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  • 2005-2009  (7)
  • 2000-2004  (160)
  • 1940-1944
  • 2008  (7)
  • 2000  (160)
  • Immunohistochemistry  (100)
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  • 2005-2009  (7)
  • 2000-2004  (160)
  • 1940-1944
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  • 1
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    Vickrey Auctions for Railway Tracks (2008)
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    Publication Date: 2020-08-05
    Description: We consider an auction of slots to run trains through a railway network. In contrast to the classical setting for combinatorial auctions, there is not only competition for slots, but slots can mutually exclude each other, such that general conflict constraints on bids arise. This turns the winner determination problem associated with such an auction into a complex combinatorial optimization problem. It also raises a number of auction design questions, in particular, on incentive compatibilty. We propose a single-shot second price auction for railway slots, the Vickrey Track Auction (VTA). We show that this auction is incentive compatible, i.e., rational bidders are always motivated to bid their true valuation, and that it produces efficient allocations, even in the presence of constraints on allocations. These properties are, however, lost when rules on the submission of bids such as, e.g., lowest bids, are imposed. Our results carry over to generalized" Vickrey auctions with combinatorial constraints.
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  • 2
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    Balancing Efficiency and Robustness – A Bi-criteria Optimization Approach to Railway Track Allocation (2008)
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    Publication Date: 2020-08-05
    Description: Technical restrictions and challenging details let railway traffic become one of the most complex transportation systems. Routing trains in a conflict-free way through a track network is one of the basic scheduling problems for any railway company. This article focuses on a robust extension of this problem, also known as train timetabling problem (TTP), which consists in finding a schedule, a conflict free set of train routes, of maximum value for a given railway network. However, timetables are not only required to be profitable. Railway companies are also interested in reliable and robust solutions. Intuitively, we expect a more robust track allocation to be one where disruptions arising from delays are less likely to be propagated causing delays of subsequent trains. This trade-off between an efficient use of railway infrastructure and the prospects of recovery leads us to a bi-criteria optimization approach. On the one hand we want to maximize the profit of a schedule, that is more or less to maximize the number of feasible routed trains. On the other hand if two trains are scheduled as tight as possible after each other it is clear that a delay of the first one always affects the subsequent train. We present extensions of the integer programming formulation in [BorndoerferSchlechte2007] for solving (TTP). These models can incorporate both aspects, because of the additional track configuration variables. We discuss how these variables can directly be used to measure a certain type of robustness of a timetable. For these models which can be solved by column generation techniques, we propose so-called scalarization techniques, see [Ehrgott2005], to determine efficient solutions. Here, an efficient solution is one which does not allow any improvement in profit and robustness at the same time. We prove that the LP-relaxation of the (TTP) including an additional $\epsilon$-constraint remains solvable in polynomial time. Finally, we present some preliminary results on macroscopic real-world data of a part of the German long distance railway network.
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  • 3
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    Simulations of QCD in the Era of Sustained Tflop/s Computing (2008)
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    Publication Date: 2016-06-30
    Description: The latest machine generation installed at supercomputer centres in Germany offers a peak performance in the tens of Tflop/s range. We study performance and scaling of our quantum chromodynamics simulation programme BQCD that we obtained on two of these machines, an IBM Blue Gene/L and an SGI Altix 4700. We compare the performance of Fortran/MPI code with assembler code. The latter allows to exploit concurrency at more levels, in particular in overlapping communication and computation as well as prefetching data from main memory.
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  • 4
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    The minimization of an L^{\infty}-functional subject to an elliptic PDE and state constraints (2008)
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    Publication Date: 2016-06-09
    Description: We study the optimal control of a maximum-norm objective functional subject to an elliptic-type PDE and pointwise state constraints. The problem is transformed into a problem where the non-differentiable L^{\infty}-norm in the functional will be replaced by a scalar variable and additional state constraints. This problem is solved by barrier methods. We will show the existence and convergence of the central path for a class of barrier functions. Numerical experiments complete the presentation.
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  • 5
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    Mehr Mathematik wagen in der Medizin (2008)
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    Publication Date: 2020-11-16
    Description: Der Artikel gibt einen Einblick in das reiche Feld der Zusammenarbeit zwischen Mathematik und Medizin. Beispielhaft werden drei Erfolgsmodelle dargestellt: Medizinische Bildgebung, mathematische Modellierung und Biosignalverarbeitung im Bereich der Dynamik des Herzens sowie mathematische Modellierung und Simulation in der Krebstherapie Hyperthermie und der Mund-Kiefer-Gesichts-Chirurgie. In allen Fällen existiert ein Gleichklang der Interessen von Medizin und Mathematik: Beide Disziplinen wollen die Resultate schnell und zuverlässig. Für die Klinik heißt das, dass notwendige Rechnungen in möglichst kurzer Zeit, und zwar auf dem PC, ablaufen müssen und dass die Resultate so genau und belastbar sein müssen, dass medizinische Entscheidungen darauf aufbauen können. Für die Mathematik folgt daraus, dass höchste Anforderungen an die Effizienz der verwendeten Algorithmen und die darauf aufbauende Software in Numerik und Visualisierung zu stellen sind. Jedes Kapitel endet mit einer Darstellung der Perspektive des jeweiligen Gebietes. Abschließend werden mögliche Handlungsoptionen für Politik und Wirtschaft diskutiert.
    Keywords: ddc:000
    Language: German
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  • 6
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    Constraint Integer Programming: Techniques and Applications (2008)
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    Publication Date: 2022-03-14
    Description: This article introduces constraint integer programming (CIP), which is a novel way to combine constraint programming (CP) and mixed integer programming (MIP) methodologies. CIP is a generalization of MIP that supports the notion of general constraints as in CP. This approach is supported by the CIP framework SCIP, which also integrates techniques for solving satisfiability problems. SCIP is available in source code and free for noncommercial use. We demonstrate the usefulness of CIP on three tasks. First, we apply the constraint integer programming approach to pure mixed integer programs. Computational experiments show that SCIP is almost competitive to current state-of-the-art commercial MIP solvers. Second, we demonstrate how to use CIP techniques to compute the number of optimal solutions of integer programs. Third, we employ the CIP framework to solve chip design verification problems, which involve some highly nonlinear constraint types that are very hard to handle by pure MIP solvers. The CIP approach is very effective here: it can apply the full sophisticated MIP machinery to the linear part of the problem, while dealing with the nonlinear constraints by employing constraint programming techniques.
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  • 7
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    Weiterentwicklung und Ausbau des Internet-Informationsdienstes "Math&Industry" (2008)
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    Publication Date: 2022-04-11
    Description: Mit dem Informationsdienst Math&Industry soll ein Prototyp eines dezentralen Informationssystems für Förderprogramme und Forschungsprojekte geschaffen werden, das sich auf andere Programme (bezüglich angewandter Mathematik, aber auch darüber hinaus) übertragen lässt. Das betrifft sowohl die Konzeption (Strukturierung der Informationen) als auch die Werkzeuge, die anderen BMBF-Förderprogrammen zur Verfügung gestellt werden können. Damit sollen diese in die Lage versetzt werden, die in Math&Industry entwickelten Konzepte und Werkzeuge an ihre spezifischen Bedürfnisse anzupassen.
    Keywords: ddc:000
    Language: German
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  • 8
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    Two-Dimensional Adaptive Simulation of Dopant Diffusion in Silicon (2000)
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    Publication Date: 2014-02-26
    Description: One important step in the fabrication of silicon-based integrated circuits is the creation of semiconducting areas by diffusion of dopant impurities into silicon. Complex models have been developed to investigate the redistribution of dopants and point defects. In general, numerical analysis of the resulting PDEs is the central tool to assess the modelling process. We present an adaptive approach which is able to judge the quality of the numerical approximation and which provides an automatic mesh improvement. Using linearly implicit methods in time and multilevel finite elements in space, we are able to integrate efficiently the arising reaction-drift-diffusion equations with high accuracy. Two different diffusion processes of practical interest are simulated.
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  • 9
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    An Uncoupling-Coupling Technique for Markov Chain Monte Carlo Methods (2000)
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    Publication Date: 2014-02-26
    Description: Uncoupling-coupling Monte Carlo (UCMC) combines uncoupling techniques for finite Markov chains with Markov chain Monte Carlo methodology. By determining almost invariant sets of the associated Markov operator, the Monte Carlo sampling splits by a hierarchical annealing process into the essential regions of the state space; therefore UCMC aims at avoiding the typical metastable behavior of Monte Carlo techniques. From the viewpoint of Monte Carlo, a slowly converging long-time Markov chain is replaced by a limited number of rapidly mixing short-time ones. The correct weighting factors for the various Markov chains are obtained via a coupling matrix, that connects the samplings from the different almost invariant sets. The underlying mathematical structure of this approach is given by a general examination of the uncoupling-coupling procedure. Furthermore, the overall algorithmic scheme of UCMC is applied to the $n$-pentane molecule, a well-known example from molecular dynamics.
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  • 10
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    News from the Online Traveling Repairman (2000)
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    Publication Date: 2020-11-13
    Description: The traveling repairman problem (TRP) is a variant of the famous traveling salesman problem (TSP). The objective for the TRP is to minimize the latency, that is the the weighted sum of completion times of the cities, where the completion time of a city is defined to be the time in the tour before the city is reached. In the online traveling repairman problem (OLTRP) requests for visits to cities (points in a metric space) arrive online while the repairman is traveling. We analyze the performance of algorithms using competitive analysis, where the cost of an online algorithm is compared to that of an optimal offline algorithm. An optimal offline algorithm knows the entire request sequence in advance and can serve it with minimum cost. Recently, Feuerstein and Stougie presented a $9$-competitive algorithm for the OLTRP on the real line. In this paper we show how to use techniques from online-scheduling to obtain an $8$-competitive deterministic algorithm which works for any metric space. We also present a randomized algorithm which has a competitive ratio of $\frac{4}{\ln 2}\approx 5.7708$ against an oblivious adversary. All of our results also hold for the ``dial-a-ride'' generalization of the OLTRP, where objects have to be picked up and delivered by a server.
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  • 11
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    The Online-TSP Against Fair Adversaries (2000)
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    Publication Date: 2020-11-13
    Description: In the online traveling salesman problem requests for visits to cities (points in a metric space) arrive online while the salesman is traveling. The salesman moves at no more than unit speed and starts and ends his work at a designated origin. The objective is to find a routing for the salesman which finishes as early as possible. Performance of algorithms is measured through their competitive ratio, comparing the outcome of the algorithms with that of an adversary who provides the problem instance and therefore is able to achieve the optimal offline solution. Objections against such omnipotent adversaries have lead us to devise an adversary that is in a natural way, in the context of routing problems, more restricted in power. For the exposition we consider the online traveling salesman problem on the metric space given by the non-negative part of the real line. We show that a very natural strategy is~$3/2$-competitive against the conventional adversary, which matches the lower bound on competitive ratios achievable for algorithms for this problem. Against the more ``\emph{fair adversary}'', that we propose, we show that there exists an algorithm with competitive ratio $\frac{1+\sqrt{17}}{4}\approx 1.28$ and provide a matching lower bound. We also show competitiveness results for a special class of algorithms (called zealous algorithms) that do not allow waiting time for the server as long as there are requests unserved.
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  • 12
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    Progress Towards a Combined MRI/Hyperthermia System (2000)
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    Publication Date: 2020-03-09
    Description: Regional hyperthermia, a clinical cancer therapy, is the main topic of the Sonderforschungsbereich Hyperthermia: Scientific Methods and Clinical Applications'' at Berlin. In recent years, technological improvements towards a better concentration of heat to the desired target region have been achieved. These include a rather sophisticated integrated software environment for therapy planning and a new hyperthermia applicator. In a next step, a detailed closed loop monitoring of the actual treatment is to be developed. For this purpose the hyperthermia applicator is combined with an MRI system, which will allow to check the positioning of the patients and to measure individual blood perfusion as well as the 3D temperature distribution. The measurements will then be employed for an on-line control of the whole treatment. In this intended setting, new fast feedback control algorithms will come into play.
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  • 13
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    Kooperativer Bibliotheksverbund Berlin-Brandenburg: Erste Erfahrungen im Produkionsbetrieb (2000)
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    Publication Date: 2020-03-11
    Description: In diesem Artikel wird der Status des Projekts Kooperativer Bibliotheksverbund Berlin-Brandenburg beschrieben, der im November 1999 mit der KOBV-Suchmaschine seinen produktiven Betrieb aufgenommen hat. Die Recherchemöglichkeiten im WWW werden erläutert, Zugriffszahlen genannt und Entwicklungsperspektiven skizziert. Dieser Bericht entspricht der schriftlichen Fassung eines gleichnamigen Vortrages, der auf dem 1. Gemeinsamen Kongreß der Bundesvereinigung Deutscher Bibliotheksverbände e.V. und der Deutschen Gesellschaft für Informationswissenschaft und Informationspraxis e.V. Information und Öffentlichkeit gehalten wurde, der vom 20. bis 23. März 2000 in Leipzig stattfand.
    Keywords: ddc:000
    Language: German
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  • 14
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    Asymptotic Results and a Markovian Approximation for the M(n)/M(n)/s+GI System (2000)
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    Publication Date: 2014-02-26
    Description: In this paper for the $M(n)/M(n)/s+GI$ system, i.e.\ for a $s$-server queueing system where the calls in the queue may leave the system due to impatience, we present new asymptotic results for the intensities of calls leaving the system due to impatience and a Markovian system approximation where these results are applied. Furthermore, we present a new proof for the formulae of the conditional density of the virtual waiting time distributions, recently given by Movaghar for the less general $M(n)/M/s+GI$ system. Also we obtain new explicit expressions for refined virtual waiting time characteristics as a byproduct.
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  • 15
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    Budget Constrained Minimum Cost Connected Medians (2000)
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    Publication Date: 2020-11-13
    Description: Several practical instances of network design problems require the network to satisfy multiple constraints. In this paper, we address the \emph{Budget Constrained Connected Median Problem}: We are given an undirected graph $G = (V,E)$ with two different edge-weight functions $c$ (modeling the construction or communication cost) and $d$ (modeling the service distance), and a bound~$B$ on the total service distance. The goal is to find a subtree~$T$ of $G$ with minimum $c$-cost $c(T)$ subject to the constraint that the sum of the service distances of all the remaining nodes $v \in V\setminus T$ to their closest neighbor in~$T$ does not exceed the specified budget~$B$. This problem has applications in optical network design and the efficient maintenance of distributed databases. We formulate this problem as bicriteria network design problem, and present bicriteria approximation algorithms. We also prove lower bounds on the approximability of the problem that demonstrate that our performance ratios are close to best possible
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  • 16
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    Polyhedral Results for the Edge Capacity Polytope (2000)
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    Publication Date: 2014-02-26
    Description: Network loading problems occur in the design of telecommunication networks, in many different settings. The polyhedral structure of this problem is important in developing solution methods for the problem. In this paper we investigate the polytope of the problem restricted to one edge of the network (the edge capacity problem). We describe classes of strong valid inequalities for the edge capacity polytope, and we derive conditions under which these constraints define facets. As the edge capacity problem is a relaxation of the network loading problem, their polytopes are intimately related. We, therefore, also give conditions under which the inequalities of the edge capacity polytope define facets of the network loading polytope. Furthermore, some structural properties are derived, such as the relation of the edge capacity polytope to the knapsack polytope. We conclude the theoretical part of this paper with some lifting theorems, where we show that this problem is polynomially solvable for most of our classes of valid inequalities. In a computational study the quality of the constraints is investigated. Here, we show that the valid inequalities of the edge capacity polytope are not only important for solving the edge capacity problem, but also for the network loading problem, showing that the edge capacity problem is an important subproblem.
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  • 17
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    Über Suchmaschinen, Verbünde und die Integration von Informationsangeboten (2000)
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    Publication Date: 2014-02-26
    Description: Die Entwicklung einer bibliothekarischen Suchmaschine ist das technisch-organisatorische Herztück des Kooperativen Bibliotheksverbundes Berlin-Brandenburg (KOBV). Auf dem Wege über diese Innovation verfolgen die Länder Berlin und Brandenburg und ihre Bibliotheken das Ziel, ihr Bibliothekswesen zu erneuern und zu reorganisieren. Die Entwicklung der Suchmaschine ist für die Partner im KOBV-Projekt kein Selbstzweck, sondern nur Mittel zum Zweck - insbesondere, um die heterogene Welt der in Berlin und in Brandenburg eingesetzten integrierten Bibliotheksinformationssysteme harmonisch miteinender zu verbinden. Mit der KOBV-Suchmaschine sind informationstechnische Sichtweisen und Methoden entstanden, die sich potentiell auch auf die überregionale Arbeit des KOBV auswirken können und in Kooperation mit den Bibliotheksverbänden auf die Zusammenarbeit der Verbünde insgesamt. Der Artikel konzentriert sich am Beispiel der KOBV-Such¡ma¡schine auch auf diesen Aspekt. Auf die Bibliotheken kommen mit dem Internet und dem World Wide Web für sie neuartige Medien, Mittel und Aufgaben zu, in erster Linie aus dem Bereich der Wissenschaften und der wissenschaftlichen Fachgesellschaften. Die Herausforderung besteht darin, die neuen elektronischen Informationen und Angebote zu integrieren. Das Stichwort hierzu lautet digitale Bibliothek bzw. virtuelle Fachbibliothek. Auch zu der Diskussion um diese aktuelle Entwicklung will der Artikel einen Beitrag leisten.
    Keywords: ddc:000
    Language: German
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  • 18
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    Parallel tempering and decorrelation of topological charge in full QCD (2000)
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    Publication Date: 2014-02-26
    Description: The improvement of simulations of QCD with dynamical Wilson fermions by combining the Hybrid Monte Carlo algorithm with parallel tempering is studied on $10^4$ and $12^4$ lattices. As an indicator for decorrelation the topological charge is used.
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  • 19
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    Re-Optimization of Signaling Transfer Points (2000)
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    Publication Date: 2014-02-26
    Description: In this paper we describe the results of a computational study towards the (re)optimization of signaling transfer points (STPs) in telecommunication networks. The best performance of an STP is achieved whenever the traffic load is evenly distributed among the internal components. Due to the continuously changing traffic pattern, the load of the components has to be re-optimized on a regular basis. Besides the balancing objective also the number of rearrangements have to be taken into account. In this paper we present two alternative formulations to deal with both requirements. Computational results show that for both formulations (near) optimal solutions can be obtained within reasonable time limits.
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  • 20
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    Density functional study of guanine and uracil quartets and of guanine quartet metal/ion complexes (2000)
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    Publication Date: 2014-02-26
    Description: The structures and interaction energies of guanine and uracil quartets have been determined by B3LYP hybrid density functional calculations. The total interaction energy $\Delta$E$^{T}$ of the $\it{C}$$_{4h}$-symmetric guanine quartet consisting of Hoogsteen type base pairs with two hydrogen bonds between two neighbour bases is -66.07 kcal/mol at the highest level. The uracil quartet with C6-H6...O4 interactions between the individual bases has only a small interaction energy of -20.92 kcal/mol and the interaction energy of -24.63 kcal/mol for the alternative structure with N3-H3...O4 hydrogen bonds is only slightly more negative. Cooperative effects contribute between 10 and 25 \% to all interaction energies. Complexes of metal ions with G-quartets can be classified into different structure types. The one with Ca$^{2+}$ in the central cavity adopts a $\it{C}$$_{4h}$-symmetric structure with coplanar bases, whereas the energies of the planar and non-planar Na$^{+}$ complexes are almost identical. The small ions Li$^{+}$, Be$^{2+}$, Cu$^{+}$ and Zn$^{2+}$ prefer a non-planar $\it{S}$$_{4}$-symmetric structure. The lack of co-planarity prevents probably a stacking of these base quartets. The central cavity is too small for K$^{+}$ ions and therefore this ion favours in contrast to all other investigated ions a $\it{C}$$_{4}$-symmetric complex, which is 4.73 kcal/mol more stable than the $\it{C}$$_{4h}$-symmetric one. The distance 1.665 {\AA} between K$^{+}$ and the root mean squares plane of the guanine bases is approximately half of the distance between two stacked G-quartets. The total interaction energy of alkaline earth ion complexes exceeds the ones with alkali ions. Within both groups of ions the interaction energy decreases with an increasing row position in the periodic table. The B3LYP and BLYP methods lead to similar structures and energies. Both methods are suitable for hydrogen-bonded biological systems. Compared with the before mentioned methods the HCTH functional leads to longer hydrogen bonds and different relative energies for two U-quartets. Finally we calculated also structures and relative energies with the MMFF94 forcefield. Contrary to all DFT methods, MMFF94 predicts bifurcated C-H...O contacts in the uracil quartet. In the G-quartet the MMFF94 hydrogen bond distances N2-H22...N7 are shorter than the DFT distances, whereas the N1-H1...O6 distances are longer.
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  • 21
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    Graphentheoretische Konzepte und Algorithmen (2000)
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    Publication Date: 2020-11-13
    Description: Das vorliegende Skript bietet eine Einf{ü}hrung in die Graphentheorie und graphentheoretische Algorithmen. Im zweiten Kapitel werden Grundbegriffe der Graphentheorie vorgestellt. Das dritte Kapitel besch{ä}ftigt sich mit der Existenz von Wegen in Graphen. Hier wird auch die L{ö}suung des ber{ü}hmten K{ö}nigsberger Br{ü}ckenproblems aufgezeigt und der Satz von Euler bewiesen. Im vierten Kapitel wird gezeigt, wie man auf einfache Weise die Zusammenhangskomponenten eines Graphen bestimmen kann. Im Kapitel sechs wird dann sp{ä}ter mit der Tiefensuche ein Verfahren vorgestellt, das schneller arbeitet und mit dessen Hilfe man noch mehr Informationen {ü}ber die Struktur eines Graphen gewinnen kann. In den folgenden Kapiteln werden Algorithmen vorgestellt, um minimale aufspannenden B{ä}ume, k{ü}rzeste Wege und maximale Fl{ü}sse in Graphen zu bestimmen. Am Ende des Skripts wird ein kurzer Einblick in die planaren Graphen und Graphhomomorphismen geboten.
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    Language: German
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  • 22
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    Computer-aided design of novel siderophores: Pyridinochelin (2000)
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    Publication Date: 2014-02-26
    Description: Pyridinochelin, a novel catecholate type siderophore, has been designed on the basis of the active analog enterobactin. Growth promotion tests indicate that this synthetic siderophore feeds various pathogenic bacteria effectively with iron even though it lacks one catecholate group compared to enterobactin. The superposition of the siderophore structures suggests that the structure of the skeleton connecting the catecholate groups might be an important factor for the iron transport.
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  • 23
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    Adaptive Linearly Implicit Methods for Heat and Mass Transfer Problems (2000)
    Details
    Publication Date: 2019-05-10
    Description: Dynamical process simulation of complex real-life problems often requires the use of modern algorithms, which automatically adapt both the time and space discretization in order to get error-controlled approximations of the solution. In this paper, a combination of linearly implicit time integrators of Rosenbrock type and adaptive multilevel finite elements based on a posteriori error estimates is presented. This approach has proven to work quite satisfactorily for a wide range of challenging practical problems. We show the performance of our adaptive method for two applications that arise in the study of flame balls and brine transport in porous media.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 24
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    The Essential Spectral Radius and Asymptotic Properties of Transfer Operators (2000)
    Details
    Publication Date: 2014-02-26
    Description: The statistical behavior of deterministic and stochastic dynamical systems may be described using transfer operators, which generalize the notion of Frobenius Perron and Koopman operators. Since numerical techniques to analyze dynamical systems based on eigenvalues problems for the corresponding transfer operator have emerged, bounds on its essential spectral radius became of interest. This article shows that they are also of great theoretical interest. We give an analytical representation of the essential spectral radius in $L^{1}\!(\mu)$, which then is exploited to analyze the asymptotical properties of transfer operators by combining results from functional analysis, Markov operators and Markov chain theory. In particular, it is shown, that an essential spectral radius less than $1$, constrictiveness and some weak form'' of the so--called Doeblin condition are equivalent. Finally, we apply the results to study three main problem classes: deterministic systems, stochastically perturbed deterministic systems and stochastic systems.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 25
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    The Classes of Critically and Anticritically Perfect Graphs (2000)
    Details
    Publication Date: 2014-02-26
    Description: We focus on two new types of extremal graphs with respect to perfectness: critically and anticritically perfect graphs that lose their perfectness by simply deleting and adding an arbitrary edge, respectively. We present examples and study properties in order to compare critically and anticritically perfect graphs with minimally imperfect graphs, another type of extremal graphs with respect to perfectness. We discuss two attempts to characterize the classes of all critically and anticritically perfect graphs and give a brief overview on classes of perfect graphs which contain critically or anticritically perfect graphs.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 26
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    A path-following method for linear complementarity problems based on the affine invariant Kantorovich Theorem (2000)
    Details
    Publication Date: 2014-02-26
    Description: A path following algorithm for linear complementarity problems is presented. Given a point $z$ that approximates a point $z(\tau)$ on the central path with complementarity gap $\tau$, one determines a parameter $\theta\in (0,1)$ so that this point satisfies the hypothesis of the affine invariant Kantorovich Theorem for the equation defining $z((1-\theta)\tau)$. It is shown that $\theta$ is bounded below by a multiple of $n^{-1/2}$, where $n$ is the dimension of the problem. Since the hypothesis of of the Kantorovich Theorem is satisfied the sequence generated by Newton's method, or by the simplified Newton method, will converge to $z((1-\theta)\tau)$. We show that the number of steps required to obtain an acceptable approximation of $z((1-\theta)\tau)$ is bounded above by a number independent of $n$. Therefore the algorithm has $O(\sqrt{n}L)$-iteration complexity. The parameters of the algorithm can be determined in such a way that only one Newton step is needed each time the complementarity gap is decreased.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 27
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    Counting stable solutions of sparse polynomial systems in chemistry (2000)
    Details
    Publication Date: 2014-02-26
    Description: The polynomial differential system modelling the behavior of a chemical reaction is given by graphtheoretic structures. The concepts from toric geometry are applied to study the steady states and stable steady states. Deformed toric varieties give some insight and enable graph theoretic interpretations. The importance of the circuits in the directed graph are emphazised. The counting of positive solutions of a sparse polynomial system by B.\ Sturmfels is generalized to the counting of stable positive solutions in case of a polynomial differential equation. The generalization is based on a method by sparse resultants to detect whether a system may have a Hopf bifurcation. Special examples from chemistry are used to illustrate the theoretical results.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 28
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    Distributed Visualization with OpenGL Vizserver: Practical Experiences (2000)
    Details
    Publication Date: 2020-03-09
    Description: The increasing demand for distributed solutions in computing technology does not stop when it comes to visualization techniques. However, the capabilities of todays applications to perform remote rendering are limited by historical design legacys. Especially the popular X11 protokoll, which has been proven to be extremely flexible and usefull for remote 2D graphics applications, breaks down for the case of remote 3D rendering. In this white paper, we give a short overview of generic remote rendering technologies available today, and compare their performance to the recently released vizserver by SGI: a network extension to the SGI OpenGL rendering engines.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 29
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    Semidefinite Programming for Combinatorial Optimization (2000)
    Details
    Publication Date: 2020-08-05
    Description: This book offers a self-contained introduction to the field of semidefinite programming, its applications in combinatorial optimization, and its computational methods. We equip the reader with the basic results from linear algebra on positive semidefinite matrices and the cone spanned by them. Starting from linear programming, we introduce semidefinite programs and discuss the associated duality theory. We then turn to semidefinite relaxations of combinatorial optimization and illustrate their interrelation. In the second half we deal with computational methods for solving semidefinite programs. First, the interior point approach, its iteration complexity, and implementational issues are discussed. Next, we explain in great detail the spectral bundle method, which is particularly suited for large scale semidefinite programming. One of the most successful techniques in integer linear programming is the cutting plane approach which improves an initial relaxation by adding violated inequalities. We explore possibilities to combine the two solution methods with the cutting plane approach in order to strengthen semidefinite relaxations of combinatorial optimization problems.
    Keywords: ddc:000
    Language: English
    Type: doctoralthesis , doc-type:doctoralThesis
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  • 30
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    Ermittlung von Programmlaufzeiten anhand von Speicherzugriffen, Microbenchmarks und Simulation vonSpeicherhierarchien (2000)
    Details
    Publication Date: 2021-01-21
    Description: \\{\bf Zusammenfassung:} Kostenmodelle dienen der Ermittlung von Programmlaufzeiten, zum Vergleich der Effizienz von Algorithmen und zur Analyse des Verhaltens von Speicherhierarchien. Ein neuartiges Kostenmodell ist das Latency-of-Data-Access (LDA) Modell, das mehrere hierarchische Speicherebenen mit unterschiedlichen Latenzzeiten berü{}cksichtigt. In dieser Diplomarbeit wird ein Simulator fü{}r Speicherhierarchien prä{}sentiert, der die Berechnung von Programmausfü{}hrungszeiten nach dem LDA-Modell erlaubt. Mit Hilfe des Simulators wird die These geprü{}ft, da\ss{} mit diesem Modell die Ausfü{}hrungszeit eines Programms adä{}quat abgeschä{}tzt werden kann. Mit dem Simulator ist es erstmals praktikabel mö{}glich, Programmausfü{}hrungszeiten nach dem LDA-Modell zu bestimmen. Der Simulator kann fü{}r Systeme mit unterschiedlichen Speicherarchitekturen konfiguriert werden und unterstü{}tzt Mehrprozessorsysteme mit gemeinsamem Speicher (SMP-Systeme) mit verschiedenen Kohä{}renzprotokollen. Der Simulator kann mit den Ergebnissen von Microbenchmarks konfiguriert werden, die die Architekturparameter einer Speicherhierarchie messen. Die Ergebnisse bestä{}tigen die These nicht nur fü{}r Einzelprozessorsysteme, sondern auch fü{}r SMP-Systeme, wo gleichzeitig interagierende Prozessoren gegenseitig ihre Zugriffssequenz auf Zwischenspeicher beeinflussen. Zusä{}tzlich wurde eine neue Einsatzmö{}glichkeit des LDA-Modells entwickelt, um die Ausfü{}hrungszeit von Programmteilen zu bestimmen. Einzelne Zugriffskosten kö{}nnen einem mehrerer parallel laufender Modelle zugeordnet werden. Dadurch kö{}nnen Kosten, die Zugriffe auf einzelne Speicherbereiche verursachen, separat bestimmt werden. Diese Profiling-Technik erlaubt Optimierungen an Datenstrukturen und Speicherzugriffsmustern durch prä{}zise und gezielte Informationsproduktion.Cost models are used to determine the execution time of programs, to compare the efficiency of algorithms, and to analyse the behaviour of memory hierarchies. The Latency-of-Data-Access (LDA) model that takes into account multiple hierarchical memory levels with different latencies, is a newly proposed, innovative cost model. In this diploma-thesis, a simulator for memory hierarchies is presented that allows the calculation of execution times using the LDA-model. The simulator is used to prove the claim that the execution time of a program can be accurately estimated with the LDA-model. With the simulator, it is for the first time possible to determine the execution time of programs with this model in a practical way. The simulator can be configured for systems with various cache architectures and supports shared memory (SMP) multiprocessor systems with different cache coherence protocols. The simulator can be configured with the results from microbenchmarks which measure the architectural properties of a memory hierarchy. The results confirm the claim not only for single processor systems, but also for SMP systems, where concurrently interacting processors influence each others cache access sequence. Additionally, a new field of usage of the LDA-model was developed to determine execution times of program parts. Single access costs can be assigned to one of several parallel running models. As an example the costs of accesses to different memory areas can be split and determined separately. This profiling technique allows to optimise data structures and memory access patterns of sequential and parallel SMP programs by precise production of information.
    Keywords: ddc:000
    Language: German
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    SBmethod --- A C++ Implementation of the Spectral Bundle Method. Manual to Version 1.1 (2000)
    Details
    Publication Date: 2014-02-26
    Description: \texttt{SBmethod}, Version 1.1, is an implementation of the spectral bundle method for eigenvalue optimization problems of the form \begin{displaymath} \min_{y\in \mathbf{R}^m}\;\; a\;\lambda_{\max}(C-\sum_{i=1}^{m} A_i y_i)+b^Ty. \end{displaymath} The design variables $y_i$ may be sign constrained, $C$ and and $A_i$ are given real symmetric matrices, $b\in\mathbf{R}^m$ allows to specify a linear cost term, and $a〉0$ is a constant multiplier for the maximum eigenvalue function $\lambda_{\max}(\cdot)$. The code is intended for large scale problems and allows to exploit structural properties of the matrices such as sparsity and low rank structure. The manual contains instructions for installation and use of the program. It describes in detail input format, options, and output. The meaning of the variables and parameters is made precise by relating them to a mathematical description of the algorithm in pseudocode.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 32
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    Stable Multi-Sets (2000)
    Details
    Publication Date: 2014-11-10
    Description: In this paper we introduce a generalization of stable sets: stable multi-sets. A stable multi-set is an assignment of integers to the vertices of a graph, such that specified bounds on vertices and edges are not exceeded. In case all vertex and edge bounds equal one, stable multi-sets are equivalent to stable sets. For the stable multi-set problem, we derive reduction rules and study the associated polytope. We state necessary and sufficient conditions for the extreme points of the linear relaxation to be integer. These conditions generalize the conditions for the stable set polytope. Moreover, the classes of odd cycle and clique inequalities for stable sets are generalized to stable multi-sets and conditions for them to be facet defining are determined. The study of stable multi-sets is initiated by optimization problems in the field of telecommunication networks. Stable multi-sets emerge as an important substructure in the design of optical networks.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 33
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    SteinLib: An Updated Library on Steiner Tree Problems in Graphs (2000)
    Details
    Publication Date: 2020-02-11
    Description: In this paper we present the {\em SteinLib}, a library of data sets for the Steiner tree problem in graphs. This library extends former libraries on Steiner tree problems by many new interesting and difficult instances, most of them arising from real-world applications. We give a survey on the difficulty of these problem instances by giving references to state-of-the-art software packages that were the first or are currently among the best to solve these instances.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 34
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    Anatomy of a Resource Management System for HPC-Clusters (2000)
    Details
    Publication Date: 2014-02-26
    Description: Workstation clusters are often not only used for high-throughput computing in time-sharing mode but also for running complex parallel jobs in space-sharing mode. This poses several difficulties to the resource management system, which must be able to reserve computing resources for exclusive use and also to determine an optimal process mapping for a given system topology. On the basis of our CCS software, we describe the anatomy of a modern resource management system. Like Codine, Condor, and LSF, CCS provides mechanisms for the user-friendly system access and management of clusters. But unlike them, CCS is targeted at the effective support of space-sharing parallel and even metacomputers. Among other features, CCS provides a versatile resource description facility, topology-based process mapping, pluggable schedulers, and hooks to metacomputer management.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 35
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    Autos, Ziegen und Streithähne (2000)
    Details
    Publication Date: 2021-02-01
    Description: Das aus den Medien bekannte umstrittene Ziegenproblem (auch Drei-Türen-Problem genannt) wird vollständig analysiert und gelöst. In der Streitfrage spielen sprachliche Mehrdeutigkeiten der Problemformulierung eine wesentliche Rolle; zudem werden Zufallsereignisse mit willkürlicher Information über deren Ergebnisse verwechselt. Tatsächlich erweisen sich beide strittigen Lösungen als teilweise richtige Bestandteile der Gesamtlösung. Die Argumentation wird in allgemeinverständlicher Sprache geführt und anschliessend durch eine formale mathematische Betrachtung ergänzt.
    Keywords: ddc:000
    Language: German
    Type: reportzib , doc-type:preprint
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  • 36
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    Kooperativer Bibliotheksverbund Berlin-Brandenburg (KOBV) - Konzept, Erfahrungen, Ausblick - (2000)
    Details
    Publication Date: 2020-11-13
    Description: Der Aufsatz ist die ausgearbeitete Fassung eines Vortrages, gehalten auf dem 2. BSZ-Kolloquium des Bibliotheksservice-Zentrums Baden-Württemberg (BSZ) am 10. Oktober 2000 in Konstanz. Der Kooperative Bibliotheksverbund Berlin-Brandenburg, kurz KOBV, ist ein sehr junger Verbund - genauer gesagt, befindet er sich im Oktober 2000 immer noch in der Aufbauphase. Das KOBV-Projekt hat am 1. April 1997 begonnen und wird am 31. Dezember 2000 enden. Ab 2001 wird der KOBV in eine institutionalisierte Form überführt, die - wie bereits das Projekt - am Konrad-Zuse-Zentrum für Informationstechnik Berlin (ZIB) - angesiedelt wird. Mit dem KOBV wurde ein in technischer wie auch in organisatorischer Hinsicht neuartiger Bibliotheksverbund aufgebaut, der auf der \glqq Internetphilosophie\grqq basiert: Den technischen Kern bildet eine eigens entwickelte Suchmaschine; die Organisation ist dezentral ausgerichtet und gründet sich auf der Kooperation der KOBV-Partner. In dem Vortrag werden das technische und das organisatorische Verbundkonzept vorgestellt, über die Erfahrungen nach einjähriger Betriebsdauer berichtet und ein kurzer Ausblick darüber gegeben, wie es mit dem KOBV weitergeht.
    Keywords: ddc:000
    Language: German
    Type: reportzib , doc-type:preprint
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    Spezifikation der Schnittstelle zwischen KOBV-Suchmaschine und Lokalsystemen (2000)
    Details
    Publication Date: 2020-11-13
    Description: Die Kommunikation zwischen der KOBV-Suchmaschine und entfernten Bibliotheksinformationssystemen unterschiedlicher Hersteller wird über das Standardprotokoll Z39.50 abgewickelt. Die Suchmaschine ermöglicht Online-Recherchen in lokalen Bibliotheksinformationssystemen, die dazu ein Z39.50 Target (Server) zur Verfügung stellen müssen. Die Suchmaschine liefert ihre Daten ebenfalls über Z39.50 aus. Ein Lokalsystem benötigt hierfür einen Z39.50 Origin (Client). In dem Papier wird die Schnittstelle zwischen der KOBV-Suchmaschine und lokalen Bibliothekssystemen spezifiziert: Es werden die grundlegenden Anforderungen an Lokalsysteme definiert und die Konfigurationsparameter für die Z39.50-Kommunikation zwischen KOBV-Suchmaschine und Lokalsystemen beschrieben.
    Keywords: ddc:000
    Language: German
    Type: reportzib , doc-type:preprint
    Format: application/postscript
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  • 38
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    Implementation von WAP-Diensten für die SGI/CRAY T3E des ZIB (2000)
    Details
    Publication Date: 2014-02-26
    Description: Die zunehmende Verfügbarkeit von mobilen Geräten, die mit einem Internetanschluß ausgerüstet sind, bringt auch eine steigende Nachfrage nach Informationsdiensten für diese Art von Clients mit sich. Das ZIB stellt mit seinem Höchstleistungsrechner vom Typ SGI/CRAY T3E Wissenschaftlern große Rechenkapazitäten zur Verfügung. Im Rahmen dieser Studienarbeit wurde ein WAP-Interface zur T3E entwickelt, das es den Nutzern ermöglicht, über ein mobiles, WAP-fähiges Gerät Informationen zur Betriebsbereitschaft und zur Auslastung des Höchstleistungsrechners, sowie Informationen zu den von ihnen in Auftrag gegebenen Rechenjobs abzurufen. Die Untersuchung der aktuellen Möglichkeiten in der mobilen Kommunikation brachte einige Einschränkungen für das geplante Informationsangebot mit sich. So mußte auf Grund von Sicherheitsbedenken auf eine tatsächliche Interaktionsmöglichkeit (z.B. neue Rechenjobs zu starten) verzichtet werden. Demgegenüber konnte gezeigt werden, daß die Bereitstellung der gleichen Informationen für unterschiedliche Arten von Clients (WWW-Browser $\rightarrow$ HTML, WAP-Browser $\rightarrow$ WML) durch die Verwendung von XML als internes Datenformat problemlos möglich ist. Es hat sich gezeigt, daß die Bereitstellung eines WAP-Informationsdienstes auf Grund verschiedener Inkompatibilitätsprobleme (verschiedene Gateways, verschiedene WAP-Browser) mit erheblichem Aufwand verbunden sein kann. An dieser Stelle besteht noch Handlungsbedarf seitens der Hersteller dieser Softwarepakete.
    Keywords: ddc:000
    Language: German
    Type: reportzib , doc-type:preprint
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    Jahresbericht 1999 (2000)
    Details
    Publication Date: 2019-10-24
    Keywords: ddc:000
    Language: German
    Type: annualzib , doc-type:report
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  • 40
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    Verkehrsplanung: Bessere Lösungen mit Mathematik (2000)
    Details
    Publication Date: 2014-02-26
    Description: Anwendungen der Mathematik in der Verkehrs- und Transporttechnologie haben eine große und bedeutende Tradition. Natürlich wurden die ersten Fahrzeuge mit der ingenieurmäßigen Methode von Versuch, Irrtum und Verbesserung entworfen. Aber schon sehr bald kamen mathematische Berechnungen hinzu, mit denen mechanische Eigenschaften von Fahrzeugteilen ermittelt und zum Teil optimiert wurden. Die hierzu erforderliche Mathematik wurde in diesem Jahrhundert zu einem mächtigen Werkzeugkasten ausgebaut. Mit diesem kann man heute z.B. hocheffiziente Motoren mit geringem Schadstoffausstoß entwerfen, aerodynamisch günstige Fahrzeugprofile ermitteln und Flugzeugflügel berechnen, die die gewünschte Last sicher und mit geringem Treibstoffaufwand tragen. Die Mathematik unterstützt die Technologie des Verkehrs beginnend bei globalen Designfragen bis hin zur Spezifizierung von Materialeigenschaften kleinster Bauteile; sie berechnet mit hoher Präzision energieoptimale Bahnen von Raumflugkörpern oder zeitoptimale Trajektorien für Flugzeuge, steuert automatische Roboteranlagen oder innerbetriebliche Transportsysteme.
    Keywords: ddc:000
    Language: German
    Type: reportzib , doc-type:preprint
    Format: application/postscript
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  • 41
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    Hierarchical Sparsity in Multistage Convex Stochastic Programs (2000)
    Details
    Publication Date: 2021-02-01
    Description: Interior point methods for multistage stochastic programs involve KKT systems with a characteristic global block structure induced by dynamic equations on the scenario tree. We generalize the recursive solution algorithm proposed in an earlier paper so that its linear complexity extends to a refined tree-sparse KKT structure. Then we analyze how the block operations can be specialized to take advantage of problem-specific sparse substructures. Savings of memory and operations for a financial engineering application are discussed in detail.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/postscript
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  • 42
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    Adaptive hierarchical cluster analysis by Self-Organizing Box Maps (2000)
    Details
    Publication Date: 2014-02-26
    Description: The present paper aims at an extension of {\sc Kohonen's} Self-Organizing Map (SOM) algorithm to be called Self-Organizing Box Map (SOBM) algorithm; it generates box codebooks in lieu of point codebooks. Box codebooks just like point codebooks indirectly define a Voronoi tessellation of the input space, so that each codebook vector represents a unique set of points. Each box codebook vector comprises a multi-dimensional interval that approximates the related partition of the Voronoi tessellation. Upon using the automated cluster identification method that has recently been developed by the authors, the codebook vectors can be grouped in such a way that each group represents a point cluster in the input space. Since the clustering usually depends on the size of the SOM, one cannot be sure, whether the clustering comes out to be optimal. Refinement of part of the identified clusters would often improve the results. This paper presents the concept of an adaptive multilevel cluster algorithm that performs such refinements automatically. Moreover the paper introduces a concept of essential dimensions and suggests a method for their identification based on our herein suggested box codebooks. Applications of the algorithm to molecular dynamics will be described in a forthcoming paper.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 43
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    Capacitated Network Design with Multicast Commodities (2000)
    Details
    Publication Date: 2014-02-26
    Description: This paper addresses the problem of designing a minimum cost network whose capacities are sufficiently large to allow a feasible routing of a given set of multicast commodities. A multicast commodity consists of a set of two or mo re terminals that need to be connected by a so called broadcast tree, which consumes on all of its edges a capacity as large as the demand value associated with that commodity. We model the network design problem with multicast commodities as the problem of packing capacitated Steiner trees in a graph. In the first part of the paper we present three mixed-integer programming formulations for this problem. The first natural formulation uses only one integer capacity variable for each edge and and one binary tree variable for each commodity-edge pair. Applying well-known techniques from the Steiner tree problem, we then develop a stronger directed and a multicommodity flow based mixed-integer programming formulation. In the second part of the paper we study the associated polyhedra and derive valid and even facet defining inequalities for the natural formulation. Finally, we describe separation algorithms for these inequalities and present computational results that demonstrate the strength of our extended formulations.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/postscript
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  • 44
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    Ermittlung von Programmlaufzeiten anhand von Speicherzugriffen, Microbenchmarks und Simulation von Speicherhierarchien (2000)
    Details
    Publication Date: 2021-01-21
    Description: Kostenmodelle dienen der Ermittlung von Programmlaufzeiten, zum Vergleich der Effizienz von Algorithmen und zur Analyse des Verhaltens von Speicherhierarchien. Ein neuartiges Kostenmodell ist das Latency-of-Data-Access (LDA) Modell, das mehrere hierarchische Speicherebenen mit unterschiedlichen Latenzzeiten berücksichtigt. In dieser Diplomarbeit wird ein Simulator für Speicherhierarchien präsentiert, der die Berechnung von Programmausführungszeiten nach dem LDA-Modell erlaubt. Mit Hilfe des Simulators wird die These geprüft, daß mit diesem Modell die Ausführungszeit eines Programms adäquat abgeschätzt werden kann. Mit dem Simulator ist es erstmals praktikabel möglich, Programmausführungszeiten nach dem LDA-Modell zu bestimmen. Der Simulator kann für Systeme mit unterschiedlichen Speicherarchitekturen konfiguriert werden und unterstützt Mehrprozessorsysteme mit gemeinsamem Speicher (SMP-Systeme) mit verschiedenen Kohärenzprotokollen. Der Simulator kann mit den Ergebnissen von Microbenchmarks konfiguriert werden, die die Architekturparameter einer Speicherhierarchie messen. Die Ergebnisse bestätigen die These nicht nur für Einzelprozessorsysteme, sondern auch für SMP-Systeme, wo gleichzeitig interagierende Prozessoren gegenseitig ihre Zugriffsse-quenz auf Zwischenspeicher beeinflussen. Zusätzlich wurde eine neue Einsatzmöglichkeit des LDA-Modells entwickelt, um die Ausführungszeit von Programmteilen zu bestimmen. Einzelne Zugriffskosten können einem mehrerer parallel laufender Modelle zugeordnet werden. Dadurch können Kosten, die Zugriffe auf einzelne Speicherbereiche verursachen, separat bestimmt werden. Diese Profiling-Technik erlaubt Optimierungen an Datenstrukturen und Speicherzugriffsmustern durch präzise und gezielte Informationsproduktion.
    Description: Cost models are used to determine the execution time of programs, to compare the efficiency of algorithms, and to analyse the behaviour of memory hierarchies. The Latency-of-Data-Access (LDA) model that takes into account multiple hierarchical memory levels with different latencies, is a newly proposed, innovative cost model. In this diploma-thesis, a simulator for memory hierarchies is presented that allows the calculation of execution times using the LDA model. The simulator is used to prove the claim that the execution time of a program can be accurately estimated with the LDA model. With the simulator, it is for the first time possible to determine the execution time of programs with this model in a practical way. The simulator can be configured for systems with various cache architectures and supports shared memory (SMP) multiprocessor systems with different cache coherence protocols. The simulator can be configured with the results from Microbenchmarks which measure the architectural properties of a memory hierarchy. The results confirm the claim not only for single processor systems, but also for SMP systems, where concurrently interacting processors influence each others cache access sequence. Additionally, a new field of usage of the LDA model was developed to determine execution times of program parts. Single access costs can be assigned to one of several parallel running models. As an example the costs of accesses to different memory areas can be split and determined separately. This profiling technique allows to optimise data structures and memory access patterns of sequential and parallel SMP programs by precise production of information.
    Keywords: ddc:000
    Language: German
    Type: masterthesis , doc-type:masterThesis
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    Visions of Numerical Relativity 1999 (2000)
    Details
    Publication Date: 2020-03-09
    Description: We present visualizations of recent supercomputer simulations from numerical relativity, exploiting the progress in visualization techniques and numerical methods also from an artistic point of view. The sequences have been compiled into a video tape, showing colliding black holes, orbiting and merging neutron stars as well as collapsing gravitational waves. In this paper we give some background information and provide a glance at the presented sequences.
    Keywords: ddc:000
    Language: English
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    The Symbolic Integration of Exact PDEs (2000)
    Details
    Publication Date: 2014-02-26
    Description: An algorithm is described to decide if a given polynomial differential expression $\Delta$ of multivariate functions is exact, i.e. whether there exists a first integral $P$ such that $D_xP = \Delta$ for any one of a set of variables $x$ and to provide the integral $P$. A generalization is given to allow integration in the case that the exactness is prohibited by terms which contain only functions of not all the independent variables.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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    Algorithmen- und Softwareoptimierung für die Satellitenbahn- und Schwerefeldmodellierung (2000)
    Details
    Publication Date: 2014-02-26
    Description: Dieser Report enthält die Ergebnisse der Untersuchungen, die gemäss dem Forschungs-- und Entwicklungsvertrag Gravity zwischen dem GeoForschungsZentrum Potsdam und dem Konrad--Zuse--Zentrum Berlin vorgenommen wurden. Die damit vereinbarte wissenschaftliche Kooperation hat die folgenden Ziele: \item{die am GFZ vorhandenen Algorithmen und Softwaremodule auf ihre Effizienz hisichtlich Nutzung der Rechnerresourcen zu untersuchen und Lösungen für einen schnelleren Datendurchsatz zu entwickeln und zu implementieren,} \item{Methoden zur Regularisierung und Lösung schlecht konditionierter Normalgleichungssysteme (für Schwerefeldkoeffizienten) kritisch zu untersuchen und eine mathematisch objektive Strategie der Regularisierung zu entwickeln, und} \item{insbesondere im Hinblick auf die Anforderungen bei GRACE, verschiedene Bahnintegrationsverfahren hinsichtlich ihrer numerischen Genauigkeit und Einsatzmöglichkeiten zu untersuchen.}
    Keywords: ddc:000
    Language: German
    Type: reportzib , doc-type:preprint
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    A Projection Method for Two-Phase Incompressible Flow with Surface Tension and Sharp Interface Resolution (2000)
    Details
    Publication Date: 2014-02-26
    Description: We present a fully second order projection method for the simulation of two-phase incompressible flow with surface tension. The Navier-Stokes equations are solved with a projection method on a fixed Cartesian grid. The free interface between the two fluids is tracked with a level set approach. The conditions at the interface for the pressure, the pressure gradient, and the velocity are explicitly incorporated into the scheme leading to a sharp representation of the pressure discontinuity and the interfacial force. The scheme in the presented form does not introduce additional points in the standard finite difference stencils. Computational results are compared with analytic solutions for a static round bubble, damped surface waves, and Rayleigh-Taylor instabilities.
    Keywords: ddc:000
    Language: English
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    Hyperthermia Treatment Planning with HyperPlan - User's Manual (2000)
    Details
    Publication Date: 2020-03-09
    Description: HyperPlan is a software system for performing 3D-simulations and treatment planning in regional hyperthermia. It allows the user to understand the complex effects of electromagnetic wave propagation and heat transport inside a patient's body. Optimized power amplitudes and phase settings can be calculated for the BSD radiowave applicators Sigma 60 and Sigma 2000 (eye-applicator). HyperPlan is built on top of the modular, object-oriented visualization system Amira. This system already contains powerful algorithms for image processing, geometric modelling and 3D graphics display. HyperPlan provides a number of hyperthermia-specific modules, allowing the user to create 3D tetrahedral patient models suitable for treatment planning. In addition, all numerical simulation modules required for hyperthermia simulation are part of HyperPlan. This guide provides a step-by-step introduction to hyperthermia planning using HyperPlan. It also describes the usage of the underlying visualization system Amira.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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    Electromagnetic phased arrays for regional hyperthermia -- optimal frequency and antenna arrangement (2000)
    Details
    Publication Date: 2014-02-26
    Description: In this paper we investigate the effects of the three-dimensional arrangement of antennas and frequency on temperature distributions that can be achieved in regional hyperthermia using an electromagnetic phased array. We compare the results of power-based and temperature-based optimization. Thus we are able to explain the discrepancies between previous studies favouring more antenna rings on the one hand and more antennas per ring on the other hand. We analyze the sensitivity of the results with respect to changes in amplitudes and phases as well as patient position. This analysis can be used for different purposes. First, it provides additional criteria for selecting the optimal frequency. Second, it can be used for specifying the required phase and amplitude accuracy for a real phased array system. Furthermore, it may serve as a basis for technological developments in order to reduce both types of sensitivities described above.
    Keywords: ddc:000
    Language: English
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    Kooperativer Bibliotheksverbund Berlin-Brandenburg (KOBV) (2000)
    Details
    Publication Date: 2020-11-13
    Description: Der Kooperative Bibliotheksverbund Berlin-Brandenburg (KOBV) wurde in den Jahren 1997-2000 im Rahmen eines wissenschaftlichen Projektes eingerichtet. Er stellt eine neuartige Form von Bibliotheksverbund dar. Sein technisches Konzept und sein organisatorischer Aufbau basieren auf der Internetphilosophie. Den informationstechnischen Kern bildet eine Suchmaschine, die die heterogenen lokalen Bibliothekssysteme miteinander verbindet. Die KOBV-Organisation ist dezentral. Sie wird getragen von der Kooperation der Bibliotheken in Berlin und Brandenburg; diese werden von einer kleinen Verbundzentrale unterstützt. Die KOBV-Suchmaschine ist zu erreichen unter: {\begin{rawhtml}〈a href="http://www.kobv.de/suche/"〉 〈i〉 http://www.kobv.de/suche/ 〈/i〉 〈/a〉\end{rawhtml}}
    Keywords: ddc:000
    Language: German
    Type: reportzib , doc-type:preprint
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    Mathematik in der Industrie: interessante Branchen und zukünftige Einsatzfelder (2000)
    Details
    Publication Date: 2014-02-26
    Description: Dieser kurze Artikel hat keine umfassende Übersicht zum Ziel. Basierend auf eigenen Erfahrungen durch Projekte mit Industriefirmen möchte ich einige Branchen erwähnen, bei denen nach meiner Einschätzung Mathematik in Zukunft zunehmend Anwendung finden wird. Ich werde das anhand konkreter Beispiele erläutern. Mathematik ersetzt in der Regel traditionelle Analyse-, Planungs- und Entwurfstechniken. Den (nicht leichten) Schritt zum Einsatz mathematischer Methoden macht ein Praktiker nur, wenn es sich für ihn ``lohnt''. Wann sich dies lohnt, ist schwer abzuschätzen. Man kann aber einige Indikatoren dafür finden, ob eine Branche für den Einsatz von Mathematik ``reif'' ist. Ob es dann dazu kommt, hängt von vielen Faktoren ab, nicht zuletzt von der Psychologie und dem sozialen Umfeld der beteiligten Personen sowie der Bereitschaft, sich auf ein so schwieriges Terrain zu begeben und Kompromisse einzugehen. Gerade letzteres fällt Mathematikern gelegentlich schwer.
    Keywords: ddc:000
    Language: German
    Type: reportzib , doc-type:preprint
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    Circuit Admissible Triangulations of Oriented Matroids (2000)
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    Publication Date: 2014-11-10
    Description: All triangulations of euclidean oriented matroids are of the same PL-homeomorphism type by a result of Anderson. That means all triangulations of euclidean acyclic oriented matroids are PL-homeomorphic to PL-balls and that all triangulations of totally cyclic oriented matroids are PL-homeomorphic to PL-spheres. For non-euclidean oriented matroids this question is wide open. One key point in the proof of Anderson is the following fact: for every triangulation of a euclidean oriented matroid the adjacency graph of the set of all simplices ``intersecting'' a segment $[p_-p_+]$ is a path. We call this graph the $[p_-p_+]$-adjacency graph of the triangulation. While we cannot solve the problem of the topological type of triangulations of general oriented matroids we show in this note that for every circuit admissible triangulation of an arbitrary oriented matroid the $[p_-p_+]$-adjacency graph is a path.
    Keywords: ddc:000
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    Triangulierungen von Punktmengen und Polyedern (2000)
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    Publication Date: 2014-11-10
    Description: Dieser Report wurde im Sommersemester 2000 an der TU Berlin in einer Spezialvorlesung über Triangulierungen von Punktmengen und Polyedern als Skriptum verwendet. Nach einem motivierenden Kapitel werden grundlegende Begriffe und Konstruktionen in der Theorie der Triangulierungen von Punktmengen und Polyedern vorgestellt. Danach werden als weiterführende Themen reguläre Triangulierungen, Sekundärpolytope, bistellare Operationen, höhere Stasheff-Tamari-Halbordnungen und Triangulierungen mit wenigen bzw. gar keinen Flips behandelt. Ein Kapitel über Enumeration und Optimierung beschließt die Zusammenstellung.
    Keywords: ddc:000
    Language: German
    Type: reportzib , doc-type:preprint
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    Optimierung in der Planung und beim Aufbau des G-WiN (2000)
    Details
    Publication Date: 2020-02-11
    Description: Ende Juni diesen Jahres wurde das Gigabit-Wissenschaftsnetz offiziell gestartet. In der zweijährigen Vorbereitungsphase wurden nicht nur die technischen Möglichkeiten der neuen Übertragungstechniken und Dienste getestet. Es wurden auch verschiedene Fragestellungen zum effizienten Einsatz der verfügbaren Ressourcen für den Betrieb des G-WiN untersucht. In diesem Artikel beschreiben wir, wie das G-WiN zu seiner jetzigen Struktur und Topologie gekommen ist.
    Keywords: ddc:000
    Language: German
    Type: reportzib , doc-type:preprint
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    Critical and Anticritical Edges in Perfect Graphs (2000)
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    Publication Date: 2014-02-26
    Description: We call an edge $e$ of a perfect graph $G$ critical if $G-e$ is imperfect and say further that $e$ is anticritical with respect to the complementary graph $\overline G$. We ask in which perfect graphs critical and anticritical edges occur and how to find critical and anticritical edges in perfect graphs. Finally, we study whether we can order the edges of certain perfect graphs such that deleting all the edges yields a sequence of perfect graphs ending up with a stable set.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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    Fast Surface Reconstruction Using a Probe Sphere (2000)
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    Publication Date: 2014-02-26
    Description: We introduce a new method for reconstructing a triangular surface from an unorganized set of points in space. It is based on placing a probe sphere on the point set and rolling it around, connecting all triples of points with a triangle that the sphere comes to rest on. Therefore, the algorithm interpolates, rather than approximates, the input points. The method needs considerably less running time than previous algorithms and yields good results on point sets that are reasonably well-behaved.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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    Frequency Planning and Ramifications of Coloring (2000)
    Details
    Publication Date: 2014-11-11
    Description: This paper surveys frequency assignment problems coming up in planning wireless communication services. It particularly focuses on cellular mobile phone systems such as GSM, a technology that revolutionizes communication. Traditional vertex coloring provides a conceptual framework for the mathematical modeling of many frequency planning problems. This basic form, however, needs various extensions to cover technical and organizational side constraints. Among these ramifications are $T$-coloring and list coloring. To model all the subtleties, the techniques of integer programming have proven to be very useful. The ability to produce good frequency plans in practice is essential for the quality of mobile phone networks. The present algorithmic solution methods employ variants of some of the traditional coloring heuristics as well as more sophisticated machinery from mathematical programming. This paper will also address this issue. Finally, this paper discusses several practical frequency assignment problems in detail, states the associated mathematical models, and also points to public electronic libraries of frequency assignment problems from practice. The associated graphs have up to several thousand nodes and range from rather sparse to almost complete.
    Keywords: ddc:000
    Language: English
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    Hadron masses from dynamical, non-perturbatively O(a) improved Wilson fermions (2000)
    Details
    Publication Date: 2014-02-26
    Description: We present results on light hadron masses from simulations of full QCD and report on experiences in running such simulations on a Hitachi SR8000-F1 supercomputer.
    Keywords: ddc:000
    Language: English
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    Automatic Identification of Metastable Conformations via Self-Organized Neural Networks (2000)
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    Publication Date: 2014-02-26
    Description: As has been shown recently, the identification of metastable chemical conformations leads to a Perron cluster eigenvalue problem for a reversible Markov operator. Naive discretization of this operator would suffer from combinatorial explosion. As a first remedy, a pre-identification of essential degrees of freedom out of the set of torsion angles had been applied up to now. The present paper suggests a different approach based on neural networks: its idea is to discretize the Markov operator via self-organizing (box) maps. The thus obtained box discretization then serves as a prerequisite for the subsequent Perron cluster analysis. Moreover, this approach also permits exploitation of additional structure within embedded simulations. As it turns out, the new method is fully automatic and efficient also in the treatment of biomolecules. This is exemplified by numerical results.
    Keywords: ddc:000
    Language: English
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    An Approximation Algorithm for the Non-Preemptive Capacitated Dial-a-Ride Problem (2000)
    Details
    Publication Date: 2020-11-13
    Description: In the Capacitated Dial-a-Ride Problem (CDARP) we are given a transportation network and a finite set of transportation jobs. Each job specifies the source and target location which are both part of the network. A server which can carry at most $C$~objects at a time can move on the transportation network in order to process the transportation requests. The problem CDARP consists of finding a shortest transportation for the jobs starting and ending at a designated start location. In this paper we are concerned with the restriction of CDARP to graphs which are simple paths. This setting arises for instance when modelling applications in elevator transportation systems. It is known that even for this restricted class of graphs CDARP is NP-hard to solve. We provide a polynomial time approximation algorithm that finds a transportion of length at most thrice the length of the optimal transportation.
    Keywords: ddc:000
    Language: English
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    Affine Invariant Convergence Analysis for Inexact Augmented Lagrangian-SQP Methods (2000)
    Details
    Publication Date: 2019-01-29
    Description: An affine invariant convergence analysis for inexact augmented Lagrangian-SQP methods is presented. The theory is used for the construction of an accuracy matching between iteration errors and truncation errors, which arise from the inexact linear system solves. The theoretical investigations are illustrated numerically by an optimal control problem for the Burgers equation.
    Keywords: ddc:000
    Language: English
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    Online Optimierung (2000)
    Details
    Publication Date: 2020-11-13
    Description: Wie soll man einen Aufzug steuern, wenn man keine Informationen über zukünftige Fahraufträge besitzt? Soll man eine Bahncard kaufen, wenn die nächsten Bahnreisen noch unbekannt sind? In der klassischen kombinatorischen Optimierung geht man davon aus, daß die Daten jeder Probleminstanz vollständig gegeben sind. In vielen Fällen modelliert diese \emph{Offline-Optimierung} jedoch die Situationen aus Anwendungen nur ungenügend. Zahlreiche Problemstellungen in der Praxis sind in natürlicher Weise \emph{online}: Sie erfordern Entscheidungen, die unmittelbar und ohne Wissen zukünftiger Ereignisse getroffen werden müssen. Als ein Standardmittel zur Beurteilung von Online-Algorithmen hat sich die \emph{kompetitive Analyse} durchgesetzt. Dabei vergleicht man den Zielfunktionswert einer vom Online-Algorithmus generierten Lösung mit dem Wert einer optimalen Offline-Lösung. Mit Hilfe der kompetitiven Analyse werden im Skript Algorithmen zum Caching, Netzwerk-Routing, Scheduling und zu Transportaufgaben untersucht. Auch die Schwächen der kompetitiven Analyse werden aufgezeigt und alternative Analysekonzepte vorgestellt. Neben der theoretischen Seite werden auch die Anwendungen der Online-Optimierung in der Praxis, vor allem bei Problemen der innerbetrieblichen Logistik, beleuchtet. Bei der Steuerung automatischer Transportsysteme tritt eine Fülle von Online-Problemen auf. Hierbei werden an die Algorithmen oftmals weitere Anforderungen gestellt. So müssen Entscheidungen unter strikten Zeitbeschränkungen gefällt werden (Echtzeit-Anforderungen). Dieses Skript ist aus dem Online-Teil der Vorlesung -Ausgewählte Kapitel aus der ganzzahligen Optimierung- (Wintersemester~1999/2000) und der Vorlesung -Online Optimierung- (Sommersemester~2000) an der Technischen Universität Berlin entstanden.
    Keywords: ddc:000
    Language: German
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    Portale, Search Engines und Math-Net (2000)
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    Publication Date: 2022-04-11
    Description: Wie sucht ein Wissenschaftler im Internet die ben"otigten Informationen für seine Arbeit? Welche relevanten Informationen gibt es überhaupt im Web? Sind dafür solche Suchmaschinen wie AltaVista, Google oder HotBot die richtigen Werkzeuge? Die Antwort der Mathematiker heisst Math-Net, ein Informations- und Kommunikationssystem für die Mathematik. Math-Net besteht zunächst aus den Informationen von Personen und Institutionen, die ihre für die Mathematik relevanten Informationen dort bereitstellen wollen. Das soll i.a. auf den Web-Servern der Personen oder Institutionen geschehen. Hierin unterscheidet sich die Situation im Math-Net nicht von der im WWW insgesamt. Im Math-Net sollen aber die Informationen in einheitlicher Weise erschlossen werden. Dazu gibt es sowohl für Server als auch für die Dokumente Empfehlungen für deren Strukturierung. Die lokalen Informationen werden dann im Math-Net durch automatische Verfahren gesammelt, ausgewertet und indexiert. Diese Indexe sind die Basis für die Math-Net Dienste. Das sind Search Engines und Portale, die einen qualifizierten und effizienten Zugang zu den Informationen im Math-Net bieten. Die Math-Net Dienste sind auf die Mathematik spezialisiert. Im Gegensatz zu den oben erwähnten universellen Suchmaschinen decken sie nur einen winzigen Bruchteil des Web ab, aber dafür den für die Mathematik relevanten Teil. Math-Net ist mehr als nur Search Engine oder Portal zu Informationen in der Mathematik. Es ist auch ein Informations- und Kommunikationssystem sowie ein Publikationsmedium für die Mathematik. Die mathematische Community hat sich in der Math-Net Initiative organisiert. Diese Initiative wird von der International Mathematical Union (IMU), der weltweiten Dachorganisation der mathematischen Gesellschaften, koordiniert. Die Entwicklung des Math-Net wird von dem breiten Konsens der Mathematiker getragen, den Zugang zu der für die Mathematik relevanten Information zu erleichtern und zu verbessern.
    Keywords: ddc:000
    Language: German
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    A Comparison of Transparent Boundary Conditions for the Fresnel Equation (2000)
    Details
    Publication Date: 2022-07-07
    Description: We establish the relationship between the transparent boundary condition (BPP) of Baskakov and Popov [Wave Motion 14 (1991) 121-128] and Pakpadakis et. al. [J. Acoust. Soc. Am. 92 (1992) 2030-2038] and a second boundary condition (SDY) introduced by Schmidt and Deuflhard [Comp. Math. Appl. 29 (1995) 53-76] and Schmidt and Yevick [J. Compu. Phys. 134 (1997) 96-107], that is explicitly tailored to the form of the underlying numerical propagation scheme. Our analysis demonstrates that if the domain is first discretized in the propagation direction, the SDY expression can be obtained by applying the exact sequence of steps used to derive the BPP procedure. The BPP method is thus an approximate realization of the computationally far simpler and unconditionally stable SDY boundary condition.
    Keywords: ddc:000
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    Discrete Nonreflecting Boundary Conditions for the Helmholtz Equation (2000)
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    Publication Date: 2022-07-07
    Description: We derive exact discrete nonreflecting boundary conditions for time-harmonic scattering problems modeled by the Helmholtz equation. The main idea is to consider the exterior problem as an initial value problem with initial data given on the boundary of the computational domain. The solution of the exterior problem is obtained via Laplace transformation techniques which supply the boundary conditions in terms of discrete Dirichlet-to-Neumann operators.
    Keywords: ddc:000
    Language: English
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  • 67
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    Adaptive Multigrid Methods for the Vectorial Maxwell Eigenvalue Problem for Optical Waveguide Design (2000)
    Details
    Publication Date: 2022-07-07
    Description: This paper has been motivated by the need for a fast robust adaptive multigrid method to solve the vectorial Maxwell eigenvalue problem arising from the design of optical chips. Our nonlinear multigrid methods are based on a previous method for the scalar Helmholtz equation, which must be modified to cope with the null space of the Maxwell operator due to the divergence condition. We present two different approaches. First, we present a multigrid algorithm based on an edge element discretization of time-harmonic Maxwell's equations, including the divergence condition. Second, an explicit elimination of longitudinal magnetic components leads to a nodal discretization known to avoid discrete \emph{spurious modes} also and a vectorial eigenvalue problem, for which we present a multigrid solver. Numerical examples show that the edge element discretization clearly outperforms the nodal element approach.
    Keywords: ddc:000
    Language: English
    Type: reportzib , doc-type:preprint
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  • 68
    Electronic Resource
    Electronic Resource
    Immunohistochemical localization of cathepsin D in colorectal tumors (2000)
    Springer
    Diseases of the colon & rectum 43 (2000), S. 396-401 
    Details
    ISSN: 1530-0358
    Keywords: Colorectal carcinoma ; Cathepsin D ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract PURPOSE: Although it has been suggested that cathepsin D, a lysosomal protease, is involved in tumor invasion and metastasis in human colorectal cancers, conflicting studies have also been reported recently. In addition, this issue has been only rarely studied in human colorectal tumors by use of immunohistochemical methods. The aim of the study presented here was to clarify not only the correlation between cathepsin D expression and tumor invasion or metastasis but also the correlation between the intracellular immunostaining pattern of cathepsin D and tumor invasion and metastasis in human colorectal tumors. METHODS: Thirty-four primary colorectal adenocarcinomas and 24 adenomas were immunostained by use of an anticathepsin D antibody. Both the incidence and the immunostaining patterns of cathepsin D were investigated in all tissue samples. RESULTS: Three different immunostaining patterns,i.e., supranuclear, basal, and diffuse, were observed in samples containing cathepsin D. Although the incidence of cathepsin D-positive carcinomas was not correlated with tumor progression, invasion, or metastasis, the immunostaining pattern was significantly correlated with lymphatic invasion. CONCLUSIONS: The results of this study suggest that abnormal cathepsin D immunostaining patterns (basal or diffuse) can be used to predict a potential for lymphatic invasion in colorectal carcinoma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02258308
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  • 69
    Electronic Resource
    Electronic Resource
    Sentinel Node Biopsies in Melanoma Patients: A Protocol for Accurate, Efficient, and Cost-Effective Analysis by Preselection for Immunohistochemistry on the Basis of Tyr-PCR (2000)
    Springer
    Annals of surgical oncology 7 (2000), S. 51-54 
    Details
    ISSN: 1534-4681
    Keywords: Melanoma ; Sentinel node analysis ; Tyrosinase RT-PCR ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: Immunohistochemistry (IHC) of serial sectioning is considered the gold standard for detection of melanoma activity in sentinel node (SN) biopsies. However, this is cost and labor intensive. In contrast, tyrosinase reverse transcription-polymerase chain reaction (RT-PCR) is simple and quick, but it is hampered by its extreme sensitivity. This study was performed to test whether a strategy that combines the two methods, using tyrosinase RT-PCR to preselect nodes for IHC, could be accurate and cost effective. Methods: In 36 patients, SNs were identified by scintigraphy and patent blue uptake. Of each SN, one cross section was analyzed first by hematoxylin and eosin staining. Next, all nodes were examined by serial sectioning and IHC of one-half and tyrosinase RT-PCR of the other. Before comparison, all results were documented in a blinded manner. Material costs and workload estimates were noted per SN. Results: Fifty-five SNs were retrieved from the 36 patients. Hematoxylin and eosin staining of the first cross section revealed tumor positivity in 3 patients (6 SN). Tyrosinase RT-PCR was positive in 11 of the remaining 33 patients (19 of 49 SN). Of these same 11 patients, only 5 were shown to have tumor-positive SNs by using IHC on serial sections (7 SN). All these nodes had been positive for tyrosinase on PCR. For IHC, an average of 40 sections were prepared and examined per SN at a cost of $200(U.S.)/SN. In contrast, routine tyrosinase RT-PCR costs $37(U.S.)/SN, and takes 5% of the time necessary for IHC. A strategy including hematoxylin and eosin staining on the first cross section, followed by tyrosinase RT-PCR on half of each negative (half) node, could preselect nodes to be taken through serial sectioning. In these series, such a strategy would have prevented serial sectioning and IHC of 30 SN from 22 patients. Apart from a considerable gain in efficiency, this would have reduced material costs by a minimum of $6000 (U.S.). This iscrepancy would be even higher if work intensity of analysts and pathologists were considered. Conclusions: In routine analysis of SN biopsies in melanoma patients, tyrosinase RT-PCR can be used effectively to preselect nodes for further IHC of serial sections. This method seems both time and cost effective.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s10434-000-0051-8
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  • 70
    Electronic Resource
    Electronic Resource
    Micrometastasis in lymph nodes of mucosal gastric cancer (2000)
    Springer
    Gastric cancer 3 (2000), S. 91-96 
    Details
    ISSN: 1436-3305
    Keywords: Key words Mucosal gastric cancer ; Micrometastasis ; Cytokeratin ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background. Endoscopic mucosal resection is frequently used in the treatment of mucosal gastric cancer. Micrometastasis in the lymph nodes of mucosal gastric cancer remains unclear. Methods. We examined 2526 lymph nodes from 84 patients with mucosal gastric cancer. Two consecutive sections were prepared, for simultaneous staining with hematoxylin and eosin and immunostaining with CAM 5.2 monoclonal antibody against cytokeratin (CK), respectively. A clinicopathological comparison was made between patients with and without lymph node involvement. Results. Lymph node involvement was detected in 45 of 2526 (1.8%) lymph nodes. The incidence of nodal involvement was significantly increased, from 1.2% (1/84 patients) with hematoxylin and eosin staining, to 19% (16/84 patients) with CK immunostaining. Although no significant difference was found, micrometastasis to lymph nodes was more frequently detected in tumors larger than 1.0 cm (15/72 patients, 21%) than in those less than or equal to 1.0 cm (1/12 patients; 8%, P = 0.307). However, discrete CK-positive cancer cells or clusters of CK-positive cancer cells were detected only in tumors larger than 2 cm. Conclusion. Because mucosal gastric cancer of more than 1.0 cm in superficial diameter may indicate a risk of micrometastasis to lymph nodes, endoscopic mucosal resection is not recommended for these patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00011702
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  • 71
    Electronic Resource
    Electronic Resource
    Immunohistochemical investigation of a pulmonary surfactant in fatal mechanical asphyxia (2000)
    Springer
    International journal of legal medicine 113 (2000), S. 268-271 
    Details
    ISSN: 1437-1596
    Keywords: Key words Surfactant-associated protein A ; Immunohistochemistry ; Asphyxia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Notes: Abstract We evaluated the usefulness of pulmonary surfactant protein A (SP-A) as a practical diagnostic marker of fatal mechanical asphyxia in forensic autopsy cases. ¶A total of 27 cases of asphyxia were examined histologically and immunohistochemically and compared with a control group consisting of 16 cases of poisoning (n = 9) and peracute death (n = 7). Both groups showed histological findings of local atelectasis and local emphysema, congestion, intra-alveolar and interstitial edema in most cases and pulmonary hemorrhages in some cases. The mechanical asphyxia group showed a significantly increased intensity of SP-A staining in the intra-alveolar space accompanied by many massive aggregates in approximately 60% of cases, which was not found in the control group. These structures may be interpreted as aggregates of pulmonary surfactant released from the alveolar wall due to enhanced secretion caused by strong forced breathing or over-excitement of the autonomic nervous system by mechanical asphyxia. The results of our investigation suggest the practical usefulness of the immunohistochemical detection of SP-A in distinguishing mechanical asphyxia from other types of hypoxia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004149900109
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  • 72
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    The time course of the vascular response to human brain injury – an immunohistochemical study (2000)
    Springer
    International journal of legal medicine 113 (2000), S. 288-292 
    Details
    ISSN: 1437-1596
    Keywords: Key words Brain injury ; Cortical contusion ; Vascular ¶reaction ; Immunohistochemistry ; Wound age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Notes: Abstract In a total of 104 individuals who had sustained traumatic brain injury (TBI), the time-dependent vascular response was investigated at the injured cortical area during the first 30 weeks after the trauma. The immunohistochemical staining of the cerebral blood vessels was performed with antibodies against laminin, type IV collagen, tenascin, thrombomodulin and factor VIII associated antigen. Compared to the immunoreactivity in unaltered control tissue, a significantly increased vascular expression could be detected in cortical contusions after a postinfliction interval of at least 3 h for factor VIII, after 1.6 days for tenascin or after 6.8 days for thrombomodulin, whereas the immunostaining for laminin and type IV collagen was regularly positive even in the vascular endothelium of uninjured brain tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004149900126
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  • 73
    Electronic Resource
    Electronic Resource
    Clinical significance of disordered beta-catenin expression pattern in human gastric cancers (2000)
    Springer
    Gastric cancer 3 (2000), S. 193-201 
    Details
    ISSN: 1436-3305
    Keywords: Key words Gastric cancer ; Beta-catenin ; E-cadherin ; Immunohistochemistry ; Western blot
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Background. Beta-catenin plays two distinct roles, in intercellular adhesion by E-cadherin, and in transcriptional activation via TCF/LEF. Theoretically, the former role is tumor-suppressive, while the latter is oncogenic. We investigated the involvement of beta-catenin in the histogenesis and clinical outcome of gastric cancers. Methods. The expression pattern of beta-catenin was evaluated in stomach and lymph nodes from 82 patients with gastric cancer by immunohistochemistry and Western blot. Its association with E-cadherin expression and clinicopathological factors, including histological type and postoperative survival, was examined. Results. Beta-catenin expression was classified into two patterns, normal (23.2%; 19 patients) and disordered (76.8%; 63 patients), the latter being subclassified as overexpressed (7.3%; 6 patients) and reduced (69.5%; 57 patients). A disordered beta-catenin expression pattern was significantly correlated with diffuse type adenocarcinoma and deep tumor infiltration (P = 0.0154), but was not associated with lymph node metastasis (P = 0.7877). E-cadherin was always expressed at the cell membrane, and disordered beta-catenin expression was significantly associated with reduced E-cadherin expression (P 〈 0.0001). On univariate analysis, the beta-catenin pattern, as well as depth of invasion and lymph node metastasis, was associated with postoperative prognosis; however, only lymph node metastasis was an independent prognostic factor on multivariate analysis. Interestingly, different disordered patterns of beta-catenin expression, both overexpressed and reduced, were associated with E-cadherin reduction and poorer postoperative survival. Conclusion. Although disordered patterns of beta-catenin expression varied in gastric cancers, they were consistently associated with cancer progression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00011717
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  • 74
    Electronic Resource
    Electronic Resource
    Histological study on pN upgrading of oral cancer (2000)
    Springer
    Virchows Archiv 437 (2000), S. 116-121 
    Details
    ISSN: 1432-2307
    Keywords: Key words Oral cancer ; pN upgrading ; Immunohistochemistry ; Micrometastasis ; Semiserial sectioning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The International Union Against Cancer (UICC) does not define the number of sections required from each regional lymph node to record pTNM classification. This study was designed to clarify the incidence of occult metastasis and to assess the pN upgrading of patients with oral cancer. Ultimately, this study led to a proposal for appropriate semiserial sectioning guidelines. Five hundred fifty-four nonmetastatic cervical lymph nodes taken from 73 patients with oral cancer were subjected to hematoxylin-eosin (HE) staining and keratin immunohistochemistry. Micrometastases, defined as foci ≤3 mm, were detected in 29 sites of 23 lymph nodes (4.2%) of 16 patients (21.9%). In 9 patients (12.3%) pN upgrading was needed: in 6 from pN0 to pN1, in 1 from pN0 to pN2b, and in 2 from pN1 to pN2b. The remaining 13 lymph nodes with occult metastasis were found in 5 pN2b and 2 pN2c patients, resulting in no pN upgrading. Occult metastasis was also detected in 6 small lymph nodes ≤5 mm in diameter. The average minor axis of the micrometastasis was 1.36±0.85 mm. We propose that the lymph nodes should be cut and examined at 1-mm intervals to detect micrometastatic foci and to evaluate the pN classification accurately.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280000199
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  • 75
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    In situ reverse-transcriptase polymerase chain reaction demonstration of the EWS/FLI-1 fusion transcript in Ewing’s sarcomas and peripheral primitive neuroectodermal tumors (2000)
    Springer
    Virchows Archiv 437 (2000), S. 234-240 
    Details
    ISSN: 1432-2307
    Keywords: Keywords Small round cell tumors ; Ewing’s sarcoma ; Translocation ; Immunohistochemistry ; Differential diagnosis ; RT-PCR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  It is now widely accepted that the EWS/FLI-1 fusion transcript is associated with tumors of the Ewing family. To test whether it is possible to detect the fusion transcript by means of combining polymerase chain reaction (PCR) methodology and immunohistochemistry, we investigated tumors of the Ewing family using in situ reverse transcriptase (RT)-PCR. We were able to demonstrate the t(11;22) fusion transcript in five of six cases of Ewing’s sarcoma and four of four peripheral primitive neuroectodermal tumors. These results were confirmed using fluorescence in situ hybridization in seven tumor samples. In situ RT-PCR-labeled fusion transcripts were found in virtually all tumor cells within a given sample, indicating that each cell possessed the t(11;22) transcript. We conclude from these results that in situ RT-PCR can be used for the rapid detection of EWS/FLI-1 fusion transcripts in biopsy material. The findings also suggest that all cells of the tumors of the Ewing family carry the EWS/FLI-1 fusion transcript.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280000252
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  • 76
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    Detection of gonadotropin-releasing hormone receptor in normal human pituitary cells and pituitary adenomas using immunohistochemistry (2000)
    Springer
    Virchows Archiv 437 (2000), S. 264-269 
    Details
    ISSN: 1432-2307
    Keywords: Keywords Gonadotropin-releasing hormone receptor ; Pituitary gland ; Immunohistochemistry ; Colocalization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Gonadotropin-releasing hormone (GnRH), which is a well-known regulator of gonadotroph function, has recently been considered to be a paracrine factor involved in the control of somatotroph, lactotroph, and corticotroph cells. GnRH action is initiated by binding to a specific cell surface receptor, the gonadotropin-releasing hormone receptor (GnRHR), which is expressed by follicle-stimulating hormone/luteinizing hormone (FSH/LH) cells. Using in situ hybridization techniques, GnRHR messenger ribonucleic acid (mRNA) has recently been detected in normal human anterior pituitary gland and in various pituitary adenomas, including FSH/LH-cell, growth hormone (GH)-cell, adrenocorticotropic hormone (ACTH)-cell, and null-cell adenomas. However, immunohistochemical studies indicating the specific cell distribution of GnRHR in normal pituitary cells have never been reported. The aim of the present investigation was to evaluate the immunohistochemical expression of GnRHR in different types of normal pituitary cells and related tumors. Using double-label immunohistochemical techniques on formalin-fixed and paraffin-embedded tissues and specific antibodies directed against pituitary hormones and GnRHR, we found GnRHR immunoreactivity not only in FSH/LH cells, but also in GH- and thyroid-stimulating hormone (TSH) cells. GnRHR was detected in FSH/LH-cell, GH-cell, mixed GH- and prolactin (PRL)-cell, and α-subunit (α-SU)/null-cell adenomas. The findings of this study suggest that the interaction between GnRH and GnRHR may play a role in paracrine/autocrine regulation of different types of normal pituitary cells and pituitary adenomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280000247
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  • 77
    Electronic Resource
    Electronic Resource
    CD99 immunoreactivity in gastrointestinal and pulmonary neuroendocrine tumours (2000)
    Springer
    Virchows Archiv 437 (2000), S. 270-274 
    Details
    ISSN: 1432-2307
    Keywords: Keywords CD99 antigen ; Neuroendocrine tumours ; Immunohistochemistry ; Cell-to-cell adhesion ; Proliferative activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Although considered a specific marker for Ewing’s sarcoma/peripheral neuroectodermal tumour, the MIC2 gene product (CD99) has been immunolocalised in a variety of human tumours. The present study evaluated immunohistochemically the prevalence of CD99 expression in a series of 68 neuroendocrine tumours of different gastrointestinal and pulmonary sites. We now report on membrane and/or granular cytoplasmic immunoreactivity in 25% of these tumours, independent of their anatomical sites. In lung neuroendocrine tumours, CD99 was preferentially confined to typical carcinoids (P=0.009). A statistically significant relationship was observed between the number of CD99 positive cells but not the immunostaining patterns and the presence of local invasion and/or distant metastases (P〈0.001). Moreover, there was a tendency for CD99-reactive tumours to show a reduced proliferative activity expressed by a Ki67 index of 2% (P=0.119). The number of CD99 immunoreactive cells or patterns of immunoreactivity did not correlate with the presence of associated clinical syndrome or particular hormonal immunostaining. Although the molecular basis underlying CD99 expression in neuroendocrine tumours is still poorly understood, our data suggest that CD99 may be involved in cell-to-cell adhesion of neuroendocrine tumour cells and in downregulation of their proliferative activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280000240
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  • 78
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    Solitary fibrous tumour of the adrenal gland associated with pregnancy (2000)
    Springer
    Virchows Archiv 437 (2000), S. 445-449 
    Details
    ISSN: 1432-2307
    Keywords: Keywords Solitary fibrous tumour ; Adrenal gland ; Pregnancy ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Solitary fibrous tumour (SFT), first described as a pleural lesion, has been reported in several extrathoracic sites over the past 10 years. We describe a SFT of the left adrenal gland incidentally discovered in a 23-year-old, 22-week pregnant woman and characterised by a rapid growth during the third trimester of pregnancy. Elevated serum and urinary levels of cortisol and elevated blood levels of delta 4 androstendione and 17-OH progesterone were observed. After spontaneous delivery, the patient underwent laparoscopic resectioning of the mass and of the left adrenal gland from which the tumour was apparently originating. The kidney was not involved, and no other abdominal tumours were found. Histological and immunohistochemical features were typical of SFT of pleura and other locations. Only one case of adrenal SFT is on record, and the adrenal gland is to be added to the long list of extrathoracic locations of SFT. The association with pregnancy was a previously unrecognised event in SFT. The focal expression of progesterone receptors in the tumour cells may be related to pregnancy. This observation prompted an analysis of steroid hormone receptors in SFT of classical sites (pleura). Two of five cases had focal progesterone receptors too, a finding which deserves further investigations in a much larger series of SFTs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280000268
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  • 79
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    A case of anaplastic lymphoma kinase-positive anaplastic large cell lymphoma presenting with spontaneous splenic rupture: an extremely unusual presentation (2000)
    Springer
    Virchows Archiv 437 (2000), S. 459-464 
    Details
    ISSN: 1432-2307
    Keywords: Keywords Non-Hodgkin’s lymphoma ; Immunohistochemistry ; ALK1 ; T-cell lymphoma ; Splenic rupture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  In a 22-year-old male with a 10-day history of fever, painful swelling in the left groin, and abdominal complaints, emergency surgery was performed because of spontaneous splenic rupture. At histology, a cellular infiltrate of intermediate-sized atypical lymphocytes was seen in the splenic white pulp, staining for T-cell markers. In addition, CD30 and anaplastic lymphoma kinase 1 (ALK) were diffusely positive, thus, representing a case of anaplastic large cell lymphoma (ALCL), T-cell, ALK-positive, small cell monomorphic variant. ALK-positive ALCL patients generally bear a much better prognosis than patients with T-cell lymphomas, unspecified, or ALK-negative ALCL. Therefore, besides the very unusual clinical presentation, this case highlights the importance of immunostaining for CD30 and ALK in all T-cell lymphomas. This report is the first extensive description of ALK-positive ALCL involvement of the spleen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280000251
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  • 80
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    Dopamine D1-D5 receptor protein immunohistochemistry in dog pial arteries (2000)
    Springer
    The journal of headache and pain 1 (2000), S. 163-168 
    Details
    ISSN: 1129-2377
    Keywords: Key words Dopamine receptors ; Pial arteries ; Immunohistochemistry ; Prejunctional receptors ; Post-junctional receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The localization of dopamine D1-D5 receptor protein was investigated in different sized dog pial arteries. This was done to further understand the pathophysiology of cerebrovascular dopaminergic system in migraine. The study was performed in sections of dog brain including the pia-arachnoid membrane, which were processed for indirect immunohistochemistry using antibodies raised against dopamine D1-D5 receptor protein. A faint dopamine D1 receptor protein immunoreactivity was observed in smooth muscle of the tunica media of different sized pial arteries. Dopamine D2 receptor protein immunoreactivity was located in the adventitia and adventitia-media border of pial arteries. In the same area tyrosine hydroxylase immunoreactive nerve fibers were found. No dopamine D3 receptor immunoreactivity was detectable in dog pial arteries. A faint dopamine D4 receptor protein immunoreactivity was observed in dog pial arteries, with a localization similar to that of D2 receptor protein. A moderate dopamine D5 receptor protein immunostaining was observed in smooth muscle of the tunica media. These findings indicate that dog pial arteries express dopamine D1-like (D1 and D5) and D2-like (D2 and D4) receptor subtypes and display, respectively, a muscular (post-junctional) and probably prejunctional localization. These results, the first analysis of dopamine D1-D5 receptor subtype distribution in the cerebrovascular tree, suggest that dopamine is involved in the regulation of cerebral circulation. These finding may help evaluate the role of cerebrovascular dopaminergic mechanisms in the pathogenesis of migraine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101940070038
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  • 81
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    Excitatory amino acids, monoamine, and nitric oxide synthase systems in organotypic cultures: biochemical and immunohistochemical analysis (2000)
    Springer
    Amino acids 19 (2000), S. 33-43 
    Details
    ISSN: 1438-2199
    Keywords: Keywords: Amino acids ; Basal ganglia ; Dopamine ; Nitric oxide ; Excitatory amino acids ; Organotypic culture ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary. The nigrostriatal and mesolimbic systems of the rat have been re-constructed using the organotypic culture model, whereby neonatal brain tissue is grown in vitro for approximately one month. The nigrostriatal cultures consisted of tissue from the substantia nigra, dorsal striatum and frontoparietal cortex; while the mesolimbic cultures included the ventral tegmental area, ventral striatum and cingulate cortex. The cultures were grown at 35°C in normal atmosphere, using a tube-roller device placed in a cell incubator and changing the medium every 3–4 days. The in vitro development was evaluated with an inverted microscope equipped with a variable relief contrast function. Samples were taken directly from the medium in the culture tube and analysed for several amino acids with HPLC. After a month the cultures were fixed and processed for immunohistochemistry. High levels of glutamate and aspartate were observed every time the medium was changed, but the levels rapidly decreased reaching a steady state after approximately 24 h. A decrease in the levels was also observed along development, reaching stable values (∼2 μM and ∼0.12 μM for glutamate and aspartate, respectively) at approximately two weeks, but only when the cultures showed an apparently healthy development. The levels were approximately 10 times higher in deteriorating or apparently damaged cultures. Glutamine levels were in the mM range and remained stable along the entire experiment. No differences were observed among nigrostriatal and mesolimbic cultures. Immunohistochemistry confirmed the impressions obtained from microscopic and biochemical analysis along the in vitro development, revealing apparently healthy neuronal systems with characteristics similar to those observed in vivo, when tyrosine hydroxylase and nitric oxide synthase, markers for dopamine and nitric oxide containing neurons, respectively, were analysed. In the substantia nigra, nitric oxide synthase-positive networks surrounded tyrosine hydroxylase-positive neurons, while in the striatum nitric oxide synthase dendrites were surrounded by tyrosine hydroxylase-positive nerve terminals, suggesting a reciprocal interaction among dopamine and nitric oxide containing neurons. Thus, the organotypic model appears to capture many of the neurochemical and morphological features seen in vivo, providing a valuable model for studying in detail the neurocircuitries of the brain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007260070031
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    Neurotrophic factors influence upregulation of constitutive isoform of heme oxygenase and cellular stress response in the spinal cord following trauma (2000)
    Springer
    Amino acids 19 (2000), S. 351-361 
    Details
    ISSN: 1438-2199
    Keywords: Keywords: Amino acids ; Spinal cord injury ; Heme oxygenase ; Heat shock protein ; Carbon monoxide ; Growth factors ; BDNF ; IGF-1 ; Immunohistochemistry ; Cell injury ; Spinal cord edema
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary. The influence of brain derived neurotrophic factor (BDNF) or insulin like growth factor-1 (IGF-1) on spinal cord trauma induced carbon monoxide (CO) production and cellular stress response was examined using immunostaining of the constitutive isoform of the hemeoxygenase (HO-2) enzyme and the heat shock protein (HSP 72 kD) expression in a rat model. Subjection of rats to a 5 h spinal trauma inflicted by an incision into the right dorsal horn at T10–11 segment markedly upregulated the HO-2 and HSP expression in the adjacent spinal cord segments (T9 and T12). Pretreatment with BDNF or IGF-1 significantly attenuated the trauma induced HSP expression. The upregulation of HO-2 was also considerably reduced. These results show that BDNF and IGF-1 attenuate cellular stress response and production of CO following spinal cord injury which seems to be the key factors in neurotrophins induced neuroprotection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007260070066
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  • 83
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    Expression of extracellular matrix proteins in the fetal rat gastric mucosa (2000)
    Springer
    Anatomy and embryology 201 (2000), S. 149-156 
    Details
    ISSN: 1432-0568
    Keywords: Key words Cell differentiation ; Cell proliferation ; Collagen ; Fetal development ; Fibronectin ; Immunohistochemistry ; Keratin ; Laminin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  At gestational day 16 the epithelium of the rat stomach consists of a stratified layer of undifferentiated cells, and two days later glandular structures appear. The present study was carried out to identify extracellular matrix proteins that could be involved in the epithelial cell proliferation and differentiation processes that occur in the fetal rat stomach during this period. For comparative purposes the expression of the same components in the adult gastric mucosa was examined. Pregnant Sprague-Dawley rats received an intraperitoneal injection of 5-bromo-2’-deoxyuridine to label proliferating cells. One, 3.5, or 6 h post-injection the stomachs were excised and immediately frozen. The specimens were sectioned and stained with hematoxylin and eosin or for 5-bromo-2’-deoxyuridine, cytokeratin no. 8, H,K-ATPase, and the extracellular matrix proteins fibronectin, laminin, and collagens type I and IV. A stratified layer of proliferating cells was observed in the epithelium of the fetal stomachs, while in adult stomachs proliferating cells were detected in the isthmus/neck region of the glands. Cytokeratin, an epithelial cell marker, was sparse at gestational day 16 but abundant both at gestational day 18 and in the isthmus/neck region of gastric glands of the adult stomach. The parietal cell marker H,K-ATPase could not be detected in the fetal stomachs during this period. Fibronectin was observed in the stroma of both fetal and adult stomachs. Collagen type I could only be detected in the stroma close to the oesophagus at gestational day 16. Two days later, collagen type I was abundant in the lamina propria, the submucosa and in the serosa of the fetal stomachs. In adult tissue collagen type I was detected in the surface epithelium, the submucosa and in the serosa of the stomach. Collagen type IV and laminin were expressed in the lamina propria, the basement membranes around blood vessels, muscle cells, and nerve bundles, as well as in the serosa of both 16- and 18-day-old fetal and adult rat stomachs. In conclusion, a high cell proliferation rate was observed in the epithelium at both gestational days 16 and 18. The increased expression of cytokeratin observed during this period indicates that the epithelial character of the embryonic cells becomes more distinct, while the remarkable change in the expression of collagen type I might reflect an important role of collagen type I in the development of the gastric epithelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00008236
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  • 84
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    Mandibular deformities in parathyroid hormone-related protein (PTHrP) deficient mice: possible involvement of masseter muscle (2000)
    Springer
    Anatomy and embryology 202 (2000), S. 85-93 
    Details
    ISSN: 1432-0568
    Keywords: Key words Intramembranous ossification ; Immunohistochemistry ; Muscle fiber type
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Previous studies using parathyroid hormone-related protein (PTHrP) null mutant mice have indicated severe abnormalities in the endochondral ossification, suggesting that PTHrP affects chondrocyte differentiation. In this study, we found in newborn PTHrP-deficient mice some deformities in the mandible that is formed via intramembranous ossification. The mandibular ramus was bent downwards and a prominent bone crest to which the deep layer of masseter muscle was tendinously attached was observed in the mandibular body. Transmission electron microscopic studies showed that active bone formation was progressing along the tendon fibers of the masseter muscle. The examination of 3-D reconstruction models indicated that the mandibular ramus was bent at the site of muscle attachment, which was shifted in the direction of the muscle fibers. Muscle fiber type analysis using myosin ATPase staining showed that the masseter muscle in the newborn PTHrP-deficient mice contained numerous type 2B fibers, demonstrating premature maturation of this muscle. Based on these findings, we speculated that premature maturation of the masseter muscle leads, probably due to increased tensile forces, to accelerated bone crest formation and subsequent bending of the mandibular ramus. These results further suggest that PTHrP is involved in the regulation of muscle development in normal animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290000100
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  • 85
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    Electronic Resource
    Organ-specific expression of the intestinal epithelium-related antigen A33, a cell surface target for antibody-based imaging and treatment in gastrointestinal cancer (2000)
    Springer
    Cancer chemotherapy and pharmacology 46 (2000), S. S27 
    Details
    ISSN: 1432-0843
    Keywords: Key words Monoclonal antibody ; A33 ; Gastric cancer ; Immunohistochemistry ; Tumor targeting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Murine monoclonal antibody A33 (mA33) was developed by the Memorial Sloan-Kettering Cancer Center and by the New York Branch of the Ludwig Institute for Cancer Research. It is an immunoglobulin (Ig)G2a antibody that detects a protease- and neuraminidase-resistant, periodate-sensitive epitope. Serological analysis of the antigen showed that it is expressed in a few colorectal cancer cell lines and a pancreatic cancer cell line, but is basically not reactive with other types of cell line. Normal fibroblasts and normal kidney cell lines reacted negatively to mA33. Immunohistochemical study of normal tissues identified the large and small intestinal mucosa as the principal site of A33 expression. Tests in tumor samples demonstrated that only tumors of the gastrointestinal tract are consistently A33 positive. A33 is found in 95% of primary and metastatic colorectal cancers, with uniform expression throughout the tumors in most cases. A33 is also detected in 63% of gastric cancers, with uniform expression in 45% of cases. Eighty-three percent of intestinal-type gastric cancers were positive for A33, and about 50% of the diffuse-type and mucinous cancers were mA33 positive. A33 was expressed in 50% of the pancreatic cancers but with marked heterogeneity. Other epithelial cancers, sarcomas, neuroectodermal tumors, and lymphoid neoplasms were generally A33 negative. A33 is the first example of a constitutively expressed, organ-specific epithelial membrane antigen permitting highly specific tumor targeting in patients with gastrointestinal cancer. Encouraged by the success of the biodistribution and imaging characteristic studies performed at Memorial Sloan-Kettering Cancer Center by the New York Branch of the Ludwig Institute in colorectal cancers, a new clinical study of humanized monoclonal antibody huA33 against A33 antigen-positive gastric cancers has been initiated in Japan.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00014045
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  • 86
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    Electronic Resource
    Heat shock protein 72 expression in chondrosarcoma correlates with differentiation (2000)
    Springer
    Journal of cancer research and clinical oncology 126 (2000), S. 667-670 
    Details
    ISSN: 1432-1335
    Keywords: Key words Chondrosarcoma ; Heat shock protein ; Differentiation ; Diagnosis ; Immunohistochemistry ; Chondroma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: Heat shock proteins (hsp) are involved in tumor immunity, and a correlation with survival, occurrence of metastases, and drug resistance has been reported. It was the aim of this study to investigate the expression of heat shock proteins in chondrosarcomas and chondromas. Methods: Hsp expression was investigated immunohistochemically on paraffin-embedded sections of 37 consecutive patients (24 male and 13 female, mean age 48 years) with chondrosarcoma and of ten patients (six male, four female, mean age 36 years) with chondroma. Results: Chondromas showed a positive staining for hsp27 in 100%, for hsp60 in 30%, for hsp72 in 80%, for hsp73 in 80%, and for hsp90 in 90%. In chondrosarcoma a decreased expression was found for hsp27 (62% positive, P 〈 0.05) and hsp72 (43% positive, P 〈 0.05), whereas no significant difference to chondromas was detected in the expression of hsp60 (49% positive), hsp73 and hsp90 (73% and 81% positive, respectively). In addition, hsp72 expression showed a correlation with differentiation of the tumors (P 〈 0.05); the lowest hsp72 expression was found in G3 chondrosarcomas (only 13% positive). No correlation with respect to differentiation was found for the expression of the other hsps. Conclusions: This study shows a different expression of hsps in chondrosarcomas and chondromas. Together with the correlation of hsp72 expression with low differentiation, this finding could lead to new experimental and diagnostic strategies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004320000167
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  • 87
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    Electronic Resource
    Identifizierung eines Nasenrachenkarzinoms mit Hilfe der EBV-Diagnostik (2000)
    Springer
    HNO 48 (2000), S. 314-317 
    Details
    ISSN: 1433-0458
    Keywords: Schlüsselwörter ; Nasenrachenkarzinom ; Epstein-Barr-Virus ; Immunhistologie ; Polymerasekettenreaktion ; Keywords ; Nasopharyngeal carcinoma ; Epstein-Barr virus ; Immunohistochemistry ; Polymerase chain reaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract We report the case of a 36-year-old women who was found to have a malignant tumor extending from the side of her right nasal cavity to the nasopharynx. Magnetic resonance imaging and computed tomography were not able to define the primary site of the tumor. Histologic evaluation demonstrated an undifferentiated squamous cell carcinoma. Because of the different treatment concepts for carcinomas of the nasal cavity and nasopharynx, we tried to identify the primary site by diagnosing Epstein-Barr virus (EBV) infection, which is associated with carcinoma of the nasopharynx. By using immunohistochemistry and polymerase chain reaction EBV could be identified in the cells of the carcinoma. This showed that the primary site of the tumor was located in the nasopharynx and resulted in the patient being treated with simultaneous radiochemotherapy.
    Notes: Zusammenfassung Eine 36 Jahre alte Patientin stellte sich mit einem ausgedehnten Tumor der rechten Nasenhöhle und des rechten Nasenrachens vor. Die histologische Untersuchung ergab ein undifferenziertes Plattenepithelkarzinom. Sowohl mit Hilfe der computertomographischen, als auch der kernspintomographischen Befunde, war keine eindeutige Bestimmung der Primärtumorregion möglich. Anhand der bekannten Assoziation zwischen Karzinomen des Nasenrachens und Epstein-Barr Virus (EBV) wurde versucht, die Primärlokalisation des Tumors zu klären. Immunhistologisch und durch „polymerase chain reaction” war es möglich, eine EBV-Infektion im Tumor nachzuweisen. Die Primärlokalisation des Tumors wurde damit dem Nasenrachen zugeordnet und die entsprechende Therapie für diese Lokalisation in Form einer simultanen Radiochemotherapie eingeleitet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001060050572
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  • 88
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    Electronic Resource
    Immunohistochemical investigations on the course of astroglial GFAP expression following human brain injury (2000)
    Springer
    International journal of legal medicine 113 (2000), S. 70-75 
    Details
    ISSN: 1437-1596
    Keywords: Key words Brain injury ; Cortical contusion ; GFAP ¶expression ; Immunohistochemistry ; Wound age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Notes: Abstract The course of GFAP expression by astrocytes has been immunohistochemically investigated during the first 30 weeks after human brain injury. In order to provide reliable data for a forensic wound age estimation, a quantitative morphometric analysis was performed considering the different topographic regions of the cortex as well as of the white matter. Compared to the GFAP immunoreactivity in unaltered control tissue, significantly increased numbers of GFAP positive astroglial cells could be detected adjacent to the cortical contusion from 1 day up to 4 weeks after brain injury.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00007711
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  • 89
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    Electronic Resource
    Demonstration of morphine in ganglion cells of the hippocampus from victims of heroin overdose by means of anti-morphine antiserum (2000)
    Springer
    International journal of legal medicine 113 (2000), S. 117-120 
    Details
    ISSN: 1437-1596
    Keywords: Key words Ganglion cells ; Hippocampus ; Immunohistochemistry ; Mean optical density (MOD) ; Morphine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Notes: Abstract To investigate the topography of morphine distribution in the human brain, a method has been developed to detect morphine immunohistochemically. In this study hippocampus tissue from victims of heroin overdose (blood morphine concentrations 220 ng/g–1500 ng/g; 6-MAM positive urine sample), known for its high concentration of μ-opiate receptors was used. The immunohistochemical staining was performed with an anti-morphine antiserum originally developed for radio-immuno-assays. In comparison with control specimens from cases of sudden death without morphine exposition or a history of heroin abuse, the brains from victims of heroin overdose showed selectively stained ganglion cells, axons and dendrites, suggesting a massive concentration of morphine in the neuronal structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004140050012
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  • 90
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    Electronic Resource
    Immunohistochemical localization of mitogen-activated protein kinase (MAPK) family and morphological changes in rat heart after ischemia-reperfusion injury (2000)
    Springer
    Medical electron microscopy 33 (2000), S. 74-81 
    Details
    ISSN: 1437-773X
    Keywords: Key words Mitogen-activated protein kinase (MAPK) ; Ischemia reperfusion injury ; Heart ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The mitogen-activated protein kinase (MAPK) family is considered to be activated by stress, but the role of the MAPK family is still unknown in cardiac pathology. In the present study, not only the localization of MAPKs such as the extracellular responsive kinase (ERK), c-jun N-terminal kinase (JNK), and p38 MAPK (p38), but also ultrastructural changes were investigated in the ischemia-reperfusion model of Wistar rats. At 5, 10, 30, 60, and 180 min reperfusion after 30 min ischemia by occluding the coronary artery, the expression of these MAPKs was increased in blood vessels and cardiomyocytes by Western blotting and immunohistochemical methods. In addition, after ischemia reperfusion, various ultrastructural changes such as decreased glycogen granules, mitochondrial swelling, and myolysis were observed in the blood vessels and cardiomyocytes. These results suggest that protein kinases may regulate numerous biological processes, including the regulation of contraction and ion transport.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007950070005
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  • 91
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    Electronic Resource
    An immunohistochemical and ultrastructural study of a follicle-stimulating hormone-secreting gonadotroph adenoma occurring in a 10-year-old girl (2000)
    Springer
    Medical electron microscopy 33 (2000), S. 25-31 
    Details
    ISSN: 1437-773X
    Keywords: Key words Gonadotroph adenoma ; FSH ; Childhood ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Female gonadotroph adenomas with endocrinological symptoms are uncommon. Six cases of such adenomas have been reported in the literature: two were girls who presented with precocious puberty and four were premenopausal women with accompanying multiple ovarian cysts. We describe here a 10-year-old Japanese girl with a gonadotroph macroadenoma and present detailed morphological findings of the tumor. The patient's chief complaints were nausea, abdominal distention, and abdominal pain. Abdominopelvic ultrasonography and magnetic resonance imaging (MRI) revealed bilateral multiple ovarian cysts. Endocrinological assays showed elevated serum follicle-stimulating hormone (FSH) (33.7 mIU/ml) and estradiol (3840 pg/ml). MRI of the head showed a large pituitary tumor. Two transsphenoidal operations and subsequent radiation therapy were performed. Immunohistochemically, more than half the tumor cells were positive for anti-FSH-β monoclonal antibody. Ultrastructurally, the tumor cells exhibited a fairly uniform picture of rounded cells. Their nuclei were slightly irregular and contained heterochromatin, and their cytoplasm contained many round, dense core granules, measuring 140–260 nm in diameter, together with well-developed organelles. An in vitro study showed that the tumor cells in primary culture produced FSH (1089.0 mIU/ml). To our knowledge, this is the first immunohistochemical and ultrastructural study of an FSH-secreting gonadotroph adenoma occurring in childhood.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007950000004
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  • 92
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    Electronic Resource
    Mesangial myofibroblastic transformation in steroid-dependent minimal change nephrotic syndrome (2000)
    Springer
    Medical electron microscopy 33 (2000), S. 102-107 
    Details
    ISSN: 1437-773X
    Keywords: Key words Minimal change nephrotic syndrome ; α-Smooth muscle actin ; Vimentin ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Patients with minimal change nephrotic syndrome (MCNS) occasionally show frequent relapses with proteinuria after cessation of steroid treatment, even though no significant pathological abnormalities are found in the glomeruli, compared with those in nonrelapsed and good-prognosis cases of MCNS. To resolve this contradiction, we immunohistochemically and ultrastructurally examined a biopsied renal tissue of a patient who showed glomerular features of MCNS and frequent clinical relapses. Immunohistochemistry demonstrated the overexpression of α-smooth muscle actin (ASMA) and vimentin in glomerular mesangial cells despite no mesangial cell proliferation, compared with nine nonrelapsed cases of MCNS. These facts may be an important clue to the investigation of the pathogenesis of steroid-dependent MCNS with frequent relapses. Furthermore, the immunohistochemical examination of ASMA and vimentin may be useful to detect mesangial myofibroblastic transformation that is not demonstrated in conventional light microscopy and immunofluorescence study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007950070009
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  • 93
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    Electronic Resource
    Structural immaturity of the pylorus muscle in infantile hypertrophic pyloric stenosis (2000)
    Springer
    Pediatric surgery international 16 (2000), S. 282-284 
    Details
    ISSN: 1437-9813
    Keywords: Key words Desmin ; Infantile hypertrophic pyloric stenosis ; Immunohistochemistry ; Fetus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Recent reports indicate that extracellular matrix and cytoskeleton plasmalemmal elements are altered in infantile hypertrophic pyloric stenosis (IHPS). Desmin is a cytoskeletal protein that is important for the organization and function of muscular fibers. It has been found to be increased in the smooth muscle in chronic intestinal pseudo-obstruction and in skeletal muscle in some forms of myopathies as well as in unexplained hypertrophic cardiomyopathies. The aim of this study was to analyze the expression of desmin in IHPS. Full-thickness muscle-biopsy specimens were obtained from 8 IHPS patients (age range 23 to 41 days) at pyloromyotomy, from 8 age-matched controls without evidence of gastrointestinal (GI) disease at autopsy, and from 2 stillborns who died at 27 and 30 weeks of gestation without evidence of GI disease. Indirect immunohistochemistry was performed using the avidin-biotin-peroxidase complex method with anti-desmin and visualized by development with 3-diaminobenzidine tetrahydrochloride. Pyloric muscle in IHPS demonstrated strong desmin immunoreactivity. The expression of desmin was also strong in the muscular layers of fetal pylorus. In the age-matched controls absent or weak desmin immunoreactivity was seen in the pyloric muscle layer. The increased amount of desmin in hypertrophied pyloric muscle in IHPS may result in inco-ordination of contraction and relaxation of the pylorus, thus causing motility dysfunction. The similar pattern of desmin expression in IHPS and fetal pylorus suggests that the organization of intermediate filaments in IHPS is in a fetal stage of development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003830050745
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  • 94
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    Electronic Resource
    Organ-specific distribution of major histocompatibility antigens in rats (2000)
    Springer
    Pediatric surgery international 16 (2000), S. 285-292 
    Details
    ISSN: 1437-9813
    Keywords: Key words Major histocompatibility complex (MHC) ; Rat ; Immunohistochemistry ; Distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The present study systematically investigated the expression and distribution of the major histocompatibility complex (MHC) classes I and II in the rat. About 150 native tissue probes from eight adult Lewis rats were taken, representative for most organs, tissues, and the vascular system. MHC expression was analyzed by two monoclonal antibodies (mAb) generated against the non-polymorphic determinants of rat MHC class I (Ox-18) and class II (Ox-6). Immunoreactivities were compared to those of different endothelial (HIS52, TLD-3A12, Ox-43, REHA-1 antigen), histiocytic (ED1, ED2), B-cell (RLN-9D3), and T-cell (MRC Ox-52) markers. A nonspecific mAb (MR12/53) served as a negative control. Pretested concentrations on various tissues and the alkaline phosphatase-anti-alkaline phosphatase technique allowed semiquantitative evaluation of serial cryostat tissue sections. MHC class I expression was detected on most immunocompetent cells. Endothelial cells were stained heterogeneously along the vascular system and the organ-specific microcirculation. Furthermore, some organs showed staining of parenchymal cells. MHC class II was found on all immunocompetent cells positive for the B-cell marker and about 15% of cells positive for the histiocytic markers. Besides the well-known expression of MHC class II in the outer zone of the renal proximal tubule, further organ-specific cell forms were found positive. In conclusion, the present study outlines tissue-specific distribution of MHC I/II and implies that each organ carries a variable immunologic burden that needs to be considered for any transplantation model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003830050746
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  • 95
    Electronic Resource
    Electronic Resource
    Appearance of denuded hepatic stellate cells and their subsequent myofibroblast-like transformation during the early stage of biliary fibrosis in the rat (2000)
    Springer
    Medical electron microscopy 33 (2000), S. 217-230 
    Details
    ISSN: 1437-773X
    Keywords: Key wordsα-Smooth muscle actin ; Transforming growth factor-β1 ; Bile ductule ; Bile duct ligation ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To investigate the early in vivo response of hepatic stellate cells in biliary fibrosis, we examined rat livers during the first 7 days after bile duct ligation using light microscopy, immunohistochemistry, electron microscopy, and immunoelectron microscopy. At day 1 after bile duct ligation, α-smooth muscle actin-positive fibroblasts appeared and then increased in number around the proliferating bile ductules. With time, the destruction of the external limiting plate became accentuated because of the invasion of the proliferating bile ductules and periductural fibrosis. At day 7, stromal cells containing fat droplets appeared in the fibrous tissue adjacent to the periportal parenchyma; these are termed denuded hepatic stellate cells. In the fibrous tissue disconnected from the liver parenchyma, the denuded hepatic stellate cells were replaced by myofibroblast-like cells. Meanwhile, the expression of transforming growth factor-β1 on biliary epithelial cells increased. These results indicate the dual origin of myofibroblasts in experimental biliary fibrosis, the periductural and periductal fibroblasts in the initial stage, and the denuded hepatic stellate cells in the subsequent stage. These two types of stromal cells may undergo myofibroblastic transformation by the transforming growth factor-β1 secreted by the proliferating biliary epithelial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007950000022
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  • 96
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    Electronic Resource
    Prognostic value of P-glycoprotein expression in bone and soft-tissue sarcoma (2000)
    Springer
    International journal of clinical oncology 5 (2000), S. 164-170 
    Details
    ISSN: 1437-7772
    Keywords: Key words P-glycoprotein ; Osteosarcoma ; Soft-tissue sarcoma ; Prognosis ; Immunohistochemistry ; RT-PCR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background. The purpose of this study was to investigate the correlation between P-glycoprotein status and outcome in adult patients with high-grade osteosarcomas and soft-tissue sarcomas. Methods. P-glycoprotein status was determined im-munohistochemically in specimens from 28 patients with osteosarcoma and 34 patients with soft-tissue sarcoma. The polyclonal antibody mdr(Ab-1) was used for either decalcified or undecalcified tissue samples which were formalin-fixed and paraffin-embedded. The expression of P-glycoprotein mRNA was also determined by the polymerase chain reaction in 23 fresh sarcoma specimens. P-glycoprotein status was analyzed in relation to the duration of event-free survival. Results. Positivity for P-glycoprotein was found in 29% of the osteosarcomas and 34% of the soft-tissue sarcomas. Consistent results were obtained at both the immunohistochemical and reverse transcriptase-polymerase chain reaction (RT-PCR) levels in 19 of 23 sarcomas (83%). In patients with osteosarcoma, the presence of increased levels of P-glycoprotein was significantly associated with a decreased probability of event-free survival after diagnosis (P = 0.022). In contrast, in patients with soft-tissue sarcoma there was no correlation between the level of P-glycoprotein and prognosis. Conclusions. In patients with high-grade osteosarcomas, the presence of increased levels of P-glycoprotein detected by polyclonal antibody mdr(Ab-1) was associated with a significantly increased risk of adverse events. This association was not found in patients with soft-tissue sarcomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00012032
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  • 97
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    Electronic Resource
    “Gut-feeling” or evidence-based approaches in the evaluation and treatment of human short-bowel syndrome (2000)
    Springer
    Pediatric surgery international 16 (2000), S. 155-164 
    Details
    ISSN: 1437-9813
    Keywords: Key words Short-bowel syndrome ; Intestinal adaptation ; Sugar absorption test ; Gut hormones ; Electrophysiology ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Short bowel syndrome is the malabsorptive state that often follows extensive resection of the small intestine. Long-term survival without parenteral nutrition depends on the process of intestinal adaptation, through which the remaining small bowel gradually increases its absorptive capacity. The process of intestinal adaptation is almost exclusively luminal nutrient dependent. To date the clinical management of short bowel patients is mostly based on a “trial and error” regimen because human data and randomised trials using trophic substances are lacking due to the small number of patients annually present in pediatric surgical centres. We evaluate here the currently available as well as some more recently developed methods of measuring intestinal absorption and adaptation in short bowel patients. New techniques such as measurements of (1) intestinal permeability and carbohydrate absorption using the sugar absorption test, (2) gastrointestinal hormone production of gastrin, cholecystokinin and peptide YY, (3) transmural potential difference of the gastrointestinal tract using electrophysiology and (4) mucosal enzyme expression of lactase and sucrase-isomaltase using immunohistochemistry were evaluated. These new techniques are promising in monitoring the process of adaptation of the remaining intestine and evaluating the effect of therapeutic interventions in patients with short bowel syndrome.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003830050713
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  • 98
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    Electronic Resource
    Variation among giant rice bodies: report of four cases and their clinicopathological features (2000)
    Springer
    Skeletal radiology 29 (2000), S. 525-529 
    Details
    ISSN: 1432-2161
    Keywords: Key words Giant rice body ; Ultrastructure ; Immunohistochemistry ; Histogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Objective: To report four cases of rice bodies (RBs) showing remarkable size variations and discuss their pathogenesis. Design and patients: Based on analysis of the clinical data, we speculate on the pathogenesis of RBs using immunohistochemical and ultrastructural methods. The patients comprised three men and one woman, three with RBs in the subacromial bursae and one in the wrist synovial sheath, aged 28 (woman), 44, 50 and 81 (wrist) years, respectively. Results: There were no particular differences in clinical data among the patients. T2-weighted MR imaging was very useful for diagnosis of the RBs, allowing their clear delineation from the bursal fluid. The RBs consisted of a layered protein- aceous substance with vague targetoid cut surfaces. Much fibrin and a lesser amount of collagen fibers were recognized together with various mononuclear cells, which were few in number and predominantly T cells. The bursae and synovial sheath had multiple fibrinoid spheroids at the luminal surface. Conclusion: Fibrinoid nodular deposits probably became detached, forming the nuclei of RBs and growing to a giant RB 65 mm in diameter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002560000258
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  • 99
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    Electronic Resource
    Peripheral papillary tumor of type-II pneumocytes: a rare neoplasm of undetermined malignant potential (2000)
    Springer
    Virchows Archiv 436 (2000), S. 289-295 
    Details
    ISSN: 1432-2307
    Keywords: Key words Unusual lung tumors ; Papillary adenoma ; Surfactant proteins ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Peripheral papillary adenomas of the lung are uncommon neoplasms (only ten cases have been described so far in the English literature) composed predominantly of type-II pneumocytes and generally considered benign. We describe here two additional cases of this lung tumor. In both cases histological examination revealed an encapsulated papillary neoplasm with invasion of the capsule and, in one case, invasion of the adjacent alveoli and visceral pleura too. The proliferative index (Ki67) was less than 2% and the epithelial cells were positive for cytokeratins, surfactant apoproteins (SP), and nuclear thyroid transcription factor-1 (TTF-1). Ultrastructurally, the epithelial cells showed the characteristic surface microvilli and cytoplasmic lamellar inclusions of type-II cells. Review of the literature has revealed two other cases of peripheral papillary adenoma of type-II pneumocytes with infiltrative features. Thus, we propose replacing the term peripheral papillary adenoma with peripheral papillary tumor of undetermined malignant potential.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280050043
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    Electronic Resource
    Electronic Resource
    Differential expression of CD44s and CD44v3-10 in adenocarcinoma cells and reactive mesothelial cells in effusions (2000)
    Springer
    Virchows Archiv 436 (2000), S. 330-335 
    Details
    ISSN: 1432-2307
    Keywords: Key words Adenocarcinoma cell ; Mesothelial cells ; Effusions ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The detection of malignant cells in serous effusions obtained from patients diagnosed with cancer marks the presence of metastatic disease and is associated with a poor outcome. The purpose of this study was to evaluate the role of CD44s and CD44v isoforms in the distinction between mesothelial cells and malignant epithelial cells in effusions. Fifty-nine fresh pleural and peritoneal effusions were studied. These consisted of 41 specimens from patients with known gynecological neoplasms, 9 from patients diagnosed with breast adenocarcinoma, and 9 effusions from patients with various nongynecological malignancies or tumors of unknown origin. Forty-three effusions contained malignant/atypical epithelial cells, and 16 effusions were diagnosed as reactive. Three effusions contained exclusively malignant cells. Specimens were stained with anti-CD44s, v3, v5, v6, v7 and v3-10. The presence of staining in cancer cells, benign mesothelial cells and lymphocytes was evaluated. CD44s immunoreactivity was seen in 10 of 43 (23%) cases in malignant/atypical epithelial cells and in 53 of 56 (94%) cases in benign cells. In contrast, CD44v3-10 was seen in 23 of 43 (55%) cases in malignant/atypical epithelial cells and in 3 of 56 (6%) cases in benign cells. We advocate the use of CD44s and CD44v3-10 immunostaining in diagnostic evaluation of difficult serous effusions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280050455
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