Techn. University, Diss., 2004--München.

Leischmaniasis ist ein ernstzunehmende bedrohliche Erkrankung in vielen Ländern. Epidemien sind nicht unter Kontrolle, Neusbrüche werden in endemischen Ländern registriert. Darüber hinaus gibt es eine zunehmende Anzahl von Krankheitsfällen bei Reiserückkehrern in nicht endemischen Ländern . Für den individuellen Patienten sowie auch allgemein für die epidemiologische Kontrolle ist eine frühe und angemessene Therapie sehr wichtig. Als Voraussetzung ist eine präzise Diagnostik unabdingbar. Die Polymerase Ketten Reaktion (PCR) besitzt das größte Potential für die sensitive und spezies-spezifische Diagnostik der Leischmaniasis. Diese Studie ist in Israel und in der West Bank durchgeführt worden mit dem Ziel, eine sensitive und spezies-spezifische Diagnostik für Leischmaniasis im Land zu etablieren. Drei Arten von Leischmanien sind endemisch, Leishmania major,L.tropica, L.d.infantum, mit neuausbrechenden endemischen Foci in einigen Gegenden des Landes. Israelische Reiserückkehrer aus Zentral- und Südamerika kehren gelegentlich mit Infektionen aus der Neuen Welt zurück (L.braziliensis, L.mexicana Komplex). In dieser Studie wurden vor allem Proben direkt von denHautläsionen entnommen und auf Filter Papiekonserviert. Verschiedene DNA Extraktions- und PCR-Methoden wurden getestet. PCR wurde eingeführt für die Diagnostik von Patienten und auch zur Untersuchung von Infektionsraten bei Reservoirtieren. Ein Hauptziel der Studie war, die Methoden nach Praktikabilität, Zeit- und Kosteneffizienz testen, im Hinblick auf die Einführung der Methoden in klinischen Labors. / Leishmaniasis is a serious health threat in many countries around the world.Epidemics are hardly controlled, new foci are emerging in endemic countries. In addition,through tourism increasing numbers of infections are seen in non endemic countries. Early and adequate treatment is essential for the individual as well as for the control of the disease in general. As a prerequisite precise diagnosis is necessary. Diagnosis by the polymerase chain reaction (PCR) has the greatest potential for sensitive and species-specific diagnosis of leishmaniasis. This study has been carried out in Israel and the West Bank with the purpose to establish sensitive and species-specific diagnosis of leishmaniasis in the country. Three species of Leishmania are endemic, Leishmania major, L.tropica and L.d.infantumwith emerging foci in many parts of the country. Other species of the New World are occasionally imported by Israeli travelers returning from Central or South America (L.braziliensis and L.mexicana complex). The study focused on dermal lesion scrapings collected from suspected lesions and preserved on filter paper. Different DNA extraction and PCR methods have been tested. PCR was introduced forthe diagnosis of individual patients as well as for epidemiological studies in reservoir animals. It has been a major goal to select time and cost saving methods with regard to the introduction of PCR diagnosis of leishmaniasis to clinical laboratories.

Die Arbeit beschäftigt sich mit der Untersuchung der Beanspruchungen von Staurollenketten. Zunächst wurde in den Grundlagen der Aufbau von unterschiedlichen Staurollenkettenarten dargestellt, die Eigenschaften miteinander verglichen und kategorisiert. Aufbauend auf dem anschließend geschaffenen Verständnis der wirkenden Reibpaarungen bzw. -arten wurden FEM-Analysen durchgeführt, um dadurch auftretende Spannungen zu detektieren und das thermische Verhalten der unterschiedlichen Werkstoffpaarungen zu ermitteln. Innerhalb der praktischen Versuche der Arbeit kam es zur Ermittlung der Bruch- und Dauerfestigkeiten nach ISO15654 [DIN04]. Zur Untersuchung der Eigenschaften der Ketten unter praxisnahen Randbedingungen wurde ein Versuchsstand konzipiert, welcher die Ermittlung von Kennwerten zwei unterschiedlicher Kettengrößen unter härtesten Bedingungen ermöglicht. Durch diesen Versuchsstand wurden die Staukraft, die Kettenzugkraft durch das Drehmoment am Antrieb, die Kettengeschwindigkeit, die Kettenlängung und das Temperaturverhalten dauerhaft überwacht. Im letzten Kapitel der Arbeit wurde eine Überwachungsstation für unterschiedliche Baugrößen von Staurollenketten entwickelt und die Funktionsweise durch Versuche nachgewiesen. / This dissertation is dealing with the investigation of the load behaviour of accumulation roller chains. Initially, the structures of different types of accumulation roller chains are described, properties are compared and categorised. Based on the created understanding of acting tribological pairing and friction mechanisms, FEM analysis have been performed to evaluate occurring stresses and determine the thermal behaviour of the various material combinations. Within the testing procedures, breaking strength and fatigue strength have been investigated in accordance with DIN ISO 15654 [cf. DIN04]. A test bench has been developed for practically relevant testing of the chains, where determination of characteristic values can be done under hard testing conditions for two different chain types. The test bench ensures measurement and survey of accumulation forces, tensile chain forces (by torque moment at drive), chain speed, chain elongation and chain temperature during whole testing time. The last chapter of the dissertation deals with the development of a 'control and monitoring unit' for accumulation roller chains with various dimensions including proof of function by trials.

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Objective: The aim of this study was to develop an immunomagnetic/real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay and assess its clinical value for the molecular detection of circulating tumor cells (CTCs) in peripheral blood of pancreatic cancer patients. Methods: The presence of CTCs was evaluated in 34 pancreatic cancer patients before systemic therapy and in 40 healthy controls, through immunomagnetic enrichment, using the antibodies BM7 and VU1D9 [targeting mucin 1 and epithelial cell adhesion molecule (EpCAM), respectively], followed by real-time RT-PCR analysis of the genes KRT19, MUC1, EPCAM, CEACAM5 and BIRC5. Results: The developed assay showed high specificity, as none of the healthy controls were found to be positive for the multimarker gene panel. CTCs were detected in 47.1% of the pancreatic cancer patients before the beginning of systemic treatment. Shorter median progression-free survival (PFS) was observed for patients who had at least one detectable tumor-associated transcript, compared with patients who were CTC negative. Median PFS time was 66.0 days [95% confidence interval (CI) 44.8–87.2] for patients with baseline CTC positivity and 138.0 days (95% CI 124.1–151.9) for CTC-negative patients (p = 0.01, log-rank test). Conclusion: Our results suggest that in addition to the current prognostic methods, CTC analysis represents a potential complementary tool for prediction of outcome in pancreatic cancer patients. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Hierarchical Markovian Models (HMMs) are composed of multiple low level models (LLMs) and high level model (HLM) that defines the interaction among LLMs. The essence of the HMM approach is to model the system at hand in the form of interacting components so that its (larger) underlying continous-time Markov chain (CTMC) is not generated but implicitly represented as a sum of Kronecker products of (smaller) component matrices. The Kronecker structure of an HMM induces nested block partitionings in its underlying CTMC. These partitionings may be used in block versions of classical iterative methods based on splittings, such as block SOR (BSOR), to solve the underlying CTMC for its stationary vector. Therein the problem becomes that of solving multiple nonsingular linear systems whose coefficient matrices are the diagonal blocks of a particular partitioning. This paper shows that in each HLM state there may be diagonal blocks with identical off-diagonal parts and diagonals differing from each other by a multiple of the identity matrix. Such diagonal blocks are named candidate blocks. The paper explains how candidate blocks can be detected and how the can mutually benefit from a single real Schur factorization. It gives sufficient conditions for the existence of diagonal blocks with real eigenvalues and shows how these conditions can be checked using component matrices. It describes how the sparse real Schur factors of candidate blocks satisfying these conditions can be constructed from component matrices and their real Schur factors. It also demonstrates how fill in- of LU factorized (non-candidate) diagonal blocks can be reduced by using the column approximate minimum degree algorithm (COLAMD). Then it presents a three-level BSOR solver in which the diagonal blocks at the first level are solved using block Gauss-Seidel (BGS) at the second and the methods of real Schur and LU factorizations at the third level. Finally, on a set of numerical experiments it shows how these ideas can be used to reduce the storage required by the factors of the diagonal blocks at the third level and to improve the solution time compared to an all LU factorization implementation of the three-level BSOR solver.

Kronecker structured representations are used to cope with the state space explosion problem in Markovian modeling and analysis. Currently an open research problem is that of devising strong preconditioners to be used with projection methods for the computation of the stationary vector of Markov chains (MCs) underlying such representations. This paper proposes a block SOR (BSOR) preconditioner for hierarchical Markovian Models (HMMs) that are composed of multiple low level models and a high level model that defines the interaction among low level models. The Kronecker structure of an HMM yields nested block partitionings in its underlying continuous-time MC which may be used in the BSOR preconditioner. The computation of the BSOR preconditioned residual in each iteration of a preconditioned projection method becoms the problem of solving multiple nonsingular linear systems whose coefficient matrices are the diagonal blocks of the chosen partitioning. The proposed BSOR preconditioner solvers these systems using sparse LU or real Schur factors of diagonal blocks. The fill-in of sparse LU factorized diagonal blocks is reduced using the column approximate minimum degree algorithm (COLAMD). A set of numerical experiments are presented to show the merits of the proposed BSOR preconditioner.

A Markov chain is introduced to the major steps of the process of learning a subject matter by a group of students in the classroom, in order to obtain a mathematical representation of the above process. A classroom experiment for learning mathematics is also presented illustrating the applicability of our results in practice.

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