1,048 research outputs found
Serial antiepileptic blood levels in epileptic patients
To evaluate complacence in chronic epileptic women we collected weekly 144 blood samples from 38 patients for antiepileptic drugs determination. All the patients were supposed to have uncontrolled seizures using phenobarbital, phenytoin or carbamazepine mo-notherapeutically. We found that 34% of the blood levels were below the standard normal range. Blood level with great weekly variations were interpreted as inadequate intake by the patient. We conclude that repetitive antiepileptic blood levels determination may elucidate if the patient has drug-resistant seizures or if the patient is not complacent to the drug therapy.Para avaliação da aderência ao tratamento em epilépticas crônicas estudamos 38 pacientes através de 144 dosagens séricas repetidas de anticonvulsivantes a intervalos semanais. Todas as pacientes apresentavam crises supostamente de difícil controle, isto é, tiveram crises no mês anterior à última consulta. O nível sérico da droga antiepiléptica estava abaixo da faixa terapêutica em 34% das amostras analisadas. Houve ainda variações semanais importantes do nível terapêutico para subterapêutico das drogas e vice-versa. Baseados nestes achados sugere-se que a estratégia de dosagens séricas repetidas possa diferenciar as pacientes resistentes à droga daquelas que não fazem uso regular do medicamento.364
Reciclado de hormigón fresco mediante el uso de adición pelletizante
El retorno del hormigón fresco a la planta de elaboración es un problema económico y medioambiental. Aproximadamente el 2% de la producción de hormigón regresa a la planta y, en la mayoría de los casos, se elimina en gran medida como material de desecho. La producción de bloques, agregados triturados o la separación de sus componentes son algunas de las alternativas informadas para su reciclado. Recientemente se desarrolló una nueva tecnología basada en una adición en polvo de dos componentes que permite que el hormigón fresco se convierta fácilmente en un agregado artificial que puede reincorporarse a la producción de hormigón. En este trabajo se estudiaron las propiedades de los agregados pelletizados (AP) obtenidos a partir de dos formulaciones de hormigón con diferente tamaño máximo nominal de agregados naturales (AN). Asimismo, se evaluaron mezclas de hormigón que tuvieron diferentes niveles de reemplazo de AN por AP en su dosificación. En las formulaciones con sustitución parcial de AN por AP se observó una reducción de alrededor del 20% en la resistencia a la compresión respecto a la muestra control, incluso para porcentajes de sustitución muy elevados (60%). A pesar de la disminución, los hormigones basados en AP cumplen en todos los casos con los requisitos de resistencia y permiten revalorizar un residuo de la industria y cuidar el medio ambiente.Returned fresh mix concrete to the processing plant is an economic and environmental problem. About 2% of concrete production returns to the plant and, in most cases, is largely disposed of as waste material. The production of blocks, crushed aggregates or the separation of their main components are some of the alternatives reported for recycling. Recently, a new technology based on two-component powder additive has been developed, allowing the fresh returned concrete to be easily converted into an artificial aggregate, which can be incorporated into the production of concrete. In this paper, the properties of pelletized aggregates (AP) obtained from two concrete formulations with different maximum nominal natural aggregate size (AN) were studied. Also, concrete mixtures that had different levels of replacement of AN by AP in the formulation were evaluated. In the formulations with partial replacement of AN by AP, a 20% reduction in the compressive strength was observed compared to the control sample, even for very high percentages of substitution (60%). Despite the decrease, AP-based concretes comply in all cases with the resistance requirements and allow to revalue an industrial waste and take care of the environment.Fil: Schust, C.. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Ramos, M.. Coarco S.A; ArgentinaFil: Stefani, Pablo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin
Reciclado de hormigón fresco mediante el uso de adición pelletizante
El retorno del hormigón fresco a la planta de elaboración es un problema económico y medioambiental. Aproximadamente el 2% de la producción de hormigón regresa a la planta y, en la mayoría de los casos, se elimina en gran medida como material de desecho. La producción de bloques, agregados triturados o la separación de sus componentes son algunas de las alternativas informadas para su reciclado. Recientemente se desarrolló una nueva tecnología basada en una adición en polvo de dos componentes que permite que el hormigón fresco se convierta fácilmente en un agregado artificial que puede reincorporarse a la producción de hormigón. En este trabajo se estudiaron las propiedades de los agregados pelletizados (AP) obtenidos a partir de dos formulaciones de hormigón con diferente tamaño máximo nominal de agregados naturales (AN). Asimismo, se evaluaron mezclas de hormigón que tuvieron diferentes niveles de reemplazo de AN por AP en su dosificación. En las formulaciones con sustitución parcial de AN por AP se observó una reducción de alrededor del 20% en la resistencia a la compresión respecto a la muestra control, incluso para porcentajes de sustitución muy elevados (60%). A pesar de la disminución, los hormigones basados en AP cumplen en todos los casos con los requisitos de resistencia y permiten revalorizar un residuo de la industria y cuidar el medio ambiente.Returned fresh mix concrete to the processing plant is an economic and environmental problem. About 2% of concrete production returns to the plant and, in most cases, is largely disposed of as waste material. The production of blocks, crushed aggregates or the separation of their main components are some of the alternatives reported for recycling. Recently, a new technology based on two-component powder additive has been developed, allowing the fresh returned concrete to be easily converted into an artificial aggregate, which can be incorporated into the production of concrete. In this paper, the properties of pelletized aggregates (AP) obtained from two concrete formulations with different maximum nominal natural aggregate size (AN) were studied. Also, concrete mixtures that had different levels of replacement of AN by AP in the formulation were evaluated. In the formulations with partial replacement of AN by AP, a 20% reduction in the compressive strength was observed compared to the control sample, even for very high percentages of substitution (60%). Despite the decrease, AP-based concretes comply in all cases with the resistance requirements and allow to revalue an industrial waste and take care of the environment.Fil: Schust, C.. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Ramos, M.. Coarco S.A; ArgentinaFil: Stefani, Pablo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin
Evaluation of thermal corrections to false vacuum decay rates
We examine the computation of the nucleation barrier used in the expression
for false vacuum decay rates in finite temperature field theory. By a detailed
analysis of the determinantal prefactor, we show that the correct bounce
solution used in the computation of the nucleation barrier should not include
loop corrections coming from the scalar field undergoing decay. Temperature
corrections to the bounce appear from loop contributions from other fields
coupled to the scalar field. We compute the nucleation barrier for a model of
scalar fields coupled to fermions, and compare our results to the expression
commonly used in the literature. We find that, for large enough self-couplings,
the inclusion of scalar loops in the expression of the nucleation barrier leads
to an underestimate of the decay rate in the neighborhood of the critical
temperature.Comment: 31 pages, 4 Figures appended as encapsulated PostScript at the end of
file (line 2136), used RevTeX Macros, DART-HEP-93/0
Nonequilibrium Precursor Model for the Onset of Percolation in a Two-Phase System
Using a Boltzmann equation, we investigate the nonequilibrium dynamics of
nonperturbative fluctuations within the context of Ginzburg-Landau models. As
an illustration, we examine how a two-phase system initially prepared in a
homogeneous, low-temperature phase becomes populated by precursors of the
opposite phase as the temperature is increased. We compute the critical value
of the order parameter for the onset of percolation, which signals the
breakdown of the conventional dilute gas approximation.Comment: 4 pages, 4 eps figures (uses epsf), Revtex. Replaced with version in
press Physical Review
BRS Sarandi: A New Andropogon Gayanus Cultivar for Tropical Pastures
BRS Sarandi is adapted to low and medium fertility soils. It has a medium-high height, with a semi-erect growth habit and a high total number of tillers. The annual productivity of dry matter is 11 t ha-1, concentrated in the rainy season (90%). Of the total DM produced, 60% are leaves. The levels of crude protein (CP), in vitro dry matter digestibility (IVDMD), neutral detergent fiber (NDF) and acid detergent fiber (ADF) are, on average, 8.7, 56.5, 66.7 and 38.2%, respectively. . The average daily weight gain was 0.7 kg/head/day, the gain per was and 1.7 kg ha-1 day with no supplementation except for mineral salt. The weight gain per area (AG) reached 15 @/ha/year with an average stocking rate of 2.5 AU. BRS Sarandi was registered in the Brazilian Cultivar Registry (Registro Nacional de Cultivares - RNC/MAPA) and is protected in the National Cultivar Protection System (Sistema Nacional de Proteção de Cultivares - SNPC/MAPA)
THE USE OF N400 IN STUDIES OF STIMULUS EQUIVALENCE: A REVIEW OF METHODS AND PARAMETERS
The N400 is defined as an event-related brain potential that is sensitive to the semantic relations between stimuli. For instance, when a pair of words belong to the same semantic domain (e.g., monkey-banana), the N400 will be significantly reduced in comparison to the N400 evoked by unrelated words (e.g., monkey-carburetor). Notably, the N400 responses are also sensitive to the arbitrary stimulus-stimulus relations formed by matching-to-sample procedures (MTS), supporting the notion that stimulus equivalence is a behavioristic model of semantic relations. In this study, we presented a methodological review of studies on stimulus equivalence that used the N400 as dependent measure of “equivalent” and “non-equivalent” stimulus-stimulus relations formed by MTS procedures. First, we searched on databases for studies that used the descriptive terms “equivalence relations”, “matching-to-sample”, “MTS”, “N400”, “relational learning”, and “derived relations” on the title and the abstract. Then, we categorized the number of experiments in each study, population, nature of stimuli, the event-related brain potential used as a dependent measure and whether the critical probes comprised baseline, reflexive, symmetric or transitive relations. We found that the MTS variables differed substantially from one study to another. Considering that most of these MTS variables may be critical to the establishment of stimulus equivalence, we encourage follow-up studies that aim at verifying whether and to what extent they can be related to the N400 outcomes.Key-words: Matching-to-sample, equivalence-relatedness-based-procedure, stimulus equivalence, N400, semantic relations, methodological review
Effectiveness of silver nitrate compared to talc slurry as pleural sclerosing agent in rabbits. Influence of concomitant intrapleural lidocaine
Não está ainda definido, qual o agente ideal para a produção de uma pleurodese efetiva. O talco é o agente mais freqüentemente utilizado apesar de suas manifestações colaterais. Outra possibilidade é o nitrato de prata, largamente usado no passado. OBJETIVOS: Determinar a influência da injeção intrapleural de lidocaina na produção de pleurodese com nitrato de prata, definir o efeito da lidocaina na maturação das fibras colágenas e confirmar que a pleurodese produzida pelo nitrato de prata é mais potente que a conseqüente à injeção intrapleural de talco. MÉTODOS: Foram estudados três grupos de 8 coelhos. Dois receberam nitrato de prata a 0,5%; em um deles, foi injetado previamente 0,5 ml de lidocaina a 2%. O terceiro grupo recebeu 2 ml de talco (400 mg/kg). Os animais foram sacrificados após 28 dias da injeção intrapleural e as cavidades pleurais examinadas macroscopicamente, analisando-se a presença de fusão entre os folhetos pleurais e microscopicamente avaliando-se a inflamação e a fibrose. Quantificou-se o total de colágeno na pleura e a distribuição de fibras finas e grossas, utilizando-se a coloração de pricrosirius. RESULTADOS: Nos dois grupos em que se injetou nitrato de prata (s/ lidocaina: 3.5 + 0.3 e com lidocaina: 3.2 + 0.3), a pleurodese macroscópica (scala 0 - 4) foi significantemente (p = 0.001) melhor do que a pleurodese resultante do talco (1.6 + 0.2). A média da fibrose pleural induzida pelo nitrato de prata (3.5 + 0.2) foi significantemente (p = 0.004) mais acentuada do que a produzida por talco (1.9 + 0.1). A instilação prévia de lidocaina determinou tendência a diminuir a quantidade de fibrose (3.1 + 0.4). A média (10³mm²) do colágeno pleural foi significantemente (p = 0.009) maior nos coelhos que receberam nitrato de prata (116.9 + 22.7) do que naqueles que receberam talco (10.7 + 3.4). A injeção de lidocaina reduziu discretamente o colágeno (80.1 + 30.3). A distribuição das fibras colágenas não foi diferente entre os grupos estudados. CONCLUSÃO: Este modelo animal confirma que, o nitrato de prata injetado no espaço pleural mais efetivo do que o talco na produção de pleurodese. A injeção intrapleural de lidocaina determina uma tendência a reduzir a quantidade de colágeno, mas não muda a efetividade da sínfise pleural ou modifica a maturação do colágeno.The ideal agent for producing pleurodesis has not been identified. Talc, the most commonly used, poses several problems. Another possibility is silver nitrate, which was widely used in the past. PURPOSE: To determine the influence of the intrapleural instillation of lidocaine in producing a pleurodesis with silver nitrate, to define the effect of lidocaine in the maturation of the collagen fibers, and to confirm that the pleurodesis after silver nitrate is stronger than after talc. METHODS: We studied three groups of 8 rabbits. Two groups received 0.5% silver nitrate; in one we had previously injected 0.5 ml of 2% lidocaine. The third group received 400 mg/kg talc (2 ml). The animals were sacrificed 28 days after the injection, and the pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of inflammation and fibrosis. The total amount of pleural collagen and the distribution of thick and thin collagen fibers were quantified. Collagen was identified using picrosirius red stain. RESULTS: In the two groups that received silver nitrate (without lidocaine: 3.5 + 03 and with lidocaine: 3.2 + 0.3), the macroscopic pleurodesis (scale 0 -- 4) was significantly (p = 0.001) better than that resulting from talc (1.6 + 0.2). The mean degree of pleural fibrosis induced by silver nitrate (3.5 + 0.2) was significantly (p = 0.004) higher than that induced by talc (1.9 + 0.1). The previous instillation of lidocaine resulted in a tendency for decreased amounts of fibrosis (3.1 + 0.4). The mean amount (10³mm²) of pleural collagen was significantly (p = 0.009) greater in the rabbits that received silver nitrate (116.9 + 22.7) than in those that received talc (10.7 + 3.4). The injection of lidocaine slightly reduced the collagen (80.1 + 30.3). The distribution of collagen fibers did not differ among the groups. CONCLUSION: This rabbit model clearly confirms that intrapleural silver nitrate is more effective than talc for producing pleurodesis. The previous intrapleural instillation of lidocaine results in a decreasing trend in the amount of collagen, but does not change the effectiveness of the pleural fusion or modify the process of collagen maturation
Efeitos de um programa domiciliar de exercícios após um treinamento resistido supervisionado em pacientes com doença pulmonar obstrutiva crônica
Design of the study: clinical Trial. Objective: This study aimed to evaluate the effects of a homebased resistance exercise program with elastic tubing after supervised resistance training on peripheral muscle strength and quality of life in patients with chronic obstructive pulmonary disease (COPD). Methods: The study included 22 COPD patients, aged 55-70 years. Peripheral muscle strength and quality of life were evaluated through digital dynamometer and Chronic Respiratory Disease Questionnaire (CRDQ) respectively after supervised resistance training program, and then the patients were divided into two groups: home-based treatment (n = 10) and control (n = 12). After 16 weeks the assessments were repeated. Results: The home resistance training showed no significant increase in peripheral muscle strength and quality of life, however, was able to maintain the gains made in the previous supervised training. Conclusion: The continuity of home-based treatment did not promote additional improvements to supervised training after the protocol, since the gains were maintained in both assessed groups after 4 monthsDesenho do estudo: ensaio clínico. Objetivo: Avaliar os efeitos de um programa de exercícios resistidos em domicílio, com tubos elásticos, após o treinamento resistido supervisionado sobre a força muscular periférica e qualidade de vida de pacientes com doença pulmonar obstrutiva crônica (DPOC). Métodos: O estudo incluiu 22 pacientes com DPOC, com idade entre 55-70 anos. A força muscular periférica e a qualidade de vida foram avaliados por meio da dinamometria e do questionário Chronic Respiratory Questionare (CRQ), respectivamente, após o programa de treinamento de resistência supervisionado, e, em seguida, os pacientes foram divididos em dois grupos: tratamento domiciliar (n = 10) e controle (n = 12). Após 16 semanas, as avaliações foram repetidas. Resultados: O treinamento resistido em domicílio não mostrou aumento significativo sobre a força muscular periférica e qualidade de vida, no entanto, foi capaz de manter os ganhos obtidos após o programa de treinamento supervisionado. Conclusão: A continuidade do tratamento em domicílio não promoveu melhorias adicionais após o protocolo, uma vez que os ganhos foram mantidos nos dois grupos avaliados após 4 mese
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