7,841 research outputs found

    Desarrollo de un software en MATLAB para la simulación de campo ultrasónico

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    The study of the acoustic field generated by an ultrasonic transducer is fundamental to its construction and characterization, because it defines how it will behave before being built. It also defines whether it is feasible or not, for the application to which it was designed. It can also lead to modifications to the project so it behaves as expected. In this work, a software was implemented in MATLAB®, for computational simulation of acoustic fields generated by ultrasonic transducers of different configurations. Two models were used, Zemanek and Stepanishen. Transducers with focus and apodization and transmission medium with attenuation may also be simulated. For the simulation of Zemanek’s model, the mathematical method of discretization was used. The Stepanishen’s model used an analytical solution for the impulse response. The developed programs were aggregated into a computer package, named FSIM, and a graphic interface was created. The user can choose among some of the transducer configurations and simulation parameters already implemented. FSIM has a modular architecture and allows further simulation modules to be added. The simulations were validated comparing results to those previously published in classical papers from Zemanek, and from Lockwood and Willete, in addition to prior results from research studies conducted at the Biomedical Engineering Department of the School of Electrical and Computing Engineering at the Universidade Estadual de Campinas (UNICAMP).El estudio del campo acústico generado por un transductor ultrasónico es fundamental para su construcción y caracterización, ya que define cómo se comportará antes de ser construido. También define si realmente es factible para la aplicación a la que fue diseñado, y también puede sugerir modificaciones al proyecto, para que se comporte como se espera. En este trabajo un software fue implementado en MATLAB®, para la simulación computacional de los campos acústicos generados por los transductores ultrasónicos de diferentes configuraciones. Dos modelos fueran usados, Zemanek y Stepanishen. Transductores con el enfoque y apodización y medios con atenuación también pueden ser simulados. Para la simulación del modelo de Zemanek, se utilizó el método matemático de discretización y para el modelo de Stepanishen, se empleó una solución analítica para la respuesta impulsiva. Los programas desarrollados fueron agregados en un paquete computacional, llamado FSIM, y una interfaz gráfica fue creada. El usuario puede elegir entre algunas configuraciones del transductor y parámetros de simulación ya implementados; FSIM tiene una arquitectura modular y permite que otros módulos de simulación sean añadidos. Las simulaciones fueron validadas comparando resultados obtenidos previamente por otros trabajos de investigación del Departamento de Ingeniería Biomédica de la Facultad de Ingeniería Eléctrica y Computación de la UNICAMP y por los artículos clásicos de Zemanek y Lockwood y Willette

    Insights Into Genetic Landscape of Large Granular Lymphocyte Leukemia

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    Large granular lymphocyte leukemia (LGLL) is a chronic proliferation of clonal cytotoxic lymphocytes, usually presenting with cytopenias and yet lacking a specific therapy. The disease is heterogeneous, including different subsets of patients distinguished by LGL immunophenotype (CD8+ T\u3b1\u3b2, CD4+ T\u3b1\u3b2, T\u3b3\u3b4, NK) and the clinical course of the disease (indolent/symptomatic/aggressive). Even if the etiology of LGLL remains elusive, evidence is accumulating on the genetic landscape driving and/or sustaining chronic LGL proliferations. The most common gain-of-function mutations identified in LGLL patients are on STAT3 and STAT5b genes, which have been recently recognized as clonal markers and were included in the 2017 WHO classification of the disease. A significant correlation between STAT3 mutations and symptomatic disease has been highlighted. At variance, STAT5b mutations could have a different clinical impact based on the immunophenotype of the mutated clone. In fact, they are regarded as the signature of an aggressive clinical course with a poor prognosis in CD8+ T-LGLL and aggressive NK cell leukemia, while they are devoid of negative prognostic significance in CD4+ T-LGLL and T\u3b3\u3b4 LGLL. Knowing the specific distribution of STAT mutations helps identify the discrete mechanisms sustaining LGL proliferations in the corresponding disease subsets. Some patients equipped with wild type STAT genes are characterized by less frequent mutations in different genes, suggesting that other pathogenetic mechanisms are likely to be involved. In this review, we discuss how the LGLL mutational pattern allows a more precise and detailed tumor stratification, suggesting new parameters for better management of the disease and hopefully paving the way for a targeted clinical approach

    Upper critical field in superconductors near ferromagnetic quantum critical points; UCoGe

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    We study the strong-coupling superconductivity near ferromagnetic quantum critical points, mainly focusing on the upper critical fields Hc2H_{c2}. Based on our simple model calculations, we discuss experimentally observed unusual behaviors of Hc2H_{c2} in a recently discovered ferromagnetic superconductor UCoGe. Especially, the large anisotropy between Hc2aH_{c2}\parallel a-axis and Hc2cH_{c2}\parallel c-axis, and the strong-coupling behaviors in Hc2aH_{c2}^{\parallel a} are investigated. We also examine effects of non-analytic corrections in the spin susceptibility on the superconductivity, which can arise from effective long range interactions due to particle-hole excitations.Comment: Proceedings of ICHE2010, Toky

    Air pollution and related respiratory diseases: the experience of a Local Health Authority in Liguria (North Italy)

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    Background. Numerous epidemiological studies have shown that air pollution due to both industry and heavy traffic has short- and long-term effects on health. The study was carried out in an industrial area with heavy urban and motorway traffic in the Province of Genoa (Italy). Methods. The study was carried out from June 2005 to July 2008. An epidemiologic study was conducted by monitoring an elementary/ middle school situated in an area of recent industrial development and an elementary/middle school located in an area free from sources of industrial pollution. Furthermore, we conducted an investigation of workers in commercial premises situated in one area of heavy vehicular traffic. In the study areas, environmental monitoring campaigns were carried out in order to determine the association between indoor and outdoor pollution and respiratory disorders. Results and discussion. The study did not bring to light any specific health problems attributable with certainty to industrial emissions. The impact of pollution caused by motor traffic proved to be greater than that due to industrial emissions. More exhaustive sampling campaigns should be implemented in order to quantify the effects of specific sources of emissions and to correlate these sources with pollutants (industry, urban traffic, motorway traffic)

    Scaling of the superfluid density in superfluid films

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    We study scaling of the superfluid density with respect to the film thickness by simulating the xyx-y model on films of size L×L×HL \times L \times H (L>>HL >> H) using the cluster Monte Carlo. While periodic boundary conditions where used in the planar (LL) directions, Dirichlet boundary conditions where used along the film thickness. We find that our results can be scaled on a universal curve by introducing an effective thickness. In the limit of large HH our scaling relations reduce to the conventional scaling forms. Using the same idea we find scaling in the experimental results using the same value of ν=0.6705\nu = 0.6705.Comment: 4 pages, one postscript file replaced by one Latex file and 5 postscript figure

    Accuracy and reproducibility of contrast-enhanced mammography in the assessment of response to neoadjuvant chemotherapy in breast cancer patients with calcifications in the tumor bed

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    This study aimed to evaluate contrast-enhanced mammography (CEM) accuracy and reproducibility in the detection and measurement of residual tumor after neoadjuvant chemotherapy (NAC) in breast cancer (BC) patients with calcifications, using surgical specimen pathology as the reference. Pre-and post-NAC CEM images of 36 consecutive BC patients receiving NAC in 2012–2020, with calcifications in the tumor bed at diagnosis, were retrospectively reviewed by two radiologists; described were absence/presence and size of residual disease based on contrast enhancement (CE) only and CE plus calcifications. Twenty-eight patients (77.8%) had invasive and 5 (13.9%) in situ-only residual disease at surgical specimen pathology. Considering CE plus calcifications instead of CE only, CEM sensitivity for invasive residual tumor increased from 85.7% (95% CI = 67.3–96%) to 96.4% (95% CI = 81.7–99.9% ) and specificity decreased from 5/8 (62.5%; 95% CI = 24.5–91.5%) to 1/8 (14.3%; 95% CI = 0.4–57.9%). For in situ-only residual disease, false negatives decreased from 3 to 0 and false positives increased from 1 to 2. CEM pathology concordance in residual disease measurement increased (R squared from 0.38 to 0.45); inter-reader concordance decreased (R squared from 0.79 to 0.66). Considering CE plus calcifications to evaluate NAC response in BC patients increases sensitivity in detection and accuracy in measurement of residual disease but increases false positives

    Scaling of thermal conductivity of helium confined in pores

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    We have studied the thermal conductivity of confined superfluids on a bar-like geometry. We use the planar magnet lattice model on a lattice H×H×LH\times H\times L with LHL \gg H. We have applied open boundary conditions on the bar sides (the confined directions of length HH) and periodic along the long direction. We have adopted a hybrid Monte Carlo algorithm to efficiently deal with the critical slowing down and in order to solve the dynamical equations of motion we use a discretization technique which introduces errors only O((δt)6)O((\delta t)^6) in the time step δt\delta t. Our results demonstrate the validity of scaling using known values of the critical exponents and we obtained the scaling function of the thermal resistivity. We find that our results for the thermal resistivity scaling function are in very good agreement with the available experimental results for pores using the tempComment: 5 two-column pages, 3 figures, Revtex

    Atypical mature T-cell neoplasms: The relevance of the role of flow cytometry

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    Lymphoproliferative disorders are a heterogeneous group of malignant clonal proliferations of lymphocytes whose diagnosis remains challenging, despite diagnostic criteria are now well established, due to their heterogeneity in clinical presentation and immunophenotypic profile. Lymphoid T-cell disorders are more rarely seen than B-cell entities and more difficult to diagnose for the absence of a specific immunophenotypic signature. Flow cytometry is a useful tool in diagnosing T-cell lymphoproliferative disorders since it is not only able to better characterize T-cell neoplasms but also to resolve some very complicated cases, in particular those in which a small size population of neoplastic cells is available for the analysis. Here, we report three patients with mature T-cell neoplasms with atypical clinical and biological features in which analysis of peripheral blood and bone marrow specimens by means of multicolor flow cytometry was very useful to identify and characterize three rare T-cell lymphoproliferative disorders, such as angioimmunoblastic T-cell lymphoma, peripheral T-cell lymphoma not otherwise specified and T-cell prolym-phocytic leukemia. The aim of this case series report is not only to describe three rare cases of lymphoproliferative neoplasms but also to raise awareness that a fast, highly sensitive, and reproducible procedure, such as flow cytometry immunophenotyping, can have a determinant diagnostic role in these patients

    Scaling of the specific heat in superfluid films

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    We study the specific heat of the xyx-y model on lattices L×L×HL \times L \times H with LHL \gg H (i.e. on lattices representing a film geometry) using the Cluster Monte--Carlo method. In the HH--direction we apply Dirichlet boundary conditions so that the order parameter in the top and bottom layers is zero. We find that our results for the specific heat of various thickness size HH collapse on the same universal scaling function. The extracted scaling function of the specific heat is in good agreement with the experimentally determined universal scaling function using no free parameters.Comment: 4 pages, uuencoded compressed PostScrip
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