Search Results (9,125)

Electromagnetic fields (EMFs), increasingly prevalent due to technological advancements, have raised significant concerns regarding their potential biological effects on living organisms. While much attention has focused on human health, growing evidence suggests that EMFs can also affect invertebrates, which play vital ecological roles. This study investigates the biochemical and cell death biomarker responses to EMF exposure for 24 h or 72 h in Parasteatoda tepidariorum. The focus is placed on the 10 MHz frequency, which is relevant to environmental exposure scenarios. Biochemical biomarkers include heat shock proteins (HSP70) and the percentage of apoptotic and living cells in individuals at their embryonic, young and adult stages. Results indicate that exposure to EMFs can induce measurable stress responses at the biochemical level, with variations depending on developmental stage and protective structures. Embryos outside of the egg sac exhibited significantly elevated levels of HSP70 and apoptosis markers compared to those within the sac, suggesting a partial protective effect of the cocoons. Furthermore, differences in biomarker sensitivity were observed across all the developmental stages and increased with prolonged exposure. These findings contribute to the understanding of EMF-induced biological effects in invertebrates and support the use of P. tepidariorum as a model species for environmental electromagnetic pollution. Full article

Heat stress is a major systemic challenge in poultry, but the role of circulating extracellular vesicles (EVs) in liver-directed adaptation remains unclear. This study investigated whether plasma-derived EVs from heat-stressed chickens (HS_EV) mediate hepatoprotective responses under thermal stress. EVs were isolated from the plasma of control and heat-stressed chickens and characterized by morphology, size distribution, and marker expression. Their biodistribution in vivo and uptake by primary hepatocytes in vitro were also evaluated. Hepatocyte injury was induced by heat exposure, and the effects of HS_EV on proliferation, apoptosis, inflammatory cytokine production, transcriptomic reprogramming, and MYD88/NF-κB/MAPK signaling were assessed. Heat stress induced systemic injury in chickens, increased the release of plasma-derived EVs, and promoted their preferential accumulation in the liver. Whole-transcriptome analysis further showed that HS_EV enhanced glutathione metabolism and related metabolic pathways while suppressing apoptosis- and inflammation-related signaling. In primary hepatocytes, HS_EV, but not control EVs, restored proliferative capacity, reduced apoptosis, suppressed the expression and secretion of IL-1β, IL-6, and TNF-α under heat stress, and was associated with attenuation of the MYD88/NF-κB/MAPK axis. These findings suggest that circulating EVs participate in adaptive intercellular communication during heat stress and identify HS_EV as a potential endogenous mediator of hepatoprotection in chickens. Full article

Urban areas in subtropical regions are increasingly exposed to heat stress as climate change intensifies extreme heat events. In high-density cities, urban renewal is widely implemented to upgrade aging building stock, yet its potential role as a passive heat adaptation strategy remains insufficiently understood, particularly for projects below environmental impact assessment thresholds. This study examines how urban renewal influences neighborhood-scale microclimates through a comparative analysis of six residential renewal cases using computational fluid dynamics (CFD) simulations. Pre- and post-renewal scenarios are evaluated to assess changes in wind environment and thermal conditions, with a particular focus on the spatial extent and distance–decay characteristics of renewal-induced effects. The results reveal a consistent distance–decay pattern of microclimate responses across all cases. The influence of urban renewal is strongest within 0–50 m, remains detectable up to approximately 100 m, and diminishes substantially beyond 100–150 m, indicating a clear neighborhood-scale impact radius. Ventilation performance improves systematically following renewal, while thermal responses are more heterogeneous. Localized cooling of up to 1.5 °C is observed in selected cases, whereas others exhibit negligible temperature change despite enhanced airflow. These findings demonstrate that improved ventilation alone does not guarantee thermal mitigation. Instead, thermal outcomes depend on the interaction between airflow, solar exposure, and surface thermal properties. Urban renewal can therefore function as a form of passive heat adaptation when morphological changes are coordinated with shading and surface design strategies. By quantifying the spatial limits of renewal-induced microclimate effects, this study provides empirical evidence for integrating microclimate considerations into neighborhood-scale planning. The identified influence radius offers a practical reference for climate-responsive urban renewal, particularly in high-density subtropical cities where incremental redevelopment plays a dominant role. Full article

Sheng Mai San (SMS), a traditional Chinese medicine formula for treating qi and yin deficiency, is widely used in the management of conditions such as cardiovascular diseases and heatstroke. However, its role in mitigating heat stress (HS)-induced liver injury remains underexplored. In this study, a rat model of HS was established under high-temperature and high-humidity conditions, and SMS was administered as an intervention. The pharmacodynamic effects of SMS were comprehensively evaluated through histopathological examination, detection of heat shock protein 70 (HSP70) and heat shock protein 90(HSP90) expression, and analysis of liver function biomarkers (AST, ALT). Meanwhile, oxidative stress indicators were measured using biochemical assay kits (GSH, SOD, CAT, MDA, T-AOC), and transmission electron microscopy was employed to observe mitochondrial ultrastructure, thereby assessing the protective effects of SMS on hepatic oxidative stress and mitochondrial damage induced by HS. In vitro, BRL-3A cells were cultured, subjected to HS, and treated with SMS. Cell viability was assessed using the CCK-8 assay, and changes in mitochondrial reactive oxygen species (ROS) levels, mitochondrial permeability transition pore (MPTP) opening, and mitochondrial membrane potential (MMP) were evaluated using fluorescent probes. The results showed that SMS effectively restored HS-induced histopathological damage in rat liver tissues, reduced serum AST and ALT levels, and downregulated the mRNA expression of HSP70 and HSP90 in liver tissues. Meanwhile, SMS strengthened the hepatic antioxidant system by increasing the levels of GSH, SOD, T-AOC, and CAT, while decreasing MDA content. In vitro experiments confirmed that SMS increased the viability of BRL-3A cells, reduced ROS production, improved MPTP opening/closing regulation, and stabilized MMP. This study provides a clinical reference for its application in treating HS-related conditions in humans and animals. Full article

Wildfires that destroy residential infrastructure can generate chemically complex soil contamination; however, post-fire screening is often limited and does not directly reflect biological hazards. Herein, we integrated a multi-stress lux-based whole-cell bioreporter panel of genetically engineered Escherichia coli strains with non-targeted LC-MS profiling to obtain a mechanism-informed assessment of soils collected from a residential property impacted by the January 2025 Los Angeles wildfires. The bioreporter panel resolved heterogeneous and statistically significant stress signatures across the analyzed samples. In particular, extracts from U3–U5 produced selective suppression of the membrane and fatty acid biosynthesis bioreporters, along with reduced growth. In contrast, extract U5 induced a proteotoxic heat-shock response signature. In parallel, non-targeted LC-MS detected 1813 chemical features and enabled the putative annotation of a subset of signals consistent with combustion-derived organics and reactive electrophiles, providing a chemical context for the observed bioassay fingerprints. The integrated workflow provides mechanism-resolved hazard triage within 48 h, as implemented herein (24 h elutriate preparation plus up to 20 h microplate kinetics), supporting the prioritization of hotspots for confirmatory analysis, remediation, and risk assessment. Full article

Climate warming in Mediterranean vineyards accelerates grape ripening and increases the incidence of sunburn and berry shriveling, leading to imbalances in grape composition and wine quality. This study evaluated the combined effects of a non-positioned training system (asymmetric sprawl) and foliar application of kaolin particle film on vine microclimate, agronomic performance and wine aroma profile in a Syrah cv. vineyard under warm conditions. Vine canopy temperature was monitored by UAV thermography at veraison and harvest, while grape damage, yield components and vegetative balance were assessed at harvest. Wines obtained from each treatment were analysed for chemical composition, volatile compounds and sensory attributes. Kaolin application significantly reduced canopy temperature, particularly under water-limited conditions at veraison (up to 1.9 °C), and the combination with sprawl training decreased the proportion of sunburnt and shrivelled clusters. These microclimatic modifications were associated with higher ethanol content, improved colour intensity and increased total polyphenol index in wines. The combined strategy also enhanced the concentration of key aroma compounds, especially terpenes and fruity esters, resulting in higher values of citrus, floral and fruity aromatic series. Sensory evaluation confirmed a better overall appreciation of wines produced from vines managed with both practices. Overall, the integration of canopy architecture modification and reflective particle film represents an effective strategy to mitigate heat stress effects in warm viticultural regions, improving grape physiological performance and contributing to the preservation of wine aromatic quality under climate change scenarios. Full article

Accurately quantifying the driving mechanisms of land surface temperature (LST) is fundamental to developing climate-resilient urban strategies. However, traditional linear models often fail to capture the complex nonlinear interactions and spatial non-stationarity inherent in urban thermal environments, especially when hindered by multicollinearity among morphological indicators. This study proposes a multi-scale spatial explainability attribution framework by integrating an XGBoost machine learning model with SHAP (SHapley Additive Explanations) to decipher the thermal dynamics of Changchun, a representative cold-region city in China. Utilizing a 500 m grid-based dataset, we incorporated 3D urban morphology (BVD), land cover (NDVI, NDWI), and socioeconomic factors. The results indicate that the XGBoost model achieves superior predictive performance (R² = 0.694) compared to traditional OLS models. SHAP global attribution identified Building Volume Density (BVD) as the primary warming driver, as its three-dimensional volume creates “thermal traps” through radiation trapping and reduced ventilation. Notably, NDVI exhibits a significant nonlinear “cooling threshold effect” at 0.3, beyond which its mitigation efficiency stagnates or even reverses due to vegetation fragmentation and heat-induced physiological stress. Furthermore, spatial mapping reveals a distinct “sign reversal” in NDWI’s impact, reflecting the dualistic thermal regulation of water bodies across different urban–rural gradients. These findings suggest that urban thermal management strategies should shift from merely restricting 2D surface occupancy (e.g., Building Density) to a more sophisticated approach focused on precisely controlling 3D volume intensity (BVD). This study provides a “point-to-area” diagnostic tool supporting a transition to spatially targeted urban planning interventions. Full article

Agricultural carbon sequestration is increasingly threatened by heatwaves, yet accurately simulating crop-explicit net ecosystem exchange (NEE) under heat stress remains challenging. In this study, we used a WRF–VPRM–CROP model to simulate the spatiotemporal dynamics of NEE for rice, wheat, and maize in China, quantifying the impacts of the record-breaking 2022 heatwave. Model validation against multi-source observations confirmed its reliability, with correlation coefficients (r) reaching 0.49–0.85 (p < 0.001). Results show that the cumulative summer NEE of the study region reaches 620.32 Tg C, with contributions of 274.94 Tg C from rice and 345.09 Tg C from maize, while wheat contributes 157.83 Tg C during spring. The 2022 heatwave led to substantial reductions in crop NEE, with decreases of 79.70 Tg C for rice, 33.13 Tg C for wheat, and 100.74 Tg C for maize. Total summer NEE decreased by 171.46 Tg C, with an annual reduction of 213.57 Tg C. Spatially, the most pronounced declines in NEE are concentrated in East China and North China, whereas slight increases are observed in western Heilongjiang (maize-growing areas) and parts of eastern coastal wheat-growing regions. At the provincial scale, the most severe yield losses occur in Henan (29.65 Mt) and Shandong (14.50 Mt). This study quantifies the impacts of extreme heatwaves on carbon exchange in China’s major staple crop systems, providing a scientific basis for regional agricultural climate adaptation and disaster risk mitigation. Full article

This review summarizes the base materials, joining methods, filler materials, and principal technical challenges in endoscope joining fabrication, and proposes practical strategies to improve joint reliability under clinical constraints. We conducted a comprehensive search in multiple databases, including Web of Science, Google Scholar, patent databases, Scopus databases, and Medline (via PubMed), for articles on the joining for precision endoscope fabrication, covering the period from 1950 to 2026. We employed the combinations of keywords, “endoscopy”, “minimally invasive surgery”, “welding”, “joining”, “sealing”, “soldering”, “bonding”, and “brazing”. Approximately 500 references were retrieved. After excluding duplicates and irrelevant studies, 158 publications met the inclusion criteria. Data on base materials, joining, processes, filler materials, and technical issues related to sterilization, corrosion, and microstructural evolution were extracted and analyzed. Endoscopes are multi-material systems, involving metallic biomaterials (stainless steels (SSs), titanium alloys, nickel-based alloys, etc.), optical functional materials (glass, sapphire, quartz, etc.), engineering plastics, ceramics, composite materials, and coatings. Joining, sealing, and functional integration have been achieved via adhesive bonding, laser soldering, laser brazing, wave soldering, reflow soldering, fusion welding, and other joining techniques. The main challenges include how to reliably join highly mismatched dissimilar materials, how to fabricate low-residual-stress joints, and how to increase the long-term resistance to sterilization-induced degradation and thermal aging over repeated 100–200 °C thermal cycles. Conventional joining techniques struggle to balance mechanical integrity, joint hermeticity, and long-term stability under such harsh cyclic conditions. The resulting joints may suffer surface yellowing, interfacial debonding, microcracking, delamination, or progressive property degradation during service. We propose the following three strategies to achieve reliable, low-residual-stress, and sterilization-resistant joining of dissimilar materials for endoscopes: (1) A synergistic design that combines thin-film engineering (including evaporation, sputtering, and electroplating) with silver anti-oxidation layers is proposed to reduce residual stresses and to enhance the joint hermeticity. (2) To develop principles for the selection of multi-joining processes to achieve the multi-material integration and functional assembly of dissimilar material components. (3) To develop the laser-based joining methods (fusion, brazing, or braze-welding) for precision control of heat input, bonding quality, and the least damage to the heat-sensitive components. Full article

Aerobic exercise capacity, best quantified by maximal oxygen uptake (VO_2max), varies between individuals and is dependent on cardiac output (CO) and oxygen uptake in the periphery (a-vO₂ diff). Environmental stressors like hypoxia, microgravity, and heat negatively impact these parameters, thereby reducing aerobic exercise capacity. However, in response to acute and chronic exposures to these environments, compensatory processes serve to counteract reductions in VO_2max. In hypoxic environments, reduced oxygen partial pressure (PO₂) leads to hypoxic pulmonary vasoconstriction (HPV) and a diffusion limitation at the level of the lungs and skeletal muscle, resulting in a reduction in VO_2max. Microgravity environments reduce VO_2max through cardiac and skeletal muscle deconditioning, as well as reductions in plasma volume (PV), resulting in an increase in sympathetic nerve activity through baroreceptor-mediated pathways. In heat stress environments, increases in skin perfusion upon acute exposure hinder exercise performance, whereas compensatory PV expansion mitigates further decreases in VO_2max. As humans are increasingly exposed to austere environments and environmental extremes, it is critical to understand how these environments impact cardiovascular exercise physiology so that effective strategies and protocols ensuring proper aerobic functioning may be implemented. Full article

Urban heat stress is a growing challenge in hot semi-arid cities, where neighbourhood urban design influences microclimate and outdoor comfort. This study evaluates the effect of neighbourhood spatial layout in Erbil city, using ENVI-met simulations. Five neighbourhoods with varying layouts were modelled under standardized conditions, including uniform building height, surface characteristics, and meteorological forcing. Hourly outputs of air temperature, relative humidity, wind speed, surface temperature, mean radiant temperature, universal thermal climate index, and sky view factor were analyzed after excluding the spin-up period. Results indicate that, while all neighbourhoods exhibited similar diurnal timing of thermal extremes, a key distinctive finding is the identification of a neighbourhood that behaves differently across seasons. The Pavilion neighbourhood remained cooler during summer conditions, while maintaining warmer thermal conditions during winter. This dual seasonal behaviour contrasts with the other neighbourhoods, which generally exhibit a trade-off between reduced summer heat stress and winter cooling. The Pavilion neighbourhood is distinguished by the presence of integrated water lagoons, suggesting that the blue infrastructure, in combination with spatial openness and greenery, can moderate thermal extremes. Overall, the study highlights the importance of neighbourhood-scale spatial design in mitigating urban heat and provides evidence to support the development of sustainable neighbourhoods. Full article

This study investigates a thermal management strategy for butyl/chloroprene rubber (IIR/CR) bladder compounds by incorporating hexagonal boron nitride (h-BN) as a thermally conductive filler to enhance heat transfer efficiency. Compounds containing 0, 10, 25, and 33 wt% h-BN were prepared via solution mixing to ensure uniform dispersion and subsequently vulcanized using a hot press. The materials were characterized in terms of morphology, cure behavior using a moving die rheometer (MDR), thermal conductivity, crosslink density, mechanical properties, and dynamic mechanical analysis (DMA). The incorporation of h-BN significantly enhanced thermal performance, nearly doubling the thermal conductivity at 33 wt%. MDR measurements demonstrated that this improved heat transfer capability accelerated the thermal onset of vulcanization, effectively reducing scorch time. Mechanical testing revealed a systematic increase in stiffness at application-relevant low strain levels (25–50%), attributed to hydrodynamic reinforcement, accompanied by a progressive increase in elongation at break. This enhanced extensibility is associated with the presence of lamellar h-BN platelets, which facilitate stress redistribution and promote dynamic chain mobility under deformation. DMA showed that h-BN incorporation increased the storage modulus and intensified the Payne effect, confirming the formation of a robust physical filler network. Overall, the incorporation of h-BN delivers a formulation pathway for energy-efficient tire curing bladders by significantly improving heat transfer efficiency and dimensional stability. Full article

The radial heat transfer mechanism of compacted conductors in overhead insulated cables is unclear, and the insulation layer complicates the thermal boundary conditions, limiting the direct applicability of existing ampacity calculation methods. Based on the Morgan model framework, this paper proposes an ampacity calculation method that accounts for the “plastic-then-elastic” deformation characteristics of compacted conductors. Material plastic flow and elastic deformation of the substrate are incorporated to refine the formulations for interlayer thermal contact conductance and thin-layer air gap thickness, while the equivalent distance of air voids is corrected using the fill factor. An iterative convergence procedure for the insulation outer surface temperature is established to accurately evaluate conductor Joule losses. Validated by wind tunnel tests on JKLGYJ 240/30 cables, the proposed method yields a radial temperature difference of 2.41 °C, closely matching the measured 2.6 °C, with an error of 7.4% compared to 13.5% for the conventional Morgan model. Parametric analysis reveals that equivalent radial thermal conductivity is independent of external environmental factors. Conductor stress has a negligible effect on the ampacity (variation < 0.1%). Under low wind speeds (0–5 m/s), the ampacity increases substantially with wind speed. Full article

The extent of, and limits of, the metabolic flexibility of feedlot cattle to cope with heat loads of varying intensity and duration is a research gap. Two cohorts of 12 Black Angus steers were housed in climate-controlled rooms (CCR) and subjected to three thermal periods: PreChallenge (5 days), Challenge (7 days) and Recovery (5 days). PreChallenge and Recovery provided thermoneutral conditions. The Challenge simulated a strong heatwave. Finally, the steers were returned to outdoor pens for 20 days. The animals were bled on days 3, 5, 7, 8, 9, 10, 11, 12, 13, 15, 17, 24 and 38. A clinical plasma biochemistry panel was used to measure the concentrations of major metabolites and electrolytes. During Challenge, energy metabolites fell (except for β-hydroxybutyrate). Creatinine, urea and total bilirubin rose rapidly. In Recovery, the major liver enzymes were released into plasma, and total bilirubin remained high. Most analytes showed non-linear relationships with core temperatures during Challenge, suggesting threshold-dependent responses rather than gradual dose-dependent adjustments. The responses and relationships differed from those reported for moderate heat load challenge and recovery. We integrated the metabolic changes over the course of the experiment with previously reported metabolic hormone and physiological responses of these steers. Full article

The continuous monoculture in Populus × euramericana ‘Neva’ plantations is closely related to the accumulation of phenolic acids in the soil, and these phenolic compounds exert a certain influence on plant nitrogen uptake. Leguminous plants can replenish soil nitrogen through biological nitrogen fixation, which is of great significance for enhancing plant productivity. This study employed different concentrations of phenolic acid treatments (0T, 0.5T, 1.0T, 1.5T, 2.0T) to analyze the photosynthetic characteristics of five phenolic compounds in a poplar–soybean (Glycine max (L.) Merr.) intercropping system, thereby providing a basis for biological management strategies aimed at increasing the yield of poplar monoculture stands. The results indicate that (1) P_n in poplar monoculture, soybean monoculture, and soybean intercropping all decreased as phenolic acid concentration increased, whereas P_n in poplar intercropping increased with rising phenolic acid concentration. Under treatments ranging from 0T to 1.5T, the decrease in P_n in the pure poplar, pure soybean, and intercropped soybean systems was primarily due to stomatal limitations, whereas under treatments ranging from 1.5T to 2.0T, it was primarily due to non-stomatal limitations. (2) Poplar, soybean, and soybean-intercropped poplar adapted to environmental stress by dissipating excess light energy absorbed by PS II as heat. The intercropping system effectively optimized poplar fluorescence parameters and mitigated the damage caused by phenolic acid stress to its photosynthetic machinery. (3) Chlorophyll A, chlorophyll B, and total chlorophyll in poplar and soybean leaves were significantly inhibited. (4) The biomass of poplars grown in monoculture decreased as phenolic acid concentration increased, whereas the biomass of poplars in intercropping showed the opposite trend. It is evident that, under phenolic acid conditions, poplar–soybean intercropping can mitigate the effects of phenolic acid stress to a certain extent. Full article