Shedding Light on the Origin of

Asymptotic giant branch stars are responsible for the production of most of the heavy isotopes beyond Sr observed in the solar system. Among them, isotopes shielded from the r-process contribution by their stable isobars are defined as s-only nuclei. For a long time the abundance of ^{204}Pb, the heaviest s-only isotope, has been a topic of debate because state-of-the-art stellar models appeared to systematically underestimate its solar abundance. Besides the impact of uncertainties from stellar models and galactic chemical evolution simulations, this discrepancy was further obscured by rather divergent theoretical estimates for the neutron capture cross section of its radioactive precursor in the neutron-capture flow, ^{204}Tl (t_{1/2}=3.78 yr), and by the lack of experimental data on this reaction. We present the first ever neutron capture measurement on ^{204}Tl, conducted at the CERN neutron time-of-flight facility n_TOF, employing a sample of only 9 mg of ^{204}Tl produced at the Institute Laue Langevin high flux reactor. By complementing our new results with semiempirical calculations we obtained, at the s-process temperatures of kT≈8 keV and kT≈30 keV, Maxwellian-averaged cross sections (MACS) of 580(168) mb and 260(90) mb, respectively. These figures are about 3% lower and 20% higher than the corresponding values widely used in astrophysical calculations, which were based only on theoretical calculations. By using the new ^{204}Tl MACS, the uncertainty arising from the ^{204}Tl(n,γ) cross section on the s-process abundance of ^{204}Pb has been reduced from ∼30% down to +8%/-6%, and the s-process calculations are in agreement with the latest solar system abundance of ^{204}Pb reported by K. Lodders in 2021.

Measurement of the

^{140}Ce(n,γ) is a key reaction for slow neutron-capture (s-process) nucleosynthesis due to being a bottleneck in the reaction flow. For this reason, it was measured with high accuracy (uncertainty ≈5%) at the n_TOF facility, with an unprecedented combination of a high purity sample and low neutron-sensitivity detectors. The measured Maxwellian averaged cross section is up to 40% higher than previously accepted values. Stellar model calculations indicate a reduction around 20% of the s-process contribution to the Galactic cerium abundance and smaller sizeable differences for most of the heavier elements. No variations are found in the nucleosynthesis from massive stars.

74 Ge( n , γ ) cross section below 70 keV measured at n_TOF CERN.

Neutron capture reaction cross sections on 74 Ge are of importance to determine 74 Ge production during the astrophysical slow neutron capture process. We present new resonance data on 74 Ge( n , γ ) reactions below 70 keV neutron energy. We calculate Maxwellian averaged cross sections, combining our data below 70 keV with evaluated cross sections at higher neutron energies. Our stellar cross sections are in agreement with a previous activation measurement performed at Forschungszentrum Karlsruhe by Marganiec et al., once their data has been re-normalised to account for an update in the reference cross section used in that experiment.

The NUMEN project: Heavy-Ion Double Charge Exchange reactions towards 0νββ NME determination / El proyecto NUMEN: reacciones de intercambio de cargas dobles de iones pesados hacia la determinación de 0νββ NME

Abstract NUMEN proposes cross sections measurements of Heavy-Ion double charge exchange reactions as an innovative tool to access the nuclear matrix elements, entering the expression of the life time of Neutrinoless double beta decay (0νββ). A key aspect of the projectis the use at INFN-Laboratori Nazionali del Sud (LNS) of the Superconducting Cyclotron (CS) for the acceleration of the required high resolution and low emittance heavy-ion beams and of MAGNEX large acceptance magnetic spectrometer for the detection of the ejectiles. The experimental measurements of double charge exchange reactions induced by heavy ions present a number of challenging aspects, since such reactions are characterized by very low cross sections. First experimental results give encouraging indication on the capability to access quantitative information towards the determination of the Nuclear Matrix Elements for 0νββ decay.

Resumen NUMEN propone mediciones de secciones eficaces de reacciones de intercambio de carga doble de iones pesados como una herramienta innovadora para acceder a los elementos de la matriz nuclear, entrando en la expresión del tiempo de vida de la desintegración beta doble sin neutrino (0νββ). Un aspecto clave del proyecto es el uso en INFN-Laboratori Nazionali del Sud (LNS) del ciclotrón superconductor (CS) para la aceleración de los haces de iones pesados de alta resolución y baja emitancia requeridos y del espectrómetro magnético de gran aceptación MAGNEX para la detección de los residuos eyectados. Las mediciones experimentales de reacciones de intercambio de carga doble inducidas por iones pesados presentan una serie de aspectos desafiantes, ya que tales reacciones se caracterizan por secciones eficaces muy bajas. Los primeros resultados experimentales dan una indicación alentadora sobre la capacidad de acceder a información cuantitativa para la determinación de los Elementos de la Matriz Nuclear para la descomposición de 0νββ.

Silicon detectors for monitoring neutron beams in n-TOF beamlines.

During 2014, the second experimental area (EAR2) was completed at the n-TOF neutron beam facility at CERN (n-TOF indicates neutron beam measurements by means of time of flight technique). The neutrons are produced via spallation, by means of a high-intensity 20 GeV pulsed proton beam impinging on a thick target. The resulting neutron beam covers the energy range from thermal to several GeV. In this paper, we describe two beam diagnostic devices, both exploiting silicon detectors coupled with neutron converter foils containing (6)Li. The first one is based on four silicon pads and allows monitoring of the neutron beam flux as a function of the neutron energy. The second one, in beam and based on position sensitive silicon detectors, is intended for the reconstruction of the beam profile, again as a function of the neutron energy. Several electronic setups have been explored in order to overcome the issues related to the gamma flash, namely, a huge pulse present at the start of each neutron bunch which may blind the detectors for some time. The two devices were characterized with radioactive sources and also tested at the n-TOF facility at CERN. The wide energy and intensity range they proved capable of sustaining made them attractive and suitable to be used in both EAR1 and EAR2 n-TOF experimental areas, where they became immediately operational.

Subthreshold Ξ

Results on the production of the double strange cascade hyperon Ξ^{-} are reported for collisions of p(3.5 GeV)+Nb, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18 at GSI Helmholtzzentrum for Heavy-Ion Research, Darmstadt. For the first time, subthreshold Ξ^{-} production is observed in proton-nucleus interactions. Assuming a Ξ^{-} phase-space distribution similar to that of Λ hyperons, the production probability amounts to P_{Ξ^{-}}=[2.0±0.4(stat)±0.3(norm)±0.6(syst)]×10^{-4} resulting in a Ξ^{-}/(Λ+Σ^{0}) ratio of P_{Ξ^{-}}/P_{Λ+Σ^{0}}=[1.2±0.3(stat)±0.4(syst)]×10^{-2}. Available model predictions are significantly lower than the measured Ξ^{-} yield.

Implementation of a new low cost detector for low intensity light pulses produced by a radioactive gamma-source.

The readout of a cheap scintillating fibre was implemented by means of a new solid-state device (Silicon Photomultiplier, SiPM), able to detect very tiny light pulses. The GEANT3.21 code was adopted to simulate the counting detection efficiency and the energy deposited inside the scintillating fibre due to the radiation of a radioactive gamma source. The results obtained show the capability to detect gamma rays producing as few as 3-4 photoelectrons. The new devices may have many applications in radioactivity metrology.

Deep subthreshold Xi;{-} production in Ar + KCl reactions at 1.76A GeV.

We report first results on a deep subthreshold production of the doubly strange hyperon Xi;{-} in a heavy-ion reaction. At a beam energy of 1.76A GeV the reaction Ar + KCl was studied with the High Acceptance Di-Electron Spectrometer at SIS18/GSI. A high-statistics and high-purity Lambda sample was collected, allowing for the investigation of the decay channel Xi;{-} --> Lambdapi;{-}. The deduced Xi;{-}/(Lambda + Sigma;{0}) production ratio of (5.6 +/- 1.2_{-1.7};{+1.8}) x 10;{-3} is significantly larger than available model predictions.

Proteases and chronic leg ulcers.

AIM: The aim of this study was to compare the effect of cadexomer on reducing wound surface area of leg ulcers compared to that obtained in a group patients whose ulcers were treated by compression therapy. METHODS: For each ulcer group, wound surface area was calculated at day 0 and after 28 days of treatment: this allowed to calculate the average wound surface area reduction, the percent reduction in wound size, as well as the weekly wound size reduction index. RESULTS: In the cadexomer-treated ulcers the total wound area reduction was 9.67 cm(2)/week, with a weekly wound size reduction index per patient of 0.96 cm(2); in the controls (compression therapy-treated patients) the total wound area reduction was 6.11 cm(2)/week, with a weekly reduction index per patient of 0.61 cm(2). At the end of treatment, in the group of patients whose ulcers were treated with cadexomer ointment the average wound size reduction was 43%, whereas in the control-treated patient group the average wound size reduction was 28%. CONCLUSION: These data suggest that cadexomer can play an important role in the healing of chronic leg ulcers.

Dielectron production in 12C+12C collisions at 2A GeV with the HADES spectrometer.

The invariant-mass spectrum of e+e- pairs produced in 12C+12C collisions at an incident energy of 2 GeV per nucleon has been measured for the first time. The measured pair production probabilities span over 5 orders of magnitude from the pi(0)-Dalitz to the rho/omega invariant-mass region. Dalitz decays of pi(0) and eta account for all the yield up to 0.15 GeV/c(2), but for only about 50% above this mass. A comparison with model calculations shows that the excess pair yield is likely due to baryon-resonance and vector-meson decays. Transport calculations based on vacuum spectral functions fail, however, to describe the entire mass region.

[A "lump" in the throat]. / Un "nodo" in gola.

This is a clinical case of a patient suspected to have a lymphoma. Later on, other diagnostic procedures and particularly a neck ultrasound, revealed an idiopathic hyperparathyroidism.

[Hyperhomocysteinemia and progression of renal disease]. / Iperomocisteinemia e progressione delle nefropatie.

The relationship between hyperhomocysteinemia and cardiovascular damage is well known, whereas the role of this alteration in renal disease progression has been scarcely studied. Experimental studies demonstrated that exposure to high levels of homocysteinemia causes glomerular and interstitial damage which is remarcably proportional to the serum concentration of this aminoacid. Until now the renal effects of hyperhomocysteinemia in man has been investigated only in observational studies. The Hoorn study, a prospective study in a Dutch population, showed that the plasma homocysteine is a strong predictor of proteinuria in diabetic and non diabetic subjects. Findings in this study were recently confirmed in a cohort study in 7500 Japanese because plasma homocysteine predicted the onset of renal failure in this population. NO-dependent endothelial dysfunction triggered by homocysteine via reduction of the activity of the enzyme that metabolizes Asimmetric Dymethilarginine (dmethylarginine dymethilaminohydrolase) is a likely mechanism whereby hyperomocysteinemia causes cardiovascular and renal damage as well.

[Large volume increase in a trastigian kidney]. / Un rene in fiamme oltre lo Stige.

With few exceptions renal volume is markedly reduced in patients with end-stage renal disease, a phenomenon which is almost always accompanied by a progressive loss of renal compliance secondary to renal structure fibrosis. We have observed a remarkable renal compliance during an episode of acute pyelonephritis in a patient on long-term dialysis.

[Bilateral hydronephrosis: a stringent diagnosis]. / Idronefrosi bilaterale: una diagnosi 'stringente'

A forty-nine year old man was admitted to the Renal Unit of our Hospital because of renal failure, loin pain, low grade fever and loss of weight. It was done a complete work-up. The ultrasound and the computed tomography of the abdomen were very helpful to get the right diagnosis.

[Spinal cord infarction during haemodialysis]. / Infarto del midollo spinale in un paziente con insufficienza renale cronica in emodialisi con estese calcificazioni cardiovascolari.

A 26-year-old patient with chronic renal failure presented a spinal cord infarction during haemodialysis. This is the first case of a patient with chronic renal failure maintained on chronic haemodialysis described in literature. In this case, the severity of vascular lesions documented by widespread vascular calcifications were particularly striking.

Strong enhancement of extremely energetic proton production in central heavy ion collisions at intermediate energy.

The energetic proton emission has been investigated as a function of the reaction centrality for the system (58)Ni + (58)Ni at 30A MeV. Extremely energetic protons (E(NN)(p) > or = 130 MeV) were measured and their multiplicity is found to increase almost quadratically with the number of participant nucleons, thus indicating the onset of a mechanism beyond one- and two-body dynamics.

A new receptor molecule for lysine and histidine in water: strong binding of basic amino acid esters by a macrocyclic host.

We present the new host molecule 1 which binds basic amino acid esters in water. It recognizes both positively charged groups of the amino acid esters by electrostatic and hydrogen bond interactions with its four strategically placed phosphonate anions. Selectivity for lysine is achieved by the correct distance between both bisphosphonate pairs. By contrast, the smaller amino acid esters arginine, ornithine, and histidine form 2:1 complexes with 1. In methanol, a double chelate assembly enforced by pi-cation interactions with the imidazolium cation leads to a very high association constant for the 1:histidine complex of 3 x 10(4) M(-)(1).