79 research outputs found

    BLAST Simulator Project: Performance assessment and preliminary tests. Administrative Arrangement No JRC 32253-2011 with DG HOME Activity A5 – Blast Simulation Technology Development

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    The Blast Simulator project involves the development of an apparatus able to reproduce the effects of a blast pressure wave on large scale structural components (such as columns, walls, etc.) with the objective to improve their strength in these severe loading situations. This technical report presents the setting up and the performance assessment of the prototype blast actuator developed at the JRC. The first preliminary tests performed have been described and evaluated. Satisfactory results have been obtained with respect to impacting masses and velocities and with the finally obtained pressure values.JRC.G.5-European laboratory for structural assessmen

    Pseudo-dynamic tests on two buildings retrofitted with damped braces

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    Seismic tests have been conducted on two 3-storey buildings protected with fluid-viscous spring damper devices. One of the buildings was a reinforced concrete frame with clay elements in the slabs, while the other one was a steel frame with steel/concrete composite slabs. The spring dampers were installed through K bracing in between the floors. The tests were performed by means of the pseudodynamic method on full-size specimens and by implementing a specific compensation strategy for the strain-rate effects at the devices. The tests results allowed to compare the behaviour of the unprotected buildings with several protected configurations showing the benefits of the application of the devices and the characteristics of their behaviour

    Procedure for load cell calibration at ELSA Reaction Wall

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    This report describes the procedure currently applied for the calibration of the load cells used for the mechanical experiments in the ELSA laboratory. The procedure is based on the international norm ISO 7500-1 and the definitions there proposed. The calibration experiment consists of applying a number of load cycles simultaneously on the object load cell in series with a traceable measuring proving instrument externally calibrated (reference load cell). The accuracy of the measures of the object load cell is the most important result of the test delimiting the maximum difference between both instruments. Other important results of the test are the resolution, repeatability and reversibility of the object load cell. All these error parameters determine the quality of the object instrument at the state of the calibration test. In order to extend the validity of the calibration test to the experiments performed with that load cell when connected to amplifiers different from the one of the calibration test, an additional gain test of the signal conditioning chain is also undertaken at ELSA after the calibration test.JRC.G.5-European laboratory for structural assessmen

    Pseudo-dynamic tests on two buildings retrofitted with damped braces

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    Blast Simulator project: First tests on reinforced concrete beams

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    The Blast Simulator project involves the development of an apparatus able to reproduce the effects of a blast pressure wave on large scale structural components (such as columns, walls, etc.) with the objective to improve their strength in these severe loading situations. After a series of preliminary tests to assess the performance of the blast actuator for what concerns the energy capability, this technical report presents some results related to a test campaign on two full scale structural components, specifically tworeinforced concrete beams.. With appropriate improvements made to the impactor, it has been possible to successfully bring the components to failure. A full suite of test parameters has also been recorded, valuable for guiding the numerical modelling. These experiments validate the potentiality of this kind of equipment to reproduce in a laboratory the effects of a blast explosion on full scale structural elements without using explosives. Further tests with the same experimental setup and with a new testing rig based on a more innovative technology (electrical linear motor) will be conducted in 2015 in the context of BUILTCIP project.JRC.G.4-European laboratory for structural assessmen

    N-methyl-D-aspartate receptor antibody-mediated neurological disease:results of a UK-based surveillance study in children

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    OBJECTIVE: N-methyl-D-aspartate receptor antibody (NMDAR-Ab) encephalitis is a well-recognised clinico-immunological syndrome that presents with neuropsychiatric symptoms cognitive decline, movement disorder and seizures. This study reports the clinical features, management and neurological outcomes of paediatric NMDAR-Ab-mediated neurological disease in the UK. DESIGN: A prospective surveillance study. Children with NMDAR-Ab-mediated neurological diseases were voluntarily reported to the British Neurological Surveillance Unit (BPNSU) from November 2010 to December 2011. Initial and follow-up questionnaires were sent out to physicians. RESULTS: Thirty-one children fulfilled the criteria for the study. Eight presented during the study period giving an incidence of 0.85 per million children per year (95% CI 0.64 to 1.06); 23 cases were historical. Behavioural change and neuropsychiatric features were present in 90% of patients, and seizures and movement disorders both in 67%. Typical NMDAR-Ab encephalitis was reported in 24 children and partial phenotype without encephalopathy in seven, including predominantly psychiatric (four) and movement disorder (three). All patients received steroids, 22 (71%) received intravenous immunoglobulin, 9 (29%) received plasma exchange,and 10 (32%) received second-line immunotherapy. Of the 23 patients who were diagnosed early, 18 (78%) made a full recovery compared with only 1 of 8 (13%) of the late diagnosed patients (p=0.002, Fisher's exact test). Seven patients relapsed, with four needing additional second-line immunotherapy. CONCLUSIONS: Paediatric NMDAR-Ab-mediated neurological disease appears to be similar to adult NMDAR-Ab encephalitis, but some presented with a partial phenotype. Early treatment was associated with a quick and often full recovery

    Progress in autoimmune epileptic encephalitis

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    Purpose of review Autoimmune epileptic encephalopathy is a potentially treatable neurological syndrome characterized by the coexistence of a neuronal antibody in serum and, often, cerebrospinal fluid. Patients present with combinations of seizures, neuropsychiatric features, movement disorder, and cognitive decline, but some patients have isolated seizures either at first presentation or during their illness. This review summarizes our current understanding of the roles of specific neuronal antibodies in epilepsy-related syndromes and aims to aid the clinician in diagnosis and treatment. Recent findings Antigen discovery methods in three neuroimmunology centres independently identified antibodies to different subunits of the Îł amino butyric acid-A receptor; high levels of these antibodies were found mainly in patients with severe refractory seizures. These and other antibodies were also found in a proportion (<10%) of children and adults with epilepsy. A clinical study comparing immunotherapy in patients with autoantibodies or without an identified target antigen found neuroinflammatory features were predictive of a therapeutic response. New in-vitro and in-vivo studies, and spontaneous animal models, have confirmed the pathogenicity and epileptogenicity of neuronal antibodies and their relevance to other mammals. Summary Neuronal antibodies are an important cause of autoimmune epileptic encephalopathy, early recognition is important as there may be an underlying tumour, and early treatment is associated with a better outcome. In the absence of an antibody, the clinician should adopt a pragmatic approach and consider a trial of immunotherapy when other causes have been excluded

    Antibody-associated epilepsies: Clinical features, evidence for immunotherapies and future research questions.

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    PURPOSE: The growing recognition of epilepsies and encephalopathies associated with autoantibodies against surface neuronal proteins (LGI1, NMDAR, CASPR2, GABABR, and AMPAR) means that epileptologists are increasingly asking questions about mechanisms of antibody-mediated epileptogenesis, and about the use of immunotherapies. This review summarizes clinical and paraclinical observations related to autoimmune epilepsies, examines the current evidence for the effectiveness of immunotherapy, and makes epilepsy-specific recommendations for future research. METHOD: Systematic literature search with summary and review of the identified publications. Studies describing the clinical characteristics of autoantibody-associated epilepsies and treatments are detailed in tables. RESULTS: Literature describing the clinical manifestations and treatment of autoimmune epilepsies associated with neuronal cell-surface autoantibodies (NSAbs) is largely limited to retrospective case series. We systematically summarize the features of particular interest to epileptologists dividing patients into those with acute or subacute encephalopathies associated with epilepsy, and those with chronic epilepsy without encephalopathy. Available observational studies suggest that immunotherapies are effective in some clinical circumstances but outcome data collection methods require greater standardization. CONCLUSIONS: The clinical experience captured suggests that clusters of clinical features associate well with specific NSAbs. Intensive and early immunotherapy is indicated when patients present with autoantibody-associated encephalopathies. It remains unclear how patients with chronic epilepsy and the same autoantibodies should be assessed and treated. Tables in this paper provide a comprehensive resource for systematic descriptions of both clinical features and treatments, and highlight limitations of current studies
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