19 resultados para Potassium acetate

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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Background: Polycystic ovary syndrome (PCOS) is an endocrine disorder associated with metabolic dysfunction and changes in cardiovascular risk markers, and using oral contraceptives (OCs) may exert a further negative effect on these alterations in patients with PCOS. Thus, the primary objective of this study was to assess the effects on arterial function and structure of an OC containing chlormadinone acetate (2 mg) and ethinylestradiol (30 mcg), alone or combined with spironolactone (OC+SPL), in patients with PCOS. Study Design: This was a randomized, controlled clinical trial. Fifty women with PCOS between 18 and 35 years of age were randomized by a computer program to use OC or OC+SPL. Brachial artery flow-mediated vasodilation, carotid intima-media thickness and the carotid artery stiffness index were evaluated at baseline and after 6 and 12 months. Serum markers for cardiovascular disease were also analyzed. The intragroup data were analyzed using analysis of variance with Tukey's post hoc test. A multivariate linear regression model was used to analyze the intergroup data. Results: At 12 months, the increase in mean total cholesterol levels was greater in the OC+SPL group than in the OC group (27% vs. 13%, respectively; p=.02). The increase in mean sex hormone-binding globulin levels was greater in the OC group than in the OC+SPL group (424% vs. 364%, respectively; p=.01). No statistically significant differences between the groups were found for any of the other variables. Conclusion: The addition of spironolactone to an OC containing chlormadinone acetate and ethinylestradiol conferred no cardiovascular risk-marker advantages in young women with PCOS. (C) 2012 Elsevier Inc. All rights reserved.

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Biochemical markers of cardiovascular disease, including matrix metalloproteinases (MMPs), are altered in women with polycystic ovary syndrome (PCOS), with many of these alterations thought to be due to excess androgen concentrations. Despite oral contraceptives (OCs) being the first-line pharmacological treatment in women with PCOS and the importance of MMPs in many physiological conditions and pathological states, including cardiovascular diseases, no study has yet evaluated whether OCs alter plasma concentrations of MMPs. We therefore assessed whether treatment with an OC containing the anti-androgenic progestogen alters MMP profiles in women with PCOS. We analysed 20 women with PCOS who wanted hormonal contraception (OC-PCOS group), 20 ovulatory women who required hormonal contraception (OC-control group) and 20 ovulatory women who wanted non-hormonal contraception (non-OC-control group). OC consisted of cyclic use of 2 mg chlormadinone acetate/30 mu g ethinylestradiol for 6 months. Plasma concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 were measured by gelatin zymography or enzyme-linked immunoassays. OC treatment for 6 months significantly reduced plasma MMP-2 concentrations in the OC-control and OC-PCOS groups and TIMP-2 and TIMP-1 concentrations levels in the OC-control group (all p < 0.05), but had no effects on MMP-9 concentrations or on MMP-2/TIMP-2 and MMP-9/TIMP-1 ratios in any group (all p > 0.05). These findings indicated that long-term treatment with an OC containing chlormadinone acetate plus ethinylestradiol reduced plasma MMP-2 concentrations in both healthy and PCOS women. As the latter have imbalances in circulating matrix MMPs, treatment of these women with an OC may be beneficial.

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In this study, particulate matter (PM) were characterized from a place impacted by heavy-duty vehicles (Bus Station) fuelled with diesel/biodiesel fuel blend (B3) in the city of Londrina, Brazil. Sixteen priority polycyclic aromatic hydrocarbons (PAH) concentrations were analyzed in the samples by their association with atmospheric PM, mass size distributions and major ions (fluorite, chloride, bromide, nitrate, phosphate, sulfate, nitrite, oxalate; fumarate, formate, succinate and acetate; lithium, sodium, potassium, magnesium, calcium and ammonium). Results indicate that major ions represented 21.2% particulate matter mass. Nitrate, sulfate, and ammonium, respectively, presented the highest concentration levels, indicating that biodiesel may also be a significant source for these ions, especially nitrate. Dibenzo[a,h]anthracene and indeno[1,2,3,-cd]pyrene were the main PAH found, and a higher fraction of PAH particles was found in diameters lower than 0.25 mu m in Londrina bus station. The fine and ultrafine particles were dominant among the PM evaluated, suggesting that biodiesel decreases the total PAH emission. However, it does also increase the fraction of fine and ultrafine particles when compared to diesel.

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The effects of silicon (Si) supplied in the form of potassium silicate (PS) were evaluated on epidemic components of powdery mildew of melon under greenhouse conditions. The PS was applied to the roots or to leaves. In the first experiment, epidemic components were evaluated after inoculation with Podosphaera xanthii. In the second experiment, the disease progress rate was evaluated on plants subjected to natural infection. The area under the disease progress curve was reduced by 65% and 73% in the foliar and root treatments, respectively, compared to control plants, as a consequence of reductions in infection efficiency, colony expansion rate, colony area, conidial production and disease progress rate. However, root application of PS was more effective than foliar application in reducing most of the epidemic components, except for infection efficiency. This can be explained by the high Si concentration in leaf tissues with root application, in contrast to the foliar treatment where Si was only deposited on the external leaf surfaces. The effects of PS reported in this study demonstrated that powdery mildew of melon can be controlled, and that the best results can be achieved when PS is supplied to the roots.

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Potassium fluorrichterite (KNaCaMg5Si8O22F2) glass-ceramics were modified by either increasing the concentration of calcium (GC5) or by the addition of P2O5 (GP2). Rods (2 x 4 mm) of stoichiometric fluorrichterite (GST), modified compositions (GC5 and GP2) and 45S5 bioglass, which was used as the reference material, were prepared using a conventional lost-wax technique. Osteoconductivity was investigated by implantation into healing defects in the midshaft of rabbit femora. Specimens were harvested at 4 and 12 weeks following implantation and tissue response was investigated using computed microtomography (mu CT) and histological analyses. The results showed greatest bone to implant contact in the 45S5 bioglass reference material at 4 and 12 weeks following implantation, however, GST, GC5 and GP2 all showed direct bone tissue contact with evidence of new bone formation and cell proliferation along the implant surface into the medullary space. There was no evidence of bone necrosis or fibrous tissue encapsulation around the test specimens. Of the modified potassium fluorrichterite compositions, GP2 showed the greatest promise as a bone substitute material due to its osteoconductive potential and superior mechanical properties.

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The Ipanema alkaline-carbonatitic complex is part of the Meso-Cenozoic alkaline magmatism located within the southeastern part of the Brazilian Platform. Drill-core and field sampling have indicated the occurrence of glimmerites, with subordinate shonkinites (mela-syenites), clinopyroxene-bearing glimmerites, diorites and syenites. The glimmerites are cross-cut by lamprophyric dykes and calciocarbonatites. Fenitization has deeply affected the country rocks, originating dioritic and syenitic rocks. The Ipanema rocks show a distinct potassic affinity. The initial Sr-Nd- isotopic composition of the Ipanema rocks ((87)Sr/(86)Sr = 0.70661-0.70754 and (143)Nd/(144)Nd = 0.51169-0.51181) is similar to that of tholeiitic and potassium-rich-alkaline rocks of the Eastern Paraguay. Stable isotope data for the Ipanema calciocarbonatite suggest interaction with fluids at temperatures typical of hydrothermal stages, as hypothesized for other carbonatite complexes from southeastern Brazil. The chemical differences between the lamprophyre, glimmerites, carbonatites, apatitites and magnetitites, and the absence of marked REE enrichment in the evolved lithologies, all indicate that fractional crystallization and accumulus of liquidus phases in a magma reservoir, likely coupled with liquid immiscibility processes, may have played an important role in the genesis of the Ipanema rocks.

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Leao RM, Li S, Doiron B, Tzounopoulos T. Diverse levels of an inwardly rectifying potassium conductance generate heterogeneous neuronal behavior in a population of dorsal cochlear nucleus pyramidal neurons. J Neurophysiol 107: 3008-3019, 2012. First published February 29, 2012; doi:10.1152/jn.00660.2011.-Homeostatic mechanisms maintain homogeneous neuronal behavior among neurons that exhibit substantial variability in the expression levels of their ionic conductances. In contrast, the mechanisms, which generate heterogeneous neuronal behavior across a neuronal population, remain poorly understood. We addressed this problem in the dorsal cochlear nucleus, where principal neurons exist in two qualitatively distinct states: spontaneously active or not spontaneously active. Our studies reveal that distinct activity states are generated by the differential levels of a Ba2+-sensitive, inwardly rectifying potassium conductance (K-ir). Variability in K-ir maximal conductance causes variations in the resting membrane potential (RMP). Low K-ir conductance depolarizes RMP to voltages above the threshold for activating subthreshold-persistent sodium channels (Na-p). Once Na-p channels are activated, the RMP becomes unstable, and spontaneous firing is triggered. Our results provide a biophysical mechanism for generating neural heterogeneity, which may play a role in the encoding of sensory information.

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Kaurenoic acid [ent-kaur-16-en-19-oic acid (1)] is a diterpene present in several plants including Sphagneticola trilobata. The only documented evidence for its antinociceptive effect is that it inhibits the writhing response induced by acetic acid in mice. Therefore, the analgesic effect of 1 in different models of pain and its mechanisms in mice were investigated further. Intraperitoneal and oral treatment with 1 dose-dependently inhibited inflammatory nociception induced by acetic acid. Oral treatment with 1 also inhibited overt nociception-like behavior induced by phenyl-p-benzoquinone, complete Freund's adjuvant (CFA), and both phases of the formalin test. Compound 1 also inhibited acute carrageenin- and PGE(2)-induced and chronic CFA-induced inflammatory mechanical hyperalgesia. Mechanistically, 1 inhibited the production of the hyperalgesic cytokines TNF-alpha and IL-1 beta. Furthermore, the analgesic effect of 1 was inhibited by L-NAME, ODQ, KT5823, and glybenclamide treatment, demonstrating that such activity also depends on activation of the NO-cyclic GMP-protein kinase G-ATP-sensitive potassium channel signaling pathway, respectively. These results demonstrate that 1 exhibits an analgesic effect in a consistent manner and that its mechanisms involve the inhibition of cytokine production and activation of the NO-cyclic GMP-protein lcinase G-ATP-sensitive potassium channel signaling pathway.

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The fine particles serving as cloud condensation nuclei in pristine Amazonian rainforest air consist mostly of secondary organic aerosol. Their origin is enigmatic, however, because new particle formation in the atmosphere is not observed. Here, we show that the growth of organic aerosol particles can be initiated by potassium-salt-rich particles emitted by biota in the rainforest. These particles act as seeds for the condensation of low- or semi-volatile organic compounds from the atmospheric gas phase or multiphase oxidation of isoprene and terpenes. Our findings suggest that the primary emission of biogenic salt particles directly influences the number concentration of cloud condensation nuclei and affects the microphysics of cloud formation and precipitation over the rainforest.

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The interference of some specific aqueous two-phase system (ATPS) phase-forming components in bovine serum albumin (BSA) determination by the Bradford method was investigated. For this purpose, calibration curves were obtained for BSA in the presence of different concentrations of salts and polymers. A total of 19 salts [Na2SO4, (NH4)(2)SO4, MgSO4, LiSO4, Na2HPO4, sodium phosphate buffer (pH 7.0), NaH2PO4, K2HPO4, potassium phosphate buffer (pH 7.0), KH2PO4, C6H8O7, Na3C6HSO7, KCHO2, NaCHO2, NaCO3, NaHCO3, C2H4O2, sodium acetate buffer (pH 4.5), and NaC2H3O2] and 7 polymers [PEG 4000, PEG 8000, PEG 20000, UCON 3900, Ficoll 70000, PES 100000, and PVP 40000] were tested, and each calibration curve was compared with the one obtained for BSA in water. Some concentrations of salts and polymers had considerable effect in the BSA calibration curve. Carbonate salts were responsible for the highest salt interference, whereas citric and acetic acids did not produce interference even in the maximum concentration level tested (5 wt%). Among the polymers, UCON gave the highest interference, whereas Ficoll did not produce interference when used in concentrations up to 10 wt%. It was concluded that a convenient dilution of the samples prior to the protein quantification is needed to ensure no significant interference from ATPS phase-forming constituents. (C) 2011 Elsevier Inc. All rights reserved.

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Three chemical species related to biomass burning, levoglucosan, potassium and water-soluble organic carbon (WSOC), were measured in aerosol samples collected in a rural area on the outskirts of the municipality of Ourinhos (Sao Paulo State, Brazil). This region is representative of the rural interior of the State, where the economy is based on agro-industrial production, and the most important crop is sugar cane. The manual harvesting process requires that the cane be first burned to remove excess foliage, leading to large emissions of particulate materials to the atmosphere. Most of the levoglucosan (68-89%) was present in small particles (<1.5 mu m), and its concentration in total aerosol ranged from 25 to 1186 ng m(-3). The highest values were found at night, when most of the biomass burning occurs. In contrast, WSOC showed no diurnal pattern, with an average concentration of 5.38 +/- 2.97 mu g m(-3) (n = 27). A significant linear correlation between levoglucosan and WSOC (r = 0.54; n = 26; p < 0.0001) confirmed that biomass burning was in fact an important source of WSOC in the study region. A moderate (but significant) linear correlation between levoglucosan and potassium concentrations (r = 0.62; n = 40; p < 0.0001) was indicative of the influence of other sources of potassium in the study region, such as soil resuspension and fertilizers. When only the fine particles (<1.5 pm; typical of biomass burning) were considered, the linear coefficient increased to 0.91 (n = 9). In this case, the average levoglucosan/K+ ratio was 0.24, which may be typical of biomass burning in the study region. This ratio is about 5 times lower than that previously found for Amazon aerosol collected during the day, when flaming combustion prevails. This suggests that the levoglucosan/K+ ratio may be especially helpful for characterization of the type of vegetation burned (such as crops or forest), when biomass-burning is the dominant source of potassium. The relatively high concentrations of WSOC (and inorganic ions) suggest an important influence on the formation of cloud condensation nuclei, which is likely to affect cloud formation and precipitation patterns. (C) 2012 Elsevier Ltd. All rights reserved.

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The lyotropic liquid crystalline quaternary mixture made of potassium laurate (KL), potassium sulphate, 1-undecanol and water was investigated by experimental optical methods (optical microscopy and laser conoscopy). In a particular temperature and relative concentrations range, the three nematic phases (two uniaxial and one biaxial) were identified. The biaxial domain in the temperature/KL concentration surface is larger when compared to other lyotropic mixtures. Moreover, this new mixture gives nematic phases with higher birefringence than similar systems. The behavior of the symmetric tensor order parameter invariants sigma(3) and sigma(2) calculated from the measured optical birefringences supports that the uniaxial-to-biaxial transitions are of second order, described by a mean-field theory.

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The nutritional management of seedlings in the nursery is one of the most important practices that influence seedling quality. The aim of this work was to evaluate the effect of nitrogen, phosphorus and potassium on the development of Schizolobium amazonicum seedlings grown in 250 cm(3) containers with a commercial substrate in the North of Mato Grosso State, Brazil. The experimental design was completely randomized design with five treatments and five replications, each replication being represented by 24 seedlings. The treatments were: control (only commercial substrate); nitrogen fertilization (150 g m(-3) N using ammonium sulfate + 1.0 kg of ammonium sulfate dissolved in 100 L of water and applied in coverage); phosphorus fertilization (300 g P2O5 m(-3) using simple superphosphate); potassium fertilization (100 g m(-3) K2O using potassium chloride + 0.3 kg of potassium chloride dissolved in 100 L of water and applied in coverage) and; complete (a mixture of the three nutrients, 150, 300 and 100 g m(-3) N, P2O5 and K2O, respectively + 1.0 kg of ammonium sulfate + 0.3 kg of potassium chloride). The commercial substrate was composted milled pine bark plus vermiculite. Evaluations of the seedlings were performed at 90 days after sowing. The complete treatment (NPK) gave the highest values for biometric and best plant indices, which express the quality. When analyzing nutrients in isolation; potassium had the lowest effect. Based on these results it can be recommended to fertilize Schizolobium amazonicum seedlings in nurseries with 150, 300 and 100 g m(-3) of N, P2O5 and K2O, respectively, plus 1.0 kg of sulfate ammonium and 0.3 kg of potassium chloride applied in coverage.

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Ethylene-vinyl acetate copolymer (EVA) with 19% of vinyl acetate and its derivatives modified by hydrolysis of 50 and 100% of the initial vinyl acetate groups were used to produce blends with thermoplastic starch (TPS) plasticized with 30 wt% glycerol. The blends were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy. X-ray diffraction, water absorption, stress-strain mechanical tests, dynamic mechanical analysis and thermogravimetric analysis. In contrast to the blends with unmodified EVA. those made with hydrolyzed EVA were compatible, as demonstrated by the brittle fracture surface analysis and the results of thermal and mechanical tests. The mechanical characteristics and water absorption of the TPS were improved even with a small addition (2.5 wt%) of hydrolyzed EVA. The glass transition temperature rose with the degree of hydrolysis of EVA by 40 and 50 degrees, for the EVA with 50 and 100% hydrolysis, respectively. The addition of hydrolyzed EVA proved to be an interesting approach to improving TPS properties, even when very small quantities were used, such as 2.5 wt%. (C) 2012 Elsevier Ltd. All rights reserved.

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Lyotropic liquid crystalline quaternary mixtures of potassium laurate (KL), potassium sulphate (K2SO4)/alcohol (n-OH)/water, with the alcohols having different numbers of carbon atoms in the alkyl chain (n), from 1-octanol to 1-hexadecanol, were investigated by optical techniques (optical microscopy and laser conoscopy). The biaxial nematic phase domain is present in a window of values of n = n(KL) +/- 2, where n(KL) = 11 is the number of carbon atoms in the alkyl chain of KL. The biaxial phase domain became smaller and the uniaxial-to-biaxial phase transition temperatures shifted to relatively higher temperatures upon going from 1-nonanol to 1-tridecanol. Moreover, compared with other lyotropic mixtures these new mixtures present high birefringence values, which we expect to be related to the micellar shape anisotropy. Our results are interpreted assuming that alcohol molecules tend to segregate in the micelles in a way that depends on the relative value of n with respect to nKL. The larger the value of n, the more alcohol molecules tend to be located in the curved parts of the micelle, favoring the uniaxial nematic calamitic phase with respect to the biaxial and uniaxial discotic nematic phases.