A. Di Leva

A new silybin-vitamin E-phospholipid complex improves insulin resistance and liver damage in patients with non-alcoholic fatty liver disease: preliminary observations

Non-alcoholic fatty liver disease (NAFLD) may occur as an expression of a metabolic syndrome or in association with hepatitis C virus (HCV) chronic infection. The contemporaneous presence of NAFLD in this later group of patients may negatively affect the progression of fibrosis and the response to antiviral treatment.1,2 It has been suggested that in the future a therapeutic approach to chronic liver disease would consist of a number of complementary approaches considering the multitude of pathogenic mechanisms.3 Silybin is a natural flavonoid that has been conjugated to vitamin E and phospholipids to improve its bioavailability, and antioxidant and antifibrotic activity.4 After approval of the ethics committee and informed consent, 85 outpatients were consecutively enrolled in the study: 59 were affected by primitive NAFLD (group A) …

First direct measurement of the total cross-section of 12C(α,γ)16O

Abstract.The total cross-section of 12C(α,γ)16O was measured for the first time by a direct and ungated detection of the 16O recoils. This measurement in inverse kinematics using the recoil mass separator ERNA in combination with a windowless He gas target allowed to collect data with high precision in the energy range E = 1.9 to 4.9 MeV. The data represent new information for the determination of the astrophysical S(E) factor.The total cross-section of 12C(α,γ)16O was measured for the first time by a direct and ungated detection of the 16O recoils. This measurement in inverse kinematics using the recoil mass separator ERNA in combination with a windowless He gas target allowed to collect data with high precision in the energy range E = 1.9 to 4.9 MeV. The data represent new information for the determination of the astrophysical S(E) factor.

First direct measurement of the total cross section of 12C(alpha,gamma)16O

Abstract.The total cross-section of 12C(α,γ)16O was measured for the first time by a direct and ungated detection of the 16O recoils. This measurement in inverse kinematics using the recoil mass separator ERNA in combination with a windowless He gas target allowed to collect data with high precision in the energy range E = 1.9 to 4.9 MeV. The data represent new information for the determination of the astrophysical S(E) factor.The total cross-section of 12C(α,γ)16O was measured for the first time by a direct and ungated detection of the 16O recoils. This measurement in inverse kinematics using the recoil mass separator ERNA in combination with a windowless He gas target allowed to collect data with high precision in the energy range E = 1.9 to 4.9 MeV. The data represent new information for the determination of the astrophysical S(E) factor.

Serum eosinophil cationic protein (ECP) as a marker of disease activity and treatment efficacy in seasonal asthma

This study was carried out to determine whether serum cosinophil cationic protein (ECP) represents a sensitive marker for disease activity in atopic asthmatic patients during the pollen season. The study. in double‐blind fashion, was performed between February and June 1994. Two groups of 10 seasonal asthmatic patients randomly received two different treatments. The first group was treated with inhaled beclomethasone dipropionate (BDP) 500 kg bid; the second received a matched placebo (P). At the beginning and every month, blood samples for determination of ECP and eosinophil count were collected and lung function (FEV1) and methacholine responsiveness (PD20) were performed. Subjects recorded daily symptoms of asthma, salbutamol consumption, and peak expiratory flow (PEF) values. In the P group, all indices, except FEV1, showed significant changes during the pollen season (P< 0.001). In the BDP group, significant changes were detected for symptom score (P<0.01). salbutamol consumption (P<0.01), and eosinophil number (P<0.05). Between the two groups, significant differences for symptom score (P<0.001), salbutamol consumption (P< 0.001), ECP levels (P<0.05), eosinophil count (P<0.02), PD20 methacholine (P<0.02), and PEF values (P<0.01) were detected. Changes in serum ECP significantly correlated with changes in other parameters (P< 0.001), except FEV1. Our results provide evidence that serum ECP is a sensitive marker for monitoring of the disease activity in seasonal asthma. Furthermore, it may offer a useful tool for estimating treatment efficacy.

Electron screening in d(d, p)t for deuterated metals: temperature effects

The electron screening in the d(d, p)t reaction has been studied for the deuterated metal Pt at a sample temperature T = 20 °C–340 °C and for Co at T = 20 °C and 200 °C. The enhanced electron screening decreases with increasing temperature, where the data agree with the plasma model of Debye applied to the quasi-free metallic electrons. The data represent the first observation of a temperature dependence of a nuclear cross section. We also measured the screening effect for the deuterated metal Ti (an element of group 4 of the periodic table) at T = −10 °C–200 °C: above 50 °C, the hydrogen solubility dropped to values far below 1 and a large screening effect became observable. Similarly, all metals of groups 3 and 4 and the lanthanides showed a solubility of a few per cent at T = 200 °C (compared to T = 20 °C) and a large screening also became observable. Within the Debye model, the deduced number of valence electrons per metallic atom agrees with the corresponding number from the Hall coefficient, for all metals investigated.

First Direct Measurement of the 17O(p,γ)18F Reaction Cross Section at Gamow Energies for Classical Novae

Classical novae are important contributors to the abundances of key isotopes, such as the radioactive (18)F, whose observation by satellite missions could provide constraints on nucleosynthesis models in novae. The (17)O(p,γ)(18)F reaction plays a critical role in the synthesis of both oxygen and fluorine isotopes, but its reaction rate is not well determined because of the lack of experimental data at energies relevant to novae explosions. In this study, the reaction cross section has been measured directly for the first time in a wide energy range E(c.m.)~/= 200-370 keV appropriate to hydrogen burning in classical novae. In addition, the E(c.m.)=183 keV resonance strength, ωγ=1.67±0.12 μeV, has been measured with the highest precision to date. The uncertainty on the (17)O(p,γ)(18)F reaction rate has been reduced by a factor of 4, thus leading to firmer constraints on accurate models of novae nucleosynthesis.

Preparation and characterisation of isotopically enriched Ta2O5 targets for nuclear astrophysics studies

The direct measurement of reaction cross-sections at astrophysical energies often requires the use of solid targets of known thickness, isotopic composition, and stoichiometry that are able to withstand high beam currents for extended periods of time. Here, we report on the production and characterisation of isotopically enriched Ta2O5 targets for the study of proton-induced reactions at the Laboratory for Underground Nuclear Astrophysics facility of the Laboratori Nazionali del Gran Sasso. The targets were prepared by anodisation of tantalum backings in enriched water (up to 66% in 17O and up to 96% in 18O. Special care was devoted to minimising the presence of any contaminants that could induce unwanted background reactions with the beam in the energy region of astrophysical interest. Results from target characterisation measurements are reported, and the conclusions for proton capture measurements with these targets are drawn.

A new study of the 22Ne(p, γ)23Na reaction deep underground: Feasibility, setup and first observation of the 186 keV resonance

The 22Ne(p,γ)23Na reaction takes part in the neon-sodium cycle of hydrogen burning. This cycle is active in asymptotic giant branch stars as well as in novae and contributes to the nucleosythesis of neon and sodium isotopes. In order to reduce the uncertainties in the predicted nucleosynthesis yields, new experimental efforts to measure the 22Ne(p,γ)23Na cross section directly at the astrophysically relevant energies are needed. In the present work, a feasibility study for a 22Ne(p,γ)23Na experiment at the Laboratory for Underground Nuclear Astrophysics (LUNA) 400 kV accelerator deep underground in the Gran Sasso laboratory, Italy, is reported. The ion-beam-induced γ-ray background has been studied. The feasibility study led to the first observation of the Ep=186 keV resonance in a direct experiment. An experimental lower limit of 0.12 × 10−6 eV has been obtained for the resonance strength. Informed by the feasibility study, a dedicated experimental setup for the 22Ne(p,γ)23Na experiment has been developed. The new setup has been characterized by a study of the temperature and pressure profiles. The beam heating effect that reduces the effective neon gas density due to the heating by the incident proton beam has been studied using the resonance scan technique, and the size of this effect has been determined for a neon gas target.

Improved Direct Measurement of the 64.5 keV Resonance Strength in the O 17 (p,α) N 14 Reaction at LUNA

The ^{17}O(p,α)^{14}N reaction plays a key role in various astrophysical scenarios, from asymptotic giant branch stars to classical novae. It affects the synthesis of rare isotopes such as ^{17}O and ^{18}F, which can provide constraints on astrophysical models. A new direct determination of the E_{R}=64.5  keV resonance strength performed at the Laboratory for Underground Nuclear Astrophysics (LUNA) accelerator has led to the most accurate value to date ωγ=10.0±1.4_{stat}±0.7_{syst}  neV, thanks to a significant background reduction underground and generally improved experimental conditions. The (bare) proton partial width of the corresponding state at E_{x}=5672  keV in ^{18}F is Γ_{p}=35±5_{stat}±3_{syst}  neV. This width is about a factor of 2 higher than previously estimated, thus leading to a factor of 2 increase in the ^{17}O(p, α)^{14}N reaction rate at astrophysical temperatures relevant to shell hydrogen burning in red giant and asymptotic giant branch stars. The new rate implies lower ^{17}O/^{16}O ratios, with important implications on the interpretation of astrophysical observables from these stars.

22Ne and 23Na ejecta from intermediate-mass stars: the impact of the new LUNA rate for 22Ne(p,γ)23Na

We investigate the impact of the new LUNA rate for the nuclear reaction