possuem um conhecimento superficial a respeito do distúrbio da leitura e escrita, sendo que muitos adquiriram tal conhecimento fora do ambiente de graduação. Verificou-se também que os professores apesar de encaminharem seus alunos ao fonoaudiólogo, possuem visão limitada quanto à atuação deste profissional. O distúrbio da leitura e escrita foi considerado como um problema próprio da criança, sendo pouco reconhecido como uma falha que também pode ser da escola ou da metodologia de ensino. CONCLUSÃO: os professores logram um saber pouco fundamentado a respeito do distúrbio da leitura e escrita; sendo que, as dificuldades giraram em torno: da identificação real do problema; de quais manifestações caracterizam esse problema; e de como intervir e prevenir.

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We report magnetic and EPR (electron paramagnetic resonance) spectroscopy studies of [Cu2(flu)4(dmf)2] (flu = flufenamate and dmf = dimethylformamide), which has CuII ions in tetracarboxylate "paddle wheel" dinuclear units. Susceptibility measurements at 10 < T < 275 K allowed the evaluation of an antiferromagnetic intradinuclear exchange coupling J0 = -294 ± 5 cm-1 between CuII ions (Hex = "J0 S1·S2). EPR experiments at 300 K in powder and single-crystals at 9.5 and 34.4 GHz indicated g// = 2.373, g⊥ = 2.073 and zero field splitting parameters D = (-0.334 ± 0.001) cm"1 and E ca. 0. EPR signal intensity measurements at X-band in the range 4 < T < 295 K indicated that J0 = "283 ± 5 cm"1. A higher limit |J´| < 5×10-3 cm-1 for the interdinuclear exchange coupling between neighbor units at ca.14.24 Å was estimated from the angular variation of the single crystal spectra around the magic angles. The results are discussed in terms of the structure of the dinuclear unit and the bridges connecting CuII ions and compared with values reported for similar compounds.

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A series of nine new [3-(disubstituted-phosphate)-4,4,4-trifluoro-butyl]-carbamic acid ethyl esters (phosphate-carbamate compounds) was obtained through the reaction of (4,4,4-trifluoro-3-hydroxybut-1-yl)-carbamic acid ethyl esters with phosphorus oxychloride followed by the addition of alcohols. The products were characterized by ¹H, 13C, 31P, and 19F NMR spectroscopy, GC-MS, and elemental analysis. All the synthesized compounds were screened for acetylcholinesterase (AChE) inhibitory activity using the Ellman method. All compounds containing phosphate and carbamate pharmacophores in their structures showed enzyme inhibition, being the compound bearing the diethoxy phosphate group (2b) the most active compound. Molecular modeling studies were performed to investigate the detailed interactions between AChE active site and small-molecule inhibitor candidates, providing valuable structural insights into AChE inhibition.

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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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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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The 4,5-diamine-2,6-dimercaptopyrimidine (DADMcP) compound is an interesting multifunctional species exhibiting a rather complex tautomerism, encompassing nine tautomeric forms. Investigation of tautomerism in this compound has been carried out by means of FTIR spectroscopy, in association with ab-initio HF/SCF and DFT calculations. According to this study three tautomers are energetically favored; the thione form being the most stable one. The theoretical vibrational spectra of such tautomeric forms have been successfully simulated by means of DFT calculations, allowing the elucidation and assignment of the complex composition of the vibrational bands observed for the mixture of isomers.

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Solid-phase microextraction, using on-line bis(trimethylsilyl)trifluoroacetamide derivatisation, gas chromatography, and mass spectrometry, was evaluated in the quantification of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) in water samples. Fibres encompassing a wide range of polarities were used with headspace and direct immersion sampling. For the immersion procedure, various parameters affecting MX extraction, including pH, salinity, temperature, and extraction time were evaluated. The optimised method (polyacrylate fibre; 20% Na2SO4; pH 2.0; 60 min; 20 °C) was applied for reservoir chlorinated water samples-either natural or spiked with MX (50 ng L-1 and 100 ng L-1). The recovery of MX ranged from 44 to 72%. Quantification of MX in water samples was done using external standard and the selected ion monitoring mode. Correlation coefficient (0.98%), relative standard deviation (5%), limit of detection (30 ng L-1) and limit of quantification (50 ng L-1) were obtained from calibration curve.

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OBJETIVOS: identificar os padrões alimentares de crianças e sua associação com o nível socioeconômico das famílias. MÉTODOS: estudo transversal com 1260 crianças de 4 a 11 anos, residentes em Salvador-Bahia que incluiu aplicação de um Questionário de Frequência Alimentar semi-quantitativo. Os padrões alimentares foram identificados, empregando-se análise fatorial por componentes principais. O nível socioeconômico foi avaliado por meio de um indicador socioeconômico composto. Regressão logística multivariada foi empregada. RESULTADOS: identificaram-se quatro padrões que explicaram 45,9% da variabilidade dos dados de frequência alimentar. Crianças que pertencem ao nível socioeconômico mais alto têm 1,60 vezes mais chance (p<0,001) de apresentarem maior frequência de consumo de alimentos do padrão 1 (frutas, verduras, leguminosas, cereais e pescados) e 3,09 vezes mais chance (p<0,001) de apresentarem maior frequência de consumo dos alimentos do padrão 2 (leite/ derivados, catchup/ maionese/ mostarda e frango), quando se compara com aquele de crianças de nível socioeconômico mais baixo. Resultado inverso foi observado no padrão 4 (embutidos, ovos e carnes vermelhas); isto é, quanto maior o nível socioeconômico menor a chance da adoção desse padrão. Tendência similar foi notada para o padrão 3 (frituras, doces, salgadinhos, refrigerante/ suco artificial). CONCLUSÕES: padrões alimentares de crianças são dependentes das condições socioeconômicas das famílias e a adoção de itens alimentares mais saudáveis associa-se aos grupos de mais altos níveis socioeconômicos.

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O objetivo deste estudo foi avaliar os efeitos hemodinâmicos e metabólicos, após a administração de solução salina hipertônica (NaCL) 7,5% ou em associação ao hidroxietilamido (HES), em cães com hipovolemia induzida e tratados com cetamina. Após a indução da hipovolemia, administrou-se NaCl 7,5% (4,0ml kg-1) no grupo hipertônica levógira (GHL) e grupo hipertônica racêmica (GHR) ou HES 130/0,4 na mesma proporção de sangue retirado, associado a NaCl 7,5% (4ml kg-1) no grupo hipertônica colóide levógira (GHCL) e no grupo hipertônica colóide racêmica (GHCR). Após 30 minutos, administrou-se, por via IV, cetamina levógira (CL) (5mg kg-1) no GHL e GHCL ou cetamina racêmica (CR) (10mg kg-1) no GHR e GHCR. Empregou-se a análise de variância de uma única via com repetições múltiplas (ANOVA) e o teste de Student Newman Keuls (P£0,05). A frequência cardíaca e a pressão arterial sistólica foram menores após a hipovolemia e após a CR. As pressões arteriais média e diastólica foram menores após a hipovolemia e cetamina. A pressão venosa central foi maior após a administração do colóide. Os índices cardíaco e sistólico foram menores após a hipovolemia em todos os grupos e, após a fase de expansão no GHL e GHR. A pressão média da artéria pulmonar foi menor após a hipovolemia em todos os grupos. A pressão de oclusão da artéria pulmonar foi maior após o colóide. O índice do trabalho ventricular esquerdo foi menor após a hipovolemia no GHCL e GHCR. O índice da resistência periférica total foi maior após a hipovolemia e menor após a CL. Observou-se acidose metabólica após a hipovolemia e após a cetamina. Ocorreu acidose respiratória após a cetamina no GHL e GHR. Conclui-se que a administração de NaCl 7,5% associado ao HES 130/0,4 promove o restabelecimento imediato dos parâmetros hemodinâmicos e metabólicos no paciente hipovolêmico; a administração isolada de NaCl 7,5% não é capaz de restaurar a PAM no período imediato, mas melhora os demais parâmetros hemodinâmicos e metabólicos; a administração de CR ou CL produz efeitos hemodinâmicos e metabólicos similares no paciente hipovolêmico.