OBJECTIVE:To determine the relationship between enteral nutrition discontinuation and outcome in general critically ill patients.MATERIALS AND METHODS:All patients admitted to a mixed intensive care unit in a tertiary care hospital from May-August 2009 were screened for an indication for enteral nutrition. Patients were followed up until leaving the intensive care unit or a maximum of 28 days. The gastrointestinal failure score was calculated daily by adding values of 0 if the enteral nutrition received was identical to the nutrition prescribed, 1 if the enteral nutrition received was at least 75% of that prescribed, 2 if the enteral nutrition received was between 50-75% of that prescribed, 3 if the enteral nutrition received was between 50-25% of that prescribed, and 4 if the enteral nutrition received was less than 25% of that prescribed.RESULTS:The mean, worst, and categorical gastrointestinal failure scores were associated with lower survival in these patients. Age, categorical gastrointestinal failure score, type of admission, need for mechanical ventilation, sequential organ failure assessment, and Acute Physiologic and Chronic Health Evaluation II scores were selected for analysis with binary regression. In both models, the categorical gastrointestinal failure score was related to mortality.CONCLUSION:The determination of the difference between prescribed and received enteral nutrition seemed to be a useful prognostic marker and is feasible to be incorporated into a gastrointestinal failure score.

Hemodialysis patients have a marked decrease in functional capacity when compared to healthy individuals. We evaluated the factors associated with functional capacity in hemodialysis patients. A total of 102 hemodialysis patients were evaluated. The patients were submitted to a 6-min walk test, peripheral muscle strength tests, and an evaluation of quality of life, anxiety, and depression. The laboratory data were measured. The 6-min walk test distance correlated significantly with age, educational level, hemoglobin, creatinine, number of comorbidities, peripheral muscle strength, and some domains of SF-36 quality of life questionnaire and depression (P < 0.05). Multiple linear regression showed that educational level, hemoglobin, peripheral muscle strength, and depression significantly affected the 6-min walk test distance (P < 0.05). The multiple correlation coefficient was 0.74, and the squared multiple correlation coefficient adjusted was 0.52. In conclusion, functional capacity was significantly associated with educational level, hemoglobin, peripheral muscle strength, and depression in hemodialysis patients.

In this study the application of the single-particle compression test is discussed as an alternative method for the mechanical characterisation of coarse aggregates generally employed in concrete manufacturing. This leads to an estimation of the tensile strength and fracture energy of the aggregate particles. A wide range of aggregate types is considered. In particular, the mechanical responses of crushed limestone and river gravel are compared with expanded clay, recycled concrete and clay brick aggregates. In addition, physical properties are assessed experimentally and correlated to the aggregates' mechanical performance. Despite the high data scatter presented, the results demonstrate the ability of the proposed approach to accurately determine fracture energy and strength histories using single-particle compression. Overall, the porosity governs the mechanical behaviour of particles. Moreover, direct relationships between mechanical and physical properties yield consistent and expected results that validate the methodology.

ResumoThe effects of the inclusion of steel fibers in concrete have been widely studied in order to investigate possible changes in mechanical properties, such as the increase in tensile strength, ductility, stiffness, toughness (energy absorption capacity), and durability. An immediate consequence of this addition is the mitigation of concrete's brittle behavior, so that the material meets new quality requirements. In this context, it is important to study the spatial distribution of the entire internal structure of these materials. Three-dimensional computed microtomography is a non-destructive inspection technique used to characterize the internal structures of various materials based on X-ray interaction with the inspected object. Topological and morphological properties can be obtained directly in three dimensions by means of mathematical reconstruction of the radiographs, which allows analyzing, for example, porosity and distribution of objects. In this context, the aim of this study is to investigate the spatial distribution of steel fibers, as well as of porosity in reinforced concrete samples. To this end, we used a microtomography system calibrated to operate at a voltage of 80 kV, electric current of 100 μA and a pixel size equal to 24 µm. The results showed low porosity and that the steel fibers were not uniformly distributed throughout the sample.Os efeitos da inserção de fibras de aço em concretos têm sido amplamente estudados com o objetivo de investigar possíveis modificações nas propriedades mecânicas, tais como, o aumento da resistência à tração, ductilidade, rigidez, tenacidade (capacidade de absorção de energia), e durabilidade. Uma das consequências imediatas dessa adição é a mitigação do comportamento frágil do concreto, de forma que o material passe a ter novas exigências de qualidade. Nesse contexto, é de grande importância o conhecimento espacial da distribuição de toda estrutura interna desses materiais. A microtomografia computadorizada tridimensional é uma técnica utilizada na caracterização de estruturas internas de diversos materiais, baseada na interação dos raios X com o objeto inspecionado, sendo considerado um ensaio não destrutivo. Propriedades morfológicas e topológicas podem ser obtidas diretamente em três dimensões através da reconstrução matemática das radiografias, o que possibilita analisar, por exemplo, a porosidade e a distribuição de diversos objetos. Nesse contexto, o objetivo desse trabalho é a investigação da distribuição espacial das fibras de aço, assim como da porosidade em amostras de concreto. Para tal, foi utilizado um sistema de microtomografia calibrado para operar com uma tensão de 80 KV, corrente elétrica de 100 µA e um tamanho de pixel igual a 24 µm. Os resultados mostraram uma porosidade baixa e que as fibras de aço não estão distribuídas uniformemente ao longo da amostra.Palavras-chave: raios X, fibras de aço, microtomografia, porosidade, concreto.

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