927 resultados para Endovascular Presence


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We investigated the possibility that Chagas' patients develop an autoimmune response to human UsnRNPs (small nuclear ribonucleoprotein) or Sm epitopes. Using purified human UsnRNPs, we detected anti-human UsnRNPs antibodies in sera from patients suffering from Chagas' disease. The antibodies it-ere also detected using peptide enzyme-linked immunosorbent assays containing the Sm-motif 1 domain. The latter technique showed that 61% (31/51) of the Chagas' patients' sera contained antibodies against Sm-motif I. The detection of anti-UsnRNPs autoantibodies in Chagas patients' sera strongly encourages further studies using animal models to determine how these autoantibodies appear.

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We detected anti-human small nuclear ribonucleoprotein (snRNP) autoantibodies in chagasic patients by different immunological methods using HeLa snRNPs. ELISA with Trypanosoma cruzi total lysate antigen or HeLa human U small nuclear ribonucleoproteins (UsnRNPs) followed by incubation with sera from chronic chagasic and non-chagasic cardiac patients was used to screen and compare serum reactivity. Western blot analysis using a T. cruzi total cell extract was also performed in order to select some sera for Western blot and immunoprecipitation assays with HeLa nuclear extract. ELISA showed that 73 and 95% of chronic chagasic sera reacted with HeLa UsnRNPs and T. cruzi antigens, respectively. The Western blot assay demonstrated that non-chagasic cardiac sera reacted with high molecular weight proteins present in T. cruzi total extract, probably explaining the 31% reactivity found by ELISA. However, these sera reacted weakly with HeLa UsnRNPs, in contrast to the chagasic sera, which showed autoantibodies with human Sm (from Stefanie Smith, the first patient in whom this activity was identified) proteins (B/B', D1, D2, D3, E, F, and G UsnRNP). Immunoprecipitation reactions using HeLa nuclear extracts confirmed the reactivity of chagasic sera and human UsnRNA/RNPs, while the other sera reacted weakly only with U1snRNP. These findings agree with previously reported data, thus supporting the idea of the presence of autoimmune antibodies in chagasic patients. Interestingly, non-chagasic cardiac sera also showed reactivity with T. cruzi antigen and HeLa UsnRNPs, which suggests that individuals with heart disease of unknown etiology may develop autoimmune antibodies at any time. The detection of UsnRNP autoantibodies in chagasic patients might contribute to our understanding of how they develop upon initial T. cruzi infection.

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Systems based on artificial neural networks have high computational rates due to the use of a massive number of simple processing elements and the high degree of connectivity between these elements. This paper presents a novel approach to solve robust parameter estimation problem for nonlinear model with unknown-but-bounded errors and uncertainties. More specifically, a modified Hopfield network is developed and its internal parameters are computed using the valid-subspace technique. These parameters guarantee the network convergence to the equilibrium points. A solution for the robust estimation problem with unknown-but-bounded error corresponds to an equilibrium point of the network. Simulation results are presented as an illustration of the proposed approach. Copyright (C) 2000 IFAC.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The general assumption under which the (X) over bar chart is designed is that the process mean has a constant in-control value. However, there are situations in which the process mean wanders. When it wanders according to a first-order autoregressive (AR (1)) model, a complex approach involving Markov chains and integral equation methods is used to evaluate the properties of the (X) over bar chart. In this paper, we propose the use of a pure Markov chain approach to study the performance of the (X) over bar chart. The performance of the chat (X) over bar with variable parameters and the (X) over bar with double sampling are compared. (C) 2011 Elsevier B.V. All rights reserved.

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This work deals with the nonlinear piezoelectric coupling in vibration-based energy harvesting, done by A. Triplett and D.D. Quinn in J. of Intelligent Material Syst. and Structures (2009). In that paper the first order nonlinear fundamental equation has a three dimensional state variable. Introducing both observable and control variables in such a way the controlled system became a SISO system, we can obtain as a corollary that for a particular choice of the observable variable it is possible to present an explicit functional relation between this variable one, and the variable representing the charge harvested. After-by observing that the structure in the Input-Output decomposition essentially changes depending on the relative degree changes, presenting bifurcation branches in its zero dynamics-we are able in to identify this type of bifurcation indicating its close relation with the Hartman - Grobman theorem telling about decomposition into stable and the unstable manifolds for hyperbolic points.

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Twenty two open-pollinated Hevea progenies from different parental clones of the Asian origin were tested at five sites in the Northwestern São Paulo State Brazil to investigate the progeny girth growth, rubber yield, bark thickness and plant height. Except for the rubber yield, the analysis of variance indicated highly significant (p<0.01) genotype x environment interaction and heterogeneity of regressions among the progenies. However, the regression stability analysis identified only a few interacting progenies which had regression coefficients significantly different from the expected value of one. The linear regressions of the progeny mean performance at each test on an environmental index (mean of all the progenies in each test) showed the general stability and adaptability of most selected Hevea progenies over the test environments. The few progenies which were responsive and high yielding on different test sites could be used to maximize the rubber cultivars productivity and to obtain the best use of the genetically improved stock under different environmental conditions.

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This thesis presents ⇡SOD-M (Policy-based Service Oriented Development Methodology), a methodology for modeling reliable service-based applications using policies. It proposes a model driven method with: (i) a set of meta-models for representing non-functional constraints associated to service-based applications, starting from an use case model until a service composition model; (ii) a platform providing guidelines for expressing the composition and the policies; (iii) model-to-model and model-to-text transformation rules for semi-automatizing the implementation of reliable service-based applications; and (iv) an environment that implements these meta-models and rules, and enables the application of ⇡SOD-M. This thesis also presents a classification and nomenclature for non-functional requirements for developing service-oriented applications. Our approach is intended to add value to the development of service-oriented applications that have quality requirements needs. This work uses concepts from the service-oriented development, non-functional requirements design and model-driven delevopment areas to propose a solution that minimizes the problem of reliable service modeling. Some examples are developed as proof of concepts

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Introduction: So far the only endovascular option to treat patients with thoraco abdominal aortic aneurysms is the deployment of branched grafts. We describe a technique consisting of the deployment of standard off-the- shelf grafts to treat urgent cases.Material and Methods: The sandwich technique consists of the deployment of ViaBahn chimney grafts in combination with standard thoracic and abdominal aortic stent grafts. The chimney grafts are deployed using a transbrachial and transaxillary access. These coaxial grafts are placed inside the thoracic tube graft. After deployment of the infrarenal bifurcated abdominal graft a bridging stent-a short tube graft is positioned inside the thoracic graft further stabilizing the chimney grafts.Results: 5 patients with symptomatic thoraco abdominal aneurysms were treated. There was one Type I endoleak that resolved after 2 months. In all patients 3 stentgrafts had to be used When possible all visceral and renal branches were revascularized. A total number of 17 arteries were reconnected with covered branches. During follow up we lost one target vessel the right renal artery.Conclusion: The sandwich technique in combination with chimney grafts permits a total endovascular exclusion of thoraco abdominal aortic aneurysms. In all cases off-the shelf products and grafts could be used. The number of patients treated so far is still too small to draw further more robust conclusions with regard to long term performance and durability. (C) 2010 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

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To report a technique to maintain pelvic flow to an internal iliac artery (IIA) with aneurysm in a patient with Marfan syndrome, and previously treated by infrarenal abdominal aortic aneurysm open procedure. Retrograde endovascular hypogastric artery preservation (REHAP) through flexible endograft implantation from external iliac artery (EIA) to internal iliac artery (IIA) was used. REHAP was a reasonable, minimally invasive and elegant alternative (new) to maintain pelvic arterial flow in Marfan syndrome. However, the long-term durability is unknown, and so, it should be used in selected patients.

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Background: Significant morbidity and mortality are related to conventional aortic replacement surgery. Endovascular debranching techniques, fenestrated or branched endografts are time consuming and costly.Objective: We alternatively propose to use endovascular approach with parallel grafts for debranching of aortic arch.Methods: Under general anesthesia, 12 F sheaths were inserted in the femoral, axillary and common carotid arteries for vascular accesses. ViaBahn grafts 10 - 15 cm in length were placed into the aortic arch from right common carotid, left common carotid and left axillary arteries, until the tip of each graft reached into the ascending aorta. Through one femoral artery, the aortic stent-graft was positioned and delivered. Soon after, the parallel grafts were sequentially delivered. Self-spanding Wallstents(R) were used for parallel grafts reinforcement. Ballooning was routinely used for parallel grafts and rarely for aortic graft.Results: This technique was used in 2 cases. The first one was a lady with 72 years old, with an aortic retrograde dissection from left subclavian artery and involving remaining arch branches. Through right common carotid artery a stent-graft was placed in the ascending aorta and through the left common carotid artery a ViaBahn was inserted parallel to the former. A thoracic endograft then covered all the aortic arch dissection extending into the ascending aorta close to the sinu-tubular junction. The second case was a 82 year old male patient with a 7 cm aortic arch aneurysm. Through both common carotid arteries ViaBahn grafts were introduced and positioned into the ascending aorta. Soon after, the deployment of the thoracic stent graft covered all parallel grafts of the aortic arch, excluding the aneurysm. Both cases did not have neurologic or cardiac complications and were discharged 10 days after the procedure.Conclusions: This technique may be a good minimal invasive off-the-shelf technical option for aortic arch "debranching". More data and further improvements are required before this promising technique can be widely advocated. (C) 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

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Perforation of inferior vena cava (IVC) by filter struts ranges from 9% to 24%, and clinical sequelae and complications are unpredictable. The aim of this article was to report an unusual case of late complication of IVC filter that caused an IVC wall perforation and penetration of the filter's hooks in the aorta, which was treated by endovascular procedure. Molding strut tip by balloon angioplasty, its accommodation with a bare stent, and its coverage and protection with an endoprosthesis is probably the first technique reported so far in this situation.