Pilotstudie zur intraoperativen Aprotinin-Applikation bei Patienten mit Rektumtumoren und ihre Auswirkung auf Transfusionsbedarf und Blutverlust

Im Rahmen dieser Arbeit wurde eine randomisierte, plazebokontrollierte Doppelblindstudie durchgeführt, in der Patienten mit Rektumkarzinom intraoperativ den Serinprotinasen-Inhibitor Aprotinin erhielten. Hauptziel dieser Studie war es, durch die Gabe von Aprotinin eine Senkung des intraoperativen Blutverlustes und eine Reduktion der Anzahl an zu verabreichenden Erythrozytenkonzentrate zu erreichen. Weitere Zielkriterien waren der Blutverlust, die Hämoglobinkonzentration und Gerinnungsparameter, die prä- und jeweils postoperativ untersucht und mit dem Kontrollkollektiv verglichen wurden. Weiterhin wurden die Patienten in Hinblick auf etwaige auftretende Nebenwirkungen untersucht

Protein/lipid interactions in phospholipid monolayers containing the bacterial antenna protein B800-850

Studies on monomolecular layers of phospholipids containing the antenna protein B800-850 (LHCP) and in some cases additionally the reaction center of the photosynthetic bacterium Rhodopseudomonas sphaeroides are reported. Information on monolayer preparation as well as on protein /lipid and protein/protein interaction is obtained by means of fluorescence spectroscopy and microscopy at the air/water interface in combination with film balance experiments. It is shown that a homogeneous distribution of functional proteins can be achieved. This can be transformed into a regular pattern-like distribution by inducing a phospholipid phase transition. Although the LHCP preferentially partitions into the fluid lipid phase, it decreases the lateral pressure necessary to crystallize the lipid. This is probably due to an increase in order of the fluid phase. A pressure-induced conformation change of the LHCP is detected via a drastic change in fluorescence yield. A highly efficient energy transfer from LHCP to the reaction center is observed. This proves the quantitative reconstitution of both types of proteins and indicates protein aggregation also in the monolayer

A Green's function approach to predict nonlinear thermoacoustic instabilities in combustors

The prediction of thermoacoustic instabilities is fundamental for combustion systems such as domestic burners and industrial gas turbine engines. High-amplitude pressure oscillations cause thermal and mechanical stress to the equipment, leading to premature wear or even critical damage. In this paper we present a new approach to produce nonlinear (i.e. amplitude-dependent) stability maps of a combustion system as a function of various parameters. Our approach is based on the tailored Green’s function of the combustion system, which we calculate analytically. To this end, we assume that the combustor is one-dimensional, and we describe its boundary conditions through reflection coefficients. The heat release is modelled by a generalised law. This includes a direct-feedback term in addition to the usual time-lag term; moreover, its parameters (time lag, coupling coefficients) depend on the oscillation amplitude. The model provides new insight into the physical mechanism of the feedback between heat release rate and acoustic perturbations. It predicts the key nonlinear features of the thermoacoustic feedback, such as limit cycles, bistability and hysteresis. It also explains the frequency shift in the acoustic modes

Analysis of the interaction of thermoacoustic modes with a Green's function approach:

In this paper, we will present a fast prediction tool based on a one-dimensional Green's function approach that can be used to bypass numerically expensive computational fluid dynamics simulations. The Green's function approach has the advantage of providing a clear picture of the physics behind the generation and evolution of combustion instabilities. In addition, the method allows us to perform a modal analysis; single acoustic modes can be treated in isolation or in combination with other modes. In this article, we will investigate the role of higher-order modes in determining the stability of the system. We will initially produce the stability maps for the first and second mode separately. Then the time history of the perturbation will be computed, where both the modes are present. The flame will be modelled by a generic Flame Describing Function, i.e. by an amplitude-dependent Flame Transfer Function. The time-history calculations show the evolution of the two modes resulting from an initial perturbation; both transient and limit-cycle oscillations are revealed. Our study represents a first step towards the modelling of nonlinearity and non-normality in combustion processes

The application of a phenomenological framework to assess user experience with museum technologies

Six Sigma is a methodology that uses data and statistical analyses on business processes to measure and improve the conduct and the output of production and service-oriented processes. Derived from a variety of quality management and industrial engineering approaches, it has emerged into one of the most popular process re-design methodologies. This paper complements the rich body of knowledge on Six Sigma methods and techniques with insights into the actual adoption of Six Sigma. Sunstate Financials 1 is one of Australia\u27s leading financial organizations. Having recognized the advantages of Six Sigma, Sunstate Financials started their Six Sigma journey in 2001. The peak of Six Sigma deployment at Sunstate Financials lasted for approximately 2 years. Almost every person in the company was aware of the Six Sigma methodology, and many projects commenced under the Six Sigma banner. Although the use of Six Sigma has shown dramatic process improvements and cost reductions, Six Sigma is no longer in use at Sunstate Financials. This teaching case explores the Six Sigma experiences of one of Australia’s leading financial service providers, and why this methodology failed as a sustainable long term approach. It describes the key issues of Six Sigma and provides valuable lessons learnt

Physically based distributed hydrological modelling of the Upper Jordan catchment and investigation of effective model equations

International audienceSufficient freshwater availability in the water scarce environment of the Upper Jordan Catchment (UJC) is a central prerequisite for peaceful agricultural and industrial development. Hydrological modelling is required to understand terrestrial water balance and to provide scientifically sound estimates on water availability. This article aims at two related objectives: First the water balance of the UJC, a hydrogeologically complex catchment located at the borders of Israel, Syria and the Lebanon, is investigated. It is for the first time that a physically based model is set up for this region that accounts both for the entire terrestrial water balance and in particular for the groundwater-surface water interaction. It is shown that the model is able to describe observed river discharges satisfactorily. Secondly, it is investigated if observed and simulated runoff components can be explained by simple lumped approaches based on 1) linear filter theory and 2) neural networks and what the number of degrees of freedom for the runoff components is. It is exemplary shown for the Ayun subcatchment of the UJC that the simulated river discharge, the direct runoff component and the interflow runoff component as modelled by the physically based distributed hydrological model WaSiM can be described by simple effective equations with only 3 to 5 degrees of freedom. Application of simple lumped approaches to observed river discharge values showed much weaker performance

Multiple genetically engineered humanized microenvironments in a single mouse

Background Immunodeficient mouse models that accept human cell and tissue grafts can contribute greater knowledge to human stem cell research. In this technical report, we used biomaterial implants seeded with genetically engineered stromal cells to create several unique microenvironments in a single mouse. The scope of study was focused on human CD34 hematopoietic stem/progenitor cell (HSPC) engraftment and differentiation within the engineered microenvironment. Results A mouse model system was created using subdermal implant sites that overexpressed a specific human cytokines (Vascular Endothelial Growth Factor A (hVEGFa), Stromal Derived Factor 1 Alpha (hSDF1a), or Tumor Necrosis Factor Alpha (hTNFa)) by stromal cells in a three-dimensional biomaterial matrix. The systemic exposure of locally overexpressed cytokines was minimized by controlling the growth of stromal cells, which led to autonomous local, concentrated sites in a single mouse for study. This biomaterial implant approach allowed for the local analysis of each cytokine on hematopoietic stem cell recruitment, engraftment and differentiation in four different tissue microenvironments in the same host. The engineered factors were validated to have bioactive effects on human CD34+ hematopoietic progenitor cell differentiation. Conclusions This model system can serve as a new platform for the study of multiple human proteins and their local effects on hematopoietic cell biology for in vivo validation studies