80 resultados para spectral reflectance
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This study describes the synthesis, IR, (1)H, and (13)C{(1)H} NMR spectroscopic as well the thermal characterization of the new palladium(II) pyrazolyl complexes [PdCl(2)(HmPz)(2)] 1, [PdBr(2)(HmPz)(2)] 2, [PdI(2)(HmPz)(2)] 3, [Pd(SCN)(2)(HmPz)(2)] 4 {HmPz = 4-methylpyrazole}. The residues of the thermal decomposition were identified as Pd(0) by X-ray powder diffraction. From the initial decomposition temperatures, the thermal stability of the complexes can be ordered in the sequence: 1 > 2 > 4 a parts per thousand 3. The cytotoxic activities of the complexes and the ligand were investigated against two murine cancer cell lines: mammary adenocarcinoma (LM3) and lung adenocarcinoma (LP07) and compared to cisplatin under the same experimental conditions.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The pyrazole ligand 3,5-dimethyl-4-iodopyrazole (HdmIPz) has been used to obtain a series of palladium(II) complexes (1-4) of the type [PdX(2)(HdmIPz)(2)] {X = Cl(-) (1); Br(-) (2); I(-) (3); SCN(-) (4)}. All compounds have been isolated, purified, and characterized by means of elemental analysis, IR spectroscopy, (1)H and (13)C{(1)H}-NMR experiments, differential thermal analysis (DTA), and thermogravimetry (TG). The TG/DTA curves showed that the compounds released ligands in the temperature range 137-605 A degrees C, yielding metallic palladium as final residue. The complexes and the ligand together with cisplatin have been tested in vitro by MTT assay for their cytotoxicity against two murine cancer cell lines: mammary adenocarcinoma (LM3) and lung adenocarcinoma (LP07).
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The aim of the present study was to assess the spectral behavior of the erector spinae muscle during isometric contractions performed before and after a dynamic manual load-lifting test carried out by the trunk in order to determine the capacity of muscle to perform this task. Nine healthy female students participated in the experiment. Their average age, height, and body mass (± SD) were 20 ± 1 years, 1.6 ± 0.03 m, and 53 ± 4 kg, respectively. The development of muscle fatigue was assessed by spectral analysis (median frequency) and root mean square with time. The test consisted of repeated bending movements from the trunk, starting from a 45º angle of flexion, with the application of approximately 15, 25 and 50% of maximum individual load, to the stand up position. The protocol used proved to be more reliable with loads exceeding 50% of the maximum for the identification of muscle fatigue by electromyography as a function of time. Most of the volunteers showed an increase in root mean square versus time on both the right (N = 7) and the left (N = 6) side, indicating a tendency to become fatigued. With respect to the changes in median frequency of the electromyographic signal, the loads used in this study had no significant effect on either the right or the left side of the erector spinae muscle at this frequency, suggesting that a higher amount and percentage of loads would produce more substantial results in the study of isotonic contractions.
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A simple proof is given that a 2 x 2 matrix scheme for an inverse scattering transform method for integrable equations can be converted into the standard form of the second-order scalar spectral problem associated with the same equations. Simple formulae relating these two kinds of representation of integrable equations are established.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Um método de correção de interferência espectral e de transporte é proposto, e foi aplicado para minimizar interferências por moléculas de PO produzidas em chama ar-acetileno e de transporte causada pela variação da concentração de ácido fosfórico. Átomos de Pb e moléculas de PO absorvem a 217,0005 nm, então Atotal217,0005 nm = A Pb217,0005 nm + A PO217,0005 nm. Monitorando o comprimento de onda alternativo de PO em 217,0458 nm, é possível calcular a contribuição relativa de PO na absorbância total a 217,0005 nm: A Pb217,0005 nm = Atotal217,0005 nm - A PO217,0005 nm = Atotal217,0005 nm - k (A PO217,0458 nm). O fator de correção k é a razão entre os coeficientes angulares de duas curvas analíticas para P obtidas a 217,0005 e 217,0458 nm (k = b217,0005 nm/b217,0458 nm). Fixando-se a taxa de aspiração da amostra em 5,0 ml min-1, e integrando-se a absorbância no comprimento de onda a 3 pixels, curvas analíticas para Pb (0,1 - 1,0 mg L-1) foram obtidas com coeficientes de correlação típicos > 0,9990. As correlações lineares entre absorbância e concentração de P nos comprimentos de onda 217,0005 e 217,0458 foram > 0,998. O limite de detecção de Pb foi 10 µg L-1. O método de correção proposto forneceu desvios padrão relativos (n=12) de 2,0 a 6,0%, ligeiramente menores que os obtidos sem correção (1,4-4,3%). As recuperações de Pb adicionado às amostras de ácido fosfórico variaram de 97,5 a 100% (com correção pelo método proposto) e de 105 a 230% (sem correção).
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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This paper describes an analytical reflectometric method that has an objective not only the industrial quality control but also to detect possible falsifications and/or adulterations of propranolol in pharmaceutical formulations. The method is based on the diffuse reflectance measurements of the colored product (III) of the spot test reaction between propranolol hydrochloride (I) and 2,6-dichloroquinone-4-chloroimide (II) using filter paper as solid support. Spot test conditions have been investigated using experimental design in order to identify and optimize the critical factors. The factors evaluated were DCQ concentration, propranolol solvent and DCQ solvent. The best reaction conditions were achieved with the addition of 30 mu L, of propranolol solution in ethanol 35% (v/v) and 30 mu L of DCQ solution at 70 mg mL(-1) in acetone, in this order. All reflectance measurements were carried out at 500 nm and the linear range was from 8.45 x 10(-4) to 8.45 x 10(-2) mol L-1 (r= 0.998). The limit of detection was 1.01 x 10(-4) mol L-1. No interference was observed from the assessed excipients and drugs. The method was applied to determine propranolol in commercial brands of pharmaceuticals. The results obtained by the proposed method were favorably compared with those given by the British Pharmacopoeia procedure. (C) 2007 Elsevier B.V. All rights reserved.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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This work describes the synthesis, IR and (13)C CPMAS NMR spectroscopic as well the thermal characterization of the new dicarboxylate complexes [Pd(2)(ox)(2)(4,4'-bipy)]n (1), [Pd(2)(ox)(2)(bpe)](n) (2) and [Pd(2)(ox)(2)(pz)](n) (3) {ox = oxalate, bipy = 4,4'-bipyridine, bpe = 1,2-bis(4-pyridyl)ethane, pz = pyrazine}. TG experiments reveal that compounds 1-3 undergo thermal decomposition in three steps. Metal palladium was the final product of the thermal decompositions, which was identified by X-ray powder diffraction.