84 research outputs found
Cardiac rehabilitation in Austria: long term health-related quality of life outcomes
<p>Abstract</p> <p>Background</p> <p>The goal of cardiac rehabilitation programs is not only to prolong life but also to improve physical functioning, symptoms, well-being, and health-related quality of life (HRQL). The aim of this study was to document the long-term effect of a 1-month inpatient cardiac rehabilitation intervention on HRQL in Austria.</p> <p>Methods</p> <p>Patients (N = 487, 64.7% male, age 60.9 ± 12.5 SD years) after myocardial infarction, with or without percutaneous interventions, coronary artery bypass grafting or valve surgery underwent inpatient cardiac rehabilitation and were included in this long-term observational study (two years follow-up). HRQL was measured with both the MacNew Heart Disease Quality of Life Instrument [MacNew] and EuroQoL-5D [EQ-5D].</p> <p>Results</p> <p>All MacNew scale scores improved significantly (p < 0.001) and exceeded the minimal important difference (0.5 MacNew points) by the end of rehabilitation. Although all MacNew scale scores deteriorated significantly over the two year follow-up period (p < .001), all MacNew scale scores still remained significantly higher than the pre-rehabilitation values. The mean improvement after two years in the MacNew social scale exceeded the minimal important difference while MacNew scale scores greater than the minimal important difference were reported by 40-49% of the patients.</p> <p>Two years after rehabilitation the mean improvement in the EQ-5D Visual Analogue Scale score was not significant with no significant change in the proportion of patients reporting problems at this time.</p> <p>Conclusion</p> <p>These findings provide a first indication that two years following inpatient cardiac rehabilitation in Austria, the long-term improvements in HRQL are statistically significant and clinically relevant for almost 50% of the patients. Future controlled randomized trials comparing different cardiac rehabilitation programs are needed.</p
Comparação entre ergômetros específico e convencionais na determinação da capacidade aeróbia de mesatenistas
Entwicklung und Anwendung partikelbasierter Simulationstechniken für die Modellierung von Umordnungseffekten und Anisotropieentwicklung in pulvertechnologischen Prozessen
In this work particle-based simulation schemes are developed and employed to investigate powder-technological processes on a fundamental level. In order to simulate sintering an existing Discrete Element Method (DEM) based model is improved to consider rotational movements, particle size distributions, grain coarsening and stress boundary conditions. The simulations show that for monomodal powders essentially no rearrangement takes place. However, it can be easily induced by applying a (small) external pressure. In this case it significantly enhances densification and decrease bulk and shear viscosities. Polydisperse size distributions also induce rearrangement which increases with distribution width. Overall, the densification rate is still lower because of a lower coordination number and higher contact areas. The model shows good quantitative agreement with experimental data on an Al2O3 powder. Anisotropic sintering behavior is studied by simulating zero radial strain rate sinter forging and constrained sintering. The developing anisotropic microstructure is characterized by anisotropic distributions of the contacts, contact areas and pore orientations, with the contact area distribution being the characteristic measure. Rearrangement and polydispersity can lead to lower anisotropy. The anisotropic microstructure results in anisotropic sintering behavior for the strain rates. Additionally, crack formation is observed for constrained sintering. The simulations agree qualitatively and in part quantitatively with analogous experiments. Anisotropic constitutive equations allow describing the observed behavior if the required anisotropic parameters are extracted from simulations. The anisotropy development during tape casting is investigated with a newly developed multi-scale simulation model, which is based on the DEM and Smoothed Particle Hydrodynamics (SPH). The microscopic DEM model shows the development of an anisotropic, hexagonal layering structure. This development can be decreased for wider particle size distributions. In order to simulate tape casting on the macroscopic scale a new non-newtonian, thixotropic rheological model is developed for the SPH method. The model, which describes the rheological behaviour of real pastes well, is employed to simulate the whole process geometry. A large eddy is observed between the blades, which is in accordance with experiments. Depending on the process and rheological parameters significant changes in the flow profiles below the blades are seen
Discrete element modeling of anisotropy development during constrained sintering of alumina
Shape distortion and delamination during constrained sintering of ceramic stripes: Discrete element simulations and experiments
Particle-based simulations using the discrete element method are applied for the sintering of thin ceramic stripes that are constrained by a rigid substrate. The inhibition of lateral particle movement in vicinity of the substrate leads to a preferred shrinkage direction perpendicular to the substrate, which causes shape distortion as well as delamination of the stripe at the interface edges. Multiple processing parameters are varied in simulations to analyze their influence on the mentioned effects. The amount of particle rearrangement and the height to width aspect ratio of the cross-section are identified to be factors that determine the level of shape distortion and edge delamination. The simulation results are compared with measurements of stripes produced by soft micromolding in capillaries. Good accordance is observed regarding parameters like axial and lateral shrinkage or delamination angle
Modification of S-metabolism in spruce trees by H2S studied by radiolabelled sulfate uptake
Modification of S-metabolism in spruce trees by H2S studied by radiolabelled sulfate uptake
Changes in antioxidant and pigment pool dimensions in UV-B irradiated maize seedlings
Ultraviolet-B (UV-B) radiation (280/320 nm) is an environmental challenge affecting a number of metabolic functions through the generation of reactive oxygen species (ROS). Plants protect themselves from this harmful radiation by synthesizing flavonoids, which act as a screen inside the epidermal cell layer, and by making adjustments to the antioxidant systems at both cell and whole organism level. This study describes the flavonoid content, the photosynthetic pigment composition and the proline, tocopherol and ascorbate content in UV-B exposed maize plants. Following exposure, the tocopherol content was slightly, but significantly lower, pointing to the membrane environment as a primary target for UV-B radiation. The water-soluble antioxidant content was largely unaffected, but an enhanced turnover in the ascorbate/glutathione cycle might be needed for tocopherol regeneration
Uptake and distribution of S-35-sulfate in needles and roots of spruce seedlings as affected by exposure to SO2 and H2S
The interaction between pedospheric and atmospheric sulfur nutrition was studied in seedlings of Norway spruce. Spruce was grown on a 25% Hoagland nutrient solution containing S-35-sulfate and simultaneously exposed to 250 nl 1(-1) atmospheric SO2 or H2S. A 6-day exposure to SO2 and H2S resulted in a substantial increase in the total sulfur concentration of the needles. This increase could be ascribed to increased needle concentrations of sulfate, water-soluble non-protein thiols and organic sulfur. SO2 and H2S exposure resulted in slight but significant increases in the concentration of sulfur compounds in roots. In all sulfur fractions, except sulfate, there was a substantial decrease in the level of S-35 in needle and root sulfur fractions upon SO2 and H2S exposure, demonstrating that spruce was able to switch from pedospheric sulfate to atmospheric sulfur as a source for growth. In needles, the amount of S-35 decreased in total organic S and glutathione fraction, whereas it increased in sulfate. This supports continued import of S taken up by the roots into the needles in spite of a decreased channeling of S-35 into synthesis in needles. A greater part of total sulfate increase was due to unlabeled S, which points towards metabolic oxidation of H2S and SO2 to sulfate. Increased concentrations of S compounds (including sulfate) in roots were mainly due to unlabeled S, indicating an import of sulfur from the foliage. The significance of glutathione in the translocation of reduced sulfur from the needles to the roots is discussed. (C) 2003 Elsevier B.V. All rights reserved
Simulation von Prozessfolgen mit der Diskrete-Elemente-Methode
Finite-Elemente basierte Methoden sind gut geeignet, um Herstellungsprozesse von Bauteilen auch mit komplexen Formen zu modellieren. In der Zwischenzeit wurden die Simulationsmöglichkeiten durch die Anwendung der Diskrete-Elemente-Methode (DEM) auf pulvertechnologische Prozessschritte erweitert. Sie eignet sich auch für Prozessschritte, die der Finite-Elemente-Methode kaum zugänglich sind, z.B. das Füllen der Matrize. Bei anderen Prozessschritten, wie z.B. beim Sintern, kommen beide Methoden in Frage. Die Diskrete-Elemente-Methode (DEM) ist ein numerisches Simulationsverfahren, das ursprüngliche für die Gesteinsmechanik entwickelt wurde. Das zu simulierende Medium wird in Form von einzelnen, diskreten Partikeln beschrieben. Alle Teilchen bewegen sich gemäß den Newtonschen Gesetzen der Mechanik, wobei die Kräfte zwischen den Teilchen entsprechend dem zu modellierenden Prozess formuliert werden, z.B. für Schütten, Foliengießen oder Sintern. Die Diskrete-Elemente-Methode (DEM) wurde auf verschiedene pulvertechnologische Prozessschritte, insbesondere das Füllen der Matrize, das Foliengießen und das Sintern, angewandt. Die DEM ist äußerst flexibel, und die Möglichkeiten sind durch die hier dargestellten Arbeiten bei weitem noch nicht ausgeschöpft. Die Methode eignet sich gut für die Prozesskettensimulation. Durch die Wahl der Wechselwirkungskräfte zwischen den Teilchen lässt sich das Materialverhalten in den verschiedenen Prozessschritten nachbilden und an reale Pulver anpassen. Zur Zeit fehlt es jedoch in vielen Fällen noch an Experimenten, um die Modelle zu überprüfen und ihre Parameter zu bestimmen
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