158 research outputs found

    A Planar Generator for a Wave Energy Converter

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    This article presents a permanent magnet planar translational generator which is able to exploit multiple modes of sea wave energy extraction. Linear electrical generators have recently been studied for the exploitation of sea wave energy, but, to the best of our knowledge, no synchronous planar translational generator has been proposed. In this article, to maximize the energy extraction, we have considered all the potential modes of motion due to wave excitation and included them within the mathematical model of the proposed system. The principle of operation of the generator can be summarized as follows: the moving part (translator) of the generator is driven from the sea waves and induces and electromotive force (EMF) on the windings mounted to the armature. The movement of the translator is 2-D and, therefore, all the movement modes of the wave, except heave, can be exploited. The proposed mathematical model includes the dynamic equations of the translator and the electric equations of the windings. The coupling parameters (inductances and fluxes) have been determined by finite element method analysis. Optimization of the device has been performed by considering both, the parameters of the electromagnetic circuit, and, the parameters associated with the stochastic features of the wave

    Enoxaparin after high-risk coronary stenting

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    EXPERIÊNCIA DE USO DE FERRAMENTAS VIRTUAIS FRENTE AO LAPSO TEMPO VERSUS ESPAÇO NA FRONTEIRA BRASIL-BOLÍVIA

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    Este artigo é fruto de pesquisa desenvolvida no âmbito da Polícia Civil de Mato Grosso do Sul, em Corumbá e Ladário, MS, fronteira com Bolívia, carreado pelo Laboratório de Estudos Fronteiriços. O objetivo foi demonstrar como o uso de ferramentas virtuais pode mitigar o lapso tempo versus espaço. Tal lapso gera limitações legais para ações dos policiais frente aos delitos. A metodologia consistiu em observações sistemáticas, revisão bibliográfica e aplicação de proposta de Grupo de Whatsapp que ampliasse o raio de ação e interações com autoridades bolivianas naquela fronteira. O Grupo tem alcançado resultados importantes, contudo necessitando de redimensionamentos institucionais

    topoisomerase iiα gene status and prediction of pathological complete remission after anthracycline based neoadjuvant chemotherapy in endocrine non responsive her2 neu positive breast cancer

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    Abstract Purpose Topoisomerase IIα (Topo II) is a potential marker of responsiveness to anthracycline-based therapy. We analyzed the role of Topo II gene status in the prediction of pathological complete remission (pCR) after primary anthracycline-based chemotherapy in non- endocrine responsive breast cancers overexpressing Her2/neu. Methods Twenty-three patients, with T2–T4, ER and PgR absent, overexpressing Her2/neu breast cancers treated with anthracycline-based chemotherapy were evaluated. Topo II gene status was assessed by FISH in pre-treatment tumor specimens and the results were correlated to pathological and clinical responses. Results Overall, six patients had a pCR (26%). Topo II was amplified in 5 (22%) of the tumors. In all patients with Topo II amplification, Her2/neu gene amplification was also detected. Among patients without amplification, one had polysomia of chromosome (Cr) 17 and four patients had deletion of the Topo II gene. A higher probability of pCR was observed when Topo II amplification and Cr 17 polysomy were present: pCR was reported in 3 of 5 amplified tumors (60%), in the polysomic tumor (amplified plus polysomic 67%) and in only 2 out of 13 tumors without alteration of Topo II status (15%). If we compare the frequency of pCR in tumors with amplification or polysomy versus the frequency of tumors with not amplification (deletion or no modification), a significant difference was detected ( p =0.02). One progressive disease (PD) was reported in one tumor with Topo II deletion (1/4, 25%) and one in tumor without any modification of Topo II gene status (1/13, 8%). Conclusions In patients with endocrine unresponsive and Her2 overexpressing tumors, Topo II amplification or the presence of chromosome 17 polysomy correlate with a significantly high probability of achieving pCR after neoadjuvant, anthracycline-based chemotherapy. Further prospective studies in order to more clearly define the predictive role of Topo II status in this subgroup of patients are warranted

    Digital volume correlation can be used to estimate local strains in natural and augmented vertebrae: An organ-level study

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    Digital Volume Correlation (DVC) has become popular for measuring the strain distribution inside bone structures. A number of methodological questions are still open: the reliability of DVC to investigate augmented bone tissue, the variability of the errors between different specimens of the same type, the distribution of measurement errors inside a bone, and the possible presence of preferential directions. To address these issues, five augmented and five natural porcine vertebrae were subjected to repeated zero-strain micro-CT scan (39 μm voxel size). The acquired images were processed with two independent DVC approaches (a local and a global one), considering different computation sub-volume sizes, in order to assess the strain measurement uncertainties. The systematic errors generally ranged within ±100 microstrain and did not depend on the computational sub-volume. The random error was higher than 1000 microstrain for the smallest sub-volume and rapidly decreased: with a sub-volume of 48 voxels the random errors were typically within 200 microstrain for both DVC approaches. While these trends were rather consistent within the sample, two individual specimens had unpredictably larger errors. For this reason, a zero-strain check on each specimen should always be performed before any in-situ micro-CT testing campaign. This study clearly shows that, when sufficient care is dedicated to preliminary methodological work, different DVC computation approaches allow measuring the strain with a reduced overall error (approximately 200 microstrain). Therefore, DVC is a viable technique to investigate strain in the elastic regime in natural and augmented bones

    A Combined Raman Spectroscopy and Atomic Force Microscopy System for In Situ and Real-Time Measures in Electrochemical Cells

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    : An innovative and versatile set-up for in situ and real time measures in an electrochemical cell is described. An original coupling between micro-Raman spectroscopy and atomic force microscopy enables one to collect data on opaque electrodes. This system allows for the correlation of topographic images with chemical maps during the charge exchange occurring in oxidation/reduction processes. The proposed set-up plays a crucial role when reactions, both reversible and non-reversible, are studied step by step during electrochemical reactions and/or when local chemical analysis is required

    Chromosome anomalies in bone marrow as primarycause of aplastic or hypoplastic conditions andperipheral cytopenia: disorders due to secondaryimpairment of RUNX1 and MPL genes

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    Background Chromosome changes in the bone marrow (BM) of patients with persistent cytopenia are often considered diagnostic for a myelodysplastic syndrome (MDS). Comprehensive cytogenetic evaluations may give evidence of the real pathogenetic role of these changes in cases with cytopenia without morphological signs of MDS. Results Chromosome anomalies were found in the BM of three patients, without any morphological evidence of MDS: 1) an acquired complex rearrangement of chromosome 21 in a boy with severe aplastic anaemia (SAA); the rearrangement caused the loss of exons 2-8 of the RUNX1 gene with subsequent hypoexpression. 2) a constitutional complex rearrangement of chromosome 21 in a girl with congenital thrombocytopenia; the rearrangement led to RUNX1 disruption and hypoexpression. 3) an acquired paracentric inversion of chromosome 1, in which two regions at the breakpoints were shown to be lost, in a boy with aplastic anaemia; the MPL gene, localized in chromosome 1 short arms was not mutated neither disrupted, but its expression was severely reduced: we postulate that the aplastic anaemia was due to position effects acting both in cis and in trans, and causing Congenital Amegakaryocytic Thrombocytopenia (CAMT). Conclusions A clonal anomaly in BM does not imply per se a diagnosis of MDS: a subgroup of BM hypoplastic disorders is directly due to chromosome structural anomalies with effects on specific genes, as was the case of RUNX1 and MPL in the patients here reported with diagnosis of SAA, thrombocytopenia, and CAMT. The anomaly may be either acquired or constitutional, and it may act by deletion/disruption of the gene, or by position effects. Full cytogenetic investigations, including a-CGH, should always be part of the diagnostic evaluation of patients with BM aplasia/hypoplasia and peripheral cytopenias

    Accurate X-ray position of the Anomalous X-ray Pulsar XTE J1810-197 and identification of its likely IR counterpart

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    We report the accurate sub-arcsec X-ray position of the new Anomalous X-ray Pulsar (AXP) XTE J1810-197, derived with a Chndra-HRC Target of Opportunity observation carried out in November 2003. We also report the discovery of a likely IR counterpart based on a VLT (IR band) Target of Opportunity observation carried out in October 2003. Our proposed counterpart is the only IR source (Ks=20.8) in the X-ray error circle. Its IR colors as well as the X-ray/IR flux ratio, are consistent with those of the counterparts of all other AXPs (at variance with field star colors). Deep Gunn-i band images obtained at the 3.6m ESO telescope detected no sources down to a limiting magnitude of 24.3. Moreover, we find that the pulsed fraction and count rates of XTE J1810-197 remained nearly unchanged since the previous Chandra and XMM-Newton observations (2003 August 27th and September 8th, respectively). We briefly discuss the implications of these results. In particular, we note that the transient (or at least highly variable) nature of this AXP might imply a relatively large number of hidden members of this class.Comment: 5 pages, 2 figures. Accepted for publication on ApJ Letters. VLT IR raw data available upon reques

    Dependência espacial de variáveis dendrométricas em diferentes idades e intensidades amostrais em povoamento de eucalipto

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    Understanding the spatial variations of dendrometric variables in a continuous forest inventory is essential to support management actions, in addition to allowing sample intensities that reflect accuracy with lower inventory cost. The objective of this study was to evaluate the spatial dependence structure of dendrometric variables over time and in different sample intensities in eucalyptus stands. The hypotheses considered were that the spatial dependence structure of dendrometric variables changes along the growth in eucalyptus stands and the sample intensity influences this structure. The variables diameter at 1.30 m of soil, basal area, total height, mean height of dominant trees and volume of wood were obtained in continuous forest inventory, at 3.5, 4.5 and 5.5 years, from 80 plots (400 m²) distributed randomly in the stand (394 ha) located in Abaeté, Minas Gerais state. Were evaluated the sample intensities of one plot every 4.9 (n = 80), 7.3 (n = 54), and 16.4 (n = 24) hectares. The highest sample intensity was reference for the others. The spherical, exponential and gaussian semivariance models were adjusted to the experimental semivariogram, where the best fit model was used by ordinary kriging in the spatialization of the analyzed variables. The results showed a predominance of strong spatial dependence of dendrometric variables, regardless of age and sample intensity, especially for mean height of dominant trees and volume of wood. The lower sample intensity influenced negatively the spatial dependence of the basal area at all ages. The structure of spatial dependence is not influenced by the increase in the age of the stand, and the geostatistical analysis of these variables is recommended in a continuous forest inventory, considering the sample intensity of one plot of each 16.4 hectares.Compreender as variações espaciais de variáveis dendrométricas em inventário florestal contínuo é imprescindível para subsidiar ações de manejo, além de permitir intensidades amostrais que reflitam em acurácia com menor custo do inventário. Nesse contexto, o objetivo deste trabalho foi avaliar a estrutura de dependência espacial de variáveis dendrométricas ao longo do tempo e em diferentes intensidades amostrais em povoamento de eucalipto. As hipóteses testadas foram que a estrutura de dependência espacial de variáveis dendrométricas se altera com o crescimento em povoamentos de eucalipto e que a intensidade amostral influencia nesta estrutura. As variáveis diâmetro a 1,30 m do solo, área basal, altura total, altura média das árvores dominantes e volume de madeira foram obtidas em inventário florestal contínuo, aos 3,5, 4,5 e 5,5 anos, em 80 unidades amostrais permanentes (400 m²), distribuídas aleatoriamente em um povoamento de eucalipto (394 ha), localizado em Abaeté, Minas Gerais. Foram avaliadas as intensidades de uma unidade amostral a cada 4,9 (n = 80), 7,3 (n = 54) e 16,4 (n = 24) hectares. Considerou-se a maior intensidade amostral como referência para as demais. Os modelos de semivariância esférico, exponencial e gaussiano foram ajustados ao semivariograma experimental, em que o modelo de melhor ajuste foi utilizado pela krigagem ordinária na espacialização das variáveis analisadas. Os resultados demonstraram predominância de forte dependência espacial das variáveis dendrométricas, independentemente da idade e intensidade amostral, sobretudo para altura média das árvores dominantes e volume de madeira. A menor intensidade amostral influenciou negativamente na dependência espacial da área basal, em todas as idades. A estrutura de dependência espacial não é influenciada pelo aumento da idade do povoamento, sendo recomendada a análise geoestatística destas variáveis em inventário florestal contínuo, considerando a intensidade amostral de uma unidade amostral a cada 16,4 hectares
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