964 resultados para Salt Water Regulator
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Purpose: Accumulating evidence suggests an association between body volume overload and inflammation in chronic kidney diseases. The purpose of this study was to evaluate the effect of dietary sodium reduction in body fluid volume, blood pressure (BP), and inflammatory state in hemodialysis (HD) patients. Methods: In this prospective controlled study, adult patients on HD for at least 90 days and those with C-reactive protein (CRP) levels ≥0.7 mg/dl were randomly allocated into two groups: group A, which included 21 patients treated with 2 g of sodium restriction on their habitual diet; and group B, which included 18 controls. Clinical, inflammatory, biochemical, hematological, and nutritional markers were assessed at baseline and after 8 and 16 weeks. Results: Baseline characteristics were not significantly different between the groups. Group A showed a significant reduction in serum concentrations of CRP, tumor necrosis factor-α, and interleukin-6 during the study period, while BP and extracellular water (ECW) did not change. In group B, there were no changes in serum concentrations of inflammatory markers, BP, and ECW. Conclusions: Dietary sodium restriction is associated with the attenuation of the inflammatory state, without changes in BP and ECW, suggesting inhibition of a salt-induced inflammatory response. © 2013 Springer Science+Business Media Dordrecht.
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Accumulating evidence suggests an association between body volume overload and inflammation in chronic kidney diseases. The purpose of this study was to evaluate the effect of dialysate sodium concentration reduction on extracellular water volume, blood pressure (BP), and inflammatory state in hemodialysis (HD) patients. In this prospective controlled study, adult patients on HD for at least 90 days and those with C-reactive protein (CRP) levels ≥ 0.7 mg/dL were randomly allocated into two groups: group A, which included 29 patients treated with reduction of dialysate sodium concentration from 138 to 135 mEq/L; and group B, which included 23 HD patients not receiving dialysate sodium reduction (controls). Of these, 20 patients in group A and 18 in group B completed the protocol study. Inflammatory, biochemical, hematological, and nutritional markers were assessed at baseline and after 8 and 16 weeks. Baseline characteristics were not significantly different between the two groups. Group A showed a significant reduction in serum concentrations of tumor necrosis factor-α, and interleukin-6 over the study period, while the BP and extracellular water (ECW) did not change. In Group B, there were no changes in serum concentrations of inflammatory markers, BP, and ECW. Dialysate sodium reduction is associated with attenuation of the inflammatory state, without changes in the BP and ECW, suggesting inhibition of a salt-induced inflammatory response. Copyright © 2013 Informa Healthcare USA, Inc.
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The present study evaluated the efficacy of fluazuron (active ingredient of the acaricide Acatak®) and its effects on Rhipicephalus sanguineus nymphs fed on rabbits exposed to different doses of this insect growth regulator. Three different doses of fluazuron (20 mg/kg, 40 mg/kg, and 80 mg/kg) were applied on the back of hosts (via pour on), while distilled water was applied to the Control group. On the first day of treatment with fluazuron (24 h), hosts were artificially infested with R. sanguineus nymphs. Once fully engorged, nymphs were removed and placed in identified Petri dishes in Biochemical Oxygen Demand (BOD) incubator for 7 days. After this period, engorged nymphs were processed for ultramorphological analysis. The results revealed alterations in the ultramorphology of many chitinous structures (smaller hypostome and chelicerae, less sclerotized scutum, fewer sensilla, fewer pores, absence of grooves, marginal and cervical strips and festoons in the body, even the anal plaque was damaged) that play essential roles for the survivor of ticks and that can compromise the total or partial development of nymphs and emergence of adults after periodic molting. Our findings confirm the efficacy of fluazuron, a more specific and less aggressive chemical to the environment and human health, and that does not induce resistance, in nymphs of the tick R. sanguineus in artificially infested rabbits treated with this arthropod growth regulator (AGR), indicating that it could be used in the control of this stage of the biological cycle of the tick R. sanguineus. © 2013 Wiley Periodicals, Inc.
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Includes bibliography
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Investigou-se a relação entre as características da água e a infestação de protozoários parasitos, Icthyophthirius multifiliis e Trichodina sp., em peixe espada, Xiphophorus helleri e em plati, Xiphophorus maculatus, coletados em uma piscicultura de peixes ornamentais no Estado de São Paulo, Brasil. Os peixes foram coletados mensalmente, durante um ano, dos viveiros e das caixas de estocagem. A prevalência da infestação nos peixes das caixas e dos viveiros foram, respectivamente, 34,2% e 22,5% para I. multifiliis e 13% e 54% para Trichodina sp. A elevada condutividade elétrica e o pH da água reduziram a infestação por I. multifiliis. A baixa concentração de oxigênio resultou em aumento na infestação por Trichodina sp. O uso do sal, para aumentar a condutividade elétrica da água, consistiu em um método de controle de I. multifiliis. A redução do oxigênio dissolvido e a adição de fertilizante orgânico favoreceram a reprodução de Trichodina sp.
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A análise de dados termohalinos e correntes medidos em uma estação fixa no Canal de Piaçaguera (Estuário de Santos) no inverno foi feita em termos de condições cíclicas da maré (quadratura e sizígia) e quase-estacionária, com o objetivo de caracterizar a estratificação da massa de água estuarina, sua circulação e transporte de sal forçados pela modulação quinzenal da maré. Foram utilizados métodos clássicos de análise de dados observacionais horários e quase sinóticos e de simulações analíticas de perfis estacionários de salinidade e do componente longitudinal da velocidade. Durante o ciclo de maré de quadratura as velocidades de enchente (v<0) e vazante (v>0) variaram de -0.20 m/s a 0.30 m/s, associadas à pequena variação de salinidade entre a superfície e o fundo (26.4 psu a 30.7 psu). No ciclo de sizígia a velocidade aumentou de -0.40 m/s a 0.45 m/s, mas a estratificação de salinidade permaneceu praticamente a mesma. Os perfis estacionários teóricos de salinidade e de velocidade apresentaram boa concordância (Skill próximo a 1,0) quando comparados aos perfis observacionais. Durante a modulação quinzenal da maré não houve alteração na classificação do canal estuarino (tipo 2a-parcialmente misturado e fracamente estratificado), pois a taxa de aumento da energia potencial não foi suficiente para ocasionar a erosão da haloclina. Esses resultados, associados à alta estabilidade vertical (RiL >20) e ao número de Richardson estuarino (1,6), permitem as seguintes conclusões: i) o mecanismo que forçou a circulação e os processos de mistura foi principalmente o balanço da descarga fluvial com a maré, associado ao componente baroclínico da força de gradiente de pressão; ii) não houve variações nas principais características termohalinas e da circulação devido à modulação quinzenal da maré; e iii) os perfis quase estacionários de salinidade e da velocidade foram adequadamente simulados com um modelo analítico clássico.
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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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Previous research has demonstrated that dehydration increases the threshold temperature for panting and decreases the thermal preference of lizards. Conversely, it is unknown whether thermoregulatory responses such as shuttling and gaping are similarly influenced. Shuttling, as an active behavioural response, is considered one of the most effective thermoregulatory behaviours, whereas gaping has been proposed to be involved in preventing brain over-heating in lizards. In this study we examined the effect of salt loading, a proxy for increased plasma osmolality, on shuttling and gaping in Pogona vitticeps. Then, we determined the upper and lower escape ambient temperatures (UETa and LETa), the percentage of time spent gaping, the metabolic rate ((V) over dot(O2)), the evaporative water loss (EWL) during gaping and non-gaping intervals and the evaporative effectiveness (EWL/(V) over dot(O2)) of gaping. All experiments were performed under isotonic (154 mmol l(-1)) and hypertonic saline injections (625, 1250 or 2500 mmol l(-1)). Only the highest concentration of hypertonic saline altered the UETa and LETa, but this effect appeared to be the result of diminishing the animal's propensity to move, instead of any direct reduction in thermoregulatory set-points. Nevertheless, the percentage of time spent gaping was proportionally reduced according to the saline concentration; (V) over dot(O2) was also decreased after salt loading. Thermographic images revealed lower head than body surface temperatures during gaping; however this difference was inhibited after salt loading. Our data suggest that EWL/(V) over dot(O2) is raised during gaping, possibly contributing to an increase in heat transfer away from the lizard, and playing a role in head or brain cooling.
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Water-miscible ionic liquids (ILs) may be salted out using kosmotropic salts such as potassium phosphate (K3PO4) to form salt-salt aqueous biphasic systems (ABS). The effect of temperature on these systems has been studied using phase diagrams and it is observed that the degree of binodal shift decreases (requiring lower IL and kosmotropic salt concentrations) with the increase of temperature following the trend [C(4)mim]Cl > [C(4)py]Cl > [C(4)mmim] Cl > [N-4444]Cl. This trend can be correlated with the decreasing hydrogen bonding abilities of each salt. The phase behavior was also interpreted on the basis of critical solution temperature behavior of pure aqueous ionic liquid solutions. Additionally, the distribution of alcohols in these systems was studied as a function of temperature and it was found that the distribution ratios did not change with changes in temperature. The Gibbs energy of transfer of a methylene group in these systems and correlation to tie-line length was also determined. It was concluded that while the miscibility of alcohols increases in the ILs with increasing temperature, phase divergence in the aqueous biphasic system decreases, and thus these competing forces tend to cancel each other out for small polar molecules. A comparison is provided for the response to temperature in the currently studied salt-salt systems and analogous ABS formed by the addition of hydrophilic polymers to kosmotropic salts (polymer-salt) or other polymers (polymer-polymer).
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Blockade of central angiotensin receptors with the specific antagonist [Leu8]-ANG II abolished water ingestion and water and sodium excretion induced by infusion of angiotensin II (ANGII) into the lateral ventricle (LV) of rats. The antagonist reduced but did not suppress the salt appetite induced by ANGII infusion. Subcutaneous injection of deoxycorticosterone acetate (DOCA) caused increases in water and 3% NaCl ingestion and decreases in sodium excretion. When central ANGII infusion was combined with peripheral DOCA, the water intake was similar to that induced by ANGII alone and the ingestion of 3% NaCl was increased, whereas sodium excretion was inhibited. When ANGII was infused alone, a detailed temporal analysis of fluid and sodium balance showed a negative balance similar those saline controls that persisted throughout the experiment. Combined administration of ANGII and DOCA induce significant changes in water and sodium balance. Sodium and water maintained a positive balance through out the 8-h experiment. The data support an interaction of central ANGII and DOCA on sodium intake and water and sodium balance. © 1994.
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The viscosity of AOT/water/decane water-in-oil microemulsions exhibits a well-known maximum as a function of water/AOT molar ratio, which is usually attributed to increased attractions among nearly spherical droplets. The maximum can be removed by adding salt or by changing the oil to CCl4. Systematic small-angle X-ray scattering (SAXS) measurements have been used to monitor the structure of the microemulsion droplets in the composition regime where the maximum appears. On increasing the droplet concentration, the scattering intensity is found to scale with the inverse of the wavevector, a behavior which is consistent with cylindrical structures. The inverse wavevector scaling is not observed when the molar ratio is changed, moving the system away from the value corresponding to the viscosity maximum. It is also not present in the scattering from systems containing enough added salt to essentially eliminate the viscosity maximum. An asymptotic analysis of the SAXS data, complemented by some quantitative modeling, is consistent with cylindrical growth of droplets as their concentration is increased. Such elongated structures are familiar from related AOT systems in which the sodium counterion has been exchanged for a divalent one. However, the results of this study suggest that the formation of non-spherical aggregates at low molar ratios is an intrinsic property of AOT.
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Background: Drought is a major abiotic stress that affects crop productivity worldwide. Sugarcane can withstand periods of water scarcity during the final stage of culm maturation, during which sucrose accumulation occurs. Meanwhile, prolonged periods of drought can cause severe plant losses. Methodology/Principal Findings: In a previous study, we evaluated the transcriptome of drought-stressed plants to better understand sugarcane responses to drought. Among the up-regulated genes was Scdr1 (sugarcane drought-responsive 1). The aim of the research reported here was to characterize this gene. Scdr1 encodes a putative protein containing 248 amino acids with a large number of proline (19%) and cysteine (13%) residues. Phylogenetic analysis showed that ScDR1is in a clade with homologs from other monocotyledonous plants, separate from those of dicotyledonous plants. The expression of Scdr1 in different varieties of sugarcane plants has not shown a clear association with drought tolerance. Conclusions/Significance: The overexpression of Scdr1 in transgenic tobacco plants increased their tolerance to drought, salinity and oxidative stress, as demonstrated by increased photosynthesis, water content, biomass, germination rate, chlorophyll content and reduced accumulation of ROS. Physiological parameters, such as transpiration rate (E), net photosynthesis (A), stomatal conductance (gs) and internal leaf CO2 concentration, were less affected by abiotic stresses in transgenic Scdr1 plants compared with wild-type plants. Overall, our results indicated that Scdr1 conferred tolerance to multiple abiotic stresses, highlighting the potential of this gene for biotechnological applications.
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Peatlands form in areas where net primary of organic matter production exceeds losses due to the decomposition, leaching or disturbance. Due to their chemical and physical characteristics, bogs can influence water dynamics because they can store large volumes of water in the rainy season and gradually release this water during the other months of the year. In Diamantina, Minas Gerais, Brazil, a peatland in the environmental protection area of Pau-de-Fruta ensures the water supply of 40,000 inhabitants. The hypothesis of this study is that the peat bogs in Pau-de-Fruta act as an environment for carbon storage and a regulator of water flow in the Corrego das Pedras basin. The objective of this study was to estimate the water volume and organic matter mass in this peatland and to study the influence of this environment on the water flow in the Corrego das Pedras basin. The peatland was mapped using 57 transects, at intervals of 100 m. Along all transects, the depth of the peat bog, the Universal Transverse Mercator (UTM) coordinates and altitude were recorded every 20 m and used to calculate the area and volume of the peatland. The water volume was estimated, using a method developed in this study, and the mass of organic matter based on samples from 106 profiles. The peatland covered 81.7 hectares (ha), and stored 497,767 m(3) of water, representing 83.7 % of the total volume of the peat bog. The total amount of organic matter (OM) was 45,148 t, corresponding to 552 t ha(-1) of OM. The peat bog occupies 11.9 % of the area covered by the Corrego das Pedras basin and stores 77.6 % of the annual water surplus, thus controlling the water flow in the basin and consequently regulating the water course.
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This study deals with the seasonal distribution of Al, Ca, Cu, Fe, K, Mg, Na, Pb and Zn and water soluble ions (Cl-, PO43-, NO3-, SO42-, HCOO-, CH3COO-, oxalate, succinate, Na+, NH4+, K+, Mg2+ and Ca2+) found in PM10 samples (particulate matter less than 10 mu m in diameter) Sao Paulo City, Brazil, (April 2003-May 2004). Higher atmospheric levels were found for SO42-, NO3-, Cl- and PO43- while the main organic anions were oxalate and formate. Atmospheric levels for elements were: Fe > Al > Ca > K > Na > Mg > Zn > Cu > Pb. Some sources were predominant for some species: (i) fuel burning and/or biomass burning (NO3-, HCOO-, C2O42-, K+, Mg2+, Ca2+, Fe, Pb, Zn, Al, Ca, K and Mg), (ii) gas-to-particle conversion (SO42- and NH4+) and (iii) sea salt spray (Cl-, Na+ and Na).