777 research outputs found

    Dynamic heterodyne near field scattering

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    The technique heterodyne near field scattering (HNFS), originally developed for low-angle static light scattering, has also been implemented for carrying out dynamic light scattering. While the classical dynamic light scattering method measures the intensity-intensity correlation function, dynamic HNFS gives directly the field-field correlation function, without any assumption on the statistical properties of the sample, as the ones required by the Siegert relation. The technique has been tested with calibrated Brownian particles and its performances compared to those of the classical dynamic light scattering method.The technique heterodyne near field scattering (HNFS), originally developed for low-angle static light scattering, has also been implemented for carrying out dynamic light scattering. While the classical dynamic light scattering method measures the intensity-intensity correlation function, dynamic HNFS gives directly the field-field correlation function, without any assumption on the statistical properties of the sample, as the ones required by the Siegert relation. The technique has been tested with calibrated Brownian particles and its performances compared to those of the classical dynamic light scattering method. \ua9 2008 American Institute of Physics

    Comparison of dogs treated for primary immune-mediated hemolytic anemia in Tuscany, Italy and Texas, USA

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    This retrospective study compared clinical characteristics between dogs treated for IMHA by veterinary teaching hospitals in Tuscany, Italy and Texas, USA between 2010 and 2018

    INCIDENTAL FINDING OF INTERRUPTED AORTIC ARCH IN AN ADULT PATIENT UNDERGOING URGENT PERCUTANEOUS CORONARY INTERVENTION

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    Interrupted Aortic Arch (IAA) is a rare congenital abnormality characterized by a complete discontinuity of the aortic lumen, usually located after the origin of the left subclavian artery. IAA is mainly diagnosed during childhood and has an extremely high mortality rate if left untreated. Therefore, only a few cases have been diagnosed in adulthood. We report the case of a patient with Non-ST Segment Elevation Myocardial Infarction (NSTEMI) and unknown IAA abnormality, who underwent urgent percutaneous coronary angioplasty (PCI). It was not possible to reach ascending aorta from the right radial artery because of the presence of tangled arteries connecting the prevertebral subclavian segment to the descending aorta. PCI was completed successfully through the left radial artery. A post-procedural Angio-CT scan confirmed the Aortic Arch interruption. The presented case highlights the crucial role of a multi-imaging modality approach for those patients with such congenital abnormalities before undergoing PCI

    Heterodyne speckle velocimetryof Poiseuille flow

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    We review the technique named heterodyne speckle velocimetry and present two applications for testing the method with a fluid moving under the conditions of Poiseuille flow. The fluid was seeded with small tracking particles diameter 300 nm and fluxed between the two parallel planes of a cell with constant or variable cross section. In the first case the velocity distribution was constant along the direction parallel to the planes and was in excellent agreement with the expected Poiseuille profile along the orthogonal direction. In the second case, where velocity gradients were present also along the planes, the technique was able to reconstruct both the orthogonal Poiseuille profile and the in-plane two dimensional mapping of the velocity vectors, with the possibility of measuring the fluid flux within an accuracy of 1%

    Mild synthesis of poly(HEMA)-networks as well-defined nanoparticles in supercritical carbon dioxide

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    Free-radical dispersion polymerisation of 2-hydroxyethyl methacrylate was carried out in supercritical carbon dioxide (scCO2) in the presence of stabilisers based on polyethylene oxide (PEO) and poly(heptadecafluorodecyl acrylate) (PFDA). Different architectures of copolymers (random, palm-tree and diblock) were tested for their surface tension, cloud point and as a stabilising agent. The diblock architecture was found to be the best candidate resulting in poly(HEMA) spherical particles with a size of 316 nm. Furthermore, the effect of the CO2-phobic block (PEO) in the diblock architecture was investigated by using three different chain lengths (1000, 2000, 5000 g mol−1). By optimizing the stabiliser composition and structure, mild reaction conditions have been identified allowing us to obtain well-defined spherical cross-linked poly(HEMA) particles with a mean diameter of unprecedented low size (216 nm) at a temperature as low as 35 °C

    Factors influencing the first thousand days of life

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    The first 1,000 days is a vulnerable phase in which parents, institutions and health professionals should create early interventions for the proper development and promotion of good health

    Unraveling population trends in Italy (1921–2021) with spatial econometrics

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    Testing density-dependence and path-dependence in long-term population dynamics under differentiated local contexts contributes to delineate the changing role of socioeconomic forces at the base of regional disparities. Despite a millenary settlement history, such issue has been rarely investigated in Europe, and especially in highly divided countries such as those in the Mediterranean region. Using econometric modeling to manage spatial heterogeneity, our study verifies the role of selected drivers of population growth at ten times between 1921 and 2021 in more than 8000 Italian municipalities verifying density-dependent and path-dependent dynamics. Results of global and quantile (spatial) regressions highlight a differential impact of density and (lagged) population growth on demographic dynamics along the urban cycle in Italy. Being weakly significant in the inter-war period (1921-1951), econometric models totalized a high goodness-of-fit in correspondence with compact urbanization (1951-1981). Model's fit declined in the following decades (1981-2021) reflecting suburbanization and counter-urbanization. Density-dependence and path-dependence were found significant and, respectively, positive or negative, with compact urbanization, and much less intense with suburbanization and counter-urbanization. A spatial econometric investigation of density-dependent and path-dependent mechanisms of population dynamics provided an original explanation of metropolitan cycles, delineating the evolution of socioeconomic (local) systems along the urban-rural gradient
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