Search Results (1,279)

Despite advances in liver machine perfusion (MP), ischemia–reperfusion injury (IRI) remains a major challenge in liver transplantation, with energetic stress and mitochondrial dysfunction recognized as key drivers of damage exacerbation. We investigated whether fractions enriched with extracellular vesicles (EVs) derived from mesenchymal stromal cells can preserve energetic homeostasis in rat livers undergoing normothermic MP (NMP). An established NMP rat model was used (n = 5 per group). After procurement, livers underwent NMP for 4 h, preceded or not by 30 min cold ischemia (CI). EVs (NMP + EVs and CI + NMP + EVs) or saline (NMP and CI + NMP) were randomly administered to the perfusion fluid. Perfusate samples were collected throughout the procedure, and biopsies were taken at the end of NMP. Ischemic livers exhibited succinate accumulation, flavin mononucleotide (FMN) release, activation of reverse electron transport, and adenosine triphosphate (ATP) depletion. EV treatment effectively counteracted these effects, restoring a metabolic profile comparable to that of non-ischemic livers. Moreover, EVs improved adenosine monophosphate/ATP ratios and prevented AMP-activated protein kinase activation, a key energy-stress sensor. Furthermore, EVs reduced oxidative stress markers, cell death mediators, and pro-inflammatory cytokines, indicating a broad cytoprotective and anti-inflammatory effect. These findings support the potential of EVs to preserve mitochondrial function, restore energy balance, and reduce inflammation, thereby improving liver cell viability during NMP. Full article

Fresh Pleurotus pulmonarius is highly perishable during logistics because of its high water content, active respiration, and susceptibility to oxidative damage and membrane deterioration. This study optimized modified atmosphere packaging (MAP) conditions and evaluated their effects on postharvest quality and membrane lipid stability under simulated logistics temperature fluctuations. Single-factor and orthogonal experiments were used to optimize the package gas composition, including O₂ and CO₂ concentrations, as well as the packaging film. The selected MAP treatment (5% O₂ + 20% CO₂ with ethylene vinyl alcohol copolymer film) was compared with the control during 3 d of simulated logistics at 25 °C followed by 2 d of cold storage at 4 °C. Compared with the control, MAP maintained higher sensory quality, reduced weight loss and browning, and preserved total phenolic and flavonoid contents. It also inhibited O₂^.− and malondialdehyde accumulation, enhanced superoxide dismutase, catalase, and ascorbate peroxidase activities, and delayed ascorbic acid and glutathione depletion. Moreover, MAP reduced membrane permeability, suppressed lipase, lipoxygenase, and phospholipase D activities, delayed phospholipid degradation, and maintained higher unsaturated fatty acid levels, U/S, and IUFA. These results indicate that MAP delays postharvest deterioration of P. pulmonarius during the 5-day simulated logistics and cold storage period, partly by maintaining ROS homeostasis and membrane lipid stability. Full article

Background: Perilla seed oil (PSO) is a high-nutritional-value oil and widely used in functional foods, and derives from the mature seeds of Perilla frutescens. This study aimed to systematically evaluate the nutritional characteristics and safety of PSO, as well as to investigate its lipid-modulating effects and the underlying changes in gut microbiota in hyperlipidemic conditions. Methods: The nutritional characteristics of PSO (prepared via seed cleaning, cold-pressing, filtration, and solvent extraction) were evaluated by comparing it with 15 representative vegetable oils, focusing on fatty acid composition, total phenolic and flavonoid contents, metal elements, and physicochemical indices. The safety of PSO was assessed through acute oral toxicity testing in Kunming mice (doses: 2.5, 5, 10 g/kg) with general observations, histopathological examination, and serum biochemical analysis. Additionally, a high-fat diet (HFD)-induced hyperlipidemic Sprague-Dawley (SD) rat model was established to explore PSO’s lipid-modulating effects and its regulatory role in gut microbiota, using serum biochemical detection, liver pathology examination, 16S rRNA gene sequencing, and short-chain fatty acid (SCFA) analysis. Results: PSO possessed the highest α-linolenic acid (ALA) content among the tested oils, along with a favorable unsaturated fatty acid ratio. Notably, PSO was rich in zinc and free of toxic elements. In HFD-fed rats, 10 g/kg PSO significantly reduced serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels, increased high-density lipoprotein cholesterol (HDL-C), and alleviated hepatic damage. Moreover, PSO modulated gut microbiota by enriching probiotic populations and elevating intestinal production of short-chain fatty acids (SCFAs), particularly propionate and butyrate. Conclusions: PSO is a nutritionally rich and safe edible oil with notable lipid-modulating properties, highlighting its potential as a dietary intervention for preventing lipid metabolism disorders. Full article

The durability degradation of airport cement concrete pavements remains a critical concern in cold and severely cold regions. Even concrete that satisfies current durability standards often exhibits rapid performance deterioration after only a few years of service under harsh environmental conditions. This study investigates the effectiveness of a silane protective material in improving the freeze–thaw resistance of airport pavement concrete. Key durability indicators, including mass loss rate and relative dynamic modulus of elasticity, were evaluated. The experimental analysis focused on the performance enhancement provided by silane impregnation treatment under both multi-cycle freeze–thaw conditions and ultra-low-temperature (−30 °C) exposure, with particular emphasis on resistance to water freeze–thaw damage and deicing-fluid freeze–thaw corrosion. The results demonstrate that silane-impregnated specimens exhibited significantly reduced mass loss after 500 freeze–thaw cycles, along with an approximately 50% increase in flexural strength. Under ultra-low temperatures, the treatment effectively mitigated freeze–thaw deterioration, reducing deicing salt scaling by over 90%. Furthermore, the abrasion loss per unit area was reduced by approximately 68%. These findings indicate that silane impregnation enhances concrete durability from multiple perspectives—including frost resistance, salt–frost resistance, and wear resistance—by improving the pore structure and interfacial properties. Consequently, it represents a reliable technical solution for improving the long-term durability of airport concrete pavements. Full article

Cold seawater immersion is a critical lethal risk in maritime accidents and military operations, frequently inducing fatal myocardial dysfunction. However, the mechanisms underlying this seawater immersion hypothermia-induced cardiac injury remain poorly defined. This study aimed to elucidate the pathological progression and underlying mechanisms of myocardial injury induced by cold seawater immersion. A male SD rat model was immersed in 15 °C seawater for 2 h. Echocardiography, transmission electron microscopy, transcriptomics, and Western blot were performed to assess cardiac function, mitochondrial ultrastructure, and molecular mechanisms. Cold stress triggered progressive bradycardia (~480 to ~100 bpm) with initial Frank–Starling compensation, followed by decompensation with reduced cardiac output and impaired diastolic function. Mitochondrial ultrastructural damage preceded histological lesions and was accompanied by elevated cardiac injury markers (cTnT, CK-MB, BNP). Cardiac tissue exhibited upregulated TNF-α, IL-1β, and IL-6, while transcriptomic analysis revealed enrichment of inflammatory pathways (TNF, NF-κB) and coordinated upregulation of pattern recognition receptors including scavenger receptor, Toll-like receptor, and NOD-like receptor families. The Western blot confirmed NF-κB activation, NLRP3 inflammasome assembly, and the N-terminal fragment of gasdermin D (GSDMD-NT) accumulation, indicating pyroptotic cell death. These findings demonstrate that cold seawater stress disrupts mitochondrial homeostasis and activates the NF-κB/NLRP3/pyroptosis cascade, contributing to inflammatory cardiomyocyte death and cardiac decompensation. This mechanistic insight may inform therapeutic strategies for seawater immersion hypothermia. Full article

Tropical mid-size cities on alluvial floodplains face compounded flood challenges combining pluvial accumulation from intense convective storms, regulated river overflow, and aging drainage networks. This study presents an integrated framework for Monteria, Colombia (~450,000 inhabitants; Sinu River, Caribbean lowlands), within Colombian Decree 1807/2014 and structured in four phases. (1) Hazard: A Rain-on-Grid 2D HEC-RAS 6.6 model covering 4090 ha, calibrated against four gauged events, identifies three dominant pluvial mechanisms (poor hydraulic connectivity, limited evacuation capacity, downstream channel overflow), plus 17 critical fluvial erosion points affecting ~289 properties at 100-year return period. (2) Vulnerability: Depth-damage functions from 1465 household surveys yield 36.36% of 3015 assets in high risk and 57.77% in medium risk. (3) Measures: Scenario M2 (channel widening plus dikes, land-raising, retention lagoons) removes 80 ha of flooding while displacing 28 ha at COP 845 million pre-design cost. Non-structural measures include a Sustainable Urban Drainage Master Plan, IoT-based Early Warning System, minimum construction-elevation map, and land-management instruments. A Monte Carlo residual-risk model reduces baseline risk to 19.9% under full implementation. (4) Emergency: A February 2026 cold-front event was addressed with a 4300 m perimeter dike and six pump stations deployed jointly by the Regional Environmental Authority (CVS) and Municipal Administration. Full article

Silicon plays an important role in enhancing plant tolerance to abiotic stress. However, the differential regulatory effects of ionic silicon (Ion-Si) and silicon nanoparticles (SiNPs) on rice seedlings under low temperature (LT) stress have been less studied. This study aimed to investigate the effects of ionic silicon and silicon nanoparticles on rice growth, photosynthetic performance, carbon metabolism, antioxidant defense, and yield formation under low-temperature stress. The results indicated that low-temperature stress significantly inhibited the growth of rice seedlings. Exogenous application of Ion-Si and SiNPs effectively alleviated LT-induced growth inhibition and promoted the recovery of rice. SiNPs demonstrated a stronger effect than Ion-Si in maintaining seedling growth, particularly in enhancing plant height, root length, leaf area, dry weight, and root activity. Low-temperature stress significantly reduced chlorophyll content and photosynthetic capacity, including net photosynthetic rate, stomatal conductance, transpiration rate, intercellular CO₂ concentration, and Rubisco activity. However, under LT stress, both Ion-Si and SiNPs increased chlorophyll content, improved photosynthesis, and enhanced Rubisco activity, with SiNPs showing greater improvement in photosynthetic performance compared to Ion-Si. Additionally, silicon application regulated carbohydrate metabolism by increasing soluble sugar content and enhancing the activities of sucrose phosphate synthase and sucrose synthase, thereby promoting osmotic regulation and energy supply. SiNPs had a stronger effect on carbohydrate metabolism and photosynthate transport than Ion-Si. Furthermore, LT stress increased oxidative damage, manifested as elevated levels of H₂O₂ and malondialdehyde. Exogenous Ion-Si and SiNPs reduced ROS accumulation and lipid peroxidation by increasing the activities of antioxidant enzymes, including superoxide dismutase, peroxidase, and catalase. Compared with Ion-Si, SiNPs showed a stronger ability to enhance antioxidant defense and alleviate oxidative damage. Application of silicon mitigated yield loss under low temperature stress, and SiNPs was more effective than Ion-Si in maintaining rice yield, mainly by increasing the number of effective panicles, grains per panicle, and seed setting rate. This study revealed the distinct physiological roles of Ion-Si and SiNPs in rice cold tolerance and provided a theoretical foundation for the application of silicon-based fertilizers in rice production under low-temperature conditions. Full article

Driven by orchard labor shortages and rising demand for intelligent harvesting, automated apple picking requires a balance between conformal enveloping and slip-resistant stability. To reduce damage and slippage caused by fragile skins, variable morphologies, and motion disturbances, this study proposes a multi-joint pneumatic flexible apple-picking hand with adjustable circumferential configuration. Based on structural configuration determining grasping stability, six apple-morphology-based finger-base supports were designed. Parametric analysis of soft gripper cavities identified an isosceles trapezoidal profile as the best configuration. Using the Yeoh constitutive model, an equivalent joint model for conformal gripping was developed, and genetic algorithm (GA) optimization selected the four-joint design as the preferred configuration. Static finite element simulations determined an operating pressure of 20.32 kPa. Grasping stability was quantified by relative slip displacement in rigid–flexible coupled dynamic simulations. Among the tested support configurations within 60–110°, the 90° bracket produced the most stable slip response under vertical and horizontal disturbances. Thin-film pressure tests showed an asymmetric but stable three-finger load-sharing pattern. Field trials in a high-density dwarf spindle orchard achieved an 83.98% harvesting success rate. After 72 h of cold storage, no obvious surface browning, epidermal abrasion, or compression marks were observed during visual inspection. This assessment was limited to visible external damage and did not include quantitative evaluation of internal bruising, firmness degradation, flesh browning, or long-term storage quality. These results demonstrate stable grasping performance and low visible external damage under the tested conditions. Full article

‘Jinyan’ is an interspecific hybrid kiwifruit (Actinidia eriantha × A. chinensis). It is a large, yellow-fleshed fruit with good taste and long storage potential. It is commonly referenced that storage potential is linked to the harvest maturity of the fruit and the subsequent temperature management. Hence, the findings from research covering the maturation, storage temperatures, ripening, and quality of ‘Jinyan’ fruit from the same orchard across three seasons have been evaluated with an overall objective of defining harvest and storage criteria for ‘Jinyan’ fruit. Good postharvest performance includes fruit not becoming too soft too soon in storage and retaining firmness at shelf temperatures. It was confirmed that harvest maturity is critical to the good storage performance of ‘Jinyan’ kiwifruit. Harvest time significantly affected fruit softening during cold storage, and treatment with the ethylene action inhibitor 1-methylcyclopropene slightly delayed fruit softening. Harvesting much before 180 days after full bloom, or at <9% soluble solids content (SSC), resulted in high incidences of chilling injury (41.8–52.0% after 24 weeks of cold storage at 1 °C + 7 d at 20 °C). These chill-damaged, early-harvested fruits also had a high incidence of rot. Leaving the fruit on the vine much after this threshold reduced chilling injury, but increased the risk of rot on otherwise sound fruit (total rot incidence ranging from 25.9% to 89.0% depending on maturity at harvest). As well as chilling risk, early-harvested fruit may reduce the consumer’s liking of the fruit because of a reduced ripe fruit SSC (rSSC). Consumer liking may also be reduced for long-stored fruit in years of low fruit dry matter content. The impact of low rSSC on consumer liking and the presence of any threshold values requires confirmation. These findings define a clear indication of when fruit should be harvested for long storage, whilst minimizing the risk of disorders. Full article

Prostate cancer remains a major therapeutic challenge, particularly after progression to castration-resistant disease, where persistent androgen receptor signaling, metabolic adaptation, immune escape, and treatment resistance jointly limit clinical benefit. Regulated cell death (RCD) is increasingly recognized not only as an endpoint of tumor cell elimination but also as a dynamic regulator of prostate cancer progression, therapeutic vulnerability, and tumor–immune interactions. In this review, we propose an immunometabolic framework in which androgen receptor signaling, lipid and redox metabolic reprogramming, oxidative stress, and therapeutic pressure converge to shape the susceptibility of prostate cancer cells to distinct RCD modalities. We focus on autophagy and ferroptosis as two extensively studied and translationally relevant pathways, while also discussing emerging roles of necroptosis, pyroptosis, and cuproptosis. Particular attention is given to how RCD-associated signals, including damage-associated molecular patterns, inflammatory mediators, and lipid peroxidation products, may remodel the tumor immune microenvironment and influence the transition between immune-cold and immune-inflamed phenotypes. We further summarize RCD-targeted therapeutic strategies, including ferroptosis induction, autophagy inhibition, nanodrug delivery systems, rational combination therapy, and biomarker-guided patient stratification. Finally, we discuss key translational barriers, including context-dependent biological effects, limited clinical validation, tumor heterogeneity, adaptive resistance, and insufficient predictive biomarkers. By integrating cell death biology with metabolic reprogramming, immune remodeling, and therapeutic resistance, this review highlights RCD as a promising but context-dependent therapeutic vulnerability in advanced prostate cancer. Full article

Chilling injury is a major problem limiting the postharvest storage and marketability of mango fruit at low temperature. The present study investigated the individual and combined effects of sodium nitroprusside (SNP), L-arginine (Arg) and salicylic acid (SA) on chilling tolerance, regulation of oxidative stress and the postharvest quality of ‘Keitt’ mango fruit stored at 5 ± 1 °C for 28 days followed by 4 days of shelf life at 23 °C. Fruits were pre-treated with 1 mM SNP, 1 mM Arg, 2 mM SA or their binary combinations before storage. The chilling injury, membrane damage, lipid peroxidation, protein oxidation and fruit softening were greatly enhanced by cold storage in untreated fruits. In contrast, all the treatments significantly ameliorated these deteriorative changes, and the combined treatments were superiorly effective. Among these, SNP + Arg was the most effective treatment, which reduced the chilling injury index from 4.05 in control fruits to 1.00 after shelf life, completely inhibiting the incidence of decay and reducing electrolyte leakage and malondialdehyde accumulation by 47.4 and 48.2%, respectively. The same treatment also maintained higher firmness, titratable acidity, visual appearance and ascorbic acid content than untreated fruits. The enhanced chilling tolerance was accompanied by increased antioxidant defense, as SNP + Arg significantly stimulated the activities of superoxide dismutase, catalase and peroxidase, but suppressed the activity of pectin methylesterase. Multivariate analyses, such as PCA, clustered heatmap and integrated stress index, demonstrated a strong negative relationship between oxidative stress markers and antioxidant metabolism. The results showed that combined SNP and Arg treatments enhanced chilling tolerance through increasing antioxidant capacity, preserving membrane integrity, and retarding ripening-related metabolism, which provides an effective way to maintain the postharvest quality of cold-stored mango fruit. Full article

Freeze–thaw cycles cause mechanical deterioration and instability of slope rock masses in open-pit coal mines located in the cold regions of Northwest China. In this study, the research object is fine-grained sandstone from the Yan’an Formation in the Tarangole mining area of the Ordos Basin. Here, indoor freeze–thaw cycling, uniaxial compression, and triaxial compression tests were conducted to systematically analyze the deformation behavior, strength evolution, and failure modes of the sandstone under varying numbers of freeze–thaw cycles, freezing temperatures, and confining pressures, thereby revealing its freeze–thaw damage mechanism. The results show that the number of freeze–thaw cycles is the dominant factor affecting the elastic modulus. Freezing temperatures (especially between −5 °C and −15 °C) and the number of freeze–thaw cycles (particularly the first 10 cycles) significantly reduce peak strength. In addition, confining pressure can significantly enhance the resistance to deformation (under 15 freeze–thaw cycles, the elastic modulus increases by 181.8% as confining pressure rises from 0 to 2 MPa). Within the low confining pressure range (0–1.5 MPa), peak strain decreases monotonically with increasing confining pressure and is independent of the number of freeze–thaw cycles. Finally, the increase in the number of freeze–thaw cycles and the decrease in temperature jointly promote crack development, and the failure mode shifts from pure shear to a shear-tension composite mode. The underlying cause lies in the evolution of interparticle cementation within the soil skeleton and in the associated pore–crack structure. In addition, based on fracture damage mechanics and the modified Weibull distribution, a damage evolution equation and a constitutive model for sandstone considering freeze–thaw cycles and temperature effects were established and validated. Therefore, the research findings can provide a theoretical basis for slope support, freeze–thaw disaster prevention and mitigation, and stability assessment in the Tarangole mining area and other cold regions. Full article

Small heat shock proteins (sHSPs) serve as “first aid” stress-response proteins in both eukaryotes and prokaryotes. Their holdase activity enables binding to partially denatured proteins, maintaining them in a folding-competent state under stress. The sHSP IbpA from the mycoplasma Acholeplasma laidlawii is a unique member of its family, combining the functions of two Escherichia coli sHSPs that typically act in tandem. In this study, we demonstrate for the first time that IbpA forms distinct supramolecular structures under contrasting temperature stresses in crowded environments without any artificial truncations or mutations at the protein termini. Upon cooling, IbpA in vitro forms long fibril bundles, whereas heating induces the formation of large, rounded agglomerates. At the temperature optimal for culture growth, the protein exists as a mixture of short fibrils and small globules, with the latter predominating. IbpA’s cellular localization mirrors in vitro properties, with an increased proportion of surface-associated proteins among the sHSP partners during cold shock. We also report, for the first time, a rapid and reversible transition of IbpA to a fibrillar form in response to cold. We propose hypotheses regarding potential roles of IbpA in the mycoplasma cell. IbpA from A. laidlawii appears to act as a “molecular equilibrist,” protecting the cell against damage under opposing stresses, though the precise mechanism of its action during cold shock remains to be elucidated. Full article

In the seasonally frozen area, slopes are exposed to freeze–thaw cycles; thus, water and heat are moved, and the foundation for the transportation infrastructure in cold regions may be weakened. Based on the relatively strong water-recharge effect and considerable fluctuations in shallow soil moisture during the spring thaw along the Naba section of the G218 Highway in Xinjiang, China, a coupled hydro-thermal model for frozen soil that considers snowmelt infiltration and rainfall recharge was developed, and it was numerically implemented in COMSOL. A one-dimensional unidirectional freezing test of a soil column was used to validate the model, and the relative errors of the simulated temperature and moisture fields were 3.8% and 4.3%, respectively; both are within the accuracy requirements for engineering-scale analysis. Then, a model was used to determine how the temperature, volumetric ice content and volumetric water content of a representative slope in the Naba section changed during a freeze–thaw cycle. Based on the above results, the annual temperature range at the surface of the topsoil on the slope is 37.61 °C, and this thermal effect extends to a depth of 0–3 m. In the spring thaw, the volumetric water content of the surface layer increased from 8.45% in February to 19.34% in May, and further to 20.65% in July; therefore, it can be inferred that the shallow soil is still being replenished by snowmelt and rain. Freezing-thaw phase change, freezing-front migration and external water infiltration work together to control hydro-thermal transport in the slope; thus, a redistribution and local accumulation of liquid water occur below the residual frozen layer and under the shallow surface. The above results can serve as a reference for drainage design and as a means to prevent or control freeze–thaw damage to the slope of a highway in Xinjiang’s seasonally frozen area during the spring thaw. Full article

Freeze–thaw durability of 3D-printed engineered cementitious composites (3DP-ECC) is strongly affected by print-induced interlayer defects and anisotropy, particularly in cold regions. This study investigated Cast-ECC and Z-direction 3DP-ECC incorporating Yellow River sediment (YRS) as an equal-mass replacement for quartz sand at 0–100%. Compressive, three-point bending, and four-point bending tests, relative dynamic elastic modulus (RDME), XCT, MIP, SEM–EDS, and Weibull damage modeling were used to evaluate degradation up to 150 freshwater freeze–thaw cycles. Moderate YRS replacement (25–50%) improved particle packing, reduced visible defects, and refined the pore structure, thereby enhancing frost resistance. The R50 mixture showed the best residual performance: after 150 cycles, compressive strength decreased from 55 to 46 MPa in Cast-ECC and from 54 to 44 MPa in 3DP-ECC, corresponding to retention rates of 83.6% and 81.5%, respectively. The residual peak load in four-point bending of 3DP-ECC-R50 was 15.4% lower than that of Cast-ECC-R50, confirming the detrimental role of interlayer defects under loading perpendicular to the layers. RDME-based Weibull fitting described the overall damage evolution (R² = 0.876–0.994), while XCT, MIP, and SEM–EDS indicated that interlayer discontinuities, pore-structure evolution, and local microstructural degradation governed anisotropic deterioration. The results support durability-oriented design of YRS-based 3DP-ECC in cold regions. Full article