959 research outputs found

    Beam Voltage Effects in the Study of Embedded Biological Materials by Secondary Electron Detectors

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    Thin and semithin sections were extensively examined by the secondary electron (SE) detector in a conventional scanning electron microscope (SEM), and in a transmission electron microscope with a scanning attachment (STEM). Various para-meters, in particular the beam voltage, were shown to affect the final SE image (SEI). As for SEM observation, a surface contrast was imaged at low primary electron (PE) voltages (0.6-2 kV), whereas a subsurface contrast predominated at higher energies (15-30 kV). In STEM, significant differences were not detected by varying the PE in the 20-100 kV range. Surface and subsurface in-formation was simultaneously imaged even though the SEI were better resolved at the highest energy

    A New Approach for Studying Semithin Sections of Human Pathological Material: Intermicroscopic Correlation Between Light Microscopy and Scanning Electron Microscopy

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    In order to obtain useful and complete information on the study of pathological material, we observed by scanning electron microscopy (SEM) the same semithin sections observed by light microscopy (LM). For this purpose, the specimen must have, at the same time, chromatic and electron dense characteristics. We thus developed different specimen preparation methods, subjecting the semithin sections to specific polychromatic staining with high atomic number (Z) elements, to monochromatic staining followed by routine contrasting with uranyl acetate and lead citrate, and to specific cytochemical and immunocytochemical procedures. The specimens were examined in sequence by LM, by SEM equipped with secondary electron, backscattered electron, transmitted electron detectors and by scanning transmission electron microscopy (S(T)EM)

    Conditions currently associated with erythema nodosum in Swiss children

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    A review was made of the 36 paediatric patients in whom the diagnosis of erythema nodosum had been established between 1977 and 1996 at the Department of Paediatrics, University of Bern, Switzerland. Infectious diseases were associated with erythema nodosum in 20 (including 10 streptococcal infections) and non-infectious inflammatory diseases in 8 patients. None of the 36 patients had tuberculosis or had been exposed to sulphonamides, phenytoin or hormonal contraceptives. There were eight patients in whom either the associated disease was not diagnosed, or there was no other disease. Conclusion Most cases of erythema nodosum are nowadays caused by non-mycobacterial infectious diseases or by non-infectious inflammatory disease

    Aspects of Cooling at the TRIÎĽ\muP Facility

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    The Triμ\muP facility at KVI is dedicated to provide short lived radioactive isotopes at low kinetic energies to users. It comprised different cooling schemes for a variety of energy ranges, from GeV down to the neV scale. The isotopes are produced using beam of the AGOR cyclotron at KVI. They are separated from the primary beam by a magnetic separator. A crucial part of such a facility is the ability to stop and extract isotopes into a low energy beamline which guides them to the experiment. In particular we are investigating stopping in matter and buffer gases. After the extraction the isotopes can be stored in neutral atoms or ion traps for experiments. Our research includes precision studies of nuclear β\beta-decay through β\beta-ν\nu momentum correlations as well as searches for permanent electric dipole moments in heavy atomic systems like radium. Such experiments offer a large potential for discovering new physics.Comment: COOL05 Workshop, Galena, Il, USA, 18-23. Sept. 2005, 5 pages, 3 figure

    Phenotypic, morphological, and metabolic characterization of vascular-spheres from human vascular mesenchymal stem cells

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    The ability to form spheroids under non-adherent conditions is a well-known property of human mesenchymal stem cells (hMSCs), in addition to stemness and multilineage differentiation features. In the present study, we tested the ability of hMSCs isolated from the vascular wall (hVW-MSCs) to grow as spheres, and provide a characterization of this 3D model. hVW-MSCs were isolated from femoral arteries through enzymatic digestion. Spheres were obtained using ultra-low attachment and hanging drop methods. Immunophenotype and pluripotent genes (SOX-2, OCT-4, NANOG) were analyzed by immunocytochemistry and real-time PCR, respectively. Spheres histological and ultrastructural architecture were examined. Cell viability and proliferative capacity were measured using LIVE/DEATH assay and ki-67 proliferation marker. Metabolomic profile was obtained with liquid chromatography–mass spectrometry. In 2D, hVW-MSCs were spindle-shaped, expressed mesenchymal antigens, and displayed mesengenic potential. 3D cultures of hVW-MSCs were CD44+, CD105low, CD90low, exhibited a low propensity to enter the cell cycle as indicated by low percentage of ki-67 expression and accumulated intermediate metabolites pointing to slowed metabolism. The 3D model of hVW-MSCs exhibits stemness, dormancy and slow metabolism, typically observed in stem cell niches. This culture strategy can represent an accurate model to investigate hMSCs features for future clinical applications in the vascular field

    Clinical Applications of Scanning Electron Microscopy in Gastrointestinal Diseases

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    We considered the role of scanning electron microscopy (SEM) in clinical investigation of different gastrointestinal diseases. The following clinical applications of SEM may be suggested on the basis of our original data and those reported in literature: in peptic ulcer: assessment of the completeness of healing, by observing the mucosal surface architecture of the scars; identification of mucosal changes, namely enterocytic surface membrane alterations, predictive of recurrence; in coeliac disease: early assessment of the response to gluten-free diet and follow-up of the patients by staging the process of mucosal repair in cerebriform, intermediate and villous patterns; in ulcerative and Crohn\u27s colitis: enhancement of the diagnostic sensitivity of perendoscopic biopsy, by detecting differences in surface structure of mucosa surrounding ulcers in both diseases. This is subverted in ulcerative colitis and preserved in Crohn\u27s colitis. Finally the complementary role of SEM in relation to endoscopy and light microscopy is emphasized

    Place branding: Are we wasting our time? Report of an AMA special session

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    © Emerald Group Publishing Limited.Purpose – The purpose of this paper is to report on a special session entitled “Place branding: Are we wasting our time?”, held at the American Marketing Association’s Summer Marketing Educators’ conference in 2014. Design/methodology/approach – The report details the outcome of an Oxford-style debate with two opposing teams of two persons – one team supporting and one team opposing the motion. The opening speaker of each team had 10 minutes to put their case across, and the closing speaker had 8 minutes. Teams took to the stand alternately, matching up against each other’s arguments. Findings – The outcome of the debate points towards a need for place brands to develop as more inclusive and organic entities, in which case it may be best for place practitioners to avoid creating and imposing a place brand and instead help shape it from the views of stakeholder constituencies. This shifts the notion of place branding towards an activity centred on “curation”. Originality/value – The use of a competitive debating format as a means for exploring academic ideas and concepts in the place management field
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