234 research outputs found

    Fluorimetric methods for the measurement of intermediate metabolites (lactate, pyruvate, alanine, ÎČ-hydroxybutyrate, glycerol) using a COBAS FARA centrifugal analyser

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    Intermediate products of the metabolism of glucose, fat and amino-acid are important in the evaluation of such metabolic disorders as diabetes mellitus, liver disease and metabolic acidosis. In the present study, methods for the measurement of intermediate metabolites (lactate, pyruvate, alanine, ÎČ-hydroxybutyrate and glycerol) have been adapted to a fast centrifugal analyzer: the COBAS FARA. Correlation coeffcients rangedfrom 0.90 to 0.99, compared to established manual spectrophotometric methods. Within-run coeffcients of variation (CVs) ranged between 2.9 and 8.8% at low levels, between 1.5 and 5.7% at medium levels and between 1.2 and 5.6% at high levels. Between-run CVs were between 4.0 and 15.0% at low levels, between 1.7 and 7.0% at medium levels and between 1.3 and 2.7% at high levels. These fluorimetric assays for the determination of intermediate metabolites on COBAS FARA (Roche) have a good sensitivity and precision, are less costly than manual methods and can be used on a routine basis

    Collective Dipole Bremsstrahlung in Fusion Reactions

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    We estimate the dipole radiation emitted in fusion processes. We show that a classical bremsstrahlung approach can account for both the preequilibrium and the thermal photon emission. We give an absolute evaluation of the pre-equilibrium component due to the charge asymmetry in the entrance channel and we study the energy and mass dependence in order to optimize the observation. This dynamical dipole radiation could be a relevant cooling mechanism in the fusion path. We stress the interest in experiments with the new available radioactive beams.Comment: 4 pages (LATEX), 4 Postscript figures, minor text modification

    The Dynamical Dipole Mode in Dissipative Heavy Ion Collisions

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    We study the effect of a direct Giant Dipole Resonance (GDRGDR) excitation in intermediate dinuclear systems with exotic shape and charge distributions formed in charge asymmetric fusion entrance channels. A related enhancement of the GDRGDR gamma yield in the evaporation cascade of the fused nucleus is expected. The dynamical origin of such GDRGDR extra strength will show up in a characteristic anisotropy of the dipole gamma-emission. A fully microscopic analysis of the fusion dynamics is performed with quantitative predictions of the GDRGDR photon yield based on a dynamics- statistics coupling model. In particular we focus our attention on the energy and mass dependence of the effect. We suggest a series of new experiments, in particular some optimal entrance channel conditions. We stress the importance of using the new available radioactive beams.Comment: 20 pages (Latex), 14 Postscript figure

    Prompt dipole radiation in fusion reactions

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    The prompt gamma ray emission was investigated in the 16A MeV energy region by means of the 36,40Ar+96,92Zr fusion reactions leading to a compound nucleus in the vicinity of 132Ce. We show that the prompt radiation, which appears to be still effective at such a high beam energy, has an angular distribution pattern consistent with a dipole oscillation along the symmetry axis of the dinuclear system. The data are compared with calculations based on a collective bremsstrahlung analysis of the reaction dynamics

    Probing the 6He halo structure with elastic and inelastic proton scattering

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    Proton elastic scattering and inelastic scattering to the first excited state of 6He have been measured over a wide angular range using a 40.9A MeV 6He beam. The data have been analyzed with a fully microscopic model of proton-nucleus scattering using 6He wave functions generated from large space shell model calculations. The inelastic scattering data show a remarkable sensitivity to the halo structure of 6He.Comment: 9 pages, 3 figures. RevTeX. Replaced figure 3 with updated figur

    PRISMA - a magnetic spectrometer for heavy ions at LNL

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    Abstract The heavy-ion magnetic spectrometer PRISMA was recently installed at Laboratori Naz. di Legnaro, in order to exploit the heavy-ion beams of the XTU Tandem-ALPI-PIAVE accelerator complex, with masses up to A≃200 at energies ≃5-10 MeV MeV A

    Evidence of dynamical dipole excitation in the fusion-evaporation of the 40Ca +152Sm heavy system

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    The excitation of the dynamical dipole mode along the fusion path was investigated for the first time in the formation of a heavy compound nucleus in the A ∌ 190 mass region. The compound nucleus was formed at identical conditions of excitation energy and spin from two entrance channels: the charge-asymmetric 40 Ca + 152 Sm and the nearly charge-symmetric 48 Ca + 144 Sm at E lab = 11 and 10.1 MeV / nucleon, respectively. High-energy Îł rays and light charged particles were measured in coincidence with evaporation residues by means of the MEDEA multidetector array (Laboratori Nazionali del Sud, Italy) coupled to four parallel plate avalanche counters. The charged particle multiplicity spectra and angular distributions were used to pin down the average excitation energy, the average mass, and the average charge of the compound nucleus. The Îł -ray multiplicity spectrum and angular distribution related to the nearly charge-symmetric channel were employed to obtain new data on the giant dipole resonance in the compound nucleus. The dynamical dipole mode excitation in the charge-asymmetric channel was evidenced, in a model-independent way, by comparing the Îł -ray multiplicity spectra and angular distributions of the two entrance channels with each other. Calculations of the dynamical dipole mode in the 40 Ca + 152 Sm channel, based on a collective bremsstrahlung analysis of the reaction dynamics, are presented. Possible interesting implications in the superheavy-element quest are discussed

    Compilation of Giant Electric Dipole Resonances Built on Excited States

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    Giant Electric Dipole Resonance (GDR) parameters for gamma decay to excited states with finite spin and temperature are compiled. Over 100 original works have been reviewed and from some 70 of which more than 300 parameter sets of hot GDR parameters for different isotopes, excitation energies, and spin regions have been extracted. All parameter sets have been brought onto a common footing by calculating the equivalent Lorentzian parameters. The current compilation is complementary to an earlier compilation by Samuel S. Dietrich and Barry L. Berman (At. Data Nucl. Data Tables 38(1988)199-338) on ground-state photo-neutron and photo-absorption cross sections and their Lorentzian parameters. A comparison of the two may help shed light on the evolution of GDR parameters with temperature and spin. The present compilation is current as of January 2006.Comment: 31 pages including 1 tabl

    The Magnetic Spectrometer Prisma at Lnl

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    The magnetic spectrometer PRISMA [1,2,3] has been recently installed at LNL. It has been designed to be used with heavy-ion beams accelerated at energies up to E = 5-10 AMeV by means of the Tandem-ALPI accelerator complex of the Laboratori Nazionali di Legnaro. The next operation of the new superconductive injector PIAVE and its coupling with the ALPI Linac will allow to extend the nuclear physics studies in the A=100-200 mass region. Moreover, PRISMA i

    Transfer vs. Breakup in the interaction of the 7Be Radioactive Ion Beam with a 58Ni target at Coulomb barrier energies

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    We measured for the first time 7Be elastically scattered nuclei as well as 3,4He reaction products from a 58Ni target at 22.3 MeV beam energy. The data were analyzed within the optical model formalism to extract the total reaction cross section. Extensive kinematical, Distorted Wave Born Approximation (DWBA)and Continuum Discretized Coupled Channel (CDCC) calculations were performed to investigate the 3,4He originating mechanisms and the interplay between different reaction channels
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