998 resultados para % of >63 µm fraction
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An observation of the Λ0b→ψ(2S)Λ0 decay and a comparison of its branching fraction with that of the Λ0b→J/ψΛ0 decay has been made with the ATLAS detector in proton--proton collisions at s√=8TeV at the LHC using an integrated luminosity of 20.6fb−1. The J/ψ and ψ(2S) mesons are reconstructed in their decays to a muon pair, while the Λ0→pπ− decay is exploited for the Λ0 baryon reconstruction. The Λ0b baryons are reconstructed with transverse momentum pT>10GeV and pseudorapidity |η|<2.1. The measured branching ratio of the Λ0b→ψ(2S)Λ0 and Λ0b→J/ψΛ0 decays is Γ(Λ0b→ψ(2S)Λ0)/Γ(Λ0b→J/ψΛ0)=0.501±0.033(stat)±0.019(syst), lower than the expectation from the covariant quark model.
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Cissampelos sympodialis Eichl species are used in folk medicine for the treatment of asthma, arthritis and rheumatism. In the present study, we investigated the immunomodulatory effect of an aqueous fraction of a 70% (v/v) ethanol extract of C. sympodialis leaves on B lymphocyte function. The hydroalcoholic extract inhibited the in vitro proliferative response of resting B cells induced by LPS (IC50 = 17.2 µg/ml), anti-delta-dextran (IC50 = 13.9 µg/ml) and anti-IgM (IC50 = 24.3 µg/ml) but did not affect the anti-MHC class II antibody-stimulated proliferative response of B cell blasts obtained by stimulation with IL-4 and anti-IgM. Incubation with the hydroalcoholic extract used at 50 µg/ml induced a 700% increase in intracellular cAMP levels. IgM secretion by resting B cells (obtained from normal mice) and polyclonally activated B cells (obtained from Trypanosoma cruzi-infected animals) was inhibited by the hydroalcoholic extract. The latter were more sensitive to the hydroalcoholic extract since 6.5 µg/ml induced a 20% inhibition in the response of cells from normal mice while it inhibited the response of B cells from infected animals by 75%. The present data indicate that the alcoholic extract of C. sympodialis inhibited B cell function through an increase in intracellular cAMP levels. The finding that the hydroalcoholic extract inhibited immunoglobulin secretion suggests a therapeutic use for the extract from C. sympodialis in conditions associated with unregulated B cell function and enhanced immunoglobulin secretion. Finally, the inhibitory effect of the hydroalcoholic extract on B cells may indicate an anti-inflammatory effect of this extract.
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The continuous intravenous administration of isotopic bicarbonate (NaH13CO2) has been used for the determination of the retention of the 13CO2 fraction or the 13CO2 recovered in expired air. This determination is important for the calculation of substrate oxidation. The aim of the present study was to evaluate, in critically ill patients with sepsis under mechanical ventilation, the 13CO2 recovery fraction in expired air after continuous intravenous infusion of NaH13CO2 (3.8 µmol/kg diluted in 0.9% saline in ddH2O). A prospective study was conducted on 10 patients with septic shock between the second and fifth day of sepsis evolution (APACHE II, 25.9 ± 7.4). Initially, baseline CO2 was collected and indirect calorimetry was also performed. A primer of 5 mL NaH13CO2 was administered followed by continuous infusion of 5 mL/h for 6 h. Six CO2 production (VCO2) measurements (30 min each) were made with a portable metabolic cart connected to a respirator and hourly samples of expired air were obtained using a 750-mL gas collecting bag attached to the outlet of the respirator. 13CO2 enrichment in expired air was determined with a mass spectrometer. The patients presented a mean value of VCO2 of 182 ± 52 mL/min during the steady-state phase. The mean recovery fraction was 0.68 ± 0.06%, which is less than that reported in the literature (0.82 ± 0.03%). This suggests that the 13CO2 recovery fraction in septic patients following enteral feeding is incomplete, indicating retention of 13CO2 in the organism. The severity of septic shock in terms of the prognostic index APACHE II and the sepsis score was not associated with the 13CO2 recovery fraction in expired air.
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Chicl( brain growth factor (CBGF) is a mitogen isolated from embryonic chick brains thought to have a potential role as a trophic factor involved in nerve dependent amphibian limb regeneration. In addition, CBGF stimulates 3H-thymidine incorporation in chick embryo brain astrocytes in vitro. In this study, cultured chick embryo brain non-neuronal cells were employed in a bioassay to monitor CBGF activity throughout various stages of its pllrification. Cell culture and assay conditions were optimized. Nonneuronal cells grew best on collagen-coated culture dishes in complete medium, were most responsive to a growth stimulus [10% fetal bovine serum (FBS)] at the second and third subcultures, and were healthiest when rendered "quiescent" in medium supplemented with 1% FBS. The most effective bioassay conditions consisted of a minimum 14.5 hour "quiescence" time (24 hours was used), a 6 hour "prestimulation" time, and a 24 hour 3H-thymidine labeling time. Four-day subconfluent primary non-neuronal cells consisted of 6.63% GFAP positive cells; as a result cultures were thought to be mainly composed of astroblasts. CBGF was purified from 18-day chick embryo brains by ultrafiltration through Amicon PM-30 and YM-2 membranes, size exclusion chromatography through a Biogel P6 column, and analytical reverse-phase high-performance liquid chromatography (rp-HPLC). The greatest activity resided in rp-HPLC fraction #7 (10 ng/ml) which was as effective as 10% FBS at stimulating 3H-thymidine incorporation in chick embryo brain nonneuronal cells. Although other researchers report the isolation of a mitogenic fraction consisting of 5'-GMP from the embryonic chick brain, UV absorbance spectra, rp-HPLC elution profiles, and fast atom bombardment (FAB) mass spectra indicated that CBGF is neither 5'-GMP nor 51-AMP. 2 Moreover, commercially available 5t-GMP was inhibitory to 3H-thymidine incorporation in the chick non-neuronal cells, while Sf-AMP had no effect. Upon treatment with pronase, the biological activity of fraction P6-3 increased; this increase was nearly 30% greater than what would be expected from a simple additive effect of any mitogenic activity of pronase alone together with P6-3 alone. This may suggest the presence of an inhibitor protein. The bioactive component may be a protein protected by a nucleoside/nucleotide or simply a nucleoside/nucleotide acting alone. While the FAB mass spectrum of rp-HPLC fraction #7 did not reveal molecular weight or sequence information, the ion of highest molecular weight was observed at m/z 1610; this is consistent with previous estimations of CBGF's size. 3
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The state of river water deterioration in the Agueda hydrographic basin, mostly in the western part, partly reflects the high rate of housing and industrial development in this area in recent years. The streams have acted as a sink for organic and inorganic loads from several origins: domestic and industrial sewage and agricultural waste. The contents of the heavy metals Cr, Cd, Ni, Cu, Pb, and Zn were studied by sequential chemical extraction of the principal geochemical phases of streambed sediments, in the <63 mum fraction, in order to assess their potential availability to the environment, investigating, the metal concentrations, assemblages, and trends. The granulometric and mineralogical characteristics of this sediment fraction were also studied. This study revealed clear pollution by Cr, Cd, Ni, Cu, Zn, and Pb, as a result from both natural and anthropogenic origins. The chemical transport of metals appears to be essentially by the following geochemical phases, in decreasing order of significance: (exchangeable + carbonates) much greater than (organics) much greater than (Mn and Fe oxides and hydroxides). The (exchangeable + carbonate) phase plays an important part in the fixation of Cu, Ni, Zn, and Cd. The organic phase is important in the fixation of Cr, Pb, and also Cu and Ni. Analyzing the metal contents in the residual fraction, we conclude that Zn and Cd are the most mobile, and Cr and Pb are less mobile than Cu and Ni. The proximity of the pollutant sources and the timing of the influx of contaminated material control the distribution of the contaminant-related sediments locally and on the network scale.
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[1] Cloud cover is conventionally estimated from satellite images as the observed fraction of cloudy pixels. Active instruments such as radar and Lidar observe in narrow transects that sample only a small percentage of the area over which the cloud fraction is estimated. As a consequence, the fraction estimate has an associated sampling uncertainty, which usually remains unspecified. This paper extends a Bayesian method of cloud fraction estimation, which also provides an analytical estimate of the sampling error. This method is applied to test the sensitivity of this error to sampling characteristics, such as the number of observed transects and the variability of the underlying cloud field. The dependence of the uncertainty on these characteristics is investigated using synthetic data simulated to have properties closely resembling observations of the spaceborne Lidar NASA-LITE mission. Results suggest that the variance of the cloud fraction is greatest for medium cloud cover and least when conditions are mostly cloudy or clear. However, there is a bias in the estimation, which is greatest around 25% and 75% cloud cover. The sampling uncertainty is also affected by the mean lengths of clouds and of clear intervals; shorter lengths decrease uncertainty, primarily because there are more cloud observations in a transect of a given length. Uncertainty also falls with increasing number of transects. Therefore a sampling strategy aimed at minimizing the uncertainty in transect derived cloud fraction will have to take into account both the cloud and clear sky length distributions as well as the cloud fraction of the observed field. These conclusions have implications for the design of future satellite missions. This paper describes the first integrated methodology for the analytical assessment of sampling uncertainty in cloud fraction observations from forthcoming spaceborne radar and Lidar missions such as NASA's Calipso and CloudSat.
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Byrsonima crassa is a plant pertaining to the Brazilian central savannah-like belt of vegetation and popularly used for the treatment of gastric dysfunctions and diarrhoea. The methanol extract contains catechin, tannins, terpenes and flavonoids; both mutagenic potential and antioxidant properties have been ascribed to flavonoids. The mutagenicity of some flavonoids is believed to be associated with the formation of reactive oxygen species and seems to depend on the number and position of hydroxyl groups. In the present study the mutagenic activity of the methanol, chloroform and 80% aqueous methanol extracts, as well as acetate and aqueous sub-fractions, of this medicinal plant were evaluated by Salmonella typhimurium assay, using strains 100, TA98, TA102 and TA97a, and in mouse reticulocytes. The results showed mutagenic activity of the methanolic extract in the TA98 strain without S9, but no mutagenicity to mouse cells in any of the extracts. The acetate fraction showed strong signs of mutagenicity without S9, suggesting that in this enriched fraction were concentrated the compounds that induced mutagenic activity. The aqueous fraction showed no mutagenic activity. The TLC and HSCCC analyses of the acetate fraction with some standard compounds permitted the isolation of the quercetin-3-O-beta-D-galactopyranoside, quercetin-3-O-alpha-L-arabinopyranoside, amentoflavone, methyl gallate and (+)-catechin, of which only the amentoflavone exhibited positive mutagenicity to TA98 (+S9, -S9). (c) 2006 Elsevier B.V.. All rights reserved.
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Biotechnological conversion of biomass into fuels and chemicals requires hydrolysis of the polysaccharide fraction into monomeric sugars. Hydrolysis can be performed enzymatically and with dilute or concentrate mineral acids. The present study used dilute sulfuric acid as a catalyst for hydrolysis of Eucalyptus grandis residue. The purpose of this paper was to optimize the hydrolysis process in a 1.41 pilot-scale reactor and investigate the effects of the acid concentration, temperature and residue/acid solution ratio on the hemicellulose removal and consequently on the production of sugars (xylose, glucose and arabinose) as well as on the formation of by-products (furfural, 5-hydroxymethylfurfural and acetic acid). This study was based on a model composition corresponding to a 2 3 orthogonal factorial design and employed the response surface methodology (RSM) to optimize the hydrolysis conditions, aiming to attain maximum xylose extraction from hemicellulose of residue. The considered optimum conditions were: H2SO4 concentration of 0.65%, temperature of 157 degrees C and residue/acid solution ratio of 1/8.6 with a reaction time of 20 min. Under these conditions, 79.6% of the total xylose was removed and the hydrolysate contained 1.65 g/l glucose, 13.65 g/l xylose, 1.55 g/l arabinose, 3.10 g/l acetic acid, 1.23 g/l furfural and 0.20 g/l 5-hydroxymethylfurfural. (c) 2006 Published by Elsevier Ltd.
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To investigate the ability of hexanic ethanolic fraction of Rubus brasiliensis Martius (Roseceae), to induce anxiolytic effect and also the possible involvement of the GABA(A)-benzodiazepine receptor complex, male Wistar rats and Swiss mice behaviour were tested in the elevated plus maze (EPM). All the doses of the extract, 50, 100 and 150 mg/kg, administered per gavage (vo), 30 min before the behavioural evaluation, induced an anxiolytic effect expressed by: increased number of entries in and time spent in the open arms and percentage of open arm entries: and decreased number of entries and time spent in the closed arms. The treatment of mice with flumazenil (Ro 15-1788), 0.5, 1.0 and 1.5 mg/kg, i.p., 15-min before the administration of hexanic fraction, 100 mg/kg, vo, blocked the hexanic fraction-induced anxiolytic effect. The LD50 for the hexanic fraction was 1512 mg/kg. In conclusion, it was shown that the hexanic fraction of R. brasiliensis induced an anxiolytic effect in rats and mice. This effect can be attributed to a liposoluble principle with low toxicity which may be acting as an agonist on GABA(A)-benzodiazepine receptor complex. (C) 1998 Elsevier B.V. Ireland Ltd. All rights reserved.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Depending on the composition, the mixture of surfactant, oil and water, may form supramolecular aggregates with different structures which can significantly influence the drug release. In this work several microemulsion (ME) systems containing soya phosphatidylcholine (SPC) and eumulgin HRE40 (TM) (EU) as surfactant, cholesterol (O) as oil phase, and ultra-pure water as an aqueous phase were studied. MEs with and without the antitumoral drug doxorubicin (DOX) were prepared. The microstructures of the systems were characterized by photon correlation spectroscopy, rheological behavior, polarized light microscopy, small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD). The results reveal that the diameter of the oil droplets was dependent on the surfactant (S) amount added to formulations. The apparent viscosity was dependent on the O/S ratio. High O/S ratio leads to the crystallization of cholesterol polymorphs phases which restricts the mobility of the DOX molecules into the ME structure. Droplets with short-range spatial correlation were formed from the ME with the low O/S ratio. The increase of the cholesterol fraction in the O/S mixture leads to the formation of ordered structures with lamellar arrangements. These different structural organizations directly influenced the drug release profiles. The in vitro release assay showed that the increase of the O/S ratio in the formulations inhibited the constant rate of DOX release. Since the DOX release ratio was directly dependent on the ratio of O/S following an exponential decay profile, this feature can be used to control the DOX release from the ME formulations. (C) 2008 Elsevier B.V. All rights reserved.
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OBJECTIVE: This study was undertaken to assess whether fine needle aspirates from non-Hodgkins lymphoma (NHL) could be used for growth fraction analysis with proliferating cell nuclear antigen (PCNA) staining and if there was a relationship between the growth fraction and cytomorphologic classification according to the Kiel classification.STUDY DESIGN: the study group consisted of 40 patients with NHL diagnosed by fine needle aspiration (FNA) cytology. The cytologic classification of the lymphomas was made by two cytopathologists on May-Grunwald-Giemsa-stained slides using the Kiel classification. There were 27 cases of low and 13 of high grade lymphoma. The estimation of the growth fraction was made by PCNA immunoreactivity. The PCNA index was quantitated in smears by counting an average of 1,000 cells, and the count teas correlated with the cytomorphologic classification.RESULTS: There was It strong correlation between the PCNA index and lymphoma grading. High grade lymphomas exhibited a mean PCNA positivity of 74.0%, which was significantly higher (P <.001) than that of low grade lymphomas (17.6%).CONCLUSION: Our study showed that PCNA evalua tion is suitable for smears obtained by FNA on NHL, correlates with increasing grades of lymphoma according to the Kiel classification and may offer a method of monitoring treatment of lymphoma.
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Sensitive immunologic techniques for the detection of alterations that occur in protein antigens were used to evaluate the immunogenicity of soybean glycinin after isolation, heat denaturation and pH alteration. The objective was to determine the effect of these agents on the immunogenic ability of this protein fraction. Immunologic assays performed on heat-denatured glycinin up to 80 degrees C in the presence of antinative glycinin serum demonstrated that glycinin retains its immunogenic properties. Above 90 degrees C this biological property begins to disappear, with protein insolubilization and epitope modification due to the conformational changes imposed by temperature. A reduction in immunogenicity also occurred when glycinin was taken to pH 2.0 (below its pi) and pH 11.00 (above its pi) and exposed to high temperatures in the presence of native antiglycinin serum. From these data one can conclude that, at extreme pH values, intramolecular reactions may occur which, in combination with the structural disorganization caused by high temperatures, may contribute to the reduction of immunogenicity.
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BACKGROUND: Trauma care is expensive. However, reliable data on the exact lifelong costs incurred by a major trauma patient are lacking. Discussion usually focuses on direct medical costs--underestimating consequential costs resulting from absence from work and permanent disability. METHODS: Direct medical costs and consequential costs of 63 major trauma survivors (ISS >13) at a Swiss trauma center from 1995 to 1996 were assessed 5 years posttrauma. The following cost evaluation methods were used: correction cost method (direct cost of restoring an original state), human capital method (indirect cost of lost productivity), contingent valuation method (human cost as the lost quality of life), and macroeconomic estimates. RESULTS: Mean ISS (Injury Severity Score) was 26.8 +/- 9.5 (mean +/- SD). In all, 22 patients (35%) were disabled, causing discounted average lifelong total costs of USD 1,293,800, compared with 41 patients (65%) who recovered without any disabilities with incurred costs of USD 147,200 (average of both groups USD 547,800). Two thirds of these costs were attributable to a loss of production whereas only one third was a result of the cost of correction. Primary hospital treatment (USD 27,800 +/- 37,800) was only a minor fraction of the total cost--less than the estimated cost of police and the judiciary. Loss of quality of life led to considerable intangible human costs similar to real costs. CONCLUSIONS: Trauma costs are commonly underestimated. Direct medical costs make up only a small part of the total costs. Consequential costs, such as lost productivity, are well in excess of the usual medical costs. Mere cost averages give a false estimate of the costs incurred by patients with/without disabilities.