982 resultados para vanadyl sulfate
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Respiratory syncytial virus is the major cause of acute lower respiratory tract illness in infants and young children. Because there is currently no licensed vaccine for RSV, there is a substantial interest in the identification and development of RSV specific inhibitory agents. There are clinical evidences that glycosaminoglycans (GAGs) are potential inhibitors of viral infection. In this study, the performance of two GAGs (heparin and dextran sulfate) were compared for their antiviral and virucidal activities on RSV. Analysis was performed using an in vitro infection model where, previously to infection, Hep-2 cells or RSV were incubated with heparin or dextran sulfate. The presence of viral particles was analyzed by Reverse Transcriptase-Polimerase Chain Reaction (RT-PCR) and indirect immunofluorescence assays (IFA). The results showed that viral infection was more efficiently inhibited when Hep-2 cells were pre-incubated with heparin or, when viral particles were pre-incubated with dextran sulfate. Our study suggest that, in the absence of cellular death, heparin and dextran sulfate reduce RSV infection by different mechanisms, antiviral and virucidal ones, respectively. These data contribute for recent medical, microbiology and biochemical studies which suggest that the use of antiviral and virucidal compounds as more effective treatment to control virus infections.
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In this work, an electrode chemically modified with polypyrrole (PCME) was employed for determination of sulfate in ethanol fuel using a FIA system. The PCME was prepared by polymerization of pyrrole at a glassy carbon electrode by means of cyclic voltammetry technique. An analytical curve from 1.0 x 10−5 to 8.0 x 10−5 mol L−1 was obtained in flow injection system based on the PCME. An amperometric sensibility of 2.3 x 10−3 A mol−1 L and a detection limit of 2.5 x 10−6 mol L−1 were achieved. The proposed method was employed for determination of sulfate ions in commercial samples of ethanol fuel. The results were in good agreement with those obtained by the ionic chromatographic method.
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Fertilizer use in no-till systems must be aligned with a correct interpretation of soil chemical attributes and crop demands. The objectives of this work were evaluate the effects of pre-sowing application of ammonium sulfate (AS) and of cover crops on the yields and soil chemical attributes of no-till cotton (Gossypium hirsutum L. r. latifolium Hutch) over two harvesting years. The experiment was arranged in randomized complete block design, with the plots in strips, and the variables were three cover crops (Raphanus sativus L., Avena strigosa L. and Avena sativa L.) and four AS doses (0, 150, 300, and 450 kg ha-1) applied over millet dry biomass. The cotton in the experimental plots was manually harvested on April 25, 2007 and April 24, 2008. The soil samples were collected between cotton rows in all plots on May 5, 2007 and May 12, 2008, at depths of 0.0-0.05, 0.05-0.10, and 0.10-0.20 m for soil fertility analyses. The increasing doses of AS induced lower soil pH, and calcium (Ca) and magnesium (Mg) levels in the superficial soil layer, as well as higher exchangeable aluminum (Al) and sulfur (S) levels until a depth of 0.20 m. Seed cotton yields increased with increasing AS doses.
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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 acid weathering of pyrite-bearing Pennsylvanian clastic sedimentary rocks in southeastern Nebraska locally produces the secondary sulfate minerals alunogen, copiapite, epsomite, felsobanyaite/basaluminite, gypsum, halotrichite, jarosite, rozenite, and slavikite. Of these mineral occurrences, four are first-time discoveries in the state or the surrounding region. Slavikite (NaMg2Fe5 (S04)7 (OH) 6• 33H20), which has been reported only once before in North America and from a handful of sites in Europe and South America, was found in abundance at an outcrop at Brownville, NE. The pH values in 1:1 solutions of deionized water of the studied minerals, excluding epsomite, range from 1.94 to 4.82. Therefore, segregations of secondary minerals in themselves are significant microenvironmental reservoirs of acid that can be mobilized during precipitation events. Because of its role in liberating and concentrating ions such as Al3+, Fe2+, Fe3+, Mg3+, and SO42-, acid rock weathering should be considered in local to regional assessments of surface-water and groundwater chemistry. Observations also suggest that rock weathering by the growth of sulfate salts is a potential factor in local hillslope development, one that has not previously been considered in the study area.
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New and improved strategies are needed for managing overabundant blackbird (Icteridae spp.) populations in some areas of the United States. From 2004 to 2007, we evaluated sodium lauryl sulfate (SLS) as a wetting agent during controlled outdoor cage and flight pen tests in Colorado and small-scale field tests at urban blackbird roosts in Missouri. In the outdoor cage tests (ambient temperature -5 to 2° C), mortality of male red-winged blackbirds (Agelaius phoeniceus) sprayed with 1, 2, and 5 ml of SLS on the back feathers only, on the breast feathers only, or on both breast and back feathers ranged from 25% to 100%. A SLS spray on male red-winged blackbirds at 2° C ambient temperature with 1 ml of SLS sprayed on breast feathers and back feathers resulted in 90% mortality in less than 60 minutes. In a flight pen test (-12 to -5° C ambient temperature ), SLS sprayed at 20 l per 3,400 l of water with a single ground-based sprinkler-head system over 35 male red-winged blackbirds roosting in cedar trees (Juniperus virginiana) resulted in 53% mortality. There was no mortality in the control group exposed to the same treatment without the SLS. Small-scale field tests conducted in Missouri at 6 sites with a single ground-based sprinkler-head spray system and at 2 sites with 4 sprinkler-head spray systems resulted in mortality that ranged from 0 to 4,750 and 4,500 to 15,000 blackbirds and starlings, respectively. Spray operations lasted from 28 to 208 minutes. Each spray covered about 200 m2 . At all sites, mortality of blackbirds sprayed with the SLS occurred as soon as 30 minutes post-SLS application. Mortality at two sites where pump problems precluded completing the spray ranged from 0 to 800 birds. Air leaving the system as the system was activated caused birds to flush from the roost trees. Poor water quality and pump durability were problems at some sites.
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Deep-sea whale falls create sulfidic habits Supporting chemoautotrophic communities, but microbial processes underlying the formation Of Such habitats remain poorly evaluated. Microbial degradation processes (sulfate reduction, methanogenesis) and biogeochemical gradients were studied in a whale-fall habitat created by a 30 t whale carcass deployed at 1675 m depth for 6 to 7 yr on the California margin. A variety of measurements were conducted including photomosaicking, microsensor measurements, radio-tracer incubations and geochemical analyses. Sediments were Studied at different distances (0 to 9 in) from the whale fall. Highest microbial activities and steepest vertical geochemical gradients were found within 0.5 m of the whale fall, revealing ex situ sulfate reduction and in vitro methanogenesis rates of up to 717 and 99 mmol m(-2) d(-1), respectively. In sediments containing whale biomass, methanogenesis was equivalent to 20 to 30%, of sulfate reduction. During in vitro sediment studies, sulfide and methane were produced within days to weeks after addition of whale biomass, indicating that chemosynthesis is promoted at early stages of the whale fall. Total sulfide production from sediments within 0.5 m of the whale fall was 2.1 +/- 3 and 1.5 +/- 2.1 mol d(-1) in Years 6 and 7, respectively, of which similar to 200 mmol d(-1) were available as free sulfide. Sulfate reduction in bones was much lower, accounting for a total availability of similar to 10 mmol sulfide d(-1). Over periods of at least 7 yr, whale falls can create sulfidic conditions similar to other chemosynthetic habitats Such as cold seeps and hydrothermal vents.
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Our objectives were to characterize the urinary excretion of glycosaminoglycans (GAGs) in horse osteoarthritis, and to investigate the effects of chondroitin sulfate (CS) and glucosamine (GlcN) upon the disease. Urinary GAGs were measured in 47 athletic horses, 20 healthy and 27 with osteoarthritis. The effects of CS and GlcN were investigated in mild osteoarthritis. In comparison to normal, urinary GAGs were increased in osteoarthritis, including mild osteoarthritis affecting only one joint. Treatment with CS + GlcN led to a long lasting increase in the urinary CS and keratan sulfate (KS), and significant improvement in flexion test of tarsocrural and metacarpophalangeal joints was observed. In conclusion, urinary CS and KS seems to reflect the turnover rates of cartilage matrix proteoglycans, and the measurement of these compounds could provide objective means of evaluating and monitoring joint diseases. (C) 2011 Elsevier Ltd. All rights reserved.
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A high molecular weight poly(ethylene oxide)/layered vanadyl phosphate di-hydrate intercalation compound was synthesized via the surfactant-assisted approach. Results confirmed that surfactant molecules were replaced with the polymer, while the lamellar structure of the matrix was retained, and that the material presents high specific surface area. In addition, intercalation produced a more thermally stable polymer as evidenced by thermal analysis. (C) 2011 Elsevier Ltd. All rights reserved.
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Ionic liquids based on 1-alkyl-3-methylimidazolium cations and the hydrogen sulfate (or bisulfate) anion, HSO4-, are much more viscous than ionic liquids with alkyl sulfates, RSO4-. The structural origin of the high viscosity of HSO4- ionic liquids is unraveled from detailed comparison of the anion Raman bands in 1-ethyl-3-methylimidazolium hydrogen sulfate and 1-butyl-3-methylimidazolium hydrogen sulfate with available data for simple HSO(4)(-) salts in crystalline phase, molten phase, and aqueous solution. Two Raman bands at 1046 and 1010 cm(-1) have been assigned as symmetric stretching modes nu(s)(S = O) of HSO4-, the latter being characteristic of chains of hydrogen-bonded anions. The intensity of this component increases in the supercooled liquid phase. For comparison purposes, Raman spectra of 1-ethyl-3-methylimidazolium ethyl sulfate and 1-butyl-3-methylimidazolium methyl sulfate have been also obtained. There is no indication of difference in the strength of hydrogen bond interactions of imidazolium cations with HSO4- or RSO4- anions. Raman spectra at high pressures, up to 2.6 GPa, are also discussed. Raman spectroscopy provides evidence that hydrogen-bonded anions resulting in anion-anion interaction is the reason for the high viscosity of imidazolium ionic liquids with HSO4-. If the ionic liquid is exposed to moisture, these structures are disrupted upon absorption of water from the atmosphere.
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A bench-scale Upflow Anaerobic Sludge Blanket (UASB) reactor was used to study the treatment of acid mine drainage through the biological reduction of sulfate. The reactor was fed with acid mine drainage collected at the Osamu Utsumi uranium mine (Caldas, MG, Brazil) and supplemented with ethanol as an external carbon source. Anaerobic granular sludge originating from a reactor treating poultry slaughterhouse wastewater was used as the inoculum. The reactor's performance was studied according to variations in the chemical oxygen demand (COD)/SO42- ratio, influent dilution and liquid-phase recirculation. The digestion of a dilution of the acid mine drainage resulted in a 46.3% removal of the sulfate and an increase in the effluent pH (COD/SO42- = 0.67). An increase in the COD/SO42- ratio to 1.0 resulted in an 85.6% sulfate reduction. The reduction of sulfate through complete oxidation of the ethanol was the predominant path in the reactor, although the removal of COD was not greater than 68% in any of the operational stages. The replenishment of the liquid phase with tap water positively affected the reactor, whereas the recirculation of treated effluent caused disequilibrium and decreased efficiency. (C) 2012 Elsevier Ltd. All rights reserved.
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DISTRIBUTION OF NITROGEN AMMONIUM SULFATE (N-15) SOIL-PLANT SYSTEM IN A NO-TILLAGE CROP SUCCESSION The N use by maize (Zea mays, L.) is affected by N-fertilizer levels. This study was conducted using a sandy-clay texture soil (Hapludox) to evaluate the efficiency of N use by maize in a crop succession, based on N-15-labeled ammonium sulfate (5.5 atom %) at different rates, and to assess the residual fertilizer effect in two no-tillage succession crops (signalgrass and corn). Two maize crops were evaluated, the first in the growing season 2006, the second in 2007, and brachiaria in the second growing season. The treatments consisted of N rates of 60, 120 and 180 kg ha(-1) in the form of labeled N-15 ammonium sulfate. This fertilizer was applied in previously defined subplots, only to the first maize crop (growing season 2006). The variables total accumulated N; fertilizer-derived N in corn plants and pasture; fertilizer-derived N in the soil; and recovery of fertilizer-N by plants and soil were evaluated. The highest uptake of fertilizer N by corn was observed after application of 120 kg ha(-1) N and the residual effect of N fertilizer on subsequent corn and Brachiaria was highest after application of 180 kg ha(-1) N. After the crop succession, soil N recovery was 32, 23 and 27 % for the respective applications of 60, 120 and 180 kg ha(-1) N.
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This paper describes the adsorption of sodium dodecyl sulfate (SDS) molecules in a low polar solvent on Ge substrate by using Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy and atomic force microscopy (AFM). The maximum SDS amount adsorbed is (5.0 +/- 0.3) x 10(14) molecules cm(-2) in CHCl3, while with the use of CCl4 as subphase the ability of SDS adsorbed is 48% lower. AFM images show that depositions are highly disordered over the interface, and it was possible to establish that the size of the SDS deposition is around 30-40 nm over the Ge surface. A complete description of the infrared spectroscopic bands for the head and tail groups in the SDS molecule is also provided.