103 resultados para Visible Light Absorption


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In order to establish the concentrations of glucose, cholesterol, total protein and growth factor insulin-like type I (IGF-I) in the follicular fluid, 26 Murrah breed river buffaloes, between 45 and 70 days postpartum, empty, multiparous, with average live weight of 675 +/- 56 kg and average body condition of 3.5 points on a scale of 1-5, were used in this study. The fluid was collected from dominant follicles with diameters between 8 and 12 mm by OPU, and was not taken into account the stage of the estrous cycle. Using this technique, the wave of follicular development was synchronized six days prior to collection. Biochemical analysis was performed to glucose and cholesterol through the enzymatic colorimetric method using commercial kit glicose CHOLESTEROL GOD-PAP and CHOD-PAP (Kovalent), respectively. Determination of total protein was carried out by using total protein commercial kit (Kovalent) Biuret method, and the readings were performed using absorption spectrophotometry with visible light. Concentration of IGF-I was measured by Radioimmunoassay (RIA) technique using commercial IRMA Kit IGF-I (INMUNOTECH). Descriptive statistics were developed using the PROC MEANS procedure of SAS (2009). Concentration of glucose (4.0 +/- 0.75 mmol / L-1) and IGF-I (340 +/- 129.83 ng / mL (-1)) were higher than those reported by other authors in river buffaloes and cows, respectively. However, cholesterol levels (0.51 +/- 0.12 mmol / L (-1)) and total protein (58.4 +/- 4.43 g / L (-1)) behaved inferior to other studies in same species. The results indicated that there is relationship among the nutritional aspects, diameter of follicles aspirated and productive period in the concentration of biochemical indicators.

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Pós-graduação em Ciência e Tecnologia de Materiais - FC

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Triacrylate resins are widely used to fabricate 3D microstructures, photonic crystals and optical devices. These resins can be doped with photosensitive materials like Disperse Red 1 (DR1), an Azo dye that changes its molecular configuration from trans to cis (photoisomerisation) with variations in their optical absorption spectrum when irradiated with ultraviolet or visible light. The reversibility of this process is thermally activated and occurs when the molecule remains at dark. In this work was prepared a 1:1 mixture of ethoxylated-6-trimethylolpropane (SR499) and tris-2-hydroxyethyl-isocyanurate (SR368) triacrylate resins, plus photoinitiator Lucirin TPOL, forming a UV curable polymeric matrix doped with DR1. Thin films were deposited onto glass slides by spin-coating technique. The films showed photochromic effect when illuminated with a low power diode laser (450 nm and 50mW/cm2). This effect is reversible after sample is left in dark. Thermochromic effect was evaluated by optical absorption measurements in the range of 40 to 140oC, heating the samples in-situ

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Photodynamic Therapy (PDT) is a technique used to treat several types of lesions, such as cancer, microbial control, and esthetic dentistry cases. The performance of PDT involves the use of a photosensitizer (PS), which mainly will be located in cancer cells and is irradiated with visible light. This process, when it occurs in the presence of oxygen triggers the formation of reactive oxygen species that are cytotoxic to cells. These species cause cell death and subsequent tumor necrosis. The use of white light as a light source for multispectral Photodynamic Therapy and its consequences to the photodynamic effect is not yet completely established, and therefore there is interest in studying the parameters involved for analyzing the best conditions for applying treatment. The wavelength is crucial to improve the therapeutic effect, since both the optical properties of the biological tissue as the PS depend on these parameters. For FS studied in this work (Photogem®) are most often used wavelengths in the red region, due to their larger penetration depth in biological tissue. Thus, the light source becomes a fundamental aspect, their choice depends on the specific application and is based on the tumor location, light dose to be delivered and FS chosen. Despite all the advantages presented by lasers, the fact of having an emission spectrum essentially monochrome makes only one possible transition possible for the absorption of FS is used. Therefore, more extensive light sources such as light emitting diodes (LED), could be better used in some cases the laser, with the additional advantage of a reduced cost. Therefore, the choice of the white LED comes from an emission spectrum that still wider LED colors defined by allowing greater use of the several absorption bands and with varying depths of operation, according to the wavelength... (Complete abstract click electronic access below)

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Twenty six Murrah female river buffaloes, between 45 and 70 d post-partum, empty, multiparae, with an average live weight of 675 ± 56 kg, and average body condition of 3.5 points, in a 1 to 5 scale, were used to determine the concentrations of glucose, cholesterol, total protein and insulin-like growth factor type I(IGF-I) in the follicular fluid. The fluid was collected from dominant follicles, with diameters between 8 and 12 mm, by in vivo follicular aspiration. The oestrous cycle stage was not taken into account. The wave of follicular development was synchronized six days prior to the collection. Biochemical analyses of glucose and cholesterol were performed by the enzymatic colorimetric method with the utilization of commercial kits of Glicose (GOD-PAP) and Cholesterol (CHOD-PAP) (Kovalent), respectively. For the determination of total protein, the commercial kit total Protein (Kovalent), method Biuret, was employed. Readings were carried out through absorption spectrophotometry with visible light. Through the radioimmunoanalysis (RIA) technique the concentration of IGF-I was obtained using commercial kits of IRMA IGF-I (IMMUNOTECH). Descriptive statistics was used, by applying the PROC MEANS procedure of the SAS (2009) statistical package. Glucose concentrations (4.0 ± 0.75 mmol/L) and IGF-I (340 ± 129.83 ng/mL) showed higher values in female river buffaloes and dairy cows regarding those reported in other studies. However, cholesterol levels (0.51 ± 0.12 mmol/L) and total proteins (58.4 ± 4.43 g/L) were lower. Results indicate that there is a relationship between the concentration of biochemical indicators, the nutritional aspects, the diameter of the aspired follicles and the productive period.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The smart thermo-optical systems studied here are based on the unusual thermoreversible sol-gel transition of zirconyl chloride aqueous solution modified by sulfuric acid in the molar ratio Zr/SO4:3/1. The transparency to the visible light changes during heating due to light scattering. This feature is related to the aggregates growth that occurs during gelation. These reversible changes can be controlled by the amount of chloride ions in solution. The thermoreversible sol-gel transition temperature increases from 323 to 343 K by decreasing the molar ratio Cl/Zr from 7.0 to 1.3. In this work the effect of the concentration of chloride ions on the structural characteristics of the system has been analyzed by in situ SAXS measurements during the sol-gel transition carried out at 323 and 333 K. The experimental SAXS curves of sols exhibit three regions at small, medium and high scattering vectors characteristics of Guinier, fractal and Porod regimes, respectively. The radius of primary particles, obtained from the crossover between the fractal and Porod regimes, remains almost invariable with the chloride concentration, and the value (4 Angstrom) is consistent with the size of the molecular precursor. During the sol-gel transition the aggregates grow with a fractal structure and the fractal dimensionality decreases from 2.4 to 1.8. This last value is characteristic of a cluster-cluster aggregation controlled by a diffusion process. Furthermore, the time exponent of aggregate growth presents values of 0.33 and 1, typical of diffusional and hydrodynamic motions. A crossover between these two regimes is observed.

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In this work a new europium (III) complex with the following formula NH(4) [Eu(bmdm)(4)] was synthesized and characterized. The bmdm (butyl methoxy-dibenzoyl-methane) is a P-diketone molecule used as UV radiation absorber in sunscreen formulations. Coordination of this ligand to the Eu(3+) ion was confinned by FT-IR, while the Raman spectrum suggests the presence of NH(4)(+) ions. The photoluminescence spectra present narrow lines arising from f-f intra-configurational transitions (5)D(0-)(7)F(0,1,2,3,4), dominated by the hypersensitive (5)D(0)-(7)F(2) transition. In the spectrum recorded at 77 K, all transitions split into 2J + 1 lines suggesting that there is just one symmetry site around Eu(3+) ion. This symmetry is not centrosymmetric. The calculated intensity parameters are ohm(2) = 30.5 x 10(-20) cm(2) and ohm(4) = 5.91 x 10(-20) cm(2) for this complex. The CIE chromaticity coordinates (x = 0.67 and y = 0.32) show a dominant wavelength of 615 nm. The color gamut achieved by this complex is a 100% in the CIE color space. (c) 2005 Elsevier B.V. All rights reserved.