Search Results (294,972)

Carbon fiber-reinforced resin matrix composites (CFRC) are extensively used in aerospace, automotive manufacturing, and sports equipment. However, the brittle nature of the resin matrix causes CFRC to exhibit severe vibrations and noise under dry friction conditions. Enhancing the intrinsic damping properties of the resin matrix serves as a fundamental and effective strategy to mitigate vibration and noise radiation in composite components. This study systematically investigates high-temperature co-curing damping composites using co-curing technology, aiming to improve the mechanical performance and damping characteristics of traditional fiber-reinforced epoxy resin composites. A novel carbon fiber-reinforced terminal carboxyl nitrile epoxy pre-polymer composite material demonstrates both stable chemical properties and excellent high-temperature resistance. Through formulation adjustments, the curing temperature and time of epoxy resin are matched with those of the terminal carboxyl nitrile epoxy pre-polymer. The performance of epoxy carbon fiber composites was evaluated through tensile tests, flexural tests, impact tests, infrared spectroscopy, thermogravimetric analysis, dynamic mechanical analysis, scanning electron microscopy, and X-ray diffraction. Results show that blending epoxy resin with terminal carboxyl nitrile liquid rubber enhances energy dissipation by increasing intermolecular friction and hydrogen bonding interactions. The damping ratio of epoxy resin-based carbon fiber composites reaches as high as 1.67%. Tensile strength, flexural strength, and impact strength reach 1968 MPa, 1343 MPa, and 127 kJ/m², respectively. The addition of terminal carboxylated nitrile liquid rubber facilitates the formation of continuous friction membranes, enhancing friction stability. Tensile tests demonstrate that carbon fiber composites containing 25% terminal carboxylated nitrile liquid rubber outperforms other formulations. As evidenced by impact tests, the performance of the prepared composites is superior to that of other configurations. Dynamic mechanical analysis indicates that the 25% rubber-containing composites exhibit enhanced damping characteristics and higher loss modulus. Experimental results confirm that this study advances the development of functional composites for vibration reduction and noise control applications. Full article

Primary liver cancer (PLC), commonly classified as hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC), is a highly aggressive malignancy with a dismal prognosis. Recent research has highlighted the crucial role of dysregulation of fatty acid metabolism in HCC progression and therapeutic resistance. Here, with a focus primarily on HCC, we review how alterations in the processes involving fatty acids dynamically contribute to the survival, proliferation, and development of the drug resistance of PLC cells. In particular, increased expression of fatty acid transporters, reprogramming of de novo lipogenesis, and altered fatty acid oxidation trigger the upregulation of oncogenic signaling pathways and adaptation to nutrient-deprived conditions inducing the rapid proliferation of PLC cells. Furthermore, fatty acid metabolism influences immune cell function and angiogenesis, thereby shaping the tumor microenvironment and promoting the progression of PLC. This review explores the complex relationship between fatty acid metabolism and the progression of PLC. It discusses future directions regarding the most promising druggable targets and their current status in clinical trials. Furthermore, it examines the advancement of innovative therapeutic strategies and highlights the significant challenges in targeting fatty acid metabolism. Finally, it discusses how precision therapies focused on fatty acid metabolism can be effectively integrated with current treatments. Full article

Magnesium phosphate cement (MPC) is widely used in rapid repair applications due to its fast setting, high early strength, and high-temperature resistance. However, the high cost of magnesium oxide (MgO) and the rapid hydration reaction make it challenging to control the setting time. In this study, steel slag powder (SSP) and ground granulated blast furnace slag (GGBS) were incorporated to partially replace MgO. The reactivity of SSP and GGBS was enhanced by an alkaline activator, promoting the dissolution of their glassy phases, which facilitated the formation of C-(A)-S-H gels and improved the performance of MPC. Experimental methods, including compressive strength testing, water resistance measurements, X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), mercury intrusion porosimetry (MIP), and thermogravimetric analysis (TG), were used to evaluate the 28-day compressive strength and the microstructural characteristics of the modified MPC. When both SSP and GGBS were incorporated at 10 wt.%, the modified MPC achieved a 7-day compressive strength of 37.2 MPa, with the 28-day strength increasing to 50.2 MPa. The addition of an alkali activator with a modulus of 1.3 significantly boosted the 28-day strength to 62.3 MPa, while maintaining high flowability (215 mm). Microscopic characterization revealed that C₂S and C₃S in SSP undergo continuous hydration under alkaline conditions, while reactive silica-aluminum in GGBS reacted with phosphate to form a water-resistant C-(A)-S-H gel phase, optimizing the pore structure of MPC. This study provides a novel approach to developing low-cost, high-durability modified MPC with improved performance. Full article

Background: Intraoperative radiotherapy (IORT) offers single-session treatment during breast-conserving surgery (BCS). Outcomes depend heavily on patient selection and tumor characteristics. Objectives: To assess local recurrence (LR) and prognosis using the 2024 American Society for Radiation Oncology (ASTRO) risk classification in IORT-treated patients. Methods: This multicenter retrospective study analyzed 358 IORT cases (356 patients) treated between 2014 and 2018 using the Zeiss INTRABEAM system. Cases were classified per the 2024 ASTRO partial-breast irradiation guidelines. The primary endpoint was local recurrence-free survival (LRFS); secondary endpoints included overall survival (OS) and mastectomy-free survival (MFS). Findings: The median age was 66 years (range 48–80); all tumors were invasive with a median tumor size of 10 mm. At a median follow-up of 7.1 years, LR occurred in 14/358 cases (3.9%) at a median of 5.2 years post-diagnosis. Five- and 8-year LRFS were 98.3% and 94.8%, respectively; 5- and 8-year OS were 99.4% and 97.7%; MFS at 8 years was 98.2%. Cases that were classified as “conditionally recommended” or “conditionally not recommended” had significantly higher LR than the “suitable” group (8.5% vs. 2.7%; HR 3.25, 95% CI 1.05–10.08, p = 0.041). Exploratory analysis showed that cases with ≥2 conditional criteria carried a markedly higher risk than those with 0–1 (21.4% vs. 3.2%; Firth-penalized Cox HR 8.26, 95% CI 2.06–26.06, p = 0.005). Conclusions: In appropriately selected patients, IORT achieves local control consistent with contemporary series. The 2024 ASTRO risk classification effectively identifies high-risk cases, supporting its use for risk-adapted candidate selection. Full article

Urban wetlands on the Qinghai–Tibetan Plateau are increasingly recognized as potentially important components of city-scale carbon budgets; however, their CO₂ flux dynamics and associated environmental drivers remain insufficiently quantified, particularly under high-altitude urban conditions. In this study, we addressed this knowledge gap by conducting continuous eddy covariance observations at Haihu Wetland Park in Xining City, China. Carbon fluxes were monitored throughout 2023 using the Huangshui Park Station flux tower. We quantified the temporal dynamics of gross primary productivity (GPP), ecosystem respiration (Re), and net ecosystem exchange (NEE), and systematically assessed their responses to key environmental drivers across multiple temporal scales. GPP and Re exhibited unimodal seasonal patterns, with substantially higher values during the growing season. NEE showed pronounced diel cycling, with nighttime CO₂ release and daytime uptake, and shifted seasonally between net source and net sink states. At the daily scale (n = 365), Pearson correlations showed that air temperature (T_a), 5 cm soil temperature (T_s5) and volumetric soil water content (SWC) exhibited the strongest associations with the flux components, whereas photosynthetic photon flux density (PPFD) showed moderate associations and precipitation was weak. At the monthly scale (n = 12), Mantel tests further highlighted a dominant thermal control on GPP and Re (T_a and T_s5), whereas precipitation showed additional associations with Re and NEE. Overall, the ecosystem acted as a net CO₂ sink in 2023 (annual NEE = −292.25 g C m⁻² yr⁻¹ under our sign convention), with uptake concentrated in the first eight months of the year. Under the combined effects of multiple environmental factors, plateau urban wetlands functioned as a strong carbon sink, and the results of this study provide a data basis for improving the accuracy of carbon budget estimates for this type of ecosystem. Full article

Carbon monoxide (CO) is a key component of syngas and an important intermediate in the chemical, metallurgical, heavy, and food industries. Although mainly associated with thermochemical processes, CO can also be generated during composting, offering an environmentally friendly biological alternative. This study assessed the potential for CO production during laboratory-scale composting of seven selected organic waste fractions: coffee grounds, green tea leaves/grounds, wheat straw, grass cuttings, branches, food waste, and a biowaste mixture with an optimal C/N ratio. Composting was carried out under laboratory conditions at 45 °C for 14 days, with daily passive aeration and monitoring of CO, CO₂, and O₂ concentrations in the reactor headspace. CO production kinetics were calculated for each substrate, and the CO mass yield was determined in each bioreactor. The study confirmed the CO generation potential of the analyzed organic waste fractions. The highest CO production was observed for grass cuttings (max. 2000 ppm, 1.21 mg), biowaste mix (2000 ppm, 0.82 mg), and wheat straw (1180 ppm, 0.24 mg). Grass cuttings exhibited the highest average reaction rate (3991.1 ppm·d⁻¹) and the most rapid process (2.920 d⁻¹). Fungal colonization was visibly present in the most CO-productive reactors, suggesting a role of fungal metabolism in CO formation. Full article

Background/Objectives: Oral and oropharyngeal cancers are highly prevalent and associated with a high mortality. The primary treatment modality is surgery with free flap reconstruction becoming the gold standard. Our study aimed to assess the anthropometric and metabolic predictors of the occurrence of postoperative complications after free flap reconstruction, and to present a PRISM (Predictive Reconstructive Index for Soft-tissue Microflaps) scoring system. Methods: This retrospective cohort study included 92 patients with advanced oral and oropharyngeal squamous cell carcinoma who underwent primary surgical treatment with microvascular free flap reconstruction between 2020 and 2024. Clinical, surgical, and biochemical parameters (operative and flap ischemia time, BMI; serum albumin, total protein, and calcium) were analyzed in relation to postoperative complications. Associations were assessed using correlation analyses and binary logistic regression. Based on the key predictive variables, the PRISM scoring system was developed to estimate perioperative risk. Results: Underweight or overweight patients showed higher complication rates (Kruskal–Wallis, p = 0.019). Longer surgeries were associated with a higher incidence of SIRS, which in turn correlated with increased flap ischemia (Man-Whitney, p = 0.032 and 0.039). Lower albumin and total protein levels on the second postoperative day were linked to more complications (Kruskal–Wallis, p = 0.001 and 0.010), as were lower calcium levels on the first postoperative day (p = 0.033). Additionally, longer hospitalization was significantly associated with complication severity (p = 0.031). The PRISM score stratified patients into low-, moderate-, and high-risk groups. Conclusions: Free flap outcomes in oral and oropharyngeal cancer are influenced by SIRS, nutritional status, and surgical factors. Longer surgeries, flap ischemia, low albumin, protein, calcium, and abnormal BMI increased the complication risk. Careful preoperative assessment, optimization of patient condition, and strategies to minimize operative time and ischemia are essential. The PRISM score may help stratify patients and guide clinical decisions. Full article

To investigate the influence of a second-phase mineral on the rheology of mantle peridotite, we conducted high-temperature deformation experiments on dry olivine–clinopyroxene (Ol-Cpx) aggregates. Cylindrical samples were manufactured using hot-isostatic pressing techniques, with Ol as the matrix phase and Cpx added at volume fractions of f_Cpx = 0.1, 0.3, and 0.5. Deformation experiments were performed in a Paterson gas-medium apparatus at a confining pressure of ~300 MPa, temperatures ranging from 1423 to 1523 K, and strain rates of ~5 × 10⁻⁶ s⁻¹, ~1 × 10⁻⁵ s⁻¹, ~2 × 10⁻⁵ s⁻¹, and ~5 × 10⁻⁵ s⁻¹. The stress exponents (n = 3.4–4.3) for two-phase aggregates are comparable to those reported for both pure Ol and pure Cpx, indicating that dislocation creep remains the dominant deformation mechanism. Increasing Cpx content does not induce a transition of dominant mechanism but leads to a slight decrease in activation energy, consistent with predictions from two-phase rheological models and reflecting the increasing contribution of Cpx to bulk deformation. Normalized flow stresses fall between the Ol and Cpx end-members within the Taylor–Sachs bounds, indicating moderate strain partitioning between phases. Aggregates with f_Cpx = 0.5 show slightly reduced strength and lower effective stress exponents. This is attributed to enhanced dynamic recrystallization, which triggers grain-size reduction and thereby increases the contribution of diffusion-assisted deformation, even though dislocation creep remains the dominant mechanism. These results suggest that under dry conditions, Cpx primarily modulates the rheology of olivine-rich aggregates through microstructural evolution and strain partitioning rather than by altering the dominant deformation mechanism. Full article

Spermidine (SPMD) is essential for numerous cellular functions and crucial for sustaining diverse biological activities. However, its antioxidant capabilities are relatively weak. In this study, we overcame this limitation by examining the antioxidant and cellular effects of ascorbic acid (AA)-conjugated spermidine (AA-SPMD) in human skin keratinocyte and fibroblast cells. AA-SPMD was successfully fabricated using an optimized design and synthetic approach, and its stability, antioxidant activity, cellular responses, and collagen I production were evaluated. In addition, we assessed the protective effects of AA-SPMD from hydrogen peroxide and UVA-induced oxidative damage in human skin cells. The AA-SPMD showed high stability under rigorous conditions and exhibited strong antioxidant activity. AA-SPMD showed no cytotoxic effect even at a concentration of 1 mM. In addition, it can increase the rate of cell proliferation and migration in skin cells without reducing the inhibition of human keratinocytes (HaCaT) and human dermal fibroblasts (HDF) at concentrations of 10 μM. Moreover, AA-SPMD can increase the amount of collagen I synthesized in HDF cells, thereby influencing cell proliferation and migration. Based on our in vitro study, AA-SPMD is expected to be more effective than AA or SPMD alone, indicating its potential utility in biomedical and cosmetic applications. Full article

The Zhunuo ore district, at the western end of the Gangdese porphyry Cu belt, hosts significant Cu mineralization and newly recognized W mineralization dominated by scheelite. However, the genetic relationship between scheelite and porphyry mineralization, and the evolution of ore-forming fluids remain poorly constrained. To address this, scheelite samples from multiple locations were analyzed for major elements (EMPA), in situ trace elements (LA-ICP-MS), and internal textures (cathodoluminescence, CL). These data, combined with machine learning methods, were used to determine scheelite genetic types and reconstruct fluid evolution. REE patterns and CL textures reveal three scheelite generations in Yalongri (early Sch I c, middle Sch I b, late Sch I a), two in Zhigunong (early Sch II a, late Sch II b), and one in Xiongbaxi (Sch III). Low Na (0–329 ppm) and Nb (3.9–39 ppm) relative to high ΣREE + Y-Eu (16–3857 ppm), indicate that the dominant substitution mechanism is 3Ca²⁺ = 2REE³⁺ + □Ca (□Ca = Ca vacancy). δEu values > 1 in Sch I a, Sch I b, Sch II a, and Sch II b indicate reducing fluids, whereas δEu < in Sch I c and Sch III reflects oxidizing conditions. Variations in REE, Mo, and Sr contents suggest that ore-forming fluids in Yalongri evolved from oxidizing to reducing conditions, with late-stage scheelite undergoing dissolution–reprecipitation. Zhigunong records two reducing stages: an early REE-rich-Mo-poor stage and a later REE-poor-Mo-rich stage. Xiongbaxi records a single oxidizing, REE-rich, Mo-rich stage. Scheelite exhibits low-to-moderate Sr/Mo ratios (0.02–6.10), consistent with a magmatic–hydrothermal origin, and relatively uniform Y/Ho ratios (12–59) indicating stable crystallization conditions. A Random Forest model classifies scheelite into orogenic, porphyry, skarn, and greisen types. Overall, the results indicate that ore-forming fluids evolved from oxidizing to reducing conditions, favoring metal transport and enrichment. Integrated geochemical and machine learning evidence suggest, strong potential for porphyry-type Cu-W(-Mo) mineralization in Yalongri and Zhigunong, and skarn-type W-Mo mineralization in Xiongbaxi, providing important guidance for future exploration in the western Gangdese metallogenic belt. Full article

Coffea canephora is economically and socially important for small-scale agriculture in Northern Brazil. To identify genotypes adapted to Amazonian edaphoclimatic conditions, clones of the species have been evaluated across multiple locations in Amazonas. Introducing genetically selected materials into comparable environments may promote consistent productivity gains in the short and medium term. In this context, the aim of this study was to assess the genetic diversity of different C. canephora genotypes using microsatellite markers, which will support the development of superior genotypes adapted to Amazon conditions. A total of 43 C. canephora genotypes were analyzed. Leaves were collected for genomic DNA extraction and were standardized and amplified by PCR using microsatellite primers. Genotyping was performed via capillary electrophoresis, allowing for the determination of allele sizes. Genetic structure was inferred, and genetic diversity parameters were estimated. The average observed heterozygosity (H_O = 0.64) exceeded the expected heterozygosity (H_E = 0.53), and the average inbreeding coefficient (f = −0.19) indicated an excess of heterozygotes. The results revealed high genetic variability among the evaluated genotypes. These findings highlight the broad genetic diversity of C. canephora, reinforcing its potential as a genetic basis for selection and the development of cultivars adapted to the environmental conditions of the Amazon. Full article

This study investigates the nutritional effects of a thyme meal and B. subtilis mixture on growth performance, immune function, antioxidant capacity, gene expression, and gut microbiota in heat-stressed rabbits. One hundred and twenty male New Zealand White rabbits were divided into four dietary treatments (five replicates/group). The rabbits in the first group were fed a basal diet, while the other three groups were fed a basal diet containing B. subtilis, thyme meal, and their mixture, respectively. The B. subtilis and thyme meal mixture increases the heat-stressed rabbits’ body weight gain and carcass weight, and enhances nutrient digestibility and the feed conversion ratio. Supplementing the CBT mixture improved the lipid profile and liver and kidney function via decreasing plasma triglycerides, cholesterol, LDL, creatinine, urea, and AST levels, while increasing total protein and albumin levels. Furthermore, the CBT mixture enhanced the immune response and oxidative stability by increasing IgA and IgG levels, GPx enzyme activity, and SOD, while decreasing plasma MDA content. Adding the CBT mixture enhanced gut health by reducing pathogens and inflammation, as well as increasing volatile fatty acid levels and the expression of CAT-1, MUC-2, and SGLT-1 genes. The combination of a thyme meal and B. subtilis enhanced growth, immune function, antioxidant capacity, gut microbiota modification, and the expression of gut health nutrient absorption-related genes in heat-stressed rabbits. Full article

Land degradation (LD) is an emerging threat of the decade that is not only deteriorating arable lands globally but also threatening global ecosystem sustainability. Therefore, the intensification of LD has stimulated global governing bodies and researchers to undertake initiatives against this dilemma through sustainable and eco-friendly approaches. Geographical mapping is critical in analysing land formation, soil composition and land use patterns, subsequently facilitating data-driven planning for soil conservation. In this review, Geographic Information System (GIS) technology, combined with Shuttle Radar Topography Mission (SRTM) data, is used to explore soil properties and land use patterns across Saudi Arabia, with a focus on soil types, soil thickness, and soil uses. Spatial analyses indicate that the most predominant soil type in the country is sandy, followed by loam and sandy loam. The soil depth distribution exhibits a notably bimodal pattern, with large areas characterized by shallow soils (0–4 m) and deep soils (43–50 m). These spatial visualizations provide valuable insights into soil heterogeneity, supporting evidence-based, site-specific strategies for sustainable land management. This study also outlines the major land degradation pathways affecting arable lands in Saudi Arabia and describes how these pathways can be used to assess the extent of land loss. Besides land loss pathways, the current study also explains the most suitable mitigation strategies, including mulching, cover cropping, and agroforestry, as well as how international governing bodies like the UNDP, UNEP, FAO, and World Bank can contribute to the mitigation of LD in Saudi Arabia. However, further studies are required to assess the intensity of these solutions for each soil type and thickness under different climatic conditions. Full article

Background and Objectives: Psoriatic arthritis (PsA) is a chronic inflammatory arthritis characterized by marked clinical heterogeneity and variable disease trajectories, underscoring the need for robust biomarkers of inflammatory burden. Serum calprotectin, a neutrophil- and monocyte-derived protein, has been proposed as a surrogate marker of active inflammation in inflammatory arthritis due to its close association with innate immune activation. In this study, we compare serum calprotectin levels among patients with PsA, axial spondyloarthritis (AxSpA), and healthy controls and evaluate their association with disease activity. Materials and Methods: This single-center, cross-sectional study included 123 patients with PsA, 119 patients with AxSpA, and 77 healthy controls. Serum calprotectin levels were measured by enzyme-linked immunosorbent assay, and their associations with disease activity were evaluated using correlation, multivariable regression, and receiver operating characteristic analyses. Results: Serum calprotectin levels were significantly higher in PsA and AxSpA patients compared with healthy controls (p < 0.001 for both) and were higher in PsA than in AxSpA (p = 0.022). In PsA, serum calprotectin levels showed significant correlations with ASDAS-CRP, DAS28-CRP, and DLQI, but not with CRP or ESR. In contrast, in AxSpA, calprotectin showed only a weak association with CRP and was not related to disease activity indices. In multivariable analysis, serum calprotectin was independently associated with ASDAS-CRP in PsA (B = 0.704, p = 0.003), but not in AxSpA. Receiver operating characteristic analysis demonstrated that serum calprotectin discriminated high disease activity in PsA with an area under the curve of 0.669 (95% CI: 0.563–0.775; p = 0.003). Conclusions: Serum calprotectin levels are elevated in patients with PsA and are associated with disease activity, supporting its potential role as a biomarker in this condition. In contrast, serum calprotectin does not appear to reflect disease activity in AxSpA, suggesting disease-specific differences in its clinical utility. Full article