8 research outputs found

    Configuration-interaction calculations of PsH and e(+)Be

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    The configuration-interaction (CI) method is applied to the study of the positronium-hydride (PsH) and positronic-beryllium (e+Be) systems. The binding energy and other properties are slowly convergent with respect to the angular momentum of the orbitals used to construct the CI basis states. The largest calculations recover 94% and 80% of the binding energy against dissociation when compared with existing calculations of PsH and e+ Be. Extrapolating using Cl convergence trends improves these results to 99% and 98%, respectively. Convergence is not so good for the electron-positron annihilation rates, but the extrapolated annihilation rates were within 10% of the best calculations. Two different schemes have been used to construct the CI basis, and it is found that it is possible to discard roughly half the CI basis with almost no degradation in the binding energy and the annihilation rate. These investigations demonstrate the feasibility of using single particle orbitals centred on the nucleus to represent positronic systems with two valence electrons

    Configuration-interaction calculations of positron binding to group-II elements

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    The configuration-interaction (CI) method is applied to the study of positronic magnesium (e+Mg), positronic calcium (e+Ca), and positronic strontium (e+Sr). The CI expansion was seen to converge slowly with respect to Lmax, the maximum angular momentum of any orbital used to construct the CI basis. Despite doing explicit calculations with Lmax=10, extrapolation corrections to the binding energies for the Lmax→∞ limit were substantial in the case of e+Ca (25%) and e+Sr (50%). The extrapolated binding energies were 0.0162 hartree for e+Mg, 0.0165 hartree for e+Ca, and 0.0101 hartree for e+Sr. The static-dipole polarizabilities for the neutral parent atoms were computed as a by-product, giving 71.7a03, 162a03, and 204a03 for Mg, Ca, and Sr, respectively

    Configuration-interaction calculations of positron binding to zinc and cadmium

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    The configuration-interaction method is applied to the study of positronic zinc (e+Zn) and positronic cadmium (e+Cd). The estimated binding energies and annihilation rates were 0.00373 hartree and 0.42×109 sec-1 for e+Zn and 0.006 10 hartree and 0.56×109 sec-1 for e+Cd. The low-energy elastic cross section and Zeff were estimated from a model potential that was tuned to the binding energies and annihilation rates. Since the scattering lengths were positive (14.5a0 for Zn and 11.6a0 for Cd) the differential cross sections are larger at backward angles than at forward angles just above threshold. The possibilities of measuring differential cross sections to confirm positron binding to these atoms is discussed

    First clinical results of a personalized immunotherapeutic vaccine against recurrent, incompletely resected, treatment-resistant glioblastoma multiforme (GBM) tumors, based on combined all- and auto-immune tumor reactivity

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    Glioblastoma multiforme (GBM) patients have a poor prognosis. After tumor recurrence statistics suggestan imminent death within 1–4.5 months. Supportive preclinical data, from a rat model, provided therational for a prototype clinical vaccine preparation, named Gliovac (or ERC 1671) composed of autologousantigens, derived from the patient’s surgically removed tumor tissue, which is administered together withallogeneic antigens from glioma tissue resected from other GBM patients. We now report the first resultsof the Gliovac treatment for treatment-resistant GBM patients.Nine (9) recurrent GBM patients, after standard of care treatment, including surgery radio- andchemotherapy temozolomide, and for US patients, also bevacizumab (AvastinTM), were treated under acompassionate use/hospital exemption protocol. Gliovac was given intradermally, together with humanGM-CSF (Leukine®), and preceded by a regimen of regulatory T cell-depleting, low-dose cyclophos-phamide.Gliovac administration in patients that have failed standard of care therapies showed minimal toxicityand enhanced overall survival (OS). Six-month (26 weeks) survival for the nine Gliovac patients was 100%versus 33% in control group. At week 40, the published overall survival was 10% if recurrent, reoperatedpatients were not treated. In the Gliovac treated group, the survival at 40 weeks was 77%. Our datasuggest that Gliovac has low toxicity and a promising efficacy. A phase II trial has recently been initiatedin recurrent, bevacizumab naïve GBM patients (NCT01903330)
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