314 research outputs found

    The evidence base for oxygen for chronic refractory breathlessness: issues, gaps, and a future work plan

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    Breathlessness or “shortness of breath”, medically termed dyspnoea, remains a devastating problem for many people and those who care for them. As a treatment intervention, administration of opioids to relieve breathlessness is an area where progress has been made with the development of an evidence base. As evidence in support of opioids has accumulated, so has our collective understanding about trial methodology, research collaboration and infrastructure that is crucial to generate reliable research results for palliative care clinical settings. Analysis of achievements to date and what it takes to accomplish these studies provides important insights into knowledge gaps needing further research as well as practical insight into design of pharmacological and non-pharmacological intervention trials in breathlessness and palliative care. This paper presents current understanding of opioids for treating breathlessness, what is still unknown as priorities for future research and highlights methodological issues for consideration in planned studies.This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors

    Different formulations of 3He and 3H photodisintegration

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    Different momentum space Faddeev-like equations and their solutions for the radiative pd-capture and the three-nucleon photodisintegration of 3He are presented. Applications are based on the AV18 nucleon-nucleon and the Urbana IX three nucleon forces. Meson exchange currents are included using the Siegert theorem. A very good agreement has been found in all cases indicating the reliability of the used numerical methods. Predictions for cross sections and polarization observables in the pd-capture and the complete three nucleon breakup of 3He at different incoming deuteron/photon energies are presented.Comment: 18 pages, 9 ps figure

    Proton Radiative Capture by Deuterium at Medium Energies

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    This work was supported by the National Science Foundation Grant NSF PHY 81-14339 and by Indiana Universit

    Observation of the Charge Symmetry Breaking d + d -> 4He + pi0 Reaction Near Threshold

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    We report the first observation of the charge symmetry breaking d + d -> 4He + pi0 reaction near threshold at the Indiana University Cyclotron Facility. Kinematic reconstruction permitted the separation of 4He + pi0 events from double radiative capture 4He + gamma + gamma events. We measured total cross sections for neutron pion production of 12.7 +- 2.2 pb at 228.5 MeV and 15.1 +- 3.1 pb at 231.8 MeV. The uncertainty is dominated by statistical errors.Comment: 7 pages, 2 figures, plain Te

    Cross section and analyzing power of pol{p}p -> pn pi+ near threshold

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    The cross section and analyzing power of the pol{p}p -> pn pi+ reaction near threshold are estimated in terms of data obtained from the pol{p}p -> d pi+ and pp -> pp pi0 reactions. A simple final state interaction theory is developed which depends weakly upon the form of the pion-production operator and includes some Coulomb corrections. Within the uncertainties of the model and the input data, the approach reproduces well the measured energy dependence of the total cross section and the proton analyzing power at a fixed pion c.m. angle of 90deg, from threshold to T_p = 330 MeV. The variation of the differential cross section with pion angle is also very encouraging.Comment: 20 pages, Latex including 4 eps figure

    Isoscalar off-shell effects in threshold pion production from pd collisions

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    We test the presence of pion-nucleon isoscalar off-shell effects in the pd→π+tpd\to \pi^+ t reaction around the threshold region. We find that these effects significantly modify the production cross section and that they may provide the missing strength needed to reproduce the data at threshold.Comment: 6 pages, REVTeX, twocolumn, including 3 figures (Postscript), uses psfig, updated and extended versio
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