193 research outputs found

    Beyond multi-view deconvolution for inherently-aligned fluorescence tomography

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    In multi-view fluorescence microscopy, each angular acquisition needs to be aligned with care to obtain an optimal volumetric reconstruction. Here, instead, we propose a neat protocol based on auto-correlation inversion, that leads directly to the formation of inherently aligned tomographies. Our method generates sharp reconstructions, with the same accuracy reachable after sub-pixel alignment but with improved point-spread-function. The procedure can be performed simultaneously with deconvolution further increasing the reconstruction resolution

    A gentrificação na malha cicloviária do Distrito Federal

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    A circulação é algo intrínseco à cidade. A mobilidade se relaciona com a qualidade dessa circulação, isto é, se é possível chegar com segurança a determinado ponto a partir de outro na cidade. A gentrificação é um fenômeno que distorce o uso e cria segregação urbana. Com esse entendimento, o presente teve como objetivo entender a dinâmica de implantação da malha cicloviária em algumas cidades no Distrito Federal (Plano Piloto, Ceilândia e Pôr do Sol) e se houve equidade em sua distribuição. O objetivo principal foi analisar a existência de uma possível gentrificação da mobilidade urbana no que diz respeito à distribuição dessa malha cicloviária, uma vez que, sem acesso à boas condições de mobilidade, o usuário sobrecarrega outros meios de transporte individual ou é obrigado a utilizar os transportes coletivos cada vez mais saturados, perdendo qualidade de vida. O foco não foi analisar as condições atuais ou a qualidade da ciclovia implantada, mas sim, a partir da análise comparativa de dados, analisar sua disposição conforme a necessidade e utilização da comunidade, demonstrando sua eficiência e atendimento às demandas de mobilidade da população. As análises dos dados de malha viárias destas cidades, juntamente com dados de renda e acidentes nos deram um panorama de como foi distribuída a malha cicloviária no Distrito Federal, levando à conclusão de que a distribuição da malha nas cidades pesquisadas não é equitativa e não contribui para a diminuição da gentrificação da mobilidade nestas comunidades

    Congenital syphilis in a two-month-old infant

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    This report describes a rare case of congenital syphilis in a two-month-old Romanian infant. Diagnosis was possible when the baby showed decrease in the left upper limb movements and a papular rash. Her father had been infected and transmitted the infection to the mother, who had two non-treponemal serological tests during pregnancy, both with negative results. Congenital syphilis was confirmed by serological tests and the newborn was successfully treated. A global overview on diagnosis and treatment of children with suspected congenital syphilis is presented

    Compressed sensing in fluorescence microscopy.

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    Compressed sensing (CS) is a signal processing approach that solves ill-posed inverse problems, from under-sampled data with respect to the Nyquist criterium. CS exploits sparsity constraints based on the knowledge of prior information, relative to the structure of the object in the spatial or other domains. It is commonly used in image and video compression as well as in scientific and medical applications, including computed tomography and magnetic resonance imaging. In the field of fluorescence microscopy, it has been demonstrated to be valuable for fast and high-resolution imaging, from single-molecule localization, super-resolution to light-sheet microscopy. Furthermore, CS has found remarkable applications in the field of mesoscopic imaging, facilitating the study of small animals' organs and entire organisms. This review article illustrates the working principles of CS, its implementations in optical imaging and discusses several relevant uses of CS in the field of fluorescence imaging from super-resolution microscopy to mesoscopy

    Potential Application of Lung Ultrasound in Children with Severe Uncontrolled Asthma: Preliminary Hypothesis Based on a Case Series

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    : In recent years, lung ultrasound (LUS) has been increasingly used for the diagnosis of respiratory diseases in both adult and pediatric patients. However, asthma is a field in which the use of LUS is not yet well defined, or is in development. In the following case series, we describe clinical, laboratory, and radiological results, as well as detailed lung ultrasound findings of six children with asthma: some of them with acute asthma attack and with inadequately controlled allergic asthma or childhood asthma; others with acute asthma and allergic or infantile asthma adequately controlled by preventive therapy. Finally, we describe the clinical, laboratory, and imaging parameters of a child with severe allergic asthma in the absence of exacerbation. In these cases, albeit at different times, LUS played an important role in both the initial diagnostic process and follow-up. It also showed different ultrasound features depending on the severity of the individual asthma based on the type of asthmatic phenotype and control of it

    Fast 3D-EM reconstruction using Planograms for stationary planar positron emission mammography camera

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    Summary At the University of Pisa we are building a PEM prototype, the YAP–PEM camera, consisting of two opposite 6×6×3 cm 3 detector heads of 30×30 YAP:Ce finger crystals, 2×2×30 mm 3 each. The camera will be equipped with breast compressors. The acquisition will be stationary. Compared with a whole body PET scanner, a planar Positron Emission Mammography (PEM) camera allows a better, easier and more flexible positioning around the breast in the vicinity of the tumor: this increases the sensitivity and solid angle coverage, and reduces cost. To avoid software rejection of data during the reconstruction, resulting in a reduced sensitivity, we adopted a 3D-EM reconstruction which uses all of the collected Lines Of Response (LORs). This skips the PSF distortion given by data rebinning procedures and/or Fourier methods. The traditional 3D-EM reconstruction requires several times the computation of the LOR-voxel correlation matrix, or probability matrix { p ij }; therefore is highly time-consuming . We use the sparse and symmetry properties of the matrix { p ij } to perform fast 3D-EM reconstruction. Geometrically, a 3D grid of cubic voxels (FOV) is crossed by several divergent 3D line sets (LORs). The symmetries occur when tracing different LORs produces the same p ij value. Parallel LORs of different sets cross the FOV in the same way, and the repetition of p ij values depends on the ratio between the tube and voxel sizes. By optimizing this ratio, the occurrence of symmetries is increased. We identify a nucleus of symmetry of LORs: for each set of symmetrical LORs we choose just one LOR to be put in the nucleus , while the others lie outside. All of the possible p ij values are obtainable by tracking only the LORs of this nucleus . The coordinates of the voxels of all of the other LORs are given by means of simple translation rules. Before making the reconstruction, we trace the LORs of the nucleus to find the intersecting voxels, whose p ij values are computed and stored with their voxel coordinates on a hard disk. Only the non-zero p ij are considered and their computation is performed just once. During the reconstruction, the stored values are loaded and are available in the random access memory for all of the operations of normalization, backprojection and projection: these are now performed rapidly, because the application of the translation rules is much faster than the probability computations. We tested the algorithm on Monte Carlo data fully simulating the typical YAP–PEM clinical condition. The adopted algorithm gives an excellent positioning capability for hot spots in the camera FOV. To use all of the possible skew LORs in the FOV avoids the software rejection of collected data. Reconstructed images indicate that a 5 mm diameter tumor of 37 kBq/cm 3 , in an active breast with a 10:1 Tissue to Background ratio (T/B), with a 10 min acquisition, for a head distance of 5 cm, can be detected by the YAP–PEM with a SNR of 8.7±1.0. The obtained SNR values depend linearly on the tumor volume. The algorithm allows one to discriminate between two hot sources of 5.0 mm diameter if they do not lie on the same axis. The YAP–PEM is now in the assembly stage

    anosmia in COVID-19. Severe acute respiratory syndrome coronavirus 2 through the nasoliary epithelium and a possible spreading way to the central nervous system—a purpose to study

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    Italy is currently one of the countries most affected by the global emergency of COVID-19, a lethal disease of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).1 A lot of emergency centers from China,2 United Kingdom, and Italy,3 including our Department of Policlinic Umberto I of Rome, reported a significant number of COVID-19 patients presenting anosmia and ageusia as onset symptoms,4 and it is reported that anosmia appear at an early stage of the disease

    Operational challenges for astronomical instrumentation in Antarctica: results from five years of environmental monitoring of AMICA at Dome C

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    The Antarctic Plateau is one of the best observing sites on Earth, especially for infrared astronomy. The extremely low temperatures (down to -80°C), the low pressure (around 650 mbar) and the very dry atmosphere (PWV less than 1 mm) allow for a very clear and dark sky, as well as for a very low instrumental background. These unique properties, however, make it also very difficult to install and operate astronomical instrumentation. AMICA (Antarctic Multiband Infrared CAmera) is an instrument especially designed for Antarctic operation, whose installation at Dome C has been completed in 2013. Since then it has been continuously working over the last five years, monitoring and controlling in particular the environmental and operating conditions through a dedicated application, its Environmental Control System (ECS). The recorded behavior of AMICA highlighted a set of peculiar aspects of the site that are hard to consider a priori. Although mechanical and electronic COTS components can reliably work in thermally insulated and controlled boxes, simple insulation causes their overheating because of the air dryness and rarefaction which make the heat transfer extremely inefficient. Heat removal is also a real problem when managing heavy-duty devices like cryocoolers, whose excess power removal needs to be fast and efficient. Finally, the lack of an electrical ground generates a wide variety of transient electrical and electromagnetic phenomena which often make electronic instrumentation very unstable. A list of new recommendations is therefore presented, as a guideline for future astronomical instruments operating in Antarctica

    Improving the performance of printable carbon electrodes by femtosecond laser treatment

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    Low-cost carbon-conductive films were screen-printed on a Plexiglas® substrate, and then, after a standard annealing procedure, subjected to femtosecond (fs) laser treatments at different values of total accumulated laser fluence ΦA. Four-point probe measurements showed that, if ΦA > 0.3 kJ/cm2, the sheet resistance of laser-treated films can be reduced down to about 15 Ω/sq, which is a value more than 20% lower than that measured on as-annealed untreated films. Furthermore, as pointed out by a comprehensive Raman spectroscopy analysis, it was found that sheet resistance decreases linearly with ΦA, due to a progressively higher degree of crystallinity and stacking order of the graphitic phase. Results therefore highlight that fs-laser treatment can be profitably used as an additional process for improving the performance of printable carbon electrodes, which have been recently proposed as a valid alternative to metal electrodes for stable and up-scalable perovskite solar cells
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