Pathophysiologie des Kapnoperitoneums: Implikationen für Beatmung und Hämodynamik

Zusammenfassung: Die laparoskopische Chirurgie wurde Anfang der 50er Jahre für gynäkologische Eingriffe eingeführt. Mit verbesserter Technik erweiterte sich das Spektrum in den letzten Jahrzehnten beträchtlich. Es wurden zunehmend komplexere und länger dauernde Operationen durchgeführt. Als Vorteile gegenüber offener Chirurgie wurden eine Reduktion der postoperativen Schmerzen, bessere kosmetische Ergebnisse, raschere Erholung und die Verkürzung der Krankenhausverweildauer angeführt. Infolgedessen wird die Laparoskopie mittlerweile auch bei immer älteren Patienten mit entsprechenden pulmonalen sowie kardiovaskulären Komorbiditäten und in der Chirurgie für adipöse Patienten eingesetzt. Eine sichere Anästhesieführung setzt detaillierte Kenntnisse der Pathophysiologie des Kapnoperitoneums voraus, insbesondere im Hinblick auf dessen respiratorische und hämodynamische Konsequenzen. Der Übersichtsartikel diskutiert die wichtigsten Effekte des Kapnoperitoneums und stellt aktuelle Forschungsergebnisse sowie deren Umsetzungsmöglichkeiten in der klinischen Praxis da

Erratum: Dirichlet Forms and Dirichlet Operators for Infinite Particle Systems: Essential Self-adjointness

We reprove the essential self-adjointness of the Dirichlet operators of Dirchlet forms for infinite particle systems with superstable and sub-exponentially decreasing interactions.Comment: This is an erratum to the work appeared in J. Math. Phys. 39(12), 6509-6536 (1998

Modeling and Analysis of Germ Layer Formations Using Finite Dynamical Systems

The development of an embryo from a fertilised egg to a multicellular organism proceeds through numerous steps, with the formation of the three germ layers (endoderm, mesoderm, ectoderm) being one of the first. In this paper we study the mesendoderm (the tissue that collectively gives rise to both mesoderm and endoderm) gene regulatory network for two species, \textit{Xenopus laevis} and the axolotl (\textit{Ambystoma mexicanum}) using Boolean networks. We find that previously-established bistability found in these networks can be reproduced using this Boolean framework, provided that some assumptions used in previously-published differential equations models are relaxed. We conclude by discussing our findings in relation to previous work modeling gene regulatory networks with Boolean network models

Replica-Aware Co-Scheduling for Mixed-Criticality

Cross-layer fault-tolerance solutions are the key to effectively and efficiently increase the reliability in future safety-critical real-time systems. Replicated software execution with hardware support for error detection is a cross-layer approach that exploits future many-core platforms to increase reliability without resorting to redundancy in hardware. The performance of such systems, however, strongly depends on the scheduler. Standard schedulers, such as Partitioned~Strict Priority Preemptive (SPP) and Time-Division Multiplexing (TDM)-based ones, although widely employed, provide poor performance in face of replicated execution. In this paper, we propose the replica-aware co-scheduling for mixed-critical systems. Experimental results show schedulability improvements of more than 1.5x when compared to TDM and 6.9x when compared to SPP

Laser Doppler velocimeter aerial spray measurements

An experimental research program for measuring the location, spatial extent, and relative concentration of airborne spray clouds generated by agricultural aircraft is described. The measurements were conducted with a ground-based laser Doppler velocimeter. The remote sensing instrumentation, experimental tests, and the results of the flight tests are discussed. The cross section of the aerial spray cloud and the observed location, extent, and relative concentration of the airborne particulates are presented. It is feasible to use a mobile laser Doppler velocimeter to track and monitor the transport and dispersion of aerial spray generated by an agricultural aircraft

Ultrasound mapping of lymph node and subcutaneous metastases in patients with cutaneous melanoma: Results of a prospective multicenter study

Background: Ultrasound (sonography, B-mode sonography, ultrasonography) examination improves the sensitivity in more than 25% compared to the clinical palpation, especially after surgery on the regional lymph node area. Objective: To evaluate the distribution of metastases during follow-up in the draining lymph node areas from the scar of primary to regional lymph nodes ( head and neck, supraclavicular, axilla, infraclavicular, groin) in patients with cutaneous melanoma with or without sentinel lymph node biopsy (SLNB) or former elective or consecutive complete lymph node dissection in case of positive sentinel lymph node (CLND). Methods: Prospective multicenter study of the Departments of Dermatology of the Universities of Homburg/Saar, Tubingen and Munich (Germany) in which the distribution of lymph node and subcutaneous metastases were mapped from the scar of primary to the lymphatic drainage region in 53 melanoma patients ( 23 women, 30 men; median age: 64 years; median tumor thickness: 1.99 mm) with known primary, visible lymph nodes or subcutaneous metastases proven by ultrasound and histopathology during the follow-up. Results: Especially in the axilla, infraclavicular region and groin the metastases were not limited to the anatomic lymph node regions. In 5 patients (9.4%) ( 4 of them were in stage IV) lymph node metastases were not located in the corresponding lymph node area. 32 patients without former SLNB had a time range between melanoma excision and lymph node metastases of 31 months ( median), 21 patients with SLNB had 18 months ( p < 0.005). In 11 patients with positive SLNB the time range was 17 months, in 10 patients with negative SLNB 21 months ( p < 0.005); in 32 patients with CLND the time range was 31 m< 0.005). In thinner melanomas lymph node metastases occurred later ( p < 0.05). Conclusions: After surgery of cutaneous melanoma, SLNB and CLND the lymphatic drainage can show significant changes which should be considered in clinical and ultrasound follow-up examinations. Especially for high-risk melanoma patients follow-up examinations should be performed at intervals of 3 months in the first years. Patients at stage IV should be examined in all regional lymph node areas clinically and by ultrasound. Copyright (c) 2006 S. Karger AG, Basel

In Vivo Evaluation of a Gastroretentive Drug Delivery System Based on Enteric-Coated Floating Tablets

Floating dosage forms are supposed to exhibit an enhanced gastric residence time. Their development is challenging as the prediction of the retention potential in humans based on in vitro studies and animal models is difficult. A strategy to determine the stomach residence time of a floating dosage form with an inherently low density in human without using imaging techniques was explored in a self-experiment. Floating tablets and non-floating controls were prepared containing caffeine as a model drug. The compacts had a pH-dependent entericcoating to assess their stomach residence time. Since caffeine is rapidly absorbed in the gastrointestinal tract, the prolonged gastric retention of tablets can be demonstrated by a delayed systemic exposure. Caffeine and paraxanthine were determined in capillary blood by liquid chromatography coupled to tandem mass spectrometry. An increase in caffeine and paraxanthine blood levels was observed in human volunteers after 90 to 180 min for the non-floating controls. For the floating tablets, no elevated blood concentrations were found in two out of three participants during 8 h of sample collection. The results demonstrate the technical feasibility of the proposed clinical study protocol. Follow-up clinical trials will be needed to confirm the preliminary data on stomach residence time of our floating dosage form

Wind on the boundary for the Abelian sandpile model

We continue our investigation of the two-dimensional Abelian sandpile model in terms of a logarithmic conformal field theory with central charge c=-2, by introducing two new boundary conditions. These have two unusual features: they carry an intrinsic orientation, and, more strangely, they cannot be imposed uniformly on a whole boundary (like the edge of a cylinder). They lead to seven new boundary condition changing fields, some of them being in highest weight representations (weights -1/8, 0 and 3/8), some others belonging to indecomposable representations with rank 2 Jordan cells (lowest weights 0 and 1). Their fusion algebra appears to be in full agreement with the fusion rules conjectured by Gaberdiel and Kausch.Comment: 26 pages, 4 figure

Quantum Enhancement of the Zero-Area Sagnac Interferometer Topology for Gravitational Wave Detection

Only a few years ago, it was realized that the zero-area Sagnac interferometer topology is able to perform quantum nondemolition measurements of position changes of a mechanical oscillator. Here, we experimentally show that such an interferometer can also be efficiently enhanced by squeezed light. We achieved a nonclassical sensitivity improvement of up to 8.2 dB, limited by optical loss inside our interferometer. Measurements performed directly on our squeezed-light laser output revealed squeezing of 12.7 dB. We show that the sensitivity of a squeezed-light enhanced Sagnac interferometer can surpass the standard quantum limit for a broad spectrum of signal frequencies without the need for filter cavities as required for Michelson interferometers. The Sagnac topology is therefore a powerful option for future gravitational-wave detectors, such as the Einstein Telescope, whose design is currently being studied.Comment: 4 pages, 4 figure