232 research outputs found

    Analysis of the Combinatory Effect of Uniaxial Electrical and Magnetic Anisotropy on the Input Impedance and Mutual Coupling of a Printed Dipole Antenna

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    The main objective of this work is to investigate the combinatory effects of both uniaxial magnetic and electrical anisotropies on the input impedance, resonant length and the mutual coupling between two dipoles printed on an anisotropic grounded substrate. Three different configurations: broadside, collinear and echelon are considered for the coupling investigation. The study is based on the numerical solution of the integral equation using the method of moments through the mathematical derivation of the appropriate Green's functions in the spectral domain. In order to validate the computing method and evaluated Matlab? calculation code, numerical results are compared with available literature treating particular cases of uniaxial electrical anisotropy; good agreements are observed. New results of dipole structures printed on uniaxial magnetic anisotropic substrates are presented and discussed, with the investigation of the combined electrical and magnetic anisotropies effect on the input impedance and mutual coupling for different geometrical configurations. The combined uniaxial (electric and magnetic) anisotropies provide additional degrees of freedom for the input impedance control and coupling reduction

    Macrospin approximation and quantum effects in models for magnetization reversal

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    The thermal activation of magnetization reversal in magnetic nanoparticles is controlled by the anisotropy-energy barrier. Using perturbation theory, exact diagonalization and stability analysis of the ferromagnetic spin-s Heisenberg model with coupling or single-site anisotropy, we study the effects of quantum fluctuations on the height of the energy barrier. Opposed to the classical case, there is no critical anisotropy strength discriminating between reversal via coherent rotation and via nucleation/domain-wall propagation. Quantum fluctuations are seen to lower the barrier depending on the anisotropy strength, dimensionality and system size and shape. In the weak-anisotropy limit, a macrospin model is shown to emerge as the effective low-energy theory where the microscopic spins are tightly aligned due to the ferromagnetic exchange. The calculation provides explicit expressions for the anisotropy parameter of the effective macrospin. We find a reduction of the anisotropy-energy barrier as compared to the classical high spin-s limit.Comment: 10 pages, 11 figure

    Prognostic factors of recurrence (Early and late) and death in breast cancer patients in Iranian women

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    Background: Breast cancer treatment success depends upon prolonging survival with effective treatment, and constant monitoring of recurrence. Survival rate can well be improved by better understanding of prognostic factors, preventive measures, and effective treatments together with follow-up and post-treatment care. Objectives: This study is aimed to know prognostic factors effective in recurrence and death in Iranian breast cancer patients. Methods: This is a retrospective study conducted by reviewing data acquired from 1604 female breast cancer patients who were admitted to Cancer Research Center at Shahid Beheshti University of Medical Sciences between October, 1982 and March, 2014. During the follow-up, after diagnosis, 313 patients experienced recurrence then were classified into two groups: early recurrence, less than 1 year and late recurrence after 5 years. We analyzed prognostic factors of recurrence in each groups and evaluated effective factors of death in this patients. Results: Median age of patients at diagnosis was 50 years. Median follow up time was 4.33 years (range: 0.005-24.9 years). Of these patients, 210 (67.09 ) and 76 (24.28), developed distant and loco -regional recurrence. Among 313 patients, 62 (21/60) and 69 (24/04) had early and late recurrence. In the univariate analysis, tumor grade, stage of disease, ER and PR status, axillary lymph node involvement and lymph vascular invasion were the prognostic factors affecting recurrence in patients, but in the multivariate analysis, ER/PR statuswasthemostimportant independent prognostic factor affecting the early recurrenceandstage of disease were prognostic factors in late recurrence. In all of the recurrent patients, 56.86 (178 individuals) survived and 43.13 (135 individuals) died at the end of follow-up period. The most important factors of death were histologic grade, disease free survival time, site of recurrence and age of disease. Conclusions: Biologic marker, estrogen and progesterone receptors status, had most influence in early recurrence, unlike late recurrence, stage of disease had a more important role. However, lymph vascular invasion has been an effective factor either in early or late recurrence. As a result of studying effective factors in death of these patients, recurrence site, DFS, pathologic grade and patients� age at the time of recurrence came to be effective. Knowing more about affecting factors on recurrence and the death of patients with recurrence, one can try to enhance survival and quality of life in patients by adopting more effective treatments. © 2016, Iranian Journal of Cancer Prevention

    Computational modeling of ovarian cancer dynamics suggests optimal strategies for therapy and screening

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    High-grade serous tubo-ovarian carcinoma (HGSC) is a major cause of cancer-related death. Treatment is not uniform, with some patients undergoing primary debulking surgery followed by chemotherapy (PDS) and others being treated directly with chemotherapy and only having surgery after three to four cycles (NACT). Which strategy is optimal remains controversial. We developed a mathematical framework that simulates hierarchical or stochastic models of tumor initiation and reproduces the clinical course of HGSC. After estimating parameter values, we infer that most patients harbor chemoresistant HGSC cells at diagnosis and that, if the tumor burden is not too large and complete debulking can be achieved, PDS is superior to NACT due to better depletion of resistant cells. We further predict that earlier diagnosis of primary HGSC, followed by complete debulking, could improve survival, but its benefit in relapsed patients is likely to be limited. These predictions are supported by primary clinical data from multiple cohorts. Our results have clear implications for these key issues in HGSC management

    COLT-Cancer: functional genetic screening resource for essential genes in human cancer cell lines

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    Genome-wide pooled shRNA screens enable global identification of the genes essential for cancer cell survival and proliferation and provide a ‘functional genetic’ map of human cancer to complement genomic studies. Using a lentiviral shRNA library targeting approximately 16 000 human genes and a newly developed scoring approach, we identified essential gene profiles in more than 70 breast, pancreatic and ovarian cancer cell lines. We developed a web-accessible database system for capturing information from each step in our standardized screening pipeline and a gene-centric search tool for exploring shRNA activities within a given cell line or across multiple cell lines. The database consists of a laboratory information and management system for tracking each step of a pooled shRNA screen as well as a web interface for querying and visualization of shRNA and gene-level performance across multiple cancer cell lines. COLT-Cancer Version 1.0 is currently accessible at http://colt.ccbr.utoronto.ca/cancer

    Política de estabilização de renda para a agricultura familiar: uma análise de risco.

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    Os produtores familiares foram prejudicados pelas políticas de substituição de importações e de modernização da agricultura, sofrendo com elevadas transferências de renda para fora do setor. Uma forma de ressarci-los seria implementando uma política de estabilização de renda que asseguraria rentabilidade estável aos produtores. O objetivo deste artigo é determinar os benefícios de uma política de estabilização de renda implementada na agricultura familiar para agricultores e consumidores de arroz, feijão, milho e mandioca, e os custos para agricultores comerciais nesses mercados. Utilizou-se o modelo de Newbery e Stiglitz, que considera a redução do risco com a política de estabilização de renda. A política implicaria aumento de receita para produtores familiares. Os benefícios de transferência superariam os de eficiência para produtores familiares e consumidores. Os benefícios para a agricultura familiar superariam os custos da agricultura comercial com a política nos mercados de feijão, mandioca e milho, e os benefícios totais superariam os custos totais nos mercados de feijão e milho, ao contrário ocorreria nos mercados de arroz e mandioca, embora neste fosse pequena a diferença. Conclui-se que a implementação da política seria viável nos mercados onde a participação da agricultura familiar fosse maior que a da comercial e naqueles importadores

    The Specificity of Peptides Bound to Human Histocompatibility Leukocyte Antigen (HLA)-B27 Influences the Prevalence of Arthritis in HLA-B27 Transgenic Rats

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    Human histocompatibility leukocyte antigen B27 is highly associated with the rheumatic diseases termed spondyloarthropathies, but the mechanism is not known. B27 transgenic rats develop a spontaneous disease resembling the human spondyloarthropathies that includes arthritis and colitis. To investigate whether this disease requires the binding of specific peptides to B27, we made a minigene construct in which a peptide from influenza nucleoprotein, NP383-391 (SRYWAIRTR), which binds B27 with high affinity, is targeted directly to the ER by the signal peptide of the adenovirus E3/gp19 protein. Rats transgenic for this minigene, NP1, were made and bred with B27 rats. The production of the NP383-391 peptide in B27+NP1+ rats was confirmed immunologically and by mass spectrometry. The NP1 product displaced ∼90% of the 3H-Arg-labeled endogenous peptide fraction in B27+NP1+ spleen cells. Male B27+NP1+ rats had a significantly reduced prevalence of arthritis, compared with B27+NP− males or B27+ males with a control construct, NP2, whereas colitis was not significantly affected by the NP1 transgene. These findings support the hypothesis that B27-related arthritis requires binding of a specific peptide or set of peptides to B27, and they demonstrate a method for efficient transgenic targeting of peptides to the ER

    Climbing walls, making bridges: children of immigrants’ identity negotiations through capoeira and parkour in Turin.

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    Capoeira and parkour are two different body practices which have gained worldwide attention in urban settings in the last few decades. The following paper will explore how capoeira and parkour relate to the construction of identity paths amongst children of immigrants between 12 and 20 in Turin, Italy. It will do so by looking at how such practices are used by young men of migrant origin to negotiate and perform narratives of self-worth, belonging and recognition within marginalising and excluding urban environments. This study acknowledges that social identifications are created, negotiated and (re)produced through bodily and spatial means and within networks of power relations. Following this premise, the insights proposed in this paper suggest that the ambivalent and fluid use of bodies and spaces implied by capoeira and parkour can represent a meaningful lens to understand the embodied and spatial identity negotiations enacted by participants in their daily lives. This theoretical perspective will illuminate the place that active bodies, spaces and leisure practices take in the negotiation of social identities, and dynamics of inclusion/exclusion, enacted by youth of migrant origin within early twenty-first century Turin cityscape

    Evolution of hepatitis B virus surface gene and protein among Iranian chronic carriers from different provinces

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    Background and Objectives: Iranian chronic HBV carrier�s population has shown a unique pattern of genotype D distribution all around the country. The aim of this study was to explore more details of evolutionary history of carriers based on structural surface proteins from different provinces. Materials and Methods: Sera obtained from 360 isolates from 12 Different regions of country were used for amplification and sequencing of surface proteins. A detailed mutational analysis was undertaken. Results: The total ratio for Missense/Silent nucleotide substitutions was 0.96. Sistan and Kermanshah showed the lowest rate of evolution between provinces (P = 0.055). On the other hand, Khorasan Razavi and Khoozestan contained the highest ratio (P = 0.055). The rest of regions were laid between these two extremes. Azarbayjan and Guilan showed the highest proportion of immune epitope distribution (91.3 and 96, respectively). Conversely, Sistan and Tehran harbored the least percentage (66.6 and 68.8, respectively). Kermanshah province contained only 5.2, whereas Isfahan had 54.5 of B cell epitope distribution. In terms of T helper epitopes, all provinces showed a somehow homogeneity: 22.58 (Fars) to 46.6 (Khuzestan). On the other hand, distribution of substitutions within the CTL epitopes showed a wide range of variation between 6.6 (Khuzestan) and 63 (Kermanshah). Conclusion: Further to low selection pressure found in Iranian population, the variations between different regions designate random genetic drift within the surface proteins. These finding would have some applications in terms of specific antiviral regimen, design of more efficient vaccine and public health issues. © 2015, Tehran University of Medical Science. All rights reserved
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