246 research outputs found

    Quantification of Optical Clarity of Transparent Soil Using the Modulation Transfer Function

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    Transparent synthetic soils have been developed as a soil surrogate to enable internal visualization of geotechnical processes in physical models. Transparency of the soil dictates the overarching success of the technique; however, despite this fundamental requirement, no quantitative framework has yet been established to appraise the visual quality of transparent soil. Previous approaches to assess and optimize transparency quality included an eye chart assessment method, although this approach is highly subjective and operator-dependent. In this paper, an independent method for quantitatively assessing the optical quality of transparent soil is proposed based on the optical calibration method, Modulation Transfer Function (MTF). The work explores this hypothesis and assesses the potential for MTF to quantify the optical quality of transparent soils for a number of aspects including (i) optimum oil blend ratio, (ii) depth of viewing plane, and (iii) temperature. The results confirmed that MTF offers a robust and reliable method to provide an independent quantitative measure of the optical quality of transparent soil. The impact of reduced soil transparency and the ability to track speckle patterns—thus accuracy and precision of displacement measurement—was correlated with MTF to evaluate the permissible viewing depth of transparent soil

    Enhancing accuracy and precision of transparent synthetic soil modelling

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    Over recent years non-intrusive modelling techniques have been developed to investigate soil-structure interaction problems of increasingly complex geometry. This paper concerns the development of a small-scale, 1 g, modelling technique using a transparent analogue for soil with particle image velocimetry for internal displacement measurement. Larger model geometry achieved in this research using fine-grained transparent synthetic soils has led to an increased need for rigorous photogrammetric correction techniques. A correction framework, based upon a modified version of the pinhole camera model, is presented that corrects for lens and camera movement induced errors as well as scaling from image space to object space. An additional statistical approach is also developed to enhance the system precision, by minimising the impact of increased non-coplanarity between the photogrammetry control plane and the target plane. The enhanced data correction and statistical precision is demonstrated using a case study examining the failure mechanism around a double helical screw pile installed in transparent synthetic soil representative of a soft clay

    Eosinophilic myocarditis mimicking acute coronary syndrome secondary to idiopathic hypereosinophilic syndrome: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Eosinophilic myocarditis is a rare form of myocarditis. It is characterized pathologically by diffuse or focal myocardial inflammation with eosinophilic infiltration, often in association with peripheral blood eosinophilia. We report a case of eosinophilic myocarditis secondary to hypereosinophilic syndrome.</p> <p>Case presentation</p> <p>A 74-year-old Caucasian woman with a history of asthma, paroxysmal atrial fibrillation, stroke and coronary artery disease presented to the emergency department of our hospital with chest pain. Evaluations revealed that she had peripheral blood eosinophilia and elevated cardiac enzymes. Electrocardiographic findings were nonspecific. Her electrocardiographic finding and elevated cardiac enzymes pointed to a non-ST-elevated myocardial infarction. Echocardiogram showed a severe decrease in the left ventricular systolic function. Coronary angiogram showed nonobstructive coronary artery disease. She then underwent cardiac magnetic resonance imaging, which showed neither infiltrative myocardial diseases nor any evidence of infarction. This was followed by an endomyocardial biopsy which was consistent with eosinophilic myocarditis. Hematologic workup regarding her eosinophilia was consistent with hypereosinophilic syndrome. After being started on steroid therapy, her peripheral eosinophilia resolved and her symptoms improved. Her left ventricular ejection fraction, however, did not improve.</p> <p>Conclusion</p> <p>Eosinophilic myocarditis can present like an acute myocardial infarction and should be considered in the differential diagnosis of acute coronary syndrome in patients with a history of allergy, asthma or acute reduction of the left ventricular function with or without peripheral eosinophilia.</p

    Measurement of matric suction using tensiometric and axis translation techniques

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    Experimental equipment for the measurement of matric suction in unsaturated soils using hydraulic tensiometers and the axis translation technique share a common working principle; that is, the measurement of a pressure differential across a high air entry porous ceramic. In this paper, the current state of the art in these two suction measurement techniques is presented and discussed together with the underlying physics thereby giving the reader the necessary basis to use and interpret the results obtained from those two techniques

    ‘Forgotten Europeans’: transnational minority activism in the age of European integration

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    YesThis article examines transnational activism by coalitions of national minorities in Europe from the early 20th century to the present, setting this within the broader ‘security versus democracy dilemma’ that continues to surround international discussions on minority rights. Specifically, we analyse two organisations – the European Nationalities Congress (1925–1938) and the Federal Union of European Nationalities (1949–) – which, while linked, have never been subject to a detailed comparison based on primary sources. In so far as comparisons do exist, they present these bodies in highly negative terms, as mere fronts for inherently particularistic nationalisms that threaten political stability, state integrity and peace. Our more in‐depth analysis provides a fresh and more nuanced perspective: it shows that, in both cases, concepts of European integration and ‘unity in diversity’ have provided the motivating goals and frameworks for transnational movements advocating common rights for all minorities and seeking positive interaction with the interstate world

    Serological assessment of gastric mucosal atrophy in gastric cancer

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    <p>Abstract</p> <p>Background</p> <p>Non-invasive tools for gastric cancer screening and diagnosis are lacking. Serological testing with the detection of pepsinogen 1 (PG1), pepsinogen 2 (PG2) and gastrin 17 (G17) offers the possibility to detect preneoplastic gastric mucosal conditions. Aim of this study was to assess the performance of these serological tests in the presence of gastric neoplasia.</p> <p>Methods</p> <p>Histological and serological samples of 118 patients with gastric cancer have been assessed for tumor specific characteristics (LaurĂŠn type, localisation), degree of mucosal abnormalities (intestinal metaplasia, atrophy) and serological parameters (PG1, PG2, PG1/2-ratio, G17, <it>H. pylori </it>IgG, CagA status). Association of the general factors to the different serological values have been statistically analyzed.</p> <p>Results</p> <p>Patients with intestinal type gastric cancer had lower PG1 levels and a lower PG1/2-ratio compared to those with diffuse type cancer (<it>p </it>= 0.003). The serum levels of PG2 itself and G17 were not significantly altered. <it>H. pylori </it>infection in general had no influence on the levels of PG1, PG2 and G17 in the serum of gastric cancer patients. There was a trend towards lower PG1 levels in case of positive CagA-status (<it>p </it>= 0.058). The degree of both intestinal metaplasia and atrophy correlated inversely with serum levels for PG1 and the PG1/2-ratio (p < 0.01). LaurĂŠn-specific analysis revealed that this is only true for intestinal type tumors. Univariate ANOVA revealed atrophy and CagA-status as the only independent factors for low PG1 and a low PG1/2-ratio.</p> <p>Conclusions</p> <p>Glandular atrophy and a positive CagA status are determinant factors for decreased pepsinogen 1 levels in the serum of patients with gastric cancer. The serological assessment of gastric atrophy by analysis of serum pepsinogen is only adequate for patients with intestinal type cancer.</p

    The role of the ubiquitination–proteasome pathway in breast cancer: Ubiquitin mediated degradation of growth factor receptors in the pathogenesis and treatment of cancer

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    Aberrant activity of growth factor receptors has been implicated in the pathogenesis of a wide variety of malignancies. The negative regulation of signaling by growth factor receptors is mediated in large part by the ubiquitination, internalization, and degradation of the activated receptor. Over the past few years, considerable insight into the mechanisms that control receptor downregulation has been gained. There are also data suggesting that mutations that lead to inhibition of downregulation of growth factor receptors could play a role in the pathogenesis of cancer. Therapies directed at enhancing the degradation of growth factor receptors offer a promising approach to the treatment of malignancies
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