Search Results (8,324)

Since γδ T cells are present in all jawed vertebrates, we wondered whether butyrophilins, proteins that play a key role in the activation of these cells, were also present in these organisms. Our analyses revealed the presence of genes encoding butyrophilins across all jawed vertebrates, including in squamates, a reptilian clade that is nonetheless reported in the literature to have lost γδ T cells. The conservation of butyrophilins in this group, despite the absence of their only known cellular partner, suggests that they may fulfill an alternative function, possibly through interaction with another ligand. Given their strong conservation across jawed vertebrates, it is reasonable to hypothesize that this alternative ligand may also be present in humans. Full article

Lightweight, lead-free polymer–mineral composites have attracted increasing interest as radiation-attenuating materials for applications where reduced mass and environmental compatibility are required. In this work, the $\gamma$-ray attenuation behavior of poly(ether ether ketone) (PEEK) reinforced with natural palygorskite and pumice was evaluated at filler concentrations of 10–40 wt%. Photon interaction parameters, including the linear attenuation coefficient ($\mu$), half-value layer (HVL), mean free path ($\lambda$), and effective atomic number ($Z_{\mathrm{eff}}$), were computed over the energy range 15 keV–15 MeV using the Phy-X/PSD platform and validated through full Geant4 Monte Carlo transmission simulations. At 15 keV, $\mu$ increased from $1.46{\mathrm{cm}}^{-1}$ for pure PEEK to $4.21{\mathrm{cm}}^{-1}$ and $8.499{\mathrm{cm}}^{-1}$ for the 40 wt% palygorskite- and pumice-filled composites, respectively, reducing the HVL from 0.69 cm to 0.24 cm and 0.11 cm. The corresponding $Z_{\mathrm{eff}}$ values increased from 6.5 (pure PEEK) to 9.4 (40 wt% palygorskite) and 15.3 (40 wt% pumice), reflecting the influence of higher-Z oxide constituents in pumice. At higher photon energies, the attenuation curves converged as Compton scattering became dominant, although pumice-filled PEEK retained marginally higher $\mu$ and shorter $\lambda$ up to the MeV region. These findings demonstrate that natural mineral fillers can enhance the photon attenuation behavior of PEEK while retaining the known thermal stability and mechanical performance of the polymer matrix as reported in the literature, indicating their potential use as lightweight, secondary radiation-attenuating components in medical, industrial, and aerospace applications. Full article

Background: The global dissemination of multidrug-resistant (MDR) Salmonella poses a persistent and serious threat to food safety systems. As a leading poultry-exporting country, Thailand requires a comprehensive understanding of how resistance plasmids spread among Salmonella populations within its chicken production chain. Methods: Between March 2023 and February 2024, 223 Salmonella isolates were collected from chicken slaughterhouses and markets in northeastern Thailand. From these, 19 representative MDR Salmonella enterica isolates, selected based on distinct spatiotemporal distributions, underwent whole-genome sequencing. Genomic analyses included sequence typing, core-genome phylogenetics, and screening for antimicrobial resistance genes. Plasmid replicons were identified, and functional annotation was performed using the COG database. Results: Phylogenetic analysis revealed 11 distinct sequence types within the population. Among these, ST1541 and ST50 showed clear evidence of clonal transmission across different production stages, with a notable clustering pattern observed during the winter season. All sequenced isolates exhibited an MDR phenotype. Plasmids were detected in 78.9% of isolates, with conjugative plasmids being the most frequent type (57.9%). The β-lactamase gene bla_TEM-60 was the most prevalent (78.9%) and showed a strong correlation (r ≥ 0.7) with resistance to both ampicillin and cefotaxime. Functional annotation further revealed an abundance of genes involved in carbohydrate and amino acid metabolism across all isolates. Conclusions: These findings indicate that MDR Salmonella dissemination is driven by two synergistic mechanisms: the clonal expansion of fit lineages and the horizontal transfer of conjugative plasmids harboring β-lactamase genes. We identified IncI-gamma-K1 and Col-related plasmids as key vectors in this process. This study advocates for targeted interventions, guided by a One Health approach, that specifically aim to disrupt plasmid transmission at critical control points, such as slaughterhouses, to curb the spread of antimicrobial resistance. Full article

Respiratory viruses such as SARS-CoV-2, influenzas A and B, respiratory syncytial virus (RSV), human metapneumovirus (hMPV), human parainfluenza virus type 3 (HPIV-3), and rhinoviruses remain major causes of global morbidity. Their rapid evolution, high transmissibility, and limited therapeutic options, together with the absence of approved vaccines for several pathogens, highlight the need for broad-acting and pathogen-independent antiviral strategies. Nitric oxide exhibits antiviral activity through redox-dependent mechanisms, including S-nitrosylation of cysteine-containing viral proteins and disruption of redox-sensitive structural domains. Clinical studies conducted during the SARS-CoV-2 pandemic demonstrated that a nitric oxide nasal spray (NONS) rapidly reduced nasal viral load and transmission. In this study, we evaluated the in vitro virucidal activity of the NONS against a panel of clinically relevant respiratory viruses representing four major virus families. Virus suspensions of approximately 10⁴ CCID₅₀ were exposed to a full-strength NONS for contact times ranging from 5 s to 2 min at room temperature, followed by neutralization and quantification of residual infectivity using endpoint dilution assays. The NONS rapidly reduced viral infectivity across all viruses tested, achieving >3 log₁₀ reductions within 2 min. SARS-CoV-2 variants including Alpha, Beta, Gamma, Delta, Omicron BA.1, and XBB 2.0 were reduced to levels at or below the assay detection limit within 30 s to 2 min. Influenza A and B viruses showed the fastest loss of infectivity, reaching detection limits within 10–15 s. RSV, hMPV, HPIV-3, and human rhinovirus 14 were similarly inactivated within 1–2 min. These findings demonstrate that the NONS exhibits rapid and broad-spectrum virucidal activity against diverse respiratory viruses and supports its potential role in pandemic preparedness but also seasonal use. Full article

Space conditions offer new insights into fundamental biological and molecular mechanisms. The study aimed to evaluate the enzymatic activity of proteinase K (PK) under extreme conditions relevant to space environments: simulated microgravity, hypergravity, and gamma radiation. PK activity was tested using azocasein (AZO) as a chromogenic substrate, with enzymatic reactions monitored spectrophotometrically at 450 nm. A rotating wall vessel (RWV) simulated microgravity, centrifugation at 1000× g (3303 rpm) generated hypergravity, and gamma radiation exposure used cesium-137 as the ionizing source. PK activity showed no remarkable changes under microgravity after 16 or 48 h; however, higher absorbance values after 96 h indicated enhanced AZO proteolysis compared to 1 g (Earth gravity) controls. In hypergravity, low PK concentrations exhibited slightly increased activity, while higher concentrations led to reduced activity. Meanwhile, gamma radiation caused a dose-dependent decline in PK activity; samples exposed to deep-space equivalent doses showed reduced substrate degradation. PK retained enzymatic activity under all tested conditions, though the type and duration of stress modulated its efficiency. The results suggest that enzyme-based systems may remain functional during space missions and, in some cases, exhibit enhanced activity. Nevertheless, their behavior must be evaluated in a context-dependent manner. These findings may be significant to advance biotechnology, diagnostics, and the development of enzyme systems for space applications. Full article

This study evaluates lead-free high-density polyethylene (HDPE) composites reinforced with high-Z oxides (Bi₂O₃, WO₃, Gd₂O₃, TeO₂, and a Bi₂O₃/WO₃ hybrid) as lightweight materials for gamma-ray and fast-neutron shielding. A hybrid computational framework combining Phy-X/PSD with Geant4 Monte Carlo simulations was used to obtain key shielding parameters, including the linear and mass attenuation coefficients (μ, μ/ρ), half-value layer (HVL), mean free path (MFP), effective atomic number (Z_eff), effective electron density (N_eff), exposure and energy-absorption buildup factors (EBF, EABF), and fast-neutron removal cross section (Σ_R). The incorporation of heavy oxides produced a pronounced improvement in gamma-ray attenuation, particularly at low energies, where the linear attenuation coefficient increased from below 1 cm⁻¹ for neat HDPE to values exceeding 130–150 cm⁻¹ for Bi- and W-rich composites. In the intermediate Compton-scattering region (≈0.3–1 MeV), all oxide-reinforced systems maintained a clear attenuation advantage, with μ values around 0.12–0.13 cm⁻¹ compared with ≈0.07 cm⁻¹ for pure HDPE. At higher photon energies, the dense composites continued to outperform the polymer matrix, yielding μ values of approximately 0.07–0.09 cm⁻¹ versus ≈0.02 cm⁻¹ for HDPE due to enhanced pair-production interactions. The Bi₂O₃/WO₃ hybrid composite exhibited attenuation behavior comparable, and in some regions slightly exceeding, that of the single-oxide systems, indicating that mixed fillers can effectively balance density and shielding efficiency. Oxide addition significantly reduced exposure and energy-absorption buildup factors below 1 MeV, with a moderate increase at higher energies associated with secondary radiation processes. Fast-neutron removal cross sections were also modestly enhanced, with Gd₂O₃-containing composites showing the highest values due to the combined effects of hydrogen moderation and neutron capture. The close agreement between Phy-X/PSD and Geant4 results confirms the reliability of the dual-method approach. Overall, HDPE composites containing about 60 wt.% oxide filler offer a practical compromise between shielding performance, manufacturability, and environmental safety, making them promising candidates for medical, nuclear, and aerospace radiation-protection applications. Full article

Microbial fermentation is an important means to enhance the nutrition and functionality of food, and soybean fermentation has a long history and a wide variety of products. This study systematically compared the effects of fermentation and post-ripening processes of Bacillus subtilis natto JLCC513 on the nutritional components, active substances, and sensory characteristics of soybeans. The experimental results showed that, in terms of basic nutrition, fermentation led to a significant decrease in fat and reducing sugar content, followed by an initial increase and then a decrease in total protein content. In contrast, water-soluble protein continued to increase, and the total amount of free amino acids surged. The active nutritional indicators before and after soybean fermentation showed that nattokinase activity continued to increase during fermentation and post-ripening. At the same time, the number of viable bacteria decreased slightly during post-ripening. The increase in the proportion of easily absorbed aglycone-type isoflavones before and after soybean fermentation is accompanied by a sustained increase in vitamin K2 and gamma aminobutyric acid (GABA) content. In terms of sensory quality, color-difference analysis shows a decrease in brightness (L value) and an increase in redness (a value), resulting in the characteristic yellow-brown color of natto. In terms of texture characteristics, the hardness decreases, while the viscosity and elasticity are significantly enhanced. Through GC-IMS analysis of volatile aromas during soybean fermentation and post-ripening, it was found that esters (such as ethyl acetate) and pyrazines (such as 2,3-dimethylpyrazine) increased, and the product flavor shifted from grassy to fruity and nutty. In summary, natto bacteria enhance the digestibility, nutritional value, and sensory acceptance of soybeans through enzymatic hydrolysis and metabolic transformation. The post-ripening stage plays a key role in flavor maturation and further accumulation of active ingredients. Full article

An experimental investigation was conducted to evaluate the statistical properties and scintillation mitigation performance of multi-aperture free-space optical transmission under real-measured atmospheric turbulence. Continuous monitoring of turbulence parameters over a 24 h period showed that the atmospheric coherence length ranged from 3 to 29 cm, indicating that the experimental link operated predominantly under weak-to-moderate turbulence conditions, while a limited number of measurement intervals exhibited relatively strong scintillation and were included for statistical modelling analysis. An 865 m four-channel receiving link was constructed under the measured turbulence conditions to acquire irradiance data for analysis. The results show that the multi-aperture reception significantly suppresses scintillation, reducing the scintillation index from 0.36 to 0.04 under moderate turbulence. The irradiance probability density functions were fitted using lognormal, Gamma–Gamma, exponentiated Weibull, and Málaga (M) distributions. The M distribution exhibited superior adaptability, with fitting accuracy improved by 18.75% under weak turbulence and 13.16% under moderate turbulence. Further analysis shows that the shape parameters of the M distribution vary systematically with turbulence strength, effectively capturing the turbulence-induced evolution of irradiance statistics and providing experimental support for turbulence channel modelling and the optimisation of FSO diversity reception architectures. Full article

Background. Acute radiation injury to the small-intestinal mucosa and the hematopoietic system is a key determinant of early mortality after high-dose total-body irradiation. ε-Aminocaproic acid (EACA), a lysine analogue with antifibrinolytic properties, has been proposed as a potential radioprotective agent, but its effects on intestinal and hematologic injury remain insufficiently characterized. Methods. In this experimental study, 240 male Wistar rats were subjected to single-dose total-body γ-irradiation at 10.6 Gy and randomized into six groups: two non-irradiated controls (CG-1, CG-2), an irradiated control without treatment (CG-3), and three experimental groups receiving EACA (EG-1: 3 h before irradiation; EG-2: 3 h after irradiation; EG-3: both 3 h before and 3 h after irradiation). Pain behavior was assessed using the Rat Grimace Scale. Intestinal damage was evaluated by a modified Radiation Injury Intestinal Mucosal Damage Score (RIIMS_sum), villus and crypt morphometry, and qualitative histology of the ileum. Hemoglobin, leukocytes, and platelets were measured serially, and 30-day survival was analyzed using Kaplan–Meier curves with log-rank tests. Results. Across all EACA regimens, the odds of being in a higher Rat Grimace Scale pain category were reduced compared with CG-3, with the strongest effect in EG-3 (OR 0.42; 95% CI 0.31–0.58). At 72 h after irradiation, the cumulative RIIMS score was lower in EACA-treated groups by approximately 17–36% versus CG-3, with the lowest injury in EG-3 (18.5 vs. 29.0 points). EACA attenuated shortening and blunting of villi, preserved crypt architecture, and mitigated anemia, leukopenia, and thrombocytopenia. Thirty-day survival was 20% in CG-3 and 60%, 65%, and 80% in EG-1, EG-2, and EG-3, respectively (all p < 0.05 vs. CG-3). Conclusions. ε-Aminocaproic acid exerts a pronounced, timing-dependent radioprotective effect in a rat model of acute total-body γ-irradiation, concurrently reducing the severity of radiation enteritis, hematologic toxicity, and early mortality. These findings support further investigation of EACA as a candidate adjunct in the prevention of acute radiation injury. Full article

Gamma-Ray Bursts (GRBs) are intense bursts of high-energy photons which, in just a few seconds, outshine all other $\gamma$-ray emitters in the sky. Due to their extreme luminosity, GRBs are not only important as high-energy astrophysical phenomena but also serve as valuable probe models of the far, high-redshift Universe. The importance of these events has pushed the High-Energy Astrophysics community to propose new mission concepts over the past decade, prompting dedicated research and development efforts to achieve the required technological readiness levels. The X and Gamma-Ray Imager and Spectrometer (XGIS) is one of the two GRB monitors onboard the proposed, upcoming THESEUS space mission. Building on strong heritage from previous studies, ongoing developments and optimizations are focused on enhancing the instrument’s capabilities and increasing its technological maturity. This work presents the current status of the XGIS instrument and the latest technological advancements achieved in preparation for its deployment on THESEUS. Full article

This study aimed to quantify and assess the spatial distribution of ²³⁸U, ²³²Th, and ⁴⁰K in the soils of the Espora Hydroelectric Power Plant (Espora HPP) and Queixada Small Hydroelectric Power Plant (Queixada SHPP) watershed (model hydraulic development areas) and their relationship with the geological, chemical, physical, and biological aspects of the soil. The study areas are located in the Corrente River drainage basin, in the southwestern portion of the state of Goiás, Brazil. Radionuclides were quantified using a PGIS-2 portable gamma spectrometer, with measurements taken at 21 sampling points. Soil samples were collected from the surface layer (0–20 cm) for particle-size and chemical analyses. The results indicated that the average radionuclide contents in the soils were 64.49 Bq/kg for ⁴⁰K, 45.44 Bq/kg for ²³⁸U, and 4.53 Bq/kg for ²³²Th. When comparing these values with the global average established by UNSCEAR, it was observed that ²³²Th and ⁴⁰K concentrations were below the global reference, whereas ²³⁸U concentration exceeded the world average of 33 Bq/kg. Particle-size characterization revealed significant variability in soil texture, with sand content ranging from 51.46 to 90.91%, clay content from 7.45 to 30.64%, and silt content from 1.64 to 17.90%. Organic matter content had an average of 10.09 g/kg, while soil pH ranged from 4.67 to 6.54. The results of this study have demonstrated the relevance of integrating radiometric and geochemical data for assessing environmental safety in hydroelectric development areas. The approach adopted can support monitoring programs and decision-making processes related to soil management and land-use planning in regions influenced by hydraulic infrastructures. Full article

Calcific aortic valve stenosis (CAVS) is a progressive cardiovascular disease associated with oxidative stress-driven osteogenic differentiation of valvular interstitial cells (VICs), yet no pharmacological therapy can prevent its progression. γ-oryzanol (γ-ORZ), a rice bran-derived phytosteryl ferulate, exhibits potent antioxidative and anti-inflammatory activities that may counteract valvular calcification. Here, we show that γ-ORZ markedly attenuates PCM-induced intracellular ROS elevation, osteogenic differentiation, and calcium phosphate deposition in porcine VICs (pVICs). In addition, RT-qPCR and Western blot analyses revealed significant downregulation of calcification markers (RUNX2, OPN, BMP2), along with suppressed SMAD1/5/9 transcription and phosphorylation, decreased p38/ERK MAPK activation, and reduced ALP activity. Collectively, these findings indicate that γ-ORZ mitigates oxidative stress-mediated valvular calcification by inhibiting both canonical and non-canonical BMP2-SMAD/MAPK signaling, suggesting its potential as a medicinal candidate for early intervention in CAVS. Full article

Keratoconjunctivitis sicca (KCS) in dogs is an immune-mediated disorder characterized by aqueous tear deficiency, ocular surface inflammation, and risk of vision loss. Although tear quantity is routinely evaluated using the Schirmer tear test (STT), the accompanying qualitative alterations in tear protein composition remain poorly understood. In this exploratory study, we identified and characterized qualitatively differentially expressed tear proteins in samples collected from seven Beagle dogs with KCS and five healthy Beagles. Samples were collected using filter paper, extracted in phosphate-buffered saline, concentrated by trichloroacetic acid precipitation, and then separated via two-dimensional electrophoresis. Differential protein spots were identified by MALDI-TOF-MS-based peptide mass fingerprinting. Total protein concentrations were determined by measuring UV absorbance at 280 nm and were found to be significantly higher in dogs with KCS (30.7 ± 13.5 mg/mL) than in healthy dogs (11.5 ± 1.8 mg/mL, p < 0.05). Five proteins were identified as differentially expressed: serum albumin, lactotransferrin isoform 1, immunoglobulin gamma heavy chain C, major allergen Can f 1, and lysozyme C. High-molecular-weight proteins were upregulated in KCS, whereas low-molecular-weight proteins (<10 kDa, proline-rich protein-like components) were markedly reduced or absent. These compositional shifts suggest that KCS alters both the quantity and qualitative integrity of the tear proteosome, reflecting impaired tear film homeostasis and diminished ocular surface defense. The results support the potential utility of the tear proteome as a source of diagnostic and therapeutic biomarkers in canine KCS. Full article

Residential water demand exhibits marked variability over time and across users, with direct implications for the sustainable and robust design of water distribution networks. In this study, a high-resolution experimental dataset is analysed to characterise the statistical structure of hourly consumption, deriving mean and variance scaling laws, cross-correlations between user groups, and probability density functions (PDFs) of aggregated demand. The results show that demand does not behave as an independent process. During the morning peak (07:00–08:00), the distribution does not converge to a unimodal shape as aggregation increases, but exhibits a clear bimodality for aggregation levels larger than approximately N ≈ 400 users. This behaviour indicates the presence of two synchronised consumption regimes and a non-negligible average correlation. In contrast, during the evening and night slots, unimodal distributions (Gamma or Lognormal) emerge, consistent with largely independent contributions and limited synchronisation. For comparison, a simplified Poisson Rectangular Pulse (PRP) model is evaluated. While this model reproduces the mean flow rate, it does not capture the observed variance, underscoring the need for models that account for heterogeneity and user correlations. The scaling laws, correlations, and empirical PDFs derived in this study provide a quantitative basis for generating probabilistic demand scenarios, supporting the sustainable, resilient, and robust design of water distribution networks. Full article

Drought, high temperature, salinity, waterlogging, and nutrient deficiency, along with metal toxicity, are among the environmental factors that have resulted in much alteration of many ecosystems by climate change. Such stresses have dramatically lowered the global average human harvest of core crops, which, in turn, has driven an overall decrease in worldwide agricultural productivity. Plants have developed a variety of defense strategies against biotic and abiotic stress. Evidence of the successful roles of phytohormone-like neurotransmitters in ameliorating the response to stress has already been established. One neurotransmitter accumulated by the plants is gamma-aminobutyric acid (GABA), a non-protein amino acid that is essential for signaling in plant growth regulation and development via the control of physiological and biochemical processes. Plant tissues demonstrate rapid accumulation of GABA when exposed to various abiotic stresses. Consequently, it is imperative to understand how this accumulation affects the resistance and productivity of crops in challenging environmental conditions. Previously, different application methods and doses of GABA on different plant species were used under various abiotic stress conditions. The research findings exhibited that the method and concentration of GABA depend on the type of crop. Furthermore, the GABA dose depends on the methods of GABA application. The present review summarizes the potential doses and methods of applications of GABA under different abiotic stress conditions to ameliorate deficiencies in plant growth, yield, and stress tolerance through the avoidance of oxidative damage and maintenance of cell organelle structures. This review will also describe the complex mechanism by which GABA contributes to the attenuation of the effects of abiotic stresses by regulating some important physiological, molecular, and biochemical processes in crops. Full article