972 resultados para Urea reabsorption


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Este trabalho visa contribuir para uma melhor percepção da problemática do analfabetismo, em Portugal, no primeiro quartel do século XX, tendo em conta o ideário educativo republicano e as suas concretizações a nível do ensino primário. Neste sentido, foram traçadas as linhas estruturantes desta problemática: uma, centrada nas ideias educativas sobre o analfabetismo e os debates no quotidiano escolar e jornalístico; e a outra referente às concretizações e realizações educativas republicanas que operacionalizaram o combate ao analfabetismo. O conceito de analfabetismo foi o fio condutor de todo o trabalho, do qual se delinearam as seguintes áreas: (i) Dos finais da Monarquia Constitucional à República: breve perspectiva histórica e educativa; (ii) O analfabetismo e suas causas; (iii) O combate ao analfabetismo; (iv) Escolas móveis e cursos nocturnos na promoção da alfabetização e, (v) Programas escolares: as propostas governamentais. A cada área corresponde um capítulo. A fonte principal deste trabalho foi a Imprensa de Educação e Ensino, consultada na Biblioteca Nacional, pois a mesma oferece uma complexa vastidão de materiais pertinentes para o tema. Entre os vários periódicos compulsados, destacam-se A Federação Escolar, Educação Nacional e O Professor Primário. A pesquisa exploratória e selectiva também conduziu ao semanário Sul da Beira. Muitas obras e estudos da época foram ainda pesquisados, com destaque para as actas dos Congressos da Liga Nacional de Instrução. Igualmente se afigurou significativo perscrutar o Diário da Câmara dos Deputados, o Diário do Senado da República e ainda o Diário do Governo para serem trabalhados, respectivamente, os debates parlamentares e a legislação. Assim, foi objectivo do trabalho configurar um painel revelador do tema que mobilizou personalidades académicas, jornalísticas e políticas, no período compreendido entre 1910 e 1926.

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As doenças cardíacas são um achado frequente na prática clínica. Saber se pacientes assintomáticos com doença mixomatosa da válvula mitral necessitam ou não de medicação numa fase inicial da doença não é tarefa fácil. A ativação neuro-hormonal, apesar de ter um efeito benéfico compensatório a curto prazo, torna-se deletéria a longo prazo, sendo que para isso é necessária intervenção farmacológica para inibir a sua atividade O SRAA (sistema renina angiotensina aldosterona) tem importantes mecanismos patofisiológicos implicados no desenvolvimento da insuficiência cardíaca congestiva e tem como produto final a aldosterona, que contribui para a remodelagem cardíaca. Neste trabalho verifiquei a inexistência de uma diferença significativa de valores de aldosterona sérica de cães assintomáticos com Doença Mixomatosa Valvular Mitral (estadio B2 da classificação ACVIM) e os valores do intervalo de referência desta hormona. Concluí também não haver relação entre a idade, ureia, creatinina, rácio Proteina-Creainina, Pressões arteriais sistólica, média e diastólica, frequência de pulso, parâmetros de remodelagem cardíaca e padrão do fluxo transmitral com os valores da aldosterona medidos. É através da evidência destes achados que sugiro a não instituição de um IECA neste tipo de pacientes. O uso precoce de IECA pode não só não trazer vantagens terapêuticas nesta fase da doença como também vai promover o aparecimento precoce de fenómenos de “escape da aldosterona”.

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Introduction: Autosomal dominant polycystic kidney disease is the most common hereditary renal disease in humans. Objective: To examine the prevalence, clinical and laboratory characteristics of patients with polycystic kidneys and relate disease manifestations by gender. Methods: This was an observational and retrospective study. All the medical records of patients with polycystic kidneys who initiated hemodialysis between 1995 and 2012, in four centers that treat patients of the coverage area of the 15th regional health Paraná (Brazil), were analyzed. Results: The study included 48 patients with polycystic kidneys, the primary cause of stage 5 CKD. Disease prevalence was one in 10,912 people. The average age of dialysis initiation was 50.7 years and the follow-up time on dialysis until transplantation (36.5 months) was lower among men. Hypertension was the most frequent diagnosis in 73% of patients, predominantly in women (51.4%). The liver cyst was the most frequent extrarenal manifestations in men (60.0%). The death occurred in 10.4% of patients using hemodialysis, and 60% of men. The class of antihypertensive drug used was that acts on the renin-angiotensin system with higher frequency of use among women (53.3%). The post-dialysis urea was significantly higher in men. Conclusion: The prevalence of the disease is low among hemodialysis patients in southern Brazil. The differences observed between genders, with the exception of the post-dialysis urea, were not significant. The findings are different from those reported in North America and Europe.

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Os Sistemas de Informação têm influenciado a vida quotidiana a um ritmo inesperado e com mudanças significativas na setor da construção, cuja importância é crucial para a economia de qualquer país. Sendo Angola, um país de economia emergente, caracterizado por um mercado em expansão e reestruturação, onde as decisões de Sistema Informação ainda são tomadas de forma isolada, e cada vez mais investidores estão a atuar no país, impulsionando o crescimento, é imperioso para o sector a identificação e exploração de Sistemas de Informação flexíveis e adaptáveis para fazer face as forças competitivas do setor. Partindo desta envolvente a presente dissertação visa ressaltar o reconhecimento da importância do Planeamento Estratégico de Sistemas de Informação-PESI para as organizações atuais. Neste contexto realizou-se o estudo de PESI em torno de um caso concreto numa Pequena Media Empresa, Angolana, a Terponte,SA, cujo objectivo é fornecer a construtora um plano em termos de SI para futuro. Os dados foram recolhidos através da utilização dos métodos qualitativos e quantitativos, sendo os mais pertinentes a análise documental, observação direta, entrevistas, questionários aos órgãos da empresa em estudo e demais intuições. A análise dos dados demonstrou uma deficiente gestão da informação, bem como inexistência de integração aplicacional. A presente dissertação pretende contribuir para o avanço do conhecimento científico no domínio do Planeamento Estratégico dos Sistemas de Informação e para a resolução de problemas específicos nomeadamente nas empresas do setor da construção civil.

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El autor relee algunas propuestas culturales de los ensayos de Montalvo. Comienza por defender el rasgo de la polémica, en cuanto una herramienta estética y ética: la emplea con afán literario –en el mismo estilo de Sarmiento, González Prada, entre otros– y también como escritor vinculado a la política militante, para incentivar así a una audiencia poco letrada. En su pensamiento, señala oscilaciones entre ideas europeizantes, hispanoamericanistas y claramente latinoamericanistas. Hay coincidencias entre Montalvo y Pedro Henríquez Ureña al pensar lo latinoamericano, su noción se mueve entre aquella de lo nacional y del sujeto popular (vínculos con Martí y Bello). Considera a la nación como una totalidad cooperativa, en una propuesta anticolonial, de carácter republicano: donde prevalecieran la libertad de opinión, la fraternidad, y la democracia. Analiza las ideas de Montalvo sobre las masas populares, destacando el rasgo humanista en las acepciones de civilización y barbarie (que sería lo opuesto a la paz que se obtiene por el respeto y no por el miedo a los gobernantes o a la Iglesia). Montalvo aboga por la creación de un pueblo virtuoso a partir del trabajo y de un equilibrio entre la razón y los placeres, justifica la necesidad de la ilustración popular y de que un héroe guíe al pueblo (no que lo esclavice). Sin embargo, al momento de definir las clases sociales significativamente no considera las nociones de casta. Al referirse al pueblo afro, vuelve a sostener que es la esclavitud la que los coloca en una situación inferior, insistiendo en que no existe una inferioridad innata.

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Sustaining soil fertility is essential to the prosperity of many households in the mid-hills of Nepal, but there are concerns that the breakdown of the traditional linkages between forest, livestock, and cropping systems is adversely affecting fertility. This study used triangulated data from surveys of households, discussion groups, and key informants in 16 wards in eastern and western Nepal to determine the existing practices for soil fertility management, the extent of such practices, and the perception of the direction of changes in soil fertility. The two principal practices for maintaining soil fertility were the application of farmyard manure (FYM) and of chemical fertilizer (mainly urea and diammonium phosphate). Green manuring, in-situ manuring, slicing terrace risers, and burning plant residues are rarely practiced. FYM usage was variable with more generally applied to khet land (average 6053 kg fresh weight manure ha(-1)) than to bari land (average 4185 kg fresh weight manure ha-1) with manure from goats and poultry preferred above that from cows and buffaloes. Almost all households (98%) apply urea to khet land and 87% to bari land, with 45% applying diammonium phosphate to both types of land. Application rates and timings of applications varied considerably both within and between wards suggesting poor knowledge transfer between the research and farming communities. The benefits of chemical fertilizers in terms of ease of application and transportation in comparison with FYM, were perceived to outweigh the widely reported detrimental hardening of soil associated with their continued usage. Among key informants, FYM applied in conjunction with chemical fertilizer was the most popular amendment, with FYM alone preferred more than chemical fertilizer alone - probably because of the latter's long-term detrimental effects. Key informant and householder surveys differed in their perception of fertility changes in the last decade probably because of differences in age and site-specific knowledge. All key informants felt that fertility had declined but among households, only about 40% perceived a decline with the remainder about evenly divided between no change and an increase. Householders with small landholdings (< 0.5 ha) were more likely to perceive increasing soil fertility while those with larger landholdings (> 2 ha) were more likely to perceive declining fertility. Perceived changes in soil fertility were not related to food self-sufficiency. The reasons for the slow spread of new technologies within wards and the poor understanding of optimal use of chemical fertilizers in conjunction with improved quality FYM may repay further investigation in terms of sustaining soil fertility in this region.

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We explore the role of crystallinity and inter- or intramolecular forces in chitosan for its solubility in water and demonstrate the expansion of its solubility to a wider pH range. Due to its semicrystalline nature, derived mainly from inter- and intramolecular hydrogen bonds, chitosan is water-soluble only at pH < 6. In acidic conditions, its amino groups can be partially protonated resulting in repulsion between positively charged macrochains, thereby allowing diffusion of water molecules and subsequent solvation of macromolecules. We show that chemical disruption of chitosan crystallinity by partial re-acetylation or physical disruption caused by the addition of urea and guanidine hydrochloride broadens the pH-solubility range for this biopolymer.

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Chitosan is a biocompatible and biodegradable amino polysaccharide, which is soluble in aqueous solutions at pH < 6.5. It has been widely used for developing drug delivery systems because of its excellent mucoadhesive properties. Although many studies report on chitosan being mucoadhesive, the nature of interactions between chitosan and mucin remains poorly defined. Here, we have examined the role of primary amino groups and the role of electrostatic attraction, hydrogen bonding, and hydrophobic effects on aggregation of gastric mucin in the presence of chitosan. Reducing the number of amino groups through their half acetylation results in expansion of chitosan’s pH-solubility window up to pH 7.4 but also reduces its capacity to aggregate mucin. We demonstrated that electrostatic attraction forces between chitosan and gastric mucin can be suppressed in the presence of 0.2 mol/L sodium chloride; however, this does not prevent the aggregation of mucin particles in the presence of this biopolymer. The presence of 8 mol/L urea or 10% v/v ethanol in solutions also affects mucin aggregation in the presence of chitosan, demonstrating the role of hydrogen bonding and hydrophobic effects, respectively, in mucoadhesion.

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A model of sugarcane digestion was applied to indicate the suitability of various locally available supplements for enhancing milk production of Indian crossbred dairy cattle. Milk production was calculated according to simulated energy, lipogenic, glucogenic and aminogenic substrate availability. The model identified the most limiting substrate for milk production from different sugarcane-based diets. For sugarcane tops/urea fed alone, milk production was most limited by amino acid followed by long chain fatty acid availability. Among the protein-rich oil cake supplements at 100, 200 and 300 g supplement/kg total DM, cottonseed oil cake proved superior with a milk yield of 5.5, 7.3 and 8.3 kg/day, respectively. This was followed by mustard oil cake with 5.1, 6.5 and 7.6 kg/day, respectively. In the case of a protein-rich supplement (fish meal), milk yield was limited to 6.6 kg/day due to a shortage of long chain fatty acids. However, at 300 g of supplementation, energy became limiting, with a milk yield of 6.7 kg/day. Supplementation with rice bran and rice polishings at 100, 200 and 300 g restricted milk yield to 4.3, 4.9 and 5.5 and 4.5, 5.3 and 6.1 kg/day, respectively, and amino acids became the factor limiting milk production. The diet comprising basal sugarcane tops supplemented by leguminous fodder, dry fodder (e.g. rice or wheat straw) and concentrates at levels of 100, 200 and 300 g supplements/kg total diet DM proved to be the most balanced with a milk yield of 5.1, 6.7 and 9.0 kg/day, respectively.

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The impact of environment on the germination biology of Striga hermonthica was studied in the laboratory by conditioning seeds at various water potentials and urea concentrations at 17.5 to 37.5°C for up to 133 days. The experimental results presented in this research are related to the effects of temperature, water potential and urea nitrogen concentration during conditioning on subsequent germination percentage of S. hermonthica. Maximum germination in S. hermonthica seeds was observed at conditioning temperatures of 20 to 25°C within the range investigated of 17.5 to 37.5°C. Water stress and also urea during conditioning suppressed maximum germination. However, the conditioning temperature ranges at which maximum germination percentages occur vary with water stress and also urea concentration. In the presence of a high concentration of urea (3.16 mM), temperatures required for maximum germination narrowed to between 17.5 to 20°C. The optimum period of conditioning decreased with increase in water stress and also urea concentration similar to previous reports. The implications of these findings on Striga hermonthica field infestations have been investigated and being reported in another paper. Germination was greatly suppressed by conditioning environments including 3.16 mM urea and at 37.5°C. At the high concentration of 3.16 mM, temperatures required for maximum germination narrowed to between 17.5 and 20°C. Optimum conditioning period decreased with water stress and with increase in urea concentration.

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The impact of environment on the germination biology of the parasite was studied in the laboratory with seeds conditioned at various water potentials, urea concentrations and at 17.5 to 37.5°C for up to 133 days. Maximum germination was observed at 20 to 25°C. Water stress and urea suppressed maximum germination. The final percentage germination response to period of conditioning showed a non-linear relationship and suggests the release of seeds from dormancy during the initial period and later on dormancy induction. Germination percentage increased with increase in conditioning period to a threshold and remained stable for variable periods followed by a decline with further extension of conditioning time. The decline in germination finally terminated in zero germination in most treatments before the end of experimentation. The investigated factors of temperature, water potential and urea showed clear effects on the expression of dormancy pattern of the parasite. The effects of water potential and urea were viewed as modifying a primary response of seeds to temperature during conditioning. The changes in germinability potential during conditioning were consistent with the hypothesis that dormancy periods are normally distributed within seed populations and that loss of primary dormancy precedes induction of secondary dormancy. Hence an additive mathematical model of loss of primary dormancy and induction of secondary as affected by environment was developed as: G = {[Φ-1 (Kp+ (po+pnN+pwW) (T-Tb) t)]-[Φ-1 (Ks+ ((swW+sa)+sorT)t)]}[Φ-1(aT2+bT+c+cwW)].

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A total of 133 samples (53 fermented unprocessed, 19 fermented processed. 62 urea-treated processed) of whole crop wheat (WCW) and 16 samples (five fermented unprocessed, six fermented processed, five urea-treated processed) of whole crop barley (WCB) were collected from commercial farms over two consecutive years (2003/2004 and 2004/2005). Disruption of the maize grains to increase starch availability was achieved at the point of harvest by processors fitted to the forage harvesters. All samples were subjected to laboratory analysis whilst 50 of the samples (24 front Year 1, 26 front Year 2 all WCW except four WCB in Year 2) were subjected to in vivo digestibility and energy value measurements using mature wether sheep. Urea-treated WCW had higher (P<0.05) pH, and dry matter (DM) and crude protein contents and lower concentrations of fermentation products than fermented WCW. Starch was generally lower in fermented, unprocessed WCW and no effect of crop maturity at harvest (as indicated by DM content) on starch concentrations was seen. Urea-treated WCW had higher (P<0.05) in vivo digestible organic matter contents in the DM (DOMD) in Year 1 although this was not recorded in Year 2. There was a close relationship between the digestibility values of organic matter and gross energy thus aiding the use of DOMD to predict metabolisable energy (ME) content. A wide range of ME values was observed (WCW. 8.7-11.8 MJ/kg DM; WCB 7.9-11.2 MJ/kg DM) with the overall ME/DOMD ratio (ME = 0.0156 DOMD) in line With Studies in other forages. There was no evidence that a separate ME/DOMD relationship was needed for WCB which is helpful for practical application. This ratio and other parameters were affected by year of harvest (P<0.05) highlighting the influence of environmental and Other undefined factors. The variability in the composition and nutritive value of WCW and WCB highlights the need for reliable and accurate evaluation methods to be available to assess the Value of these forages before they are included in diets for dairy cows. (C) 2008 Elsevier B.V. All rights reserved.

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The effects of applying nitrogen (30 or 40 kg N/ha) to wheat crops at and after anthesis, after 200 kg N/ha had already been applied to the soil during stem extension, were studied in field experiments comprising complete factorial combinations of different cultivars, fungicide applications and nitrogen treatments. Actual recoveries of late-season fertilizer nitrogen (LSFN), as indicated by N-15 studies, interacted with cultivar and fungicide treatment, and depended on nitrogen source (Urea applied as a solution to the foliage, or as ammonium nitrate applied to the soil) and year. These interactions, however, were not reflected in apparent fertilizer recoveries ((N in grain with LSFN - N in grain without LSFN)/N applied as LSFN), or in the crude protein concentration. Apparent fertilizer recovery was always lower than actual recoveries, and declined during grain filling. Fertilizer treatments with higher actual fertilizer recoveries were associated with lower net renlobilisation of non-LSFN (net remobilised N = N in above ground crop at anthesis - N in non-grain, above ground crop at harvest). LSFN also increased mineral nitrogen in the soil at harvest even when applied as a solution to the foliage. These effects are discussed in relation to potential grain N demand. (c) 2006 Elsevier B.V. All rights reserved.

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The objective of this work was to construct a dynamic model of hepatic amino acid metabolism in the lactating dairy cow that could be parameterized using net flow data from in vivo experiments. The model considers 22 amino acids, ammonia, urea, and 13 energetic metabolites, and was parameterized using a steady-state balance model and two in vivo, net flow experiments conducted with mid-lactation dairy cows. Extracellular flows were derived directly from the observed data. An optimization routine was used to derive nine intracellular flows. The resulting dynamic model was found to be stable across a range of inputs suggesting that it can be perturbed and applied to other physiological states. Although nitrogen was generally in balance, leucine was in slight deficit compared to predicted needs for export protein synthesis, suggesting that an alternative source of leucine (e.g. peptides) was utilized. Simulations of varying glucagon concentrations indicated that an additional 5 mol/d of glucose could be synthesized at the reference substrate concentrations and blood flows. The increased glucose production was supported by increased removal from blood of lactate, glutamate, aspartate, alanine, asparagine, and glutamine. As glucose Output increased, ketone body and acetate release increased while CO2 release declined. The pattern of amino acids appearing in hepatic vein blood was affected by changes in amino acid concentration in portal vein blood, portal blood flow rate and glucagon concentration, with methionine and phenylalanine being the most affected of essential amino acids. Experimental evidence is insufficient to determine whether essential amino acids are affected by varying gluconeogenic demands. (C) 2004 Published by Elsevier Ltd.