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Time-domain diffuse optics can break the pile-up bottleneck thanks to high light harvesting single-photon detectors
No full textThanks to the use of solid-state detectors such as silicon photomultipliers, time-domain diffuse optics (TD-DO) instruments are moving from bulky to compact forms, while allowing increased light harvesting capabilities, high throughput, and improved signal-to-noise ratio acquisitions. Very large area single-photon detection modules have been created within the SP-LADOS project (supported by the EU ATTRACT project), improving light harvesting capabilities and allowing the possibility of pushing towards the ultimate limits of TD-DO. However, to fully leverage the potential of this cutting-edge detector, there is a need to move beyond the limitations of single photon statistics. Thus, the unknown operating regime of
the very high count rates must be investigated. Indeed, the use of very large countrates causes a considerable signal distortion, which must be corrected. In this study, we show the large-area SiPM modules’ improved sensitivity, as well as preliminary in-silico results on the advantages of operating in a high-count rate environment
An automated tool to estimate chromatin compaction in stained nuclei
No full textChromatin organisation undergoes various structural changes during the entire cell life. The spatial arrangement of chromatin within the nucleus is not random, but how its architecture varies during cellular processes is still partially unknown. The aim of this work is to provide an automatic tool to quantify chromatin compaction from three-dimensional (3D) fluorescence microscopy images. We developed a tool to compute several morphological and statistical measures on stained nuclei. Furthermore, the nucleus is clustered, thus identifying different compactness
regions. This workflow paves the way for biologists to study how chromatin structures form and behave in various cellular processes, by providing a parameter-free and automatic numerical quantification method of chromatin compaction
Photocurrent and photovoltage generation dynamics at the organic semiconductor/water interface in p-type conjugated polymers
No full textPhotoactive organic semiconductors are envisioned as a novel class of materials able to transduce light into stimulating signals inside biological cells or tissue. The direct interface between the semiconductor and the electrolyte gives rise to different, competing electrochemical phenomena. A detailed understanding of such chemical and photo-induced interactions is necessary to develop and optimize future devices. We addressed the problem in organic polymeric photoelectrodes by gaining insights into the energetics of the involved processes, identifying the
kinetics of light stimulated charge transfer processes, and then determining the role of interfacial energy levels in the photoactivated processes. We highlight how energy diagrams enable a comprehensive understanding of the photoelectrochemical reaction pathways
Towards the first kaonic deuterium measurement with the SIDDHARTA-2 experiment at DAΦNE
No full textThe SIDDHARTA-2 experiment is going to perform the longawaited high precision X-ray measurement of kaonic deuterium, obtaining for the first time the values of the shift and the width induced by the strong interaction on the fundamental level. By combining this unprecedented result with the analogous kaonic hydrogen measurement performed by the SIDDHARTA experiment, it will be possible to extract the isospin-dependent antikaon-nucleon scattering lengths, providing direct information on the Quantum Chromodynamics (QCD) in the non-perturbative Chromodynamics (QCD) in the non-perturbative regime in the strangeness sector. This paper describes the SIDDHARTA-2 experiment, presently installed at the DAΦNE collider of Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Frascati, and the results obtained during the kaonic helium run, preparatory for the kaonic deuterium data taking campaign planned for 2022
The Nature of Science in physics teaching in Italy
No full textIn this paper, we describe two studies carried out in the research field of Nature of Science (NOS). The general aim was to explore the role of NOS in the Italian physics teaching context. In both studies, the Reconceptualized Family Resemblance Approach to NOS (RFN) was adopted as the theoretical framework. In the first study, the RFN was used to investigate the presence of NOS at an institutional level, and physics guidelines for the Italian Scientific Lyceum were analysed. Then, an Epistemic Network Analysis allowed us to visualise the connections between the elements of the nature of physics that emerged in various sections of the guidelines. In the second study, one element of NOS, scientific practices, was explored from the perspective of physics teachers. We investigated how physics
practices, such as modelling and experimenting, were taught in class by a sample of very motivated teachers
Negative heat capacity for hot nuclei: Confirmation with formulation from the microcanonical ensemble
No full textBy using freeze-out properties of multifragmenting hot nuclei produced in quasifusion central 129Xe + natSn collisions at different beam energies (32, 39, 45 and 50 AMeV) which were estimated by means of a simulation based on experimental data collected by the 4π INDRA multidetector, heat capacity in the thermal excitation energy range 4–12.5 AMeV was calculated from total kinetic energies and
multiplicities at freeze-out. The microcanonical formulation was employed. Negative heat capacity which indicates a first order phase transition for finite systems is observed and confirms previous results using a different method
Manuale sui metodi di studio e le tecniche di memorizzazione
No full textNel libro vengono affrontate le seguenti tematiche 1) Le basi neuroscientifiche dell’apprendimento. Introduzione ai fondamenti psicopedagogici dello studio. 2) La concentrazione nello studio e sul lavoro. Imparare a mantenere la concentrazione nello studio e nel lavoro su compiti complessi. 3) Tecniche di memorizzazione e di studio efficaci. Le più efficaci tecniche e strategie per memorizzare e per studiare con minore sforzo e maggior profitto. 4) Mappe e schemi mentali.
Mappe concettuali, mappe mentali, solution map, mappe miste e schemi per lo studio. 5) Lettura efficace. Tecniche, strategie e consigli per una lettura efficace. 6) Soft skill per lo studio. Analisi dei testi, organizzazione degli argomenti, capacità di sintesi, problem solving, ecc. 7) I principali metodi di studio. I più importanti metodi di studio e come personalizzarli
Parvovirus Infection Triggering Still’s Disease
Get PDFWe present the case of a 59-year-old man with acute B19 parvovirus infection who developed a systemic inflammatory reaction similar to adult-onset Still's disease (AOSD). We discuss the clinical challenge due to overlapping symptoms to distinguish between a primary B19 viral infection and the autoimmune disease it can trigger
Type II Abernethy Malformation: A Rare Cause of Hepatic Encephalopathy in Adulthood
Get PDFAbernethy malformation is a rare congenital extrahepatic portosystemic shunt with variable clinical manifestations, mainly associated with the portosystemic shunt. Hepatic encephalopathy can be the first manifestation. We present the case of a 50-year-old woman with hepatic encephalopathy without liver dysfunction. Further evaluation with contrast-enhanced abdominal computed tomography was performed, showing a large-calibre portocaval shunt from the left portal branch, suggestive of type 2 Abernethy malformation. The patient improved with lactulose and rifaximin but maintained rare encephalopathy episodes. She is therefore currently awaiting surgical treatment. Despite being a rare cause of hepatic encephalopathy, Abernethy malformation should be considered in patients with unexplained hyperammonaemia. Since it is potentially reversible, and early diagnosis and treatment may improve outcome, raising awareness of this malformation is essential
Haemophagocytic Lymphohistiocytosis as a Complication of Israeli Spotted Fever
Get PDFRickettsia spp. human infection is endemic in Portugal in the form of Mediterranean spotted fever caused by R. conorii subsp. conorii and Israeli spotted fever (ISF) caused by R. conorii subsp. israelensis. We describe a rare case of haemophagocytic lymphohistiocytosis (HLH) due to ISF, with atypical manifestations. We highlight the need for clinical suspicion for this diagnosis and the importance of timely intervention and support