2,407 research outputs found

    Measurements of ionization cross sections by molecular beam experiments: information content on the imaginary part of the optical potential

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    In this work, we present and analyze in detail new and recent ionization cross section and mass spectrum determinations, collected in the case of He*, Ne*-H2O, -H2S, and -NH3 ionizing collisions. These sets of data, obtained under the same experimental conditions, are relevant to identify differences in the autoionization stereodynamics of the three hydrogenated molecules and on the selective role of the imaginary part of the optical potential. We demonstrate that in these autoionization processes hydrogen and halogen bonds are competing because they are controlling both real and imaginary components of the optical potential that drives the complete reaction dynamics. In particular, we found that both components critically depend on the angular and radial approach between the reagent partners in determining the collision dynamics

    Coherent transport in extremely underdoped Nd1.2Ba1.8Cu3Oz nanostructures

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    Proximity-effect and resistance magneto-fluctuations measurements in submicron Nd1.2Ba1.8Cu3Oz (NBCO) nano-loops are reported to investigate coherent charge transport in the non-superconducting state. We find an unexpected inhibition of cooper pair transport, and a destruction of the induced superconductivity, by lowering the temperature from 6K to 250mK. This effect is accompanied by a significant change in the conductance-voltage characteristics and in the zero bias conductance response to the magnetic field pointing to the activation of a strong pair breaking mechanism at lower temperature. The data are discussed in the framework of mesoscopic effects specific to superconducting nanostructures, proximity effect and high temperature superconductivity.Comment: to appear on new journal of Physic

    Inequity in the provision of and access to palliative care for cancer patients. Results from the Italian survey of the dying of cancer (ISDOC)

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    <p>Abstract</p> <p>Background</p> <p>The palliative services and programs have been developed with different intensity and modalities in all countries. Several studies have reported that a geographic variation in the availability and provision of palliative care services between and within countries exists, and that a number of vulnerable groups are excluded from these services. This survey estimates the distribution of places of care for Italian cancer patients during the last three months of their lives, the proportion receiving palliative care support at home and in hospital, and the factors associated with the referral to palliative care services.</p> <p>Methods</p> <p>This is a mortality follow-back survey of 2,000 cancer deaths identified with a 2-stage probability sample, representative of the whole country. Information on patients' experience was gathered from the non-professional caregiver through an interview, using an adapted version of the VOICES questionnaire. A section of the interview concerned the places of care and the palliative care services provided to patients. Multivariate logistic regression analyses were conducted to identify the determinants of palliative care service use.</p> <p>Results</p> <p>Valid interviews were obtained for 67% of the identified caregivers (n = 1,271). Most Italian cancer patients were cared for at home (91%) or in hospital (63%), but with substantial differences within the country. Only 14% of Italian cancer patients cared for at home against 20% of those admitted to hospital, received palliative care support. The principal determinants identified for receiving these service were: an extended interval between diagnosis and death (P = 0.01) and the caregiver's high educational level (P = 0.01) for patients at home; the low patient's age (P < 0.01) and the caregiver's high educational level (P = 0.01) for patients in hospital.</p> <p>Conclusion</p> <p>In Italy palliative care services are not equally available across the country. Moreover, access to the palliative care services is strongly associated with socio demographic characteristics of the patients and their caregivers. Italian Policy-makers need to equalise palliative care provision and access across the country to meet the needs of all cancer patients.</p

    Little-Parks effect in single YBaCuO sub-micron rings

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    The properties of single submicron high-temperature superconductor (HTS) rings are investigated. The Little-Parks effect is observed and is accompanied by an anomalous behavior of the magnetic dependence of the resistance, which we ascribe to non-uniform vorticity (superfluid angular momentum) within the ring arms. This effect is linked to the peculiar HTS-relationship between the values of the coherence length and the London penetration depth.Comment: 14 pages, 3 figure

    Antioxidant properties of omeprazole

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    AbstractPotential antioxidant properties of therapeutically achievable concentrations of the protonated, active form of omeprazole (OM) were investigated in vitro at specific acidic pH values to mimic intragastric conditions in the clinical setting. We found that OM is a powerful scavenger of hypochlorous acid (HOCl) even at a drug concentration of 10 μM at pH of 5.3 or 3.5. This effect is also evident in the presence of the physiological HOCl scavenger ascorbate. Moreover, 10 and 50 μM OM inhibit significantly both iron-and copper-driven oxidant damage at pH 5.3 and 3.5, respectively. Since oxidative stress is involved the gastric injury of peptic ulcer and gastritis, it may be hypothesized that some therapeutical effects of OM could also be related to its antioxidant properties

    Squeezing out predictions with leptogenesis from SO(10)

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    We consider the see-saw mechanism within a non-supersymmetric SO(10) model. By assuming the SO(10) quark-lepton symmetry, and after imposing suitable conditions that ensure that the right-handed (RH) neutrino masses are at most mildly hierarchical (compact RH spectrum) we obtain a surprisingly predictive scenario. The absolute neutrino mass scale, the Dirac and the two Majorana phases of the neutrino mixing matrix remain determined in terms of the set of already measured low energy observables, modulo a discrete ambiguity in the signs of two neutrino mixing angles and of the Dirac phase. The RH neutrinos mass spectrum is also predicted, as well as the size and sign of the leptogenesis CP asymmetries. We compute the cosmological baryon asymmetry generated through leptogenesis and obtain the correct sign and a size compatible with observations.Comment: 18 pages, 2 figures; minor changes, version accepted for publication in PR
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