Mr imaging of avascular femoral head necrosis: pre- and postoperative studies

Forty-six patients with suspected avascular necrosis of the femoral head were examined by T2- and T1-weighted sequences before and after intravenous infusion of Gd-DTPA. Both sides were involved in 12 cases. The classification was done according to Ficat [1]. In early stages and in postoperative studies a correlation of signal intensity increase after infusion of Gd-DTPA and clinical symptoms was found. Contrast enhancement of the plain low signal intensity area or of the implanted graft on T1-weighted images was assumed vascularized or vital components in seven cases of Ficat I and in 13 postoperative studies. Contrawise, in seven patients with severe postoperative symptoms we found no contrast enhancement indicating avascular regions.     

Überlegungen zum Krankheitsbegriff aus strahlentherapeutischer Sicht

Definition of the problem: The concept of disease should be presented under the view of clinical medicine using radiooncology as an example. The interactive dualism, as described by Switankowsky, is introduced as theoretical framework for understanding the nature of disease. According to this theory, the interaction between mind and body plays a central role to treat the patient with dignity and compassion. This is true for radiotherapy, where a holistic understanding of the patient is necessary. Actual analysis of the current clinical literature is made and nevertheless shows a reductionistic concept of disease, which is based mainly on objective criteria from the physician's view. Arguments and conclusions: Considering and applying the interactive dualism physicians can overcome the reductionistic view. The discussion between doctor and patient will get a leading role. Both physician and patient can develop a common concept while discussing the disease, so that according the interactive dualism objective and subjective criteria are considered. Limitations of this new definition need special attention and should be finally described.     

Multi-valued autoepistemic logic

We generalize Moore's autoepistemic logic to multi-valued autoepistemic logic, where the set of truth-values can be any complete lattice. Multi-valued autoepistemic extensions can be characterized by admissible belief interpretations which are the conrete approximations of extensions and are appropriate to be computed and manipulated. We prove that multi-valued autoepistemic extensions are exactly the theories of maximal multi-valued Kripke models. The class of stratified theories is investigated and it is shown that stratified theories have exactly one multi-valued autoepistemic extension. Finally we present a sequent calculus for multi-valued logic which serves as a tool for a decision procedure for multi-valued autoepistemic logic.     

Two adaptive Gauss-Legendre type algorithms for the verified computation of definite integrals

We propose a two algorithms for computation of (sharp) enclosures of definite interevals: alocal adaptive algorithm (LAA) and aglobal adaptive algorithm (GAA). Both algorithms are based on Gauss-Legendre quadrature. Error terms are bounded using automatic differentiation in combination with interval evaluations. Several numerical examples are presented; these examples include comparison with an adaptive interval Romberg scheme.     

Dynamic instability analysis of elastic and inelastic shells

The present contribution is concerned with dynamic stability investigations of arbitrary structural responses, in particular shell responses. In order to trace such nonlinear fundamental processes, incremental/iterative path-following algorithms are employed to the tangential equation of motion which is derived under special regard of finite rotation shell theories, elasto-plastic material behaviour, and motion-dependent loading. Occuring instabilities can be detected with the help of Lyapunow exponents as generalized concept for the detection of quantitative stability properties. Well known investigation procedures are recognized as special cases of the Lyapunow-exponent-concept for stationary, transient, periodic, and arbitrary solution curves in the phase space. A new numerical procedure for the determination of one-dimensional Lyapunow exponents is introduced to identify critical directions in the solution space for large discretized structures by reduction to relevant manifolds.     

Untersuchungen zum Einfluss der thermischen Vergütung auf die Porosität von Fichtenholz

Ohne Zusammenfassung

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Untersuchungen zum Einfluss der thermischen Vergütung auf die Porosität von Fichtenholz