140 research outputs found

    Diseño y análisis de un elemento de suspensión por Finite Element Method (FEM)

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    Este Trabajo Fin de Grado consiste en el diseño y análisis del sistema de suspensión delantera de un monoplaza de competición perteneciente al proyecto Formula Student; utilizando software CAD y de cálculo por el método de los elementos finitos. Inicialmente se realizará un estudio teórico riguroso del funcionamiento del sistema de suspensión de un automóvil y las distintas partes que lo componen. Seguidamente, con el software Autodesk Inventor Professional 2011 se crearán los elementos mecánicos que componen la suspensión y finalmente, se estudiará el comportamiento estático del muelle helicoidal usando el módulo de análisis de Autodesk Inventor.The objective of this dissertation is to design and analyze a front suspension system of a Formula student car. For achieving this aim, we will use Computer Aided Design (CAD) software and finite element analysis software based on finite element methodology. First of all, we will perform a rigorous theoretical study of functions of the suspension system of a car and all its components. Afterwards, all the components of the suspension system are created by using Autodesk Inventor Professional 2011 software. Furthermore, the static behavior of our coil spring will be analyzed using the module of analysis of Autodesk Inventor.Grado en Ingeniería en Electrónica y Automática Industria

    Diseño y análisis de un elemento de suspensión por Finite Element Method (FEM)

    Get PDF
    Este Trabajo Fin de Grado consiste en el diseño y análisis del sistema de suspensión delantera de un monoplaza de competición perteneciente al proyecto Formula Student; utilizando software CAD y de cálculo por el método de los elementos finitos. Inicialmente se realizará un estudio teórico riguroso del funcionamiento del sistema de suspensión de un automóvil y las distintas partes que lo componen. Seguidamente, con el software Autodesk Inventor Professional 2011 se crearán los elementos mecánicos que componen la suspensión y finalmente, se estudiará el comportamiento estático del muelle helicoidal usando el módulo de análisis de Autodesk Inventor.The objective of this dissertation is to design and analyze a front suspension system of a Formula student car. For achieving this aim, we will use Computer Aided Design (CAD) software and finite element analysis software based on finite element methodology. First of all, we will perform a rigorous theoretical study of functions of the suspension system of a car and all its components. Afterwards, all the components of the suspension system are created by using Autodesk Inventor Professional 2011 software. Furthermore, the static behavior of our coil spring will be analyzed using the module of analysis of Autodesk Inventor.Grado en Ingeniería en Electrónica y Automática Industria

    Management of Neuropsychiatric Systemic Lupus Erythematosus: Current Approaches and Future Perspectives

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    Neuropsychiatric systemic lupus erythematosus (NPSLE) is a generic definition referring to a series of neurological and psychiatric symptoms directly related to systemic lupus erythematosus (SLE). NPSLE includes heterogeneous and rare neuropsychiatric (NP) manifestations involving both the central and peripheral nervous system. Due to the lack of a gold standard, the attribution of NP symptoms to SLE represents a clinical challenge that obligates the strict exclusion of any other potential cause. In the acute setting, management of these patients does not differ from other non-SLE subjects presenting with the same NP manifestation. Afterwards, an individualized therapeutic strategy, depending on the presenting manifestation and severity of symptoms, must be started. Clinical trials in NPSLE are scarce and most of the data are extracted from case series and case reports. High-dose glucocorticoids and intravenous cyclophosphamide remain the cornerstone for patients with severe symptoms that are thought to reflect inflammation or an underlying autoimmune process. Rituximab, intravenous immunoglobulins, or plasmapheresis may be used if response is not achieved. When patients present with mild to moderate NP manifestations, or when maintenance therapy is warranted, azathioprine and mycophenolate may be considered. When symptoms are thought to reflect a thrombotic underlying process, anticoagulation and antiplatelet agents are the mainstay of therapy, especially if antiphospholipid antibodies or antiphospholipid syndrome are present. Recent trials on SLE using new biologicals, based on newly understood SLE mechanisms, have shown promising results. Based on what we currently know about its pathogenesis, it is tempting to speculate how these new therapies may affect the management of NPSLE patients. This article provides a comprehensive and critical review of the literature on

    Laboratory and Neuroimaging Biomarkers in Neuropsychiatric Systemic Lupus Erythematosus: Where Do We Stand, Where To Go?

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    Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by multi-systemic involvement. Nervous system involvement in SLE leads to a series of uncommon and heterogeneous neuropsychiatric (NP) manifestations. Current knowledge on the underlying pathogenic processes and their subsequent pathophysiological changes leading to NP-SLE manifestations is incomplete. Several putative laboratory biomarkers have been proposed as contributors to the genesis of SLE-related nervous system damage. Alongside the laboratory biomarkers, several neuroimaging tools have shown to reflect the nature of tissue microstructural damage associated with SLE, and thus were suggested to contribute to the understanding of the pathophysiological changes and subsequently help in clinical decision making. However, the number of useful biomarkers in NP-SLE in clinical practice is disconcertingly modest. In some cases it is not clear whether the biomarker is truly involved in pathogenesis, or the result of non-specific pathophysiological changes in the nervous system (e.g., neuroinflammation) or whether it is the consequence of a concomitant underlying abnormality related to SLE activity. In order to improve the diagnosis of NP-SLE and provide a better targeted care to these patients, there is still a need to develop and validate a range of biomarkers that reliably capture the different aspects of disease heterogeneity. This article critically reviews the current state of knowledge on laboratory and neuroimaging biomarkers in NP-SLE, discusses the factors that need to be addressed to make these biomarkers suitable for clinical application, and suggests potential future research paths to address important unmet needs in the NP-SLE field

    Longitudinal changes in cerebral white matter microstructure in newly diagnosed systemic lupus erythematosus patients

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    Objectives To evaluate longitudinal variations in diffusion tensor imaging (DTI) metrics of different white matter (WM) tracts of newly diagnosed SLE patients, and to assess whether DTI changes relate to changes in clinical characteristics over time. Methods A total of 17 newly diagnosed SLE patients (19–55 years) were assessed within 24 months from diagnosis with brain MRI (1.5 T Philips Achieva) at baseline, and after at least 12 months. Fractional anisotropy, mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity values were calculated in several normal-appearing WM tracts. Longitudinal variations in DTI metrics were analysed by repeated measures analysis of variance. DTI changes were separately assessed for 21 WM tracts. Associations between longitudinal alterations of DTI metrics and clinical variables (SLEDAI-2K, complement levels, glucocorticoid dosage) were evaluated using adjusted Spearman correlation analysis. Results Mean MD and RD values from the normal-appearing WM significantly increased over time (P = 0.019 and P = 0.021, respectively). A significant increase in RD (P = 0.005) and MD (P = 0.012) was found in the left posterior limb of the internal capsule; RD significantly increased in the left retro-lenticular part of the internal capsule (P = 0.013), and fractional anisotropy significantly decreased in the left corticospinal tract (P = 0.029). No significant correlation was found between the longitudinal change in DTI metrics and the change in clinical measures. Conclusion Increase in diffusivity, reflecting a compromised WM tissue microstructure, starts in initial phases of the SLE disease course, even in the absence of overt neuropsychiatric (NP) symptoms. These results indicate the importance of monitoring NP involvement in SLE, even shortly after diagnosis

    Association of 25-hydroxyvitamin D with Metabolic Syndrome in Patients with Psoriasis: A Case-control Study

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    Vitamin D deficiency is associated with higher cardiovascular risk and metabolic syndrome (MeS) criteria. The main objective of this study was to analyse the association of 25-hydroxyvitamin D (25-OHD) serum levels with MeS (National Cholesterol Education Program Adult Treatment Panel-III criteria) in 46 Spanish patients with psoriasis, but without arthritis and systemic treatment, and 46 control subjects, matched by sex and age. The patients with psoriasis showed significantly lower level of 25-OHD than controls (30.5 vs. 38.3 ng/ml; p =0.0001). Patients with MeS had significantly lower serum levels of 25-OHD than those without MeS (24.1 +/- 7.5 vs. 32.8 +/- 8.9,p =0.007), and a negative correlation was found between 25-OHD and waist circumference, diastolic blood pressure, fasting glucose, and triglyceridaemia. In the control group no significant correlation between 25-OHD and MeS was found. Although the sample was small, our results suggest a potential protective role for 25-OHD in the metabolic profile of patients with psoriasis without arthritis

    Three-month follow-up after severe COVID-19 infection: are chest CT results associated with respiratory outcomes and respiratory recovery in COVID-19 patients?

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    Background: CT Severity Score (CT-SS) can be used to assess the extent of severe coronavirus disease 19 (COVID-19) pneumonia. Follow-up CT-SS in patients surviving COVID-19-associated hyperinflammation and its correlation with respiratory parameters remains unknown. This study aims to assess the association between CT-SS and respiratory outcomes, both in hospital and at three months after hospitalization. Methods: Patients from the COVID-19 High-intensity Immunosuppression in Cytokine storm Syndrome (CHIC) study surviving hospitalization due to COVID-19 associated hyperinflammation were invited for follow-up assessment at three months after hospitalization. Results of CT-SS three months after hospitalization were compared with CT-SS at hospital admission. CT-SS at admission and at 3-months were correlated with respiratory status during hospitalization and with patient reported outcomes as well as pulmonary- and exercise function tests at 3-months after hospitalization. Results: A total of 113 patients were included. Mean CT-SS decreased by 40.4% (SD 27.6) in three months (P 80%pred vs. 14.3 (3.2) in those with DLCO Pathophysiology and treatment of rheumatic disease

    Different phenotypes of neuropsychiatric systemic lupus erythematosus are related to a distinct pattern of structural changes on brain MRI

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    Objectives The underlying structural brain correlates of neuropsychiatric involvement in systemic lupus erythematosus (NPSLE) remain unclear, thus hindering correct diagnosis. We compared brain tissue volumes between a clinically well-defined cohort of patients with NPSLE and SLE patients with neuropsychiatric syndromes not attributed to SLE (non-NPSLE). Within the NPSLE patients, we also examined differences between patients with two distinct disease phenotypes: ischemic and inflammatory. Methods In this prospective (May 2007 to April 2015) cohort study, we included 38 NPSLE patients (26 inflammatory and 12 ischemic) and 117 non-NPSLE patients. All patients underwent a 3-T brain MRI scan that was used to automatically determine white matter, grey matter, white matter hyperintensities (WMH) and total brain volumes. Group differences in brain tissue volumes were studied with linear regression analyses corrected for age, gender, and total intracranial volume and expressed as B values and 95% confidence intervals. Results NPSLE patients showed higher WMH volume compared to non-NPSLE patients (p = 0.004). NPSLE inflammatory patients showed lower total brain (p = 0.014) and white matter volumes (p = 0.020), and higher WMH volume (p = 0.002) compared to non-NPSLE patients. Additionally, NPSLE inflammatory patients showed lower white matter (p = 0.020) and total brain volumes (p = 0.038) compared to NPSLE ischemic patients. Conclusion We showed that different phenotypes of NPSLE were related to distinct patterns of underlying structural brain MRI changes. Especially the inflammatory phenotype of NPSLE was associated with the most pronounced brain volume changes, which might facilitate the diagnostic process in SLE patients with neuropsychiatric symptoms.Neuro Imaging Researc

    Tocilizumab in Severe COVID-19 Pneumonia and Concomitant Cytokine Release Syndrome

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    Younger patients with COVID-19 may experience an exaggerated immune response to SARS-CoV-2 infection and develop cytokine release syndrome (CRS), which may be life threatening. There is no proven antiviral therapy for COVID-19 so far, but profound immunosuppression has recently been suggested as a treatment for COVID-19-associated CRS. We present a case of life-threatening CRS caused by COVID-19 infection with a favourable response to immunosuppressive therapy with tocilizumab (TCZ). The rapid clinical and biochemical improvement following TCZ administration suggests that treatment with immunotherapy can be life-saving in selected patients with COVID-19-induced CRS
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