1,054,239 research outputs found

    Laparoscopic transgastric circumferential stapler-assisted vs. endoscopic esophageal mucosectomy in a porcine model

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    Background and study aims Extensive endoscopic mucosal resection (EMR) for Barrett's esophagus (BE) may lead to stenosis. Laparoscopic, transgastric, stapler-assisted mucosectomy (SAM) with the retrieval of a circumferential specimen is proposed. Methods SAM was evaluated in two phases. The feasibility of SAM and the quality of specimens were assessed in eight animals. The mucosal healing was evaluated in a 6-week survival experiment comparing SAM (n = 6) with EMR (n = 6). The ratio of the esophageal lumen width (REL) at the resection level measured on fluoroscopy at 6 weeks divided by the width immediately after resection was compared. Results In all animals, a circular mucosectomy specimen was successfully obtained, with a median area of 492 mm2 (interquartile range [IQR] 426 - 573 mm2) and 941 mm2 (IQR 813 - 1209 mm2) using a 21 mm and 25 mm stapler, respectively. In the survival experiments, symptomatic stenosis developed in two animals after EMR and in none after SAM. The REL was 0.27 (0.18 - 0.39) and 0.96 (0.9 - 1.04; P < 0.0001) for EMR and SAM, respectively. Conclusions SAM provides a novel technique for en bloc mucosectomy in BE. In contrast to EMR, mucosal healing after SAM was not associated with stenosis up to 6 weeks after intervention

    Multifunctional bioresorbable phosphate glass optical fibers for theranostics

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    We report on the design and development of microstructured phosphate glass optical fibers for minimally invasive diagnosis and therapy. We discuss preliminary results of fiber drawing and characterization

    Investigating the Sequential Deposition Route for Mixed Cation Mixed Halide Wide Bandgap Perovskite Absorber Layer

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    Wide bandgap (Eg) perovskite solar cells (PSCs) are emerging as the preferred choice for top cells in a tandem architecture with crystalline silicon solar cells. Among the wide bandgap perovskites, a mixed cation mixed halide composition containing CsyFA1-yPbI3-xBrx is a popular choice because the presence of bromine widens the bandgap and addition of cesium stabilizes the crystal structure. These perovskite layers are commonly fabricated using one-step spin coating technique; however, sequential spin coating followed by dip coating has been successful in offering better control over the crystallization process for low bandgap absorber layers. In this paper, the fabrication of a Cs0.2FA0.8PbI3-xBrx perovskite absorber layer using the sequential deposition route is reported. The concentration of bromine was varied in the range 0 <= x <= 1 and optical, structural, and morphological properties of the films were studied. As the concentration was increased, the perovskite showed better crystallinity and the presence of large grains with high surface roughness, indicating the formation of the CsPbBr3 phase. Optically, the perovskite films exhibited higher absorbance in the ultraviolet (UV) range between 300 and 500 nm, hence up to x = 0.3 they can be profitably employed as a wide bandgap photon absorber layer in solar cell applications

    Fluid flow-based description of the geometrical features in fluidic channels using the Shannon’s information theory: an exploratory study

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    Inspired by Nature, where storing information is an intrinsic ability of natural systems, here we investigate the capability of interacting systems to transport/store the information generated/exchanged in the interaction process in the form of energy or matter, preserving it over time. In detail, here we test the possibility to consider a fluid as a carrier of information, speculating about how to use such information. The aim of this work is to propose that information theory can be used to enlighten physical observations, even in those cases where the equations describing the phenomenon under investigation are intractable, are affected by a budget of uncertainty that makes their solution not affordable or may not even be known. In this exploratory work, an information theory-based approach is applied to microfluidic data. In detail, the classical study of the fluid flow in a microchannel with obstacles of different geometry is faced by integrating fluid mechanics theory with Shannon’s theory of information, interpreted in terms of thermodynamics. Technically, computational fluid dynamics simulations at Reynolds’ numbers (Re) equal to 1 and 50 were carried out in fluidic channels presenting obstacles with rectangular and semicircular shape, and on the simulated flow fields, the Shannon’s information theory was applied evaluating the fluid dynamics information entropy content. It emerged that the Shannon Entropy (SE) evaluated at the outflow section of the flow channel depends upon the geometric features (i.e., position, shape, aspect ratio) of the obstacles. This suggests an interpretation of the fluid dynamics establishing in a flow channel presenting obstacles in terms of information theory, that can be used to identify a posteriori the geometric features of the obstacles the fluid interacts with. The proposed approach can be applied to flow data at the boundaries of fluid domains of interest to extract information on the process occurring inside a system, without making any appeal to the governing equations of the phenomenon under observation or intrusive measurements

    Glass and Glass–Ceramic Photonic Materials for Sensors

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    Recent developments in sensors are pushing for optimized materials that can increase their usage, bolster their sensitivity and enable new and more efficient transduction mechanisms. We hereby review some of the most relevant applications of glasses and glass-ceramics for photonic sensors considering the recent trends and innovative approaches. This review covers from bulk glasses to thin films and from fiber optics to nanocrystal-based and their applications in sensing

    CLAUDIAN, DE RAPTU PROSERPINAE 1.82 AND GEORGICS 3.68

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    Identification & analysis of an imitation of Virgil's Georgics in Claudian, De Raptu Proserpinae
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