Search Results (24,622)

In order to improve the wear resistance of titanium alloy and apply it to the high-speed train brake disc, TiNbZrV_x (x = 0, 0.2, 0.4, 0.6, 0.8) refractory medium-entropy alloy coatings were prepared on Ti-6Al-4V (TC4) substrate. The effect of V content on the microstructure, mechanical properties, and friction and wear properties of the coatings was studied. TiNbZrV_x coatings achieved good metallurgical bonding with the substrate, forming BCC and B2 phases and AlZr₃ intermetallic compound (IMC). From TiNbZr coating to TiNbZrV_0.8 coating, V promotes element segregation and new phase formation, which decreased the average grain size from 85.055 μm to 56.515 μm, increased the average hardness from 265.5 HV to 343.4 HV, and reduced the room temperature (RT) wear rate by 97.8%. However, the ductility of the coatings decreased from 15.7% to 5.8% because the grain boundary precipitates changed the dislocation arrangement, and the tensile fracture mode changed from ductile fracture to brittle fracture. Abrasive wear was the main wear mode at RT, and adhesive wear and oxidation wear were the main wear modes at elevated temperature. The COF at elevated temperature was lower than that at RT, because a large number of friction pair components were transferred to the coating surface at high temperature and were repeatedly rolled to form a dense film, which played a certain lubricating role. Full article

Chromium (Cr) is a highly toxic heavy metal, yet its effects on soil invertebrates—particularly Caenorhabditis elegans (C. elegans)—remain insufficiently understood, especially regarding how soil properties and Cr speciation change regulate its bioavailability and toxicity. In this study, the toxicity of Cr(VI) to the growth, fertility, and reproduction of C. elegans was assessed in six representative agricultural soils following 7, 60, and 120 days of spiked soil aging, following ISO 10872 guidelines. Substantial differences in toxicity were observed among soils after 7 days of aging, with toxicity ranking from low to high as black soil < yellowish-red soil < red soil < yellow–brown soil < fluvo-aquic soil < purple soil. After 60 days of aging, Cr(VI) toxicity decreased markedly, with EC₅₀ values for growth, fertility, and reproduction increasing by 1.04–2.32, 1.04–2.34, and 1.40–2.20 times, respectively. Organic matter (OM) and amorphous aluminum oxides (Al_AO) were identified as the principal soil properties that were significantly correlated with Cr(VI) toxicity and were useful for explaining and estimating toxicity thresholds within the range of soils examined in this study. In addition, the magnitude of the aging effect showed significant positive correlations with both amorphous aluminum oxides (Al_AO) and total aluminum (Al_total), suggesting that Al-bearing minerals may contribute to the time-dependent immobilization of Cr(VI) under the experimental conditions of this study. These findings expand the ecotoxicological database for chromium, improve the prediction of toxicity thresholds under diverse soil conditions, and provide a scientific basis for refining soil environmental quality standards and developing targeted management strategies for Cr-contaminated agricultural soils. Full article

Background: Cardiac ischemia (CI) remains a leading cause of death worldwide, prompting an ongoing search for new treatment options. This study explored and compared the preventive cardioprotective effects of polyphenols extracted from red (RGP) and white grape pomace (WGP) against isoproterenol (ISO)-induced myocardial ischemia, with a focus on their antioxidant and anti-inflammatory properties. Materials and Methods: Fifty male Wistar rats were divided into five groups: I—Saline, II—Saline+ISO, III—Ramipril+ISO, IV—WGP+ISO, and V—RGP+ISO. CI was induced in Groups II–V with ISO (45 mg/kg, on day 13), a dose widely used to reproducibly induce myocardial ischemic injury in experimental models. Electrocardiographic parameters, serum oxidative markers, cytokines, and tissue homogenates from the liver and heart were analyzed on day 14. Results: ISO significantly shortened the RR interval and increased the ventricular rate, without significant modulation by any treatment. The reduction in R-wave amplitude caused by ISO was lessened in all treated groups, with RGP showing values closer to Saline (RGP+ISO vs. Saline, p = 0.329). No differences were found among groups for PR segment, QRS duration, QT, or QTc intervals. Furthermore, all treated groups (III–V) showed significant improvements in oxidative and inflammatory markers compared to Saline+ISO (p < 0.05), with RGP demonstrating the strongest antioxidant activity by maintaining MDA and NO levels close to Saline (RGP+ISO vs. Saline, p > 0.05), while WGP exhibited superior anti-inflammatory effects in cardiac tissue by preserving IL-6 and IL-1β levels comparable to controls (WGP+ISO vs. Saline, p > 0.05). Conclusions: Grape pomace, especially RGP, may offer cardioprotection by decreasing oxidative stress, while WGP more effectively reduces inflammation. The complementary antioxidant and anti-inflammatory effects observed suggest that combining GP extracts may represent a promising hypothesis for future cardiovascular research. Full article

The bilberry is a low-growing plant native to northern Europe. It belongs to the genus Vaccinium. Bilberry is essential in the local diets of some countries and is used as an herbal medicine to manage several ailments. Still, it is not used for commercial farming in many countries. It has recently been known as a great source of naturally available bioactive compounds and colorants. Bilberry is a therapeutic fruit acknowledged for its rich flavonoids, anthocyanins, carotenoids, ascorbic acid, phenolic acid, tocopherols, and vitamin content. It is one of the richest sources of natural anthocyanins. The polyphenolic compounds in bilberry provide abundant antioxidant content, which are supposed to be the vital bioactive compounds accountable for various health benefits. Even though bilberry is mostly promoted for eye care or vision improvement. It is also stated to promote antioxidant defense and lower oxidative stress, having antiaging, anti-inflammatory, lipid-lowering, antimicrobial effects, lowering blood glucose and other age-related diseases, etc. Reports suggest that apart from the fruit, the leaves of bilberry are equally rich in numerous bioactive compounds of medicinal importance. This current review offers valuable insights on bilberry fruits, leaves, and extracts, providing an inclusive assessment of their bioactive compound configuration, related biological prospects, and the extraction methodology of their major compounds. This review offers a summary of the existing information on the antiaging potential of bilberry fruits and leaves, and analytically reviews the outcome of clinical trials, with special attention towards its medicinal properties. Full article

Conventional perming relies on oxidative agents that significantly damage hair. The thiol–Michael click perming strategy derived from linear aliphatic diols and diamines has been developed to avoid oxidative damage, but lacks repeatable perming capabilities. In this study, a novel thiol–Michael click perming molecule was proposed for repeatable perming while avoiding oxidative damage. N,N′-bis(maleoyl)-l-cystine (MA2-CySS) was synthesized and characterized through Raman spectroscopy and ¹H NMR with MTT assay demonstrated no cytotoxicity up to 1000 μg/mL. Click reactivity analysis revealed that the reaction reached a plateau after 30 min, with alkaline pH and elevated temperatures significantly enhancing reactivity. MA2-CySS perming achieved efficiency comparable to oxidative perming, exceeding 1300% across three perming cycles. MA2-CySS perming significantly reduced both color change and cuticle damage, as demonstrated by color difference measurements and SEM, while maintaining superior mechanical properties as revealed by tensile property tests. Raman spectroscopy demonstrated that MA2-CySS perming better preserves hair keratin’s secondary structure, maintaining superior α-helix content at 27.50% versus 24.35%, exhibiting higher disulfide bond retention at 85% versus 72%, and showing gauche–gauche–gauche to trans–gauche–trans conformational conversion at 9% versus 6%. This study demonstrates that repeatable perming via thiol–Michael click reaction represents a significant advancement in perming methodology. Full article

The aims of this study were to evaluate the impact of probiotics (added as a starter sourdough and microcapsules) on gluten-free (GF) rice–amaranth steamed bread (SB) regarding physicochemical characteristics, sensory attributes, probiotic viability, and volatile organic compounds (VOCs). Also, probiotic viability, pH, total titratable acidity (TTA), moisture content, water activity, and texture were determined for 10 days of storage. GF-SB based on rice and amaranth was formulated and cooked at 90 ± 2 °C for 40 min. Three types of GF-SB were studied: control, with 30% sourdough fermented using Lactiplantibacillus plantarum NRRL B-4496 (GF-P), and with sourdough and encapsulated Limosilactobacillus reuteri DSM 17938 (GF-PC). The encapsulation yield was 94.9%. The viability of both probiotics was drastically reduced after steamed cooking, with losses ranging from 6 to 8 log₁₀ CFU/g. Sourdough decreased the pH (from 6.04 to 5.48–5.71) and hardness (control 46 N, sourdough ~25 N) while increasing lactic and acetic acids, moisture content (control 38%, sourdough ~46%), and water activity. Sourdough and probiotic capsules did not affect volume (~1.24 cm³/g), width-to-height ratio (~2.4), color, or sensory attributes. The VOCs revealed higher relative abundances of certain yeast-derived higher alcohols and oxidation-related carbonyl-trapping derivatives in control GF-SB, whereas bread with sourdough showed higher levels of long-chain hydrocarbons and esters, such as heptacosane and decanoic acid decyl ester. During the storage, Lpb. plantarum increased to ~3 log₁₀ CFU/g and Lim. reuteri remained steady. pH and TTA (0.03–0.04%) remained constant during storage. After 10 days of storage, hardness increased significantly (p < 0.05) in all GF-SB, doubling the initial values. Moisture content remained constant, while water activity decreased in GF-P (Δ = 0.025) and the control (Δ = 0.015). The use of sourdough in GF-SB improved texture, moisture content, and VOCs without modifying physical and sensory properties. Full article

Understanding mechanisms of asphalt in the process of natural aging is crucial for predicting its long-term durability and optimizing performance under diverse environmental conditions. Despite its importance, the microstructural and micromechanical changes induced by natural aging remain poorly understood, particularly under varying climatic influences. This study addresses this gap by analyzing the effects of natural aging on asphalt’s microscopic properties and identifying key indicators that govern its degradation. Asphalt samples were subjected to natural aging across five climatically distinct regions over 6, 12, and 18 months. Atomic force microscopy (AFM) was employed to characterize surface roughness, adhesion forces, and DMT modulus, while correlation analysis and principal component analysis (PCA) were used to identify relationships among micromechanical indicators and streamline the dataset. The results reveal that natural aging induces irreversible transformations in asphalt’s microstructure, driven by the combined effects of temperature, UV radiation, humidity, and oxygen. These processes promote the evolution of “Bee structures,” increase surface roughness, and accelerate phase separation, alongside chemical modifications such as oxidation and polymerization, leading to progressive material hardening and stiffness. Significant regional and temporal variations in adhesion forces and DMT modulus were observed, reflecting the cumulative impact of environmental factors on asphalt’s aging dynamics. Correlation analysis demonstrated strong associations between surface roughness and “Bee structure” area, while mechanical properties such as stiffness and adhesion were largely decoupled from morphological features. Environmental factors interact in complex ways to drive asphalt aging. Humidity enhances adhesion and stiffness via water-induced capillary forces, while temperature reduces surface roughness and adhesion through molecular reorganization. UV radiation accelerates oxidative degradation, promoting surface erosion and stiffness loss, while altitude modulates these dynamics by influencing temperature and UV exposure. Full article

Photodynamic therapy (PDT) is a minimally invasive therapeutic modality that relies on the activation of photosensitizers (PS) by specific wavelengths of light to generate reactive oxygen species (ROS), resulting in localized cytotoxicity with relative sparing of healthy tissues. Depending on the PS properties, light dose, and intrinsic cellular features, PDT can elicit multiple cell death pathways, including apoptosis, necrosis, and autophagy. Increasing evidence indicates that PDT is also a potent inducer of ferroptosis, an iron-dependent form of regulated cell death driven by excessive lipid peroxidation (LPO), glutathione (GSH) depletion, and inactivation of glutathione peroxidase 4 (GPX4). PDT-derived ROS promote ferroptosis both indirectly by exhausting antioxidant defenses and directly by peroxidizing PUFAs within membrane phospholipids. At the same time, intense oxidative stress generated by PDT can activate adaptive responses such as mitophagy, a selective autophagic process that removes damaged mitochondria to limit ROS production and preserve redox homeostasis. Ferroptosis and mitophagy are therefore tightly interconnected, functioning as opposing yet complementary regulators of cell fate. PDT emerges as a key upstream modulator of the ferroptosis–mitophagy balance, as spatially and temporally confined oxidative stress can shift cellular responses from adaptive mitochondrial quality control to irreversible ferroptotic injury. Despite growing interest in both PDT and ferroptosis, their mechanistic interplay, particularly in relation to mitophagy, remains underexplored. This narrative review provides an integrated overview of current knowledge on how PDT influences ferroptosis and mitophagy, highlighting the molecular mechanisms that connect these pathways and discussing their implications for improving therapeutic efficacy and overcoming resistance. Full article

In this study, we report a reproducible in situ photochemical method for the simultaneous synthesis of metallic and hybrid metal/metal oxide nanoparticles (NPs) within a UV–curable polymer matrix. A series of epoxy diacrylate-based formulations (BEA) was prepared, consisting of Epoxy diacrylate, Di(Ethylene glycol)ethyl ether acrylate (DEGEEA), and Phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide (BAPO), which served as a Type I photoinitiator. These formulations were designed to enable the simultaneous photopolymerization and photoreduction of metal precursors at various Ag⁺/Co²⁺ ratios, resulting in nanocomposites containing in situ-formed Ag NPs, cobalt oxide NPs, and hybrid Ag–Co₃O₄ nanostructures. The photochemical, magnetic, and dielectric properties of the resulting nanocomposites were evaluated in comparison with those of the pure polymer using UV–Vis and Fourier Transform Infrared Spectroscopy (FT-IR), Photo-Differential Scanning Calorimetry (Photo-DSC), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Impedance Analysis, and Vibrating Sample Magnetometry (VSM). Photo-DSC studies revealed that the highest conversion values were obtained for the BEA-Ag₁Co₁, BEA-Co, and BEA-Ag₁Co₂ samples, demonstrating that the presence of Co₃O₄ NPs enhances polymerization efficiency because of cobalt species participating in redox-assisted radical generation under UV irradiation, increasing the number of initiating radicals and leading to faster curing and higher final conversion. On the other hand, the Ag NPs, due to the SPR band formation at around 400 nm, compete with photoinitiator absorbance and result in a gradual decrease in conversion values. Crystal structures of the NPs were confirmed by XRD analyses. The dielectric and magnetic characteristics of the nanocomposites suggest potential applicability in energy-storage systems, electromagnetic interference mitigation, radar-absorbing materials, and related multifunctional electronic applications. Full article

Weld quality plays a critical role in ensuring the structural integrity and long-term performance of critical piping systems used across petrochemical, oil and gas, marine, and healthcare sectors. Although gas tungsten arc welding, shielded metal arc welding, and gas metal arc welding are widely applied in pipe fabrication, existing studies often examine these processes independently and provide limited insight into the comparative influence of process parameters on weld morphology, microstructure, and mechanical performance. This review consolidates findings from recent research to evaluate how welding current, arc voltage, heat input, travel speed, shielding gas composition, and joint preparation interact to affect weld bead geometry, heat-affected zone evolution, tensile properties, hardness, and overall weld integrity in piping systems. The primary objective of this review is to critically compare fusion welding process parameter optimization strategies and to identify unresolved challenges in achieving controlled weld root geometry for high-integrity piping applications. Recent industrial failure investigations, particularly in ethylene oxide service piping, further underscore the importance of weld root control. Several documented leak events were traced to excessive root protrusion and inadequate interpretation of non-destructive testing data, where elevated reinforcement disrupted internal flow and promoted turbulence-induced degradation. These recurring issues highlight a broader industry challenge and strengthen the need for improved root-height optimization in critical piping applications. A significant research gap is identified in the limited optimization of weld root reinforcement, particularly in gas tungsten arc welding processes, where most reported studies document root heights exceeding 3 mm. Achieving a root height below 2 mm, which is an important requirement for reducing flow-induced turbulence and meeting industry acceptance criteria, remains insufficiently addressed. This review highlights this gap and outlines future research opportunities involving advanced parameter optimization and improved process monitoring techniques. The synthesis presented here provides a comprehensive reference for enhancing weld quality in critical piping systems and establishes a pathway for next-generation welding strategies aimed at producing high-integrity weld joints compliant with the American Society of Mechanical Engineers B31.3 requirements. Full article

4-hydroxy-TEMPO is a water-soluble nitroxide radical with potent antioxidant and redox-modulating properties. Its small molecular weight and membrane permeability enable it to act as a superoxide dismutase mimetic, efficiently scavenging reactive oxygen species and mitigating oxidative damage. In this study, we investigated the physiological and transcriptomic effects of 4-hydroxy-TEMPO in Saccharomyces cerevisiae, using wild-type and mutant strains deficient in key redox and DNA repair pathways (sod1Δ, sod2Δ, yap1Δ, rad52Δ). RNA-Seq analysis revealed widespread transcriptional reprogramming. Treatment with 4-hydroxy-TEMPO impaired cell growth, induced accumulation of cells with 1C (G1 phase) DNA content, and modulated chronological aging in a strain-dependent manner. Notably, low concentrations delayed aging in wild-type, yap1Δ, and rad52Δ strains, while accelerating it in sod1Δ mutants, consistent with a hormetic response. Unlike TEMPO, 4-hydroxy-TEMPO exhibited markedly reduced translational toxicity, preserved polysome structure at high doses, and triggered a non-canonical, redox-dependent transcriptional program characterized by induction of stress-response genes together with unexpected up-regulation of multiple ribosomal protein genes. This was accompanied by a biphasic, genotype-specific hormetic response and a measurable genoprotective effect. RT-qPCR confirmed key transcriptional changes, linking transcriptome remodeling to functional outcomes. Full article

Nanotechnology has emerged as a transformative tool in animal production, offering novel strategies to enhance productivity, health, and product quality. Among trace elements, selenium (Se) plays an essential role in antioxidant defence, immune regulation, and redox balance through its incorporation into selenoproteins. Selenium nanoparticles (SeNPs), synthesized via chemical, physical, or biological methods, have shown superior bioavailability, stability, and lower toxicity compared to traditional organic and inorganic selenium forms. This review explores the synthesis, physicochemical properties, and metabolic fate of SeNPs, emphasizing their advantages in poultry production systems. In poultry, SeNPs exhibit potent antioxidant and anti-stress effects by enhancing the activity of glutathione peroxidase, superoxide dismutase, and thioredoxin reductase, thereby mitigating lipid peroxidation and oxidative tissue damage. Their immunomodulatory effects are linked to improved lymphocyte proliferation, cytokine regulation, and increased immunoglobulin levels under normal and stress conditions. SeNP supplementation has been associated with enhanced growth performance, feed efficiency, carcass quality, and reproductive outcomes in broilers, layers, and quails. Furthermore, selenium nanoparticles have demonstrated therapeutic potential in preventing or alleviating chronic diseases such as cancer, diabetes, cardiovascular dysfunction, and neurodegenerative disorders. SeNPs also serve as biofortification agents, increasing selenium deposition in poultry meat and eggs, thus improving their nutritional value for human consumption. However, selenium’s narrow safety margin requires careful dose optimization to avoid potential toxicity. This review highlights the multifaceted benefits of selenium nanoparticles in poultry nutrition and health, while underscoring the need for further studies on grey SeNPs, long-term safety, and regulatory frameworks. Integrating SeNPs into poultry production represents a promising strategy to bridge animal health, food security, and public nutrition. Full article

Research has demonstrated that incorporating nitrate into animal feed can effectively decrease methane production in ruminants, though its impact on carcass characteristics and meat attributes in Hu sheep requires further investigation. This experiment examined how a dietary inclusion of 3% calcium nitrate (CN) influenced slaughter parameters, meat properties, gut microbial populations, and host gene regulation in Hu sheep. The study involved sixty healthy male Hu sheep aged 120 days with comparable body weights (31.11 ± 3.39 kg), randomly allocated into two groups: a control group receiving standard feed (CON) and a CN-supplemented group. The trial lasted 60 days, including a 15-day adaptation period and a 45-day formal trial period. They were housed individually and fed twice daily (at 8:00 and 18:00). The findings revealed that CN supplementation notably reduced the water loss rate in the longissimus dorsi muscle (LD), elevated meat color brightness, and enhanced the proportion of polyunsaturated fatty acids (PUFA), particularly n-6 PUFA, along with the n-3/n-6 PUFA ratio. Conversely, it reduced the levels of saturated fatty acids such as myristic acid (C14:0) and oleic acid (C18:1n9t). Additionally, the treatment boosted ruminal Ammoniacal nitrogen content and total short-chain fatty acid production, thereby contributing to energy metabolism in the animals. Microbiological examination demonstrated that CN supplementation led to a decrease in Fibrobacterota and Methanobrevibacter populations within the ruminal environment, while promoting the growth of Proteobacteria in the duodenal region. The gene expression profiling of digestive tract tissues showed an increased activity in nitrogen processing genes (including CA4) and oxidative phosphorylation pathways (such as ATP6), indicating an improved metabolic efficiency and acid–base homeostasis in the host animals. These findings demonstrate that CN-enriched diets enhance the carcass characteristics of Hu sheep by modifying intramuscular lipid profiles through gastrointestinal microbial community restructuring and metabolic pathway adjustments. Such modifications affect energy utilization and acid–base equilibrium, ultimately impacting muscle characteristics and adipose tissue distribution, presenting viable approaches for eco-friendly livestock farming practices. Full article

Conductive polymers (CPs), such as polypyrrole (PPy), have shown promising properties for use as electro-responsive bioactive scaffolds for tissue regeneration. PPy can be synthesized by chemical electrosynthesis and doped with biomolecules such as hyaluronic acid (HA). Taking advantage of the electrochemical synthesis versatility, nanofibers for surface-modified indium tin oxide (ITO) electrodes can be used as templates to produce tridimensional HA-doped PPy scaffolds. In this study, polyvinyl alcohol/chitosan (PVA/CTS) electrospun nanofibers deposited on ITO electrodes were used as a 3D template for the in situ electrosynthesis of HA-doped PPy to produce a bioactive scaffold for tissue engineering. The final material gathers the advantages of each biopolymer, the porous morphology of the nanofiber, and the conductivity of the electrosynthetized polymer. Furthermore, the biological activity of the NF-PVA/CTS@PPy:HA composite was evaluated in NIH-3T3 fibroblasts by MTT, resulting in a cell viability of 146 ± 40% and wound-healing capacity of 97 ± 1.9% at 24 h of culture. Full article

Ceramic matrix composites (CMCs) exhibit excellent high-temperature strength, oxidation resistance, and fracture toughness, making them superior to traditional metals and single-phase ceramics in extreme environments such as aerospace, nuclear energy equipment, and high-temperature protection systems. The mechanical properties of CMCs directly influence the reliability and service life of structures; thus, accurately predicting their mechanical response and service behavior has become a core issue in current research. However, the multi-phase heterogeneity of CMCs leads to highly complex stress distribution and deformation behavior in traditional mechanical property testing, resulting in significant uncertainty in the measurement of key mechanical parameters such as strength and modulus. Additionally, the high manufacturing cost and limited experimental data further constrain material design and performance evaluation based on experimental data. Therefore, the development of effective numerical simulation and mechanical modeling methods is crucial. This paper provides an overview of the research hotspots and future directions in the field of CMCs numerical simulation and mechanical modeling through bibliometric analysis using the CiteSpace software. The analysis reveals that China, the United States, and France are the leading research contributors in this field, with 422, 157, and 71 publications and 6170, 3796, and 2268 citations, respectively. At the institutional level, Nanjing University of Aeronautics and Astronautics (166 publications; 1700 citations), Northwestern Polytechnical University (72; 1282), and the Centre National de la Recherche Scientifique (CNRS) (49; 1657) lead in publication volume and/or citation influence. Current research hotspots focus on finite element modeling, continuum damage mechanics, multiscale modeling, and simulations of high-temperature service behavior. In recent years, emerging research frontiers such as interface debonding mechanism modeling, acoustic emission monitoring and damage correlation, multiphysics coupling simulations, and machine learning-driven predictive modeling reflect the shift in CMCs research, from traditional experimental mechanics and analytical methods to intelligent and predictive modeling. Full article