Search Results (2,988)

Background: Digital tomosynthesis (DTS) is an advanced imaging modality that enhances diagnostic accuracy by offering three-dimensional visualization from two-dimensional projections, which is particularly beneficial in breast and lung imaging. However, this increased imaging capability raises concerns about patient exposure to ionizing radiation. Methods: This study explores the energy and angular dependence of thermoluminescent dosimeters (TLDs), specifically TLD100H, to improve the accuracy of organ dose assessment during DTS. Using a comprehensive experimental approach, organ doses were measured in both DTS and traditional RX modes. Results: The results showed lung doses of approximately 3.21 mGy for the left lung and 3.32 mGy for the right lung during DTS, aligning with the existing literature. In contrast, the RX mode yielded significantly lower lung doses of 0.33 mGy. The heart dose during DTS was measured at 2.81 mGy, corroborating findings from similar studies. Conclusions: These results reinforce the reliability of TLD100H dosimetry in assessing radiation exposure and highlight the need for optimizing imaging protocols to minimize doses. Overall, this study contributes to the ongoing dialogue on enhancing patient safety in diagnostic imaging and advocates for collaboration among medical physicists, radiologists, and technologists to establish best practices. Full article

The substitution conventional steel reinforcement with glass fiber-reinforced polymer (GFRP) bars is a widely adopted strategy used to improve the durability of concrete structures in chloride environments, offering benefits such as enhanced corrosion resistance, reduced maintenance needs, and increased service life. This study investigates the bond behavior between glass fiber-reinforced polymer (GFRP) bars and concrete under long-term chloride dry–wet cycling exposure. Pull-out tests were conducted on various specimens subjected to exposure durations of 0, 3, 6, 9, and 12 months. The experimental results indicate that, after 12 months of chloride dry–wet cycling, the bond strength retention rates of threaded ribbed GFRP with a bond length of 5d, sand-coated GFRP with a bond length of 5d, and threaded ribbed GFRP with a bond length of 7d were 57.9%, 62.2%, and 63.8%, respectively. To predict the GFRP–concrete bond performance after chloride exposure, a novel bond strength model for GFRP bars embedded in concrete, considering the mechanical interlocking effect of ribs, was proposed and validated by the test results. The overall prediction errors for RG-5d, SG-5d, and RG-7d specimens were 0.98, 0.81, and 0.93, respectively. Additionally, a sensitivity analysis was conducted on the main parameters in the model. Finally, the long-term GFRP–concrete bond performance deterioration was estimated using the proposed model. These findings are expected to provide valuable insights into the long-term bond performance and service life prediction of GFRP–concrete members in chloride environments. Full article

Dietary and environmental exposure to aflatoxins via contaminated food items can pose major health challenges to both humans and animals. Studies have reported the coexistence of aflatoxins and other environmental toxins. This emphasizes the urgent need for efficient and effective mitigation strategies for aflatoxins. Previous reports from our laboratory have demonstrated the potency of the green-engineered clays (GECs) on ochratoxin and other toxic chemicals. Therefore, this study sought to investigate the binding and detoxification potential of chlorophyll (CMCH and SMCH) and chlorophyllin (CMCHin and SMCHin)-amended montmorillonite clays for aflatoxin B1 (AFB1). In addition to analyzing binding metrics including affinity, capacity, free energy, and enthalpy, the sorption mechanisms of AFB1 onto the surfaces of engineered clays were also investigated. Computational and experimental studies were performed to validate the efficacy and safety of the clays. CMCH showed the highest binding capacity (Qmax) of 0.43 mol/kg compared to the parent clays CM (0.34 mol/kg) and SM (0.32 mol/kg). Interestingly, there were no significant changes in the binding capacity of the clays at pH2 and pH6, suggesting that the clays can bind to AFB1 throughout the gastrointestinal track. In silico investigations employing molecular dynamics simulations also demonstrated that CMCH enhanced AFB1 binding as compared to parent clay and predicted hydrophobic interactions as the main mode of interaction between the AFB1 and CMCH. This was corroborated by the kinetic results which indicated that the interaction was best defined by chemosorption with favorable thermodynamics and Gibbs free energy (∆G) being negative. In vitro experiments in Hep G2 cells showed that clay treatment mitigated AFB1-induced cytotoxicity, with the exception of 0.5% (w/v) SMCH. Finally, the in vivo results validated the protection of all the clays against AFB1-induced toxicities in Hydra vulgaris. This study showed that these clays significantly detoxified AFB1 (86% to 100%) and provided complete protection at levels as low as 0.1%, suggesting that they may be used as AFB1 binders in feed and food. Full article

Vitamin D (VD), an indispensable micronutrient renowned for its pivotal role in bone health, is increasingly recognized as a frontline therapy for bone-related disorders owing to its involvement in maintaining calcium/phosphorus levels. Beyond these benefits, VD exhibits a modulatory impact on redox imbalance, inflammation, and anti-apoptotic pathways implicated in brain-related disorders. Recent findings reveal a notable decrease in VD and its receptor expression in the cerebrospinal fluid of individuals with brain diseases, indicating a positive association between VD levels and normal brain function. Moreover, emerging reports underscore VD’s potential in mitigating the pathophysiology of neurodegenerative diseases, including memory and motor impairments, mitochondrial dysfunction, and neuronal loss. Extensive in vitro and in vivo studies elucidate VD’s multifaceted neuroprotective mechanisms, effectively mitigating neuronal damage and ATP deprivation, thus reducing mortality and morbidity. This review comprehensively examines VD’s diverse attributes, encompassing antioxidative, anti-inflammatory, anti-apoptotic, and neurogenic effects. It provides contemporary insights into VD’s efficacious actions at appropriate doses and exposures across diverse neurological experimental models. Furthermore, the clinical relevance of VD in treating patients with neurological diseases is explored. Overall, this review contributes to the exploration of potential neuroprotective agents and holds promise for improving human health outcomes in the future. Full article

This study investigates the buckling performance of built-up cold-formed steel (CFS) columns, with a focus on how different thermal exposures and cooling strategies influence their susceptibility to various failure mechanisms. Addressing the gap in the literature on the fire behavior of mild steel (MS)-based CFS columns, the research aims to provide new insights. Compression tests were conducted on MS-based CFS column specimens after they were exposed to fire, to assess their post-fire buckling strength. The columns were subjected to controlled fire conditions following standardized protocols and then allowed to cool to room temperature. The study examined axial load-bearing capacity and deformation characteristics under elevated temperatures. To improve fire resistance, protective coatings—gypsum, perlite, and vermiculite—were applied to certain specimens before testing, and their performance was compared to that of uncoated specimens. A comprehensive finite element analysis (FEA) was also performed to model the structural response under different thermal and cooling scenarios, providing a detailed comparison of the coating effectiveness, which was validated against experimental results. The findings revealed significant variations in axial strength and failure mechanisms based on the type of fire-resistant coating used, as well as the heating and cooling durations. Among the coated specimens, those treated with perlite showed the best performance. For example, the air-cooled perlite-coated column (MBC2AC) retained a load capacity of 277.9 kN after 60 min of heating, a reduction of only 6.0% compared to the unheated reference section (MBREF). This performance was superior to that of the gypsum-coated (MBC1AC) and vermiculite-coated (MBC3AC) specimens, which showed reductions of 3.6% and 7.9% more, respectively. These results highlight the potential of perlite coatings to enhance the fire resistance of CFS columns, offering valuable insights for structural fire design. Full article

Natural gene variants of metabotropic glutamate receptor subtype 7 (Grm7), coding for mGluR7, affect individuals’ alcohol-drinking preference. Psychopharmacological investigations have suggested that mGluR7 is also involved in responses to cocaine, morphine, and nicotine exposures. We review the pleiotropic effects of Grm7 and the principle of recombinant quantitative trait locus introgression (RQI), which led to the discovery of the first mammalian quantitative gene accounting for alcohol-drinking preference. Grm7/GRM7 can play important roles in mammalian ontogenesis, brain development, and predisposition to addiction. It is also involved in other behavioral phenotypes, including emotion, stress, motivated cognition, defensive behavior, and pain-related symptoms. This review identified pleiotropy and the modulation of neurobehavioral processes by variations in the gene Grm7/GRM7. Patterns of pleiotropic genes can form oligogenic architectures whosecombined additive and interaction effects can significantly predispose individuals to the expressions of disorders. Identifying and characterizing pleiotropic genes are necessary for understanding the expressions of complex traits. This requires tasks, such as discovering and identifying novel genetic elements of the genetic architecture, which are unsuitable for AI but require classical experimental genetics. Full article

Teeth are highly durable and useful in forensic identification and studying the impact of environmental factors could aid forensic investigations. Accurate post-mortem interval (PMI) estimation using dental evidence is critical in legal contexts, it requires further exploration. Aims: This study included a scoping review investigating macroscopic and microscopic changes in teeth in various simulated environments (Part 1) and an experimental study assessing changes in teeth and restorations exposed to distilled water, saline water, acidic soil, and alkaline soil (Part 2). Methods: The scoping review analysed publications from five databases using keywords such as ‘Teeth’, ‘Dental’, ‘Water’, ‘Soil’, ‘Acid’, and ‘Forensic.’ The experimental study involved 40 human teeth photographed before and after a 90-day exposure period to record shade variations and macroscopic changes. Results: Part 1: Twenty-six relevant articles from 10 countries (1987–2022) were reviewed, with most focusing on human teeth (77%), unrestored teeth (54%), macroscopic changes (46%), and high-temperature environments (53%). Part 2: Teeth in distilled water (G1) showed no shade variation. In saline water (G2), 60% of teeth decreased in shade. In acidic soil (G3), 40% showed an increased shade, while 50% showed a decreased shade. In alkaline soil (G4), 70% of teeth showed an increased shade. Restorations exhibited minimal changes across environments. Conclusions: Studies on the macroscopic changes because of high temperature on teeth and dental restorative material are popular. Teeth exposed to alkaline and acidic soil showed the most changes in the structure. Full article

Background/Objectives: Regulation of acute inflammatory responses is crucial for host mortality and morbidity induced by pathogens. The pathogenesis of acute respiratory distress syndrome (ARDS) and sepsis are associated with systemic inflammation. p38 MAPK is a crucial regulator of inflammatory responses and is a potential target for acute inflammatory diseases, including ARDS and sepsis. We investigated the therapeutic effects of the TAT-TN13 peptide (TN13) on severe inflammatory diseases, including ARDS and sepsis, in vivo. Methods: To establish the ARDS model, C57BL/6 mice were intranasally (i.n.) administered lipopolysaccharide (LPS; 5 mg/kg, 40 µL) to induce lung inflammation. As a positive control, dexamethasone (DEX; 0.2 mg/kg) was administered intraperitoneally (i.n.) 1 h post-LPS exposure. In the experimental groups, TN13 was administered intranasally (i.n.) at doses of 2.5 mg or 5 mg/kg at the same time point. In the LPS-induced sepsis model, mice received an intraperitoneal injection of LPS (20 mg/kg) to induce systemic inflammation. TN13 (25 mg/kg, i.p.) was administered 1 h after LPS treatment. Control mice received phosphate-buffered saline (PBS). Lung histopathology, inflammatory cell infiltration, cytokine levels, and survival rates were assessed to evaluate TN13 efficacy. Results: TN13 significantly reduced inflammatory cell recruitment and cytokine production in the lungs, thereby mitigating LPS-induced ARDS. In the sepsis model, TN13 treatment improved survival rates by suppressing inflammatory responses. Mechanistically, TN13 exerted its effects by inhibiting the p38 MAPK/NF-κB signaling pathway. Conclusions: These results collectively suggested that TN13 could be an effective treatment option for severe inflammatory diseases. Full article

Although the use of electronic nicotine delivery systems (ENDS) among youth has declined since its peak in 2018, it remains popular among young adults. Despite its popularity, research on the health effects of secondhand exposure to ENDS remains limited. Silicone wristbands offer a simple, cost-effective method for measuring nicotine exposure. The study employed a quasi-experimental design and recruited six dyads consisting of ENDS users and non-users. Over three consecutive months, all participants wore silicone wristbands for one week at a time to assess nicotine exposure. ENDS users had a higher overall median nicotine concentration in their silicone wristbands (423.2 ng/g, IQR: 199.2–669.1) compared to non-users (17.2 ng/g, IQR: 6.5–128.0). This trend was consistent across all time points. Statistically significant differences between ENDS users and non-users were observed during months 1 and 2 (p-values = 0.0303 and 0.0411, respectively), but not during month 3 (p-value = 0.2468). Similar trends were observed in urinary cotinine levels, with higher medians among ENDS users (1013.0 ng/mL, IQL: 442.0–1490.0) compared to non-users (1.3 ng/mL, IQL: 1.0–1.4). A significant correlation was found between urinary cotinine and wristband nicotine levels only in non-users (r = 0.69, p-value = 0.0017). Silicone wristbands worn by non-users can detect secondhand nicotine exposure and are significantly correlated with urinary cotinine. Full article

Carbon dioxide (CO₂) efflux from soil (or soil respiration, SR) is one of the most important yet variable characteristics of soil. When evaluating large areas, CO₂ efflux modeling serves as a viable alternative to direct measurements. This research aims to identify site-specific differences and their effects on empirical CO₂ efflux modeling. The experimental data from 25 years of field observations were utilized to identify the optimal site- and weather-specific models, parameterized for normal, wet, and dry years, for the forest and grassland ecosystems located on similar Entic Podzols (Arenic) in the same bioclimatic coniferous–deciduous forest zone. The following parameters were considered in the examined models: mean monthly soil or air temperatures (Tsoil and Tair), amount of precipitation during the current (P) and the previous (PP) months, and the storage of soil organic carbon (SOC) in the top 20 cm of soil. The weighted non-linear regression method was employed to estimate the model parameters for the normal, wet, and dry years. To increase the magnitude of the model resolutions, we controlled the slope and intercept of the linear model comparison between the measured and modeled data through the change in R₀—CO₂ efflux at Tsoil = 0 °C. The mean bias error (MBE), root-mean-square error (RMSE), and determination coefficient (R²) were employed to assess the quality of the model’s performance. The measured Tsoil, Tair, and P, as well as the litter (for forest) or sod (for grassland) horizon (modeled by the Soil SCLmate Statistical Simulator (SCLISS)), and soil temperatures (Tlit_m, Tsoil_m) and moistures (Mlit_m, Msoil_m), were used for SR simulation. For the CO₂ efflux in the forest ecosystem with the lower SOC availability for mineralization, the direct Tsoil and Tair measurements in combination with SOC storage provided better parameterization for the empirical TPPC model. For the CO₂ efflux in the grassland ecosystem with the high SOC availability for mineralization, the temperature became the governing factor, and the TPPrh model provided better performance over all the considered models. The model’s performance was the best for the wet years, and the worst for the dry years for both ecosystems. For forest ecosystems, the model performance for average precipitation years was equivalent to that in wet years. For grassland ecosystems, however, the model performance was equivalent to that in dry years due to differing exposure and hydrothermal regimes. The wet-year R₀ obtained for both forest and grassland ecosystems differed from the normal- and dry-year values. The measured SR values relevant for the R₀ estimations distribute along the precipitation range for the forest and along the temperature range for the grassland. The SCLISS-modeled Tlit_m and Mlit_m provide good alternatives to direct atmospheric measurements, and can be used as initial temperature and moisture data for CO₂ efflux modeling when direct soil and moisture observations are not available on site. Full article

The use of virtual reality (VR) for flight simulation, particularly in the earliest stages of pilot training, is gaining attention in both research and industry. The use of the technology for this ab initio training requires suitable consideration of the risks of simulator sickness—risks that are heightened relative to conventional simulators. If simulator sickness results in the development of compensatory skills, or otherwise disrupts the training process, the benefits of the technology may be negated. Enabling the effective integration of VR within flight training requires that, to the extent that simulator sickness is an issue, practical mechanisms are developed to manage the occurrence without disrupting existing training structures. The primary objective of this research is, thus, to evaluate an intervention and a nuisance factor in relation to the reduction of simulator sickness, considering their practicality within existing flight training syllabi. The Total Severity (TS) of the Simulator Sickness Questionnaire (SSQ) was evaluated within a quasi-experimental, non-equivalent pre-test–post-test design, incorporating three groups: a prior flight experience nuisance factor group, a prior personal computer aviation training device (PCATD) exposure intervention group, and a control group with neither prior experience nor prior simulator exposure. The results indicated that the TS was significantly reduced for the prior flight experience nuisance factor (r_rb = 0.375), but that the PCATD exposure intervention produced no such reduction (r_rb = 0.016). The findings suggest that VR flight simulation is likely best used as a supplemental tool, introduced after initial airborne experience. Notwithstanding this finding, the relatively low median TS scores (<20) for all groups suggest that the technology may still be used with caution earlier in the training process. No other published research has examined this important effect in the context of the new VR situation. Full article

Radiofrequency fields in the 1–28 GHz range are ubiquitous in the modern world, giving rise to numerous studies of potential health risks such as cancer, neurological conditions, reproductive risks and electromagnetic hypersensitivity. However, results are inconsistent due to a lack of precision in exposure conditions and vastly differing experimental models, whereas measured RF effects are often indirect and occur over many hours or even days. Here, we present a simplified RF exposure protocol providing a single 1.8 GHz carrier frequency to human HEK293 cell monolayer cultures. A custom-built exposure box and antenna maintained in a fully shielded anechoic chamber emits discrete RF signals which can be precisely characterized and modelled. The chosen amplitudes are non-thermal and fall within the range of modern telecommunication devices. A critical feature of the protocol is that cell cultures are exposed to only a single, short (15 min) RF exposure period, followed by detection of immediate, rapid changes in gene expression. In this way, we show that modulation of genes implicated in oxidative stress and ROS signaling is among the earliest cellular responses to RF exposure. Moreover, these genes respond in complex ways to varying RF signal amplitudes consistent with a hormetic, receptor-driven biological mechanism. We conclude that induction of mild cellular stress and reactive oxygen species (ROS) is a primary response of human cells to RF signals, and that these responses occur at RF signal amplitudes within the range of normal telecommunications devices. We suggest that this method may help provide a guideline for greater reliability and reproducibility of research results between labs, and thereby help resolve existing controversy on underlying mechanisms and outcomes of RF exposure in the general population. Full article

This paper investigates a novel combined laser and plasma heating test technique. Integrating the 1.5 kW Raycus RFL-C1500 laser source into the VGU-4 Inductively Coupled Plasma Facility (IPMech RAS) allowed the study of fine-grain MPG-7 graphite ablation in the high-temperature range from 2920 to 3865 K under exposure to subsonic nitrogen plasma flow and combined exposure to nitrogen plasma flow and laser irradiation. Graphite nitridation and sublimation were observed. The subsonic nitrogen plasma flow was characterized by numerical modeling, probes, and spectral measurements. The proposed experimental approach is promising for simulating the entry conditions of planetary mission vehicles into different atmospheres. Full article

Effective wildfire smoke risk and evacuation communication is urgently needed to avert unnecessary deaths as wildfires increase in frequency and intensity. Human exposure to wildfires has doubled in the last two decades. Low-income, marginalized communities are the most disadvantaged in their ability to respond. A systematic literature review of wildfire and wildfire smoke risk communication research between 2014 and 2024 was conducted. Web of Science and Scopus databases were searched using the keywords “wildfire”, “communication”, “wildfire smoke”, “risk”, and “public health”, resulting in 23 studies. The findings revealed marginalized communities were ill-prepared to respond to wildfires and take protective action against wildfire smoke. The findings were summarized across eight areas: the needs of marginalized communities to respond to wildfires, the role of trusted messengers to disseminate wildfire and smoke risk messaging, using diverse channels, timing and frequency considerations for disseminating messages, time-sensitive evacuation versus wildfire smoke risk messaging, targeted messaging for subgroups, the importance of coordinating messages across agencies and local government, and government perspective. Theory did not guide these research efforts with the exception of one study, and most studies were qualitative. The literature did not report on distinguishing indoor from outdoor protective action against smoke risk, reaching vulnerable communities such as nursing and older adult facilities, and postfire messaging. Evidence is needed on these fronts, along with experimental messaging studies to determine the most persuasive messages for motivating protective actions against wildfire and smoke risk. Full article

Barley malt residue (BMR) was subjected to microwave-assisted enzymatic hydrolysis to evaluate its potential as a raw material to produce xylooligosaccharides (XOS) suitable for use as a prebiotic. The influent factors on XOS production, microwave power, exposure time, and xylanase dosage were ascertained with response surface methodology based on Box–Behnken design (BBD). The fitted models of XOS and xylose yields were in good agreement with the experimental results. Using a microwave power of 1235.1 W, a 6 min exposure time, and a xylanase concentration of 89.12 U/g substrate gave the highest yield of XOS: 208.05 mg/g substrate at 4 h of enzyme incubation time. Based on the product composition, BMR-XOS purification by Saccharomyces cerevisiae treatment was superior to the process of activated carbon adsorption and ethanol precipitation treatment and was selected for further experiments. Thin-Layer Chromatography (TLC) and high-performance liquid chromatography (HPLC) clearly elucidated the oligosaccharide compositions, and the result of Fourier Transform Infrared Spectroscopy (FTIR) confirms the molecular structure and sugar components of achieved BMR-XOS. In vitro fermentation of BMR-XOS obtained from this study by the selected probiotics, Lactococcus lactis TISTR 1401, Levicaseibacillus brevis FS 2.1, Lactobacillus casei TISTR 1463, showed similar prebiotic activity compared with the commercial XOS, galactooligosaccharides (GOS), xylose, and glucose (control). In conclusion, the present study was successful in establishing the use of barley malt residue for the extraction of xylan and XOS, which could be further used as a prebiotic. Full article