926 research outputs found

    Der Einfluß von Hybridenwein im Vergleich mit dem Wein aus Europäerreben auf den Fettgehalt der Rattenleber bei länger dauernder Verabreichung

    Get PDF
    Die Verträglichkeit eines Hyibridenweines und eines Weines von europäischen Edelreben wurde bei Wistar-Ratten verglichen. Beide Weine wurden längere Zeit an gesunde und lebergeschädigte Tiere verabreicht. Als Kontrollösung diente ein Alkoholgemisch, das den Weinen entsprach.Bei 4monatiger Verabreichung an gesunde Ratten lösten hohe Weingaben eine Zunahme des Gesamt-Lipid-Gehaltes und eine Änderung der Feinstruktur der Leber aus. Die Entwicklung des Körpergewichtes war gehemmt. Bei Ratten mit experimenteller Leberverfettung verstärkten die Weine die Vorschädigung.In beiden Versuchsreihen fehlten sichere Hinweise auf einen Unterschied zwischen Hybriden- und Edelwein. Dagegen unterschied das Alkoholgemisch sich qualitativ und quantitativ in mehreren Prüfungskriterien von den Weinen

    Von Meyenburg Complex or Liver Metastasis? Case Report and Literature Review

    Get PDF
    Hepatic lesions represent a common finding in clinical practice. Bile ducts hamartomas, also known as Von Meyenburg complex, are benign hepatic malformations composed of small dilated cystic bile ducts lined by fibrous stroma. They represent a rare and asymptomatic clinic-pathological entity. Imagiological findings are variable, and may present as multiple small scattered lesions, or rarely as a single nodule. These findings may resemble secondary lesions and, although benign, there are cases of progression to colangiocarcinoma. Thus it is important to include this complex in the differential diagnoses of focal hepatic lesions, being necessary a detailed investigation for their differentiation. This case represents an atypical presentation of a rare and not frequently considered entity in clinical practic

    The problems associated with the monitoring of complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities

    Get PDF
    The European Commission is funding within its Sixth Framework Programme a three-year project (2005-2007) called CONRAD, COordinated Network for RAdiation Dosimetry. The organisational framework for this project is provided by the European Radiation Dosimetry Group EURADOS. One task within the CONRAD project, Work Package 6 (WP6), was to provide a report outlining research needs and research activities within Europe to develop new and improved methods and techniques for the characterisation of complex radiation fields at workplaces around high-energy accelerators, but also at the next generation of thermonuclear fusion facilities. The paper provides an overview of the report, which will be available as CERN Yellow Repor

    Science verification of the new FlashCam-based camera in the 28m telescope of H.E.S.S

    Get PDF
    In October 2019 the central 28m telescope of the H.E.S.S. experiment has beenupgraded with a new camera. The camera is based on the FlashCam design whichhas been developed in view of a possible future implementation in themedium-sized telescopes of the Cherenkov Telescope Array (CTA). We report hereon the results of the science verification program that has been performedafter commissioning of the new camera, to show that the camera and softwarepipelines are working up to expectations.<br

    Momentum and Energy Distributions of Nucleons in Finite Nuclei due to Short-Range Correlations

    Full text link
    The influence of short-range correlations on the momentum and energy distribution of nucleons in nuclei is evaluated assuming a realistic meson-exchange potential for the nucleon-nucleon interaction. Using the Green-function approach the calculations are performed directly for the finite nucleus 16^{16}O avoiding the local density approximation and its reference to studies of infinite nuclear matter. The nucleon-nucleon correlations induced by the short-range and tensor components of the interaction yield an enhancement of the momentum distribution at high momenta as compared to the Hartree-Fock description. These high-momentum components should be observed mainly in nucleon knockout reactions like (e,e′p)(e,e'p) leaving the final nucleus in a state of high excitation energy. Our analysis also demonstrates that non-negligible contributions to the momentum distribution should be found in partial waves which are unoccupied in the simple shell-model. The treatment of correlations beyond the Brueckner-Hartree-Fock approximation also yields an improvement for the calculated ground-state properties.Comment: 12 pages RevTeX, 7 figures postscript files appende

    High-Efficiency Resonant RF Spin Rotator with Broad Phase Space Acceptance for Pulsed Polarized Cold Neutron Beams

    Get PDF
    We have developed a radio-frequency resonant spin rotator to reverse the neutron polarization in a 9.5 cm x 9.5 cm pulsed cold neutron beam with high efficiency over a broad cold neutron energy range. The effect of the spin reversal by the rotator on the neutron beam phase space is compared qualitatively to RF neutron spin flippers based on adiabatic fast passage. The spin rotator does not change the kinetic energy of the neutrons and leaves the neutron beam phase space unchanged to high precision. We discuss the design of the spin rotator and describe two types of transmission-based neutron spin-flip efficiency measurements where the neutron beam was both polarized and analyzed by optically-polarized 3He neutron spin filters. The efficiency of the spin rotator was measured to be 98.0+/-0.8% on resonance for neutron energies from 3.3 to 18.4 meV over the full phase space of the beam. As an example of the application of this device to an experiment we describe the integration of the RF spin rotator into an apparatus to search for the small parity-violating asymmetry A_gamma in polarized cold neutron capture on para-hydrogen by the NPDGamma collaboration at LANSCE

    Effects of Short-Range Correlations in (e,e'p) reactions and nuclear overlap functions

    Full text link
    A study of the effects of short-range correlations over the (e,e'p) reaction for low missing energy in closed shell nuclei is presented. We use correlated, quasi-hole overlap functions extracted from the asymptotic behavior of the one-body density matrix, containing central correlations of Jastrow type, up to first-order in a cluster expansion, and computed in the very high asymptotic region, up to 100 fm. The method to extract the overlap functions is checked in a simple shell model, where the exact results are known. We find that the single-particle wave functions of the valence shells are shifted to the right due to the short-range repulsion by the nuclear core. The corresponding spectroscopic factors are reduced only a few percent with respect to the shell model. However, the (e,e'p) response functions and cross sections are enhanced in the region of the maximum of the missing momentum distribution due to short-range correlations.Comment: 45 pages, 15 figure
    • …
    corecore