177 research outputs found

    Clinical usefulness of microsatellite instability for the prediction of gastric adenoma or adenocarcinoma in patients with chronic gastritis

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    To assess a role of microsatellite instability (MSI) in the development of gastric adenocarcinoma or adenoma from chronic gastritis, we analysed mutations of five microsatellite loci in gastritis, adenoma and adenocarcinoma retrospectively. Gastric mucosa was biopsied from the same area in each patient at different periods and examined for MSI. Only one of 55 patients with chronic gastritis revealed MSI-H phenotype and the other 54 patients showed microsatellite stable (MSS) phenotypes. In six of 17 patients with gastric adenoma or well-differentiated adenocarcinoma, MSI-positive phenotypes were demonstrated. Interestingly, all of six patients showing MSI, including three high-level MSI (MSI-H) cases and three low-level (MSH-L) cases, had already revealed MSI at the stage of chronic gastritis. In two of three MSI-H cases, the identical MSI patterns had been observed at the stage of gastritis 1.5–7 years before the final diagnosis of adenocarcinoma. The adjacent gastritis mucosa within 10 mm from the carcinoma demonstrated MSI as well. MSI was not found in any of 35 patients with Helicobacter pylori infection, but found in one of 30 patients without infection. Moreover, two of three cases of gastric adenoma or well-differentiated adenocarcinoma with MSI-H at the stage of chronic gastritis showed no evidence of Helicobacter pylori infection throughout the observation periods. These results indicate that MSI in biopsy specimens at the stage of chronic gastritis may predict the risk of the progression to adenoma and well-differentiated adenocarcinoma, and that Helicobacter pylori infection itself may not induce MSI directly in the gastric mucosa. © 2000 Cancer Research Campaig

    Synthesis and Photocatalytic Activity of Anatase TiO2 Nanoparticles-coated Carbon Nanotubes

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    A simple and straightforward approach to prepare TiO2-coated carbon nanotubes (CNTs) is presented. Anatase TiO2 nanoparticles (NPs) with the average size ~8 nm were coated on CNTs from peroxo titanic acid (PTA) precursor even at low temperature of 100 °C. We demonstrate the effects of CNTs/TiO2 molar ratio on the adsorption capability and photocatalytic efficiency under UV–visible irradiation. The samples showed not only good optical absorption in visible range, but also great adsorption capacity for methyl orange (MO) dye molecules. These properties facilitated the great enhancement of photocatalytic activity of TiO2 NPs-coated CNTs photocatalysts. The TiO2 NPs-coated CNTs exhibited 2.45 times higher photocatalytic activity for MO degradation than that of pure TiO2

    Excited-State Dynamics in Colloidal Semiconductor Nanocrystals

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    金属氧化物纳米材料的设计与合成策略

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    Emerging microstructure in biological tissue under thermo-mechanical actions

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    A comparative fractal analysis, about the mechanical aspects of the freezing phenomenon, in tissue (t = -30°C; t= -70°C) has been performed over the diaphragm muscle. Starting with the classical one, recalling the Stefan model we justify the no-smooth interface between soft and hard phases. So, we translate the problem as the contact problem applying the relative computational methods about the stress distribution in the contact neighbour. Fractal dimension of the interface structures increased with the lowest temperature (p<0.001), permitting to obtain an accurate quantification of the tissue damage after freezing, an important features to study effectiveness and reality of the models

    Advances in the chemical fabrication of complex multimaterial nanocrystals

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    In this work, recent achievements of nanochemistry research in the fabrication of colloidal nanoheterostructures are reviewed through revisiting relevant papers and related patents. Attention is focused on newly conceived generations of hybrid nanocrystals (HNCs) with a topologically controlled composition, in which size and shape tailored domains of different inorganic materials are permanently assembled together in a single multifunctional particle. Strategies for accessing HNCs in various configurations, such as core/shell systems, hetero-oligomers based on nearly spherical portions, and highly asymmetric nanostructures comprising joint sections with different shapes, are discussed. The chemical-physical properties and technological advantages offered by such complex nanocrystals are also highlighted

    Synthetic strategies to multi-material hybrid nanocrystals

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    Wet-chemical approaches to multi-component hybrid nanocrystals (HNCs), that incorporate nanoscale domains of different semiconductor, metallic and/or oxide materials interconnected through inorganic junctions, are illustrated and discussed. It is shown how control of interfacial lattice strain and surface energy in liquid media can be achieved within the frame of seeded-growth synthesis techniques, leading to structurally complex HNCs with purposely engineered compositional and geometric parameters. Various topological configurations are analyzed, including concentric core/shell architectures and hetero-oligomers grouping spherical and anisotropically shaped material sections. The most significant chemical-physical properties and technological advantages offered by such multifunctional HNCs are also briefly highlighted

    Colloidal Strategies for Preparing Oxide-Based Hybrid Nanocrystals

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    Recent progress of colloidal chemistry in the synthesis of multimaterial nanostructures incorporating transition-metal oxides is reviewed. Attention is focused on the emerging class of hybrid nanocrystals (HNCs), in which domains of different materials are interconnected through inorganic junctions in defined spatial arrangements. The level of expertise so far achieved in the preparation of single-material NCs with finely tuned geometric parameters has been further extended into elegant “seeded growth” approaches for accessing elaborate HNCs by control of interfacial lattice strain and surface energy in liquid media. Various topological configurations are analyzed, including concentric core/shell architectures, hetero-oligomers grouping spherical material domains and more asymmetric hybrid nanostructures based on rod-shaped sections. The chemical-physical properties and technological advantages offered by such multifunctional HNCs are also summarize

    Rapid assessment of replication error phenotype in gastric cancer

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    Forty gastric tumors were investigated for microsatellite instability at the D2S119 and L-myc loci. These tumors and 143 other gastrointestinal cancers were previously analyzed for instability at several different microsatellites. By evaluating previous and present results, repeated sequences were selected that frequently underwent replication errors (RERs). To coamplify these sequences, the following multiplex polymerase chain reactions (PCRs) were performed: 1) D2S119/L-myc/D18S59; 2) D2S119/L-myc/D3S1076; and 3) D2S177/L-myc/BAT-RII. Therefore, the 40 gastric tumors in the present survey were rescreened using multiplex PCRs. Each multiplex allowed detection of nearly all RER+ tumors (80% for multiplex 3 and 87% for multiplexes 1 and 2) that had been previously identified by amplifying 9 different loci with independent reactions. Moreover, for multiplexes 1 and 2, the size differences between normal and RER alleles were sufficient to be detected by electrophoresis on conventional polyacrylamide gels after DNA staining with ethidium bromide. This approach allows a rapid and easy assessment of RER phenotype in gastric tumors
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