405 research outputs found

    Prevalence of drug-herb and drug-supplement interactions in older adults : A cross-sectional survey

    Get PDF
    © British Journal of General PracticeBackground Polypharmacy is common among older adults, with increasing numbers also using prescription drugs with herbal medicinal products (HMPs) and dietary supplements. There is no reliable evidence from the UK on concurrent use of HMPs and dietary supplements with prescription drugs in older adults. Aim To establish prevalence of concurrent prescription drugs, HMPs, and dietary supplements among UK community-dwelling older adults and identify potential interactions. Design and setting Cross-sectional survey of older adults registered at two general practices in South East England. Method A questionnaire asking about prescription medications, HMPs, and sociodemographic information was posted to 400 older adults aged ≥65 years, identified as taking ≥1 prescription drug. Results In total 155 questionnaires were returned (response rate = 38.8%) and the prevalence of concurrent HMPs and dietary supplements with prescriptions was 33.6%. Females were more likely than males to be concurrent users (43.4% versus 22.5%; P = 0.009). The number of HMPs and dietary supplements ranged from 1 to 8, (mean = 3, median = 1; standard deviation = 1.65). The majority of concurrent users (78.0%) used dietary supplements with prescription drugs. The most commonly used dietary supplements were cod liver oil, glucosamine, multivitamins, and Vitamin D. Others (20.0%) used only HMPs with prescription drugs. Common HMPs were evening primrose oil, valerian, and Nytol Herbal® (a combination of hops, gentian, and passion flower). Sixteen participants (32.6%) were at risk of potential adverse drug interactions. Conclusion GPs should routinely ask questions regarding herbal and supplement use, to identify and manage older adults at potential risk of adverse drug interactions.Peer reviewe

    Evidence for a change in the nuclear mass surface with the discovery of the most neutron-rich nuclei with 17<Z <25

    Full text link
    The results of measurements of the production of neutron-rich nuclei by the fragmentation of a 76-Ge beam are presented. The cross sections were measured for a large range of nuclei including fifteen new isotopes that are the most neutron-rich nuclides of the elements chlorine to manganese (50-Cl, 53-Ar, 55,56-K, 57,58-Ca, 59,60,61-Sc, 62,63-Ti, 65,66-V, 68-Cr, 70-Mn). The enhanced cross sections of several new nuclei relative to a simple thermal evaporation framework, previously shown to describe similar production cross sections, indicates that nuclei in the region around 62-Ti might be more stable than predicted by current mass models and could be an indication of a new island of inversion similar to that centered on 31-Na.Comment: 4 pages, 3 figures, to be published in Physical Review Letters, 200

    Production cross sections from 82Se fragmentation as indications of shell effects in neutron-rich isotopes close to the drip-line

    Get PDF
    Production cross sections for neutron-rich nuclei from the fragmentation of a 82Se beam at 139 MeV/u were measured. The longitudinal momentum distributions of 126 neutron-rich isotopes of elements 11 <= Z <= 32 were scanned using an experimental approach of varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including several isotopes first observed in this work. These are the most neutron-rich nuclides of the elements 22 <= Z <= 25 (64Ti, 67V, 69Cr, 72Mn). One event was registered consistent with 70Cr, and another one with 75Fe. The production cross sections are correlated with Qg systematics to reveal trends in the data. The results presented here confirm our previous result from a similar measurement using a 76Ge beam, and can be explained with a shell model that predicts a subshell closure at N = 34 around Z = 20. This is demonstrated by systematic trends and calculations with the Abrasion-Ablation model that are sensitive to separation energies.Comment: 13 pages, 11 figures, accepted to Phys.Rev.

    Production cross sections of neutron rich isotopes from a 82Se beam

    Full text link
    Production cross sections for neutron-rich nuclei from the fragmentation of a 82Se beam at 139 MeV/u were measured. The longitudinal momentum distributions of 122 neutron-rich isotopes of elements 11Z3211 \le Z \le 32 were determined by varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including several isotopes first observed in this work. These are the most neutron-rich nuclides of the elements 22Z2522 \le Z \le 25 (64Ti, 67V, 69Cr, 72Mn). One event was registered consistent with 70Cr, and another one with 75Fe. A one-body Qg systematics is used to describe the production cross sections based on thermal evaporation from excited prefragments. The current results confirm those of our previous experiment with a 76Ge beam: enhanced production cross sections for neutron-rich fragments near Z=20.Comment: Talk given at the 11th International Conference on Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1, 2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference Series (JPCS

    Beta-decay of nuclei around Se-90. Search for signatures of a N=56 sub-shell closure relevant the r-process

    Full text link
    Nuclear structure plays a significant role on the rapid neutron capture process (r-process) since shapes evolve with the emergence of shells and sub-shells. There was some indication in neighboring nuclei that we might find examples of a new N=56 sub-shell, which may give rise to a doubly magic Se-90 nucleus. Beta-decay half lives of nuclei around Se-90 have been measured to determine if this nucleus has in fact a doubly-magic character. The fragmentation of Xe-136 beam at the National Superconducting Cyclotron Laboratory at Michigan State University was used to create a cocktail of nuclei in the A=90 region. We have measured the half lives of twenty-two nuclei near the r-process path in the A=90 region. The half lives of As-88 and Se-90 have been measured for the first time. The values were compared with theoretical predictions in the search for nuclear-deformation signatures of a N=56 sub-shell, and its possible role in the emergence of a potential doubly-magic Se-90. The impact of such hypothesis on the synthesis of heavy nuclei, particularly in the production of Sr, Y and Zr elements was investigated with a weak r-process network. The new half lives agree with results obtained from a standard global QRPA model used in r-process calculations, indicating that Se-90 has a quadrupole shape incompatible with a closed N=56 sub-shell in this region. The impact of the measured Se-90 half-life in comparison with a former theoretical predication associated with a spherical half-life on the weak-r-process is shown to be strong

    Shape and structure of N=Z 64Ge; Electromagnetic transition rates from the application of the Recoil Distance Method to knock-out reaction

    Get PDF
    Transition rate measurements are reported for the first and the second 2+ states in N=Z 64Ge. The experimental results are in excellent agreement with large-scale Shell Model calculations applying the recently developed GXPF1A interactions. Theoretical analysis suggests that 64Ge is a collective gamma-soft anharmonic vibrator. The measurement was done using the Recoil Distance Method (RDM) and a unique combination of state-of-the-art instruments at the National Superconducting Cyclotron Laboratory (NSCL). States of interest were populated via an intermediate-energy single-neutron knock-out reaction. RDM studies of knock-out and fragmentation reaction products hold the promise of reaching far from stability and providing lifetime information for excited states in a wide range of nuclei

    Observation of isotonic symmetry for enhanced quadrupole collectivity in neutron-rich 62,64,66Fe isotopes at N=40

    Full text link
    The transition rates for the 2_{1}^{+} states in 62,64,66Fe were studied using the Recoil Distance Doppler-Shift technique applied to projectile Coulomb excitation reactions. The deduced E2 strengths illustrate the enhanced collectivity of the neutron-rich Fe isotopes up to N=40. The results are interpreted by the generalized concept of valence proton symmetry which describes the evolution of nuclear structure around N=40 as governed by the number of valence protons with respect to Z~30. The deformation suggested by the experimental data is reproduced by state-of-the-art shell calculations with a new effective interaction developed for the fpgd valence space.Comment: 4 pages, 2 figure

    Cross Section Limits for the 208^{208}Pb(86^{86}Kr,n)293^{293}118 Reaction

    Full text link
    In April-May, 2001, the previously reported experiment to synthesize element 118 using the 208^{208}Pb(86^{86}Kr,n)293^{293}118 reaction was repeated. No events corresponding to the synthesis of element 118 were observed with a total beam dose of 2.6 x 1018^{18} ions. The simple upper limit cross sections (1 event) were 0.9 and 0.6 pb for evaporation residue magnetic rigidities of 2.00 TmT m and 2.12 TmT m, respectively. A more detailed cross section calculation, accounting for an assumed narrow excitation function, the energy loss of the beam in traversing the target and the uncertainty in the magnetic rigidity of the Z=118 recoils is also presented. Re-analysis of the primary data files from the 1999 experiment showed the reported element 118 events are not in the original data. The current results put constraints on the production cross section for synthesis of very heavy nuclei in cold fusion reactions.Comment: 7 pages, 2 figures. Submitted to EPJ
    corecore