Über offene analytische Äquivalenzrelationen auf komplexen Räumen

Ohne Zusammenfassung     

Beschleunigung eines Kolbens in einem Stosswellenrohr mit veränderlichem Querschnitt

Zusammenfassung Es wird ein vereinfachtes, eindimensionales Modell beschrieben für die Beschleunigung eines Kolbens in einem Stosswellenrohr, dessen Querschnitt sich nach einer gewissen Lauflänge sprunghaft erweitert. Numerische Rechnungen werden mit Messungen im Stosswellenrohr verglichen.

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Summary A simplified, one-dimensional model is developed to describe the acceleration of a piston in a shock tube having a discontinuous increase in cross-section. Numerical calculations are compared with shock tube experiments.

     

Atomic force microscopy study of early morphological changes during apoptosis

Apoptosis is defined by a distinct set of morphological changes observed during cell death including loss of focal adhesions, the formation of cell membrane buds or blebs, and a decrease in total cell volume. Recent studies suggest that these dramatic morphological changes, particularly apoptotic volume decrease (AVD), are an early prerequisite to apoptosis and precede key biochemical time-points. Here we use atomic force microscopy to observe early stage AVD of KB cells undergoing staurosporine-induced apoptosis. After a 3-h exposure to 1 microM staurosporine, a 32% decrease in total cell height and a 50% loss of total cell volume is observed accompanied by only a 15% change in cell diameter. The observed AVD precedes key biochemical hallmarks of apoptosis such as loss of mitochondrial membrane potential, phosphatidyl serine translocation, nuclear fragmentation, and measurable caspase-3 activity. This suggests that morphological volume changes occur very early in the induction of apoptosis.