138 research outputs found
g-factor measurements of isomeric states in 174W
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.ISBN: 978-88-7438-101-2; International audience; The experimental setup GAMIPE used for gyromagnetic factormeasurements at Laboratori Nazionali di Legnaro and a recent experimentalwork regarding K-isomers in 174W are described. Aim ofthe experiment is to study the detailed structure of the isomeric stateswave functions, by the measurement of the magnetic dipole moments.This piece of information can provide interesting hints for theoreticalmodels. Preliminary results concerning the population of the isomersof interest and half-lives are presented
Study of the in medium cross-section and of the clustering process by means of the Bayesian technique applied to a nuclear reaction at Fermi energy
A Bayesian analysis aimed at tuning two parameters of the AMD model, one of them related to the in medium nucleon nucleon cross-section and the other to the clustering, has been performed. Experimental data collected with four blocks of the FAZIA setup have been compared with simulated data built with different values of the investigated parameters
Antineoplastic effects of rosiglitazone and PPARγ transactivation in neuroblastoma cells
Neuroblastoma (NB) is the most common extracranial solid tumour in infants. Unfortunately, most children present with advanced disease and have a poor prognosis. In the present study, we evaluated the role of the peroxisome proliferator-activated receptor γ (PPARγ) agonist rosiglitazone (RGZ) in two NB cell lines (SK-N-AS and SH-SY5Y), which express PPARγ. Rosiglitazone decreased cell proliferation and viability to a greater extent in SK-N-AS than in SH-SY5Y. Furthermore, 20 μM RGZ significantly inhibited cell adhesion, invasiveness and apoptosis in SK-N-AS, but not in SH-SY5Y. Because of the different response of SK-N-AS and SH-SY5Y cells to RGZ, the function of PPARγ as a transcriptional activator was assessed. Noticeably, transient transcription experiments with a PPARγ responsive element showed that RGZ induced a three-fold increase of the reporter activity in SK-N-AS, whereas no effect was observed in SH-SY5Y. The different PPARγ activity may be likely due to the markedly lower amount of phopshorylated (i.e. inactive) protein observed in SK-N-AS. To our knowledge, this is the first demonstration that the differential response of NB cells to RGZ may be related to differences in PPARγ transactivation. This finding indicates that PPARγ activity may be useful to select those patients, for whom PPARγ agonists may have a beneficial therapeutic effect
GRB 221009A observations with LST-1 at VHE gamma rays
On October 9th, 2022, the brightest gamma-ray burst (GRB) since the first GRB observation in the late sixties was detected by the Fermi-GBM and Swift-BAT telescopes (GRB 221009A). The outstanding characteristics of this GRB triggered extensive follow-up observations of the source across all wavebands, including at very-high-energy (VHE) gamma rays with the Large-Sized Telescope prototype (LST-1) of the upcoming Cherenkov Telescope Array Observatory (CTAO). In this contribution, we present the analysis and results of the LST-1 observation campaign in October 2022, focusing on the data taken under nominal observing conditions and above 200 GeV
Detection of RS Oph with LST-1 and modelling of its HE/VHE gamma-ray emission
Context. The recurrent nova RS Ophiuchi (RS Oph) underwent a thermonuclear eruption in August 2021. In this event, RS Oph was detected by the High Energy Stereoscopic System (H.E.S.S.), the Major Atmospheric Gamma Imaging Cherenkov (MAGIC), and the first Large-Sized Telescope (LST-1) of the future Cherenkov Telescope Array Observatory (CTAO) at very-high gamma-ray energies above 100 GeV. This means that novae are a new class of very-high-energy (VHE) gamma-ray emitters. Aims. We report the analysis of the RS Oph observations with LST-1. We constrain the particle population that causes the observed emission in hadronic and leptonic scenarios. Additionally, we study the prospects of detecting further novae using LST-1 and the upcoming LST array of CTAO-North. Methods. We conducted target-of-opportunity observations with LST-1 from the first day of this nova event. The data were analysed in the framework of cta-lstchain and Gammapy, the official CTAO-LST reconstruction and analysis packages. One-zone hadronic and leptonic models were considered to model the gamma-ray emission of RS Oph using the spectral information from Fermi-LAT and LST-1, together with public data from the MAGIC and H.E.S.S. telescopes. Results. RS Oph was detected at 6.6σ with LST-1 in the first 6.35 hours of observations following the eruption. The hadronic scenario is preferred over the leptonic scenario considering a proton energy spectrum with a power-law model with an exponential cutoff whose position increases from (0.26 ± 0.08) TeV on day 1 up to (1.6 ± 0.6) TeV on day 4 after the eruption. The deep sensitivity and low energy threshold of the LST-1/LST array will allow us to detect faint novae and increase their discovery rate
Clinical nutrition in surgical oncology: Young AIOM-AIRO-SICO multidisciplinary national survey on behalf of NutriOnc research group
Malnutrition is a common condition in cancer patients which is usually associated with functional limitations, as well as increased morbidity and mortality. Based on the support of the young sections of Italian Association of Medical Oncology (AIOM), Italian Association of Radiotherapy and Clinical Oncology (AIRO) and Italian Society of Surgical Oncology (SICO) merged into the NutriOnc Research Group, we performed a multidisciplinary national survey with the aim to define the awareness of nutritional issues among healthcare professionals delivering anticancer care. The questionnaire was organized in four sections, as follows: Knowledge and practices regarding Nutritional Management of cancer patients; Timing of screening and assessment of Nutritional Status; Nutritional Treatment and prescription criteria; Immunonutrition and educational topics. The modules focused on esophagogastric, hepato-bilio-pancreatic and colorectal malignancies. Overall, 215 physicians completed the survey. As regards the management of Nutritional Status of cancer patients, many responders adopted the ERAS program (49.3%), while a consistent number of professionals did not follow a specific validated nutritional care protocol (41.8%), mainly due to lack of educational courses (14.5%) and financial support (15.3%). Nearly all the included institutions had a multidisciplinary team (92%) to finalize the treatment decision-making. Cancer patients routinely underwent nutritional screening according to 57.2% of interviewed physicians. The timing of nutritional assessment was at diagnosis (37.8%), before surgery (25.9%), after surgery (16.7%), before radiochemotherapy (13.5%) and after radiochemotherapy (7%). Most of the responders reported that nutritional status was assessed throughout the duration of cancer treatments (55.6%). An important gap between current delivery and need of nutritional assessment persists. The development of specific and defined care protocols and the adherence to these tools may be the key to improving nutritional support management in clinical practice
Detection of the Geminga pulsar at energies down to 20 GeV with the LST-1 of CTAO
Context. Geminga is the third gamma-ray pulsar firmly detected by imaging atmospheric Cherenkov telescopes (IACTs) after the Crab and the Vela pulsars. Most of its emission is expected at tens of giga-electronvolts, and, out of the planned telescopes of the upcoming Cherenkov Telescope Array Observatory (CTAO), the Large-Sized Telescopes (LSTs) are the only ones with optimised sensitivity at these energies. Aims. We aim to characterise the gamma-ray pulse shape and spectrum of Geminga as observed by the first LST (hereafter LST-1) of the Northern Array of CTAO. Furthermore, this study confirms the great performance and the improved energy threshold of the telescope, as low as 10 GeV for pulsar analysis, with respect to current-generation Cherenkov telescopes. Methods. We analysed 60 hours of good-quality data taken by the LST-1 between December 2022 and March 2024 at zenith angles below 50◦. Additionally, a new Fermi-LAT analysis of 16.6 years of data was carried out to extend the spectral analysis down to 100 MeV. Lastly, a detailed study of the systematic effects was performed. Results. We report the detection of Geminga in the energy range between 20 and 65 GeV. Of the two peaks of the phaseogram, the second one, P2, is detected with a significance of 12.2σ, while the first (P1) reaches a significance level of 2.6σ. The best-fit model for the spectrum of P2 was found to be a power law with a spectral index of Γ = (4.5±0.4stat)−+0062syssys, compatible with the previous results obtained by the MAGIC Collaboration. No evidence of curvature is found in the LST-1 energy range. The joint fit with Fermi-LAT data confirms a preference for a sub-exponential cut-off over a pure exponential, even though both models fail to reproduce the data above several tens of giga-electronvolts. The overall results presented in this paper prove that the LST-1 is an excellent telescope for the observation of pulsars, and improved sensitivity is expected to be achieved with the full CTAO Northern Array
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