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2025
- Book : 111(4)
- Pub. Date : 2025
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2025
Proton decay detection could put in evidence physics beyond the Standard Model (BSM). In this context, multiple projects are searching for such events. We focused our work on two of the expected decay modes, [Formula: see text] and [Formula: see text]. Neutrinos are particles that interact very weakly with matter, so they are not of interest in our work. The detector materials investigated in this study include liquid argon (LAr), liquid xenon (LXe), and water (H2O). Our analysis focuses on two key effects relevant to this decay process: the Fermi motion of nucleons and final state interactions. In addition to these effects, we have also examined the nuclear interaction of particles with the nuclei of the medium. This paper presents values for nucleon energy distribution, cross-sections, mean free paths, and interaction probabilities. - Book : 40(13n14)
- Pub. Date : 2025
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2025
In this paper, we consider the convergence in L2 norm, uniformly in time of
the inhomogeneous Navier-Stokes system and inhomogeneous Euler equations.
Upon the assumption of the Oleinick conditions of no back-flow in the trace
of the Euler flow, and of a lower bound for the Navier-Stokes vorticity in a
Kato-like boundary-layer, we prove that the inviscid limit holds.- Book : 29(2 Part A)
- Pub. Date : 2025
- Page : pp.1055-1062
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2025
The dependence of polyethylene deformation on applied mechanical stress under varying load conditions and radiation doses was investigated experimentally. Obtained results reveal significant alterations in the mechanical properties of polyethylene following irradiation with krypton ions at doses of 1.5 × 106, 1.6 × 107, 5.0 × 108, and 1.0 × 109 ions/s. The stress–strain curves obtained for both the unirradiated and irradiated samples are numerically modeled using frameworks developed by the authors. The findings indicate that irradiation with krypton ions at an energy level of 147 MeV exerts a pronounced impact on the deformation and strength characteristics of polyethylene. Notably, increasing the radiation dose to 109 particles/s results in a 2.5-fold increase in the rate of mechanical stress. Furthermore, the degree of deformation distortions in molecular chains induced by high-energy Kr15+ ion irradiation has been quantified as a function of irradiation fluence. Increasing the irradiation fluence from 106 ion/cm2 to 107 ion/cm2 causes only minor variations in deformation distortions, which are attributed to the localized isolation of latent tracks and associated changes in electron density. A comparative analysis of the mechanical behavior of irradiated polymer materials further revealed differences between ion and electron irradiation effects. It was observed that Teflon films lose their plasticity after irradiation, whereas polyethylene films exhibit enhanced elongation and tearing performance at higher strain values relative to their non-irradiated counterparts. This behavior was consistently observed for films irradiated with both ions and electrons. However, an important distinction was identified: high-energy electron irradiation degrades the strength of polyethylene, whereas krypton ion irradiation at 147 MeV does not result in strength reduction.- Book : 17(8)
- Pub. Date : 2025
- Page : pp.1081-1081
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2025
The joint of a shield tunnel segment is the weak part of tunnel, and the opening amount of the joint seriously affects the watertightness of the internal structure of the tunnel. In this experiment, a model was created with ANSYS, the fluid–solid coupling effect of the seawater and seabed was considered using the SuperFLUSH/2D 6.0 software, and the local site effect was considered by free-field seismic response analysis. Considering the structure and stress characteristics of the shield tunnel in conjunction with the marine area, earthquake research on shield tunnel culverts was conducted using lateral and longitudinal beam–spring models. The main focus of this article is to study the earthquake resistance of shield tunnel joints under extreme seismic excitation (SL-2) in complex marine environments. The results indicated that in the lateral analysis, under varying soil layer conditions, the diameter deformation rates for sections 1 and 2 using high-strength bolts were 1.752% and 1.334%, respectively, while the joint-opening amounts were 0.515 mm and 0.387 mm, respectively. This suggests that locations with thicker silt layers exhibit larger joint-opening amounts and are more susceptible to deformation. In the longitudinal analysis, when bolt strength varied, the maximum joint-opening ranged from 4.706 mm to 6.507 mm, and the maximum dislocation ranged from 0.625 mm to 1.326 mm. The deformation rule of the joint bolts followed the pattern that higher stiffness led to smaller deformation, whereas poorer geological conditions resulted in larger deformation. Therefore, the interface between soft and hard strata is a weak point in the longitudinal seismic resistance of the shield tunnel structure. The conclusions of this study can supplement the seismic research on shield tunnels in the marine areas of nuclear power plants.- Book : 15(8)
- Pub. Date : 2025
- Page : pp.1365-1365
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2025
Microbial biosurfactants have become increasingly attractive as promising ingredients for environmentally friendly products. The reasons for this are their generally good performance and biodegradability, low toxicity, production from renewable raw materials, and benefits for the environment perceived by consumers. In this study, we investigated the chemical structure and properties of a novel glycolipid from a new biosurfactant-producing strain, Rouxiella badensis DSM 100043T. Bioreactor cultivation was performed at 30 °C and pH 7.0 for 28 h using 15 g/L glycerol as a carbon source. The glycolipid was successfully purified from the ethyl acetate extract of the supernatant using medium pressure liquid chromatography (MPLC). The structure of the glycolipid was determined by one- and two-dimensional (1H and 13C) nuclear magnetic resonance (NMR) and confirmed by liquid chromatography electrospray ionization mass spectrometry (LC-ESI/MS). NMR analysis revealed the hydrophilic moiety as a glucose molecule and the hydrophobic moieties as 3-hydroxy-5-dodecenoic acid and 3-hydroxydecanoic acid, which are linked with the glucose by ester bonds at the C2 and C3 positions. Surface tension measurement with tensiometry indicated that the glucose–lipid could reduce the surface tension of water from 72.05 mN/m to 24.59 mN/m at 25 °C with a very low critical micelle concentration (CMC) of 5.69 mg/L. Moreover, the glucose–lipid demonstrated very good stability in maintaining emulsification activity at pH 2–8, a temperature of up to 100 °C, and a NaCl concentration of up to 15%. These results show that R. badensis DSM 100043T produced a novel glycolipid biosurfactant with excellent surface-active properties, making it promising for further research or industrial applications.- Book : 30(8)
- Pub. Date : 2025
- Page : pp.1798-1798
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2025
It has been previously advocated that the presence of the daily and annual modulations of the axion flux on the Earth’s surface may dramatically change the strategy of the axion searches. The arguments were based on the so-called Axion Quark Nugget (AQN) dark matter model which was originally put forward to explain the similarity of the dark and visible cosmological matter densities Ωdark∼Ωvisible. In this framework, the population of galactic axions with mass 10−6 eV≲ma≲10−3 eV and velocity ⟨va⟩∼10−3c will be accompanied by axions with typical velocities ⟨va⟩∼0.6c emitted by AQNs. Furthermore, in this framework, it has also been argued that the AQN-induced axion daily modulation (in contrast with the conventional weakly interactive massive particle paradigm) could be as large as (10–20)%, representing the main motivation for the present investigation. We argue that the daily modulations along with the broadband detection strategy can be very useful tools for the discovery of such relativistic axions. The data from the CAST-CAPP detector have been used following such arguments. Unfortunately, due to the dependence of the amplifier chain on temperature-dependent gain drifts and other factors, we could not conclusively show the presence or absence of a dark sector-originated daily modulation. However, this proof of principle analysis procedure can serve as a reference for future studies.
Published by the American Physical Society
2025
- Book : 111(8)
- Pub. Date : 2025
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2025
Photoelectron circular dichroism (PECD) in the ionization of chiral molecules by circularly polarized radiation is a well-established tool for chiral recognition in the gas phase. The effect consists in a forward-backward asymmetry in angular emission distributions of photoelectrons with respect to the light propagation direction, which survives averaging over molecular orientations. Its magnitude is governed by the ability of the outgoing photoelectron to probe an asymmetry of the ionic potential by multiple scattering effects, and it can be significantly enhanced by fixing molecular orientation in space. Even achiral fixed-in-space molecules can exhibit such a forward-backward asymmetry in the photoemission. In the present work, we establish a qualitative correspondence between the PECD in one-photon ionization of fixed-in-space molecules and a degree of the asymmetry of their ionic potential. For this purpose, we introduce an enantiosensitive dichroic characteristic of the ionic potential, which describes a physical mechanism behind the forward-backward asymmetry in the photoemission from fixed-in-space molecules ionized by circularly polarized light. This characteristic, as a function of molecular orientation angles, can be compared to the respective PECD landscape. The present findings are exemplified by several applications to achiral and chiral species.- Book : 12(2)
- Pub. Date : 2025
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2025
Background/Objectives: Ovarian cancer remains one of the most commonly diagnosed malignancies among women worldwide. The heterogeneity among tumor subtypes and the emergence of treatment resistance have raised significant concerns regarding the long-term efficacy of chemotherapy, radiotherapy, and immunotherapy. In response to these challenges, drug repurposing strategies—utilizing existing drugs in novel therapeutic contexts—have gained increasing attention. This study aimed to investigate the cytotoxic and apoptotic effects of the combined application of doxorubicin (DX) and thymoquinone (TQ) on ovarian adenocarcinoma cells (OVCAR3). Methods: OVCAR3 cells were cultured in RPMI medium supplemented with 10% fetal bovine serum (FBS) and 1% penicillin/streptomycin. Cell viability and proliferation were assessed using the MTT assay following treatment with various concentrations of DX and TQ. NucBlue immunofluorescence staining was employed to examine nuclear morphology and to identify apoptosis-associated changes. Additionally, quantitative real-time polymerase chain reaction (qRT-PCR) was per-formed to evaluate the expression levels of apoptosis-related and oncogenic pathway genes, including RAF, RAS, Bcl-2, and Bax. Results: The results demonstrated that the combination of DX and TQ significantly reduced OVCAR3 cell viability and induced apoptosis in a dose-dependent manner. qRT-PCR analysis revealed a downregulation of RAS, RAF, and Bcl-2 expression, along with an upregulation of Bax, indicating activation of the intrinsic apoptotic pathway. These findings suggest that thymoquinone exerts an-ti-proliferative and pro-apoptotic effects by modulating the RAS/RAF signaling cascade. Furthermore, the co-administration of thymoquinone with doxorubicin potentiated these effects, suggesting a synergistic interaction between the two agents. Conclusions: Histopathological and molecular evaluations further confirmed the activation of apoptosis and the suppression of key oncogenic pathways. Collectively, these results underscore the therapeutic potential of thymoquinone as both a monotherapy and an adjuvant to conventional chemotherapy, warranting further validation in preclinical and clinical studies.- Book : 17(4)
- Pub. Date : 2025
- Page : pp.536-536
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2025
Abstract
The Gamma-Flash program, funded by the Italian Space Agency (ASI) and led by the National Institute for Astrophysics (INAF), aims to study high-energy emissions related to thunderstorms, such as terrestrial gamma-ray flashes (TGFs) and gamma-ray glows. The program led to the development of two main detection systems: a ground-based system, installed at the “O. Vittori” Observatory on top of Mt. Cimone (Northern-Central Italy), and an airborne payload, installed on a Cessna Citation Mustang aircraft, for in-flight campaigns. The ground-based detection system consists of five γ-ray and three neutron detectors, and it has been collecting data from Jul 2022 to Oct 2023, overall experiencing 95 days of thunderstorm activity (36% of the total experiment lifetime). During this first observational survey, a gamma-ray glow of ∼ 1.5 min was revealed. The event light curve shows an abrupt interruption at the end, coinciding with the occurrence of a CG lightning discharge, that took place within 2 km from the detectors. The avionic payload consists of 6 γ-ray and 2 neutron detectors. The purpose of this second payload is to collect additional data by flying nearby convective systems, in order to reveal high-energy emissions directly from the sky. To date, two flights have been conducted: the first was an operational test flight on December 22, 2023, lasting 2 hours under clear sky conditions. The second flight, on June 4, 2024, lasted approximately 2.5 hours and took place during thunderstorm activity in Northern Italy. Additional flights are planned for the summer of 2024.- Book : 2985(1)
- Pub. Date : 2025
- Page : pp.012015-012015
- Keyword :
