943 resultados para synthetic aperture radar


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We tested the possible diagnostic utility of five Taenia saginata oncosphere-derived synthetic peptides in T. solium neurocysticercosis (NC). The five peptides correspond to protein sequences with high antigenic indexes that were cloned from a T. saginata oncosphere cDNA library. The test samples consisted of cerebrospinal fluid (CSF) samples randomly collected from patients referred from Mexican and Brazilian neurological institutes. Indirect enzyme-linked immunosorbent assays (ELISA) were carried out with the peptides either unconjugated or coupled to carrier proteins, and were compared with results obtained using T. solium cyst fluid as a positive control. For active inflammatory NC, the higher sensibility (93%) and specificity (85%) was obtained with peptides HP6-2 and Ts45W-1, respectively, coupled to ovalbumin, in both Mexican and Brazilian patients. Examining the results of the individual peptide assays in combination, in some instances, improved the sensitivity to 100%.

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The coumarin antibiotics are potent inhibitors of DNA replication whose target is the enzyme DNA gyrase, an ATP-dependent bacterial type II topoisomerase. The coumarin drugs inhibit gyrase action by competitive binding to the ATP-binding site of DNA gyrase B protein. The production of new biologically active products has stimulated additional studies on coumarin-gyrase interactions. In this regard, a 4.2 kDa peptide mimic of DNA gyrase B protein from Escherichia coli has been designed and synthesized. The peptide sequence includes the natural fragment 131-146 (coumarin resistance-determining region) and a segment containing the gyrase-DNA interaction region (positions 753-770). The peptide mimic binds to novobiocin (K-a = 1.4 +/- 0.3 x 10(5) m(-1)), plasmid (K-a = 1.6 +/- 0.5 x 10(6) m(-1)) and ATP (K-a = 1.9 f 0.4 x 10(3) m(-1)), results previously found with the intact B protein. on the other hand, the binding to novobiocin was reduced when a mutation of Arg-136 to Leu-136 was introduced, a change previously found in the DNA gyrase B protein from several coumarin-resistant clinical isolates of Escherichia coLi. In contrast, the binding to plasmid and to ATP was not altered. These results suggest that synthetic peptides designed in a similar way to that described here could be used as mimics of DNA gyrase in studies which seek a better understanding of the ATP, as well as coumarin, binding to the gyrase and also the mechanism of action of this class of antibacterial drugs. Copyright (C) 2004 European Peptide Society and John Wiley Sons, Ltd.

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The immobilization of the ruthenium moiety Ru(NH3)4SO3 by reaction of trans-[Ru(NH3)4SO2(H2O)]2+ with silica gel functionalized with 3-(1-imidazolyl)propyl groups is reported. A 60% surface coverage was obtained in the proportion of the resulting material [=Si(CH2)3imN-Ru(NH3)4SO3]. The anchored Ru(II) complex was characterized and its reactivity investigated. Derivatives of CO, pyrazine, and isonicotinamide have been prepared and characterized by electronic and vibrational spectroscopies, as well as by chemical means. The [=Si(CH2)3imN-Ru(NH3)4SO4]Cl, obtained through oxidation of the corresponding ruthenium(II) sulfite species, has been characterized and the aquo and the oxalate derivative have been synthesized.

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This work presents a new approach for rainfall measurements making use of weather radar data for real time application to the radar systems operated by institute of Meteorological Research (IPMET) - UNESP - Bauru - SP-Brazil. Several real time adjustment techniques has been presented being most of them based on surface rain-gauge network. However, some of these methods do not regard the effect of the integration area, time integration and distance rainfall-radar. In this paper, artificial neural networks have been applied for generate a radar reflectivity-rain relationships which regard all effects described above. To evaluate prediction procedure, cross validation was performed using data from IPMET weather Doppler radar and rain-gauge network under the radar umbrella. The preliminary results were acceptable for rainfalls prediction. The small errors observed result from the spatial density and the time resolution of the rain-gauges networks used to calibrate the radar.

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The capacity of goethite for Cd-II substitution has been explored in a series of synthetic samples prepared from Fe-III and Cd-II nitrate solutions aged 21 days in alkaline media. The total metal content ([ Fe] + [ Cd]) was 0.071 M in all preparations. The samples have been characterized by chemical and X-ray diffraction analysis; the morphology of the solids is described. The cell parameters for all samples were obtained by the Rietveld fits to the X-ray diffraction data. Refined structures show that for samples prepared at the final molar ratio mu(Cd)less than or equal to5.50 (expressed as mu(Cd) = 100X[Cd]/[Cd] + [Fe]), a (Cd, Fe)-goethite is the only crystalline product. In these samples, the unit cell parameters increased as a function of Cd concentration, indicating Cd incorporation in the structural frame. At the preparative ratio, mu(Cd)=7.03, the incorporation of Cd in the goethite structure is drastically reduced and a probable Cd-substituted hematite is formed together with the Fe,Cd-goethite. (C) 2003 International Centre for Diffraction Data.

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Current knowledge of the bioavailability of lycopene in humans is limited due to the inability to distinguish newly administered lycopene from the body reserves of lycopene. A quantitative method to assess the absorption and relative bioavailability of newly absorbed synthetic or natural lycopene was developed using two deuterated lycopene sources, in conjunction with an advanced LC/APCI-MS (liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry) to analyze newly absorbed lycopene in blood samples of study subjects. Two subjects (1 male and 1 female) consumed hydroponically grown tomatoes containing deuterium-enriched lycopene (8084 g wet weight tomato containing 16.3 and 17.4 mu mol lycopene, respectively) and two subjects (1 male, and 1 female) consumed 11 mu mol synthetic H-2(10) lycopene in 6 g of corn oil. Tomatoes were steamed and pureed. The doses were given together with a liquid formulated drink with 25% energy from fat. Our results showed that up to 34 days after taking an oral 2 1110 lycopene dose (synthetic or from tomato) with a liquid formula drink, the area under the curve of the average serum percent enrichment response of synthetic lycopene reached 33.9 (+/- 1.7) nmol-day/mu mol lycopene in the dose, whereas that of lycopene from the tomato dose was 11.8 (+/- 0.3) nmol-day/mu mol lycopene in the dose. Our study provides evidence that the absorption of physiological levels of lycopene in intrinsically labeled tomatoes can be studied in humans. From these preliminary investigations, we find that the bioavailability of synthetic lycopene in oil appears to be about three times higher than that of lycopene from steamed and pureed tomatoes. (c) 2005 Elsevier B.V. All rights reserved.

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The effect of nitrogen source on clavulanic acid production was investigated in shake flasks. Media containing asparagine plus one of several different amino acids or a combination of two amino acids was tested. The best result, ca. 180 mg/L clavulanic acid, CA, in 60 h, was obtained with the lysine-tyrosine pair In an aerated and agitated fermentor this medium led to CA concentrations of ca. 210 mg/L, a remarkable production for synthetic medium utilization. Amino acids analysis during cultivation indicated that, while asparagine was consumed rapidly, lysine and tyrosine were metabolized slowly, promoting CA production.

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Monodisperse spheres of silica and latex were obtained by a surfactant free styrene polimerization and the Stober method respectively. Controlling settling either by centrifugation or by dip-coating colloidal crystals could be obtained. Silica inverse opals were prepared by using the latex colloidal crystals as templates and TEOS/ethanol solution. Eu3+ containing silica spheres were obtained dispersing silica spheres in Eu(NO3)(3) isopropanol solutions. Emission spectra suggest the formation of an amorphous Eu3+ containing phase well adhered at the spheres surface. The utilization of solutions of trifluoroacetates salts of Pb2+ and Eu3+ was observed to destroy the silica spherical pattern when samples are treated at 1000degreesC. In that case nanocrystals of PbF2 and amorphous silica were obtained after heat treatment.

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Currently, the major drawback of gene therapy is the gene transfection rate. The two main types of vectors that. are used in gene therapy are based on viral or non-viral gene delivery systems. There are several non-viral systems that can be used to transfer foreign genetic material into the human body. In order to do so, the DNA to be transferred must escape the processes that affect the disposition of macromolecules. These processes include the interaction with blood components, vascular endothelial cells and uptake by the reticuloendothelial system. Furthermore, the degradation of therapeutic DNA by serum nucleases is also a potential obstacle for functional delivery to the target cell. Cationic polymers have a great potential for DNA complexation and may be useful as non-viral vectors for gene therapy applications. The objective of this review was to address the state of the art in gene therapy using synthetic and natural polycations and the latest strategies to improve the efficiency of gene transfer into the cell.

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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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Three types of imagery were evaluated for mapping drainage patterns and vegetation in a 100 000 ha area of Sao Paulo State, Brazil. The drainage measurements were drainage density, frequency of channels and texture ratio, studied on circular samples of 10 km2 for panchromatic photography and 100 km2 for radar and satellite images. The vegetation types were forest, pasture, sugar cane and rice, studied on circular samples of 100 km2. Radar images were the most convenient method to study drainage patterns and the land forms of large areas, while Landsat imagery was most efficient for the study of vegetative cover, although panchromatic photographs were the most accurate method.-from Field Crop Abstracts

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The objective of the present work was the improvement of the methodology for soil mapping through the drainage network with the aid of Landsat data. The drainage network of the area studied was delineated and the soils identified. The main problem of the method has been the characterization of the contact between soil units when it is not abrupt, and in this case field trips and the analysis of the relief has been used to solve doubts.-from English summary

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This model connects directly the radar reflectivity data and hydrological variable runoff. The catchment is discretized in pixels (4 Km × 4 Km) with the same resolution of the CAPPI. Careful discretization is made so that every grid catchment pixel corresponds precisely to CAPPI grid cell. The basin is assumed a linear system and also time invariant. The forecast technique takes advantage of spatial and temporal resolutions obtained by the radar. The method uses only the measurements of the factor reflectivity distribution observed over the catchment area without using the reflectivity - rainfall rate transformation by the conventional Z-R relationships. The reflectivity values in each catchment pixel are translated to a gauging station by using a transfer function. This transfer function represents the travel time of the superficial water flowing through pixels in the drainage direction ending at the gauging station. The parameters used to compute the transfer function are concentration time and the physiographic catchment characteristics. -from Authors