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Regioselective photodimerization as a tool for light-regulated catalyst assembly
No full textWhile photoisomerization has dominated the design of photoswitchable catalysts, this work introduces an alternative approach: leveraging light-induced photodimerization to assemble catalytically active species. The adopted strategy is based on a acrylamidylpyrene derivative equipped with a TACNZn(ii) catalytic unit. This system undergoes a visible-light-induced [2 + 2] cycloaddition, which is both regioselective and reversible, to form a catalytically active photodimer. While the E-to-Z photoisomerization of the monomer has no significant effect on catalysis, the photodimerization leads to a six-fold enhancement in catalytic activity. The photodimer's catalytic efficiency is attributed to the clustering of catalytic units, facilitating a more efficient transphosphorylation reaction. Notably, this system demonstrates the ability to temporally control catalytic reactivity, as the active dimer can be reverted to the monomers upon irradiation with UV light. This work highlights the potential of photodimerization as a robust alternative strategy for regulating catalytic activity and opens new avenues for light-responsive catalysis with temporal control
Vth and Ron Instability of GaN Power HEMTs with pGaN Gate Under Negative Gate Bias
No full textWe investigate the impact of negative gate stress on the stability of threshold voltage and on-resistance of p-GaN gate power HEMTs. We demonstrate three different trapping processes and describe the related kinetics: (process 1), trapping of electrons at the AlGaN/GaN barrier, induced by the positive gate voltage used to monitor the threshold voltage during stress; (process 2), de-trapping of electrons from donor states, with consequent negative shift in the threshold voltage; (process 3) slow electron trapping in the dielectric/semiconductor interfaces. Reverse gate leakage current was modeled in temperature to understand the physical origin of process 3. The results reported in this paper are of relevance for the stability of p-GaN gate power HEMTs in several real-life applications
Punishing one, teaching a hundred?US sanctions on Francesca Albanese and the current trends in international politics and human rights
No full textThis article examines the causes and implications of the unprecedented US sanctions imposed on the UN Special Rapporteur on the Occupied Palestinian Territories, Francesca Albanese. It discusses three interlinked hypotheses to explain this move: 1) the sanctions are the apex of a broader effort by some world leaders to side-line human rights principles and international protection mechanisms when they clash with national interests; 2) they represent an escalation in the “propaganda war” between the US, Israel and human rights advocates over the Palestinian issue; 3) they directly respond to Albanese’s investigations into the corporate role in facilitating crimes in Palestine, thereby threatening US, Israeli and European economic interests. The article concludes that the sanctions crystallize the immense power imbalances that continue to undermine the international human rights regime and the rule of law in international relations
Optimization of infrared thermography investigations for identification of subsurface anomalies in plastered masonry walls
Full text linkThis study investigates the optimization of Infrared Thermography (IRT) for detecting subsurface anomalies in plastered masonry walls typical of heritage buildings, including those restored with traditional, modern, and innovative coatings. Despite widespread application of IRT in non-destructive testing (NDT) within cultural heritage diagnostics, standardized protocols for evaluating plastered and upgraded surfaces—particularly involving materials such as reinforced concrete (RC) and Textile Reinforced Mortar (TRM)— are lacking. Despite widespread application of IRT in non-destructive testing (NDT) within cultural heritage diagnostics and the availability of research studies on the subject, standardized protocols for evaluating plastered and upgraded surfaces—particularly involving materials such as reinforced concrete (RC) and Textile Reinforced Mortar (TRM)—are lacking. To address this gap, three full-scale masonry mock-ups (rubble stone, brick, and mixed masonry) were constructed and coated with traditional fresco layers, hydraulic lime mortars, or cement-based plasters. Controlled defects—including Teflon inserts, wet sponges, metallic elements, and timber inclusions—were embedded at depths ranging from 3 to 50 mm. Independent IRT assessments were conducted by two research units under both passive (solar) and active (artificial) heating regimes. Results demonstrate that passive IRT, driven by a solar-induced thermal gradient of approximately 11°C over 10 h, effectively identified deeper defects (up to 25–30 mm), such as wooden elements, moisture accumulations, and delamination in lime-based plasters. Conversely, active IRT employing convector and infrared lamp heating with 20–35 min of exposure and surface temperature increases between 5 and 12°C allowed detection of near-surface flaws during transient heating and cooling phases, albeit with limited observation windows of 2–5 min. Detection depth was influenced by plaster type, with lime-based coatings permitting defect visibility up to 25–30 mm, whereas cement-based plasters limited detection to 15–20 mm due to lower thermal conductivity. Reinforcement materials, including steel and basalt fiber meshes, were generally undetectable under both passive and active regimes, particularly when embedded beneath coatings thicker than 30 mm. Key parameters affecting defect visibility included plaster thickness, the magnitude of the thermal gradient, and heating uniformity, with thin fresco layers exhibiting the highest defect contrast. Based on these findings, a simplified and replicable IRT protocol is proposed, tailored to common heritage masonry typologies. The study emphasizes the importance of precise calibration of acquisition timing and thermal input to optimize diagnostic accuracy. While confirming IRT strong potential for qualitative assessment of plaster detachment and heterogeneity in historic masonry, caution is advised when interpreting results in the presence of modern retrofit materials
Perceived oppression and online support for COVID-19 non-compliance: the 2021 Trieste port protests
Full text linkThe enforcement of COVID-19 containment measures, such as lockdowns or mandatory vaccination, can have significant consequences for both public health and the economic stability of institutions. As a result, widespread non-compliance poses a particular challenge for governments. In October 2021, workers in Trieste, Italy, blocked the city's commercial port in protest against new restrictions, triggering large-scale demonstrations and an explosion of related activity on Twitter. We analyze this unique case of mass non-compliance by collecting tweets about the protests and applying sentiment analysis, topic modeling, opinion analysis, user clustering, and diffusion modeling. Our findings reveal a strong connection between online support for non-compliance and emotions such as anger and mistrust, particularly toward the government, which are often framed as reactions to perceived injustice or oppression. The results suggest that social media played a key role in amplifying and normalizing non-compliant sentiment. While this study does not make normative claims about the legitimacy of either side, it offers a methodological lens for understanding how polarizing debates unfold online. This approach can also be extended to other divisive issues such as climate policy, military conflict, or artificial intelligence, or in general with regards to contrasting or diverse opinions discussed online. By better understanding the motivations and narratives of non-compliers, institutions may be better equipped to foster dialogue and reduce reliance on force
Towards a comprehensive study of the 14N(p,γ)15O astrophysical key reaction: Description of the experimental technique including novel target preparation
No full textWhile the 14N(p,γ)15O reaction plays a key role in the hydrogen-burning processes in various stellar conditions, its reaction rate is not known with sufficient precision. Therefore, the first scientific project at the recently launched Bellotti Ion Beam Facility of the Laboratori Nazionali del Gran Sasso was the measurement of the 14N(p,γ)15O reaction cross section in the proton energy range between 250 and 1500 keV. In this paper, the experimental techniques are summarized with special emphasis on the description of solid state nitrogen target production and characterization. The first results of the reaction yield measured at 55∘ detection angle are also presented
Effectiveness of sodium channel blockers in treating neonatal seizures due to arterial ischemic stroke
No full textObjective: Few studies have evaluated the efficacy of antiseizure medications (ASMs) according to the etiology of neonatal acute provoked seizures. We aimed to investigate the response to ASMs in term/near term neonates with acute arterial ischemic stroke (AIS), as well as the type of seizure at presentation and the monitoring approach. Methods: We retrospectively evaluated neonates from 15 European level IV neonatal intensive care units who presented with seizures due to AIS and were monitored by continuous electroencephalography (cEEG) and/or amplitude-integrated EEG (aEEG) in whom actual recordings, timing, doses, and response to ASMs were available for review. Results: One hundred seven neonates were referred, and 88 were included. Of those, 56 met the criteria for evaluating the treatment response. The mean time to treatment was 7.9 h (SD = 16.4), and the most frequently administered first-line ASM was phenobarbital (PB; 74/88, 84.1%). Seizures were controlled within 24 h from onset of symptoms in 64.3% (36/56) of neonates. Phenytoin (PHT) was effective in almost all neonates in whom it was trialed (24/25, 96.0%), whereas PB was effective in only 22.0% of patients (11/50). Infants treated with PB or PHT as first-line treatment (53/56, 94.6%) showed a higher response rate with PHT (6/6, 100.0%) than with PB (11/47, 23.4%). Monitoring approach and seizure types were evaluated in 88 infants. Forty-six of 88 (52.3%) were monitored with cEEG and 47.7% (42/88) with aEEG, with or without intermittent cEEG. The mean monitoring duration was 65.8 h (SD = 39.21). In 83 of 88 (94.3%) infants, the type of seizure suspected clinically prior to monitoring was confirmed afterward. Unilateral focal clonic seizures were seen in 71 of 88 infants (80.7%), whereas 11 of 88 (12.5%) presented with ictal apneas. Significance: Our findings provide evidence in a large, homogenous cohort that PHT is more effective than PB in treating neonatal acute symptomatic seizures due to AIS
