47 research outputs found

    Isotope Shift Measurements of Stable and Short-Lived Lithium Isotopes for Nuclear Charge Radii Determination

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    Changes in the mean-square nuclear charge radii along the lithium isotopic chain were determined using a combination of precise isotope shift measurements and theoretical atomic structure calculations. Nuclear charge radii of light elements are of high interest due to the appearance of the nuclear halo phenomenon in this region of the nuclear chart. During the past years we have developed a new laser spectroscopic approach to determine the charge radii of lithium isotopes which combines high sensitivity, speed, and accuracy to measure the extremely small field shift of an 8 ms lifetime isotope with production rates on the order of only 10,000 atoms/s. The method was applied to all bound isotopes of lithium including the two-neutron halo isotope Li-11 at the on-line isotope separators at GSI, Darmstadt, Germany and at TRIUMF, Vancouver, Canada. We describe the laser spectroscopic method in detail, present updated and improved values from theory and experiment, and discuss the results.Comment: 34 pages, 24 figures, 14 table

    The structure of mercantile communities in the Roman world : how open were Roman trade networks?

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    Liver-FibroSTARD checklist and glossary: tools for standardized design and reporting of diagnostic accuracy studies of liver fibrosis tests

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    Chronic liver diseases are highly prevalent and require an accurate evaluation of liver fibrosis to determine patient management. Many efforts have been made over this last decade to develop accurate non-invasive tools for liver fibrosis evaluation as alternative methods to liver biopsy. These non-invasive methods of liver fibrosis assessment including blood markers and liver stiffness measurement by elastography are increasingly well validated and contribute to safer and more practical clinical care for patients [1, 2]. These efforts have led to a dramatic increase in the number of diagnostic accuracy studies of liver fibrosis tests and to a proliferation of reports whose quality is very heterogeneous. [...

    An extension of STARD statements for reporting diagnostic accuracy studies on liver fibrosis tests: the Liver-FibroSTARD standards

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    BACKGROUND & AIMS: Chronic liver diseases are highly prevalent and require an accurate evaluation of liver fibrosis to determine patient management. Over the last decade, great effort has been made to develop non-invasive liver fibrosis tests. The ensuing increase of literature is, however, impaired by extensive heterogeneity in the quality of published reports. The Standards for Reporting of Diagnostic Accuracy Studies (STARD), first published in 2003, were developed to improve the quality of research reports on diagnostic studies. We aimed to evaluate STARD statements in the setting of diagnostic studies on non-invasive liver fibrosis tests, and to propose an extended version developed specifically for those studies. METHODS: Eight French experts evaluated STARD statement adequacy in 10 studies on non-invasive liver fibrosis tests and then developed an extended version with a glossary. The new checklist and glossary were independently evaluated by seven international experts. RESULTS: Fourteen of the 25 STARD items were considered only partially adequate for the evaluation of diagnostic studies on non-invasive liver fibrosis tests. Inter-expert agreement was at least very good for 8 STARD items (32%), moderate for 9 (36%), and poor or very poor for 8 (32%). The experts\u27 proposals were developed into the new Liver-FibroSTARD standards including a checklist with 62 items/sub-items and a corresponding comprehensive glossary. New proposals were inserted in the 25 STARD items as a complementary module. Independent evaluation of the Liver-FibroSTARD checklist showed at least very good inter-expert agreement for 39 items/sub-items (63%), moderate agreement for 11 (18%), and poor or very poor agreement for only 12 (19%). CONCLUSIONS: As a supplement of the STARD statements, the Liver-FibroSTARD checklist and its glossary are new tools specifically designed for the evaluation of diagnostic studies about non-invasive liver fibrosis tests

    New Image Similarity Measure for Bronchoscope Tracking Based on Image Registration

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    A Real-Time Deformable Model for Flexible Instruments Inserted into Tubular Structures

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