Search Results (7,836)

This study characterized the spatial distribution and assessed the ecological risks of carbon, nitrogen, and phosphorus in sediments of the Dongzhai Harbor mangrove wetland, Hainan, China. Analysis of key environmental indicators (grain size, pH, TOC, TN, TP) across twenty-seven sediment cores (0–100 cm depth) revealed distinct decreasing land–sea gradients and vertical stratification of nutrient concentrations. Mangrove plant debris was identified as the primary source of sedimentary organic matter. Elemental ratio analysis indicated terrestrial inputs as the dominant phosphorus source. Significant positive correlations between TOC, TN, and TP in surface sediments suggested coupled nutrient dynamics. Vertical distribution of C/N to C/P ratios increased with depth, which may be related to increased nitrogen and phosphorus inputs due to regional human activities. Pollution assessment showed significantly higher ecological risks in surface sediments (0–50 cm), particularly near inland areas and dense mangroves, indicating co-regulation by vegetation processes and human impacts. These findings highlight significant spatial heterogeneity in ecological risks, underscoring the need for enhanced monitoring and targeted management strategies in critical land–sea transition zones. Full article

With the growing demand for energy, oil and gas exploration and development are progressively moving into deep and ultra-deep formations, where extreme temperatures and pressures create complex challenges for drilling operations. While drilling fluids are critical for controlling bottom-hole pressure, cooling drill bits, and removing cuttings, accurately characterizing their rheological behavior under high-temperature and high-pressure (HTHP) conditions remains a key focus, as existing research has limitations in model applicability and parameter prediction range under extreme downhole environments. To address this, the study aims to determine the optimal rheological model and establish a reliable mathematical prediction model for drilling fluid rheological parameters under HTHP conditions, enhancing the precision of downhole temperature and pressure calculations. Rheological experiments were conducted on eight field-collected samples (4 water-based and four oil-based drilling fluids) using a Chandler 7600 HTHP rheometer, with test conditions up to 247 °C and 140 MPa; nonlinear fitting via a hybrid Levenberg–Marquardt and Universal Global Optimization algorithm and multivariate regression were employed for model development. Results showed that oil-based and water-based drilling fluids exhibited distinct rheological responses to temperature and pressure, with the Herschel–Bulkley model achieving superior fitting accuracy (coefficient of determination > 0.999). The derived prediction model for Herschel–Bulkley parameters, accounting for temperature-pressure coupling, demonstrated high accuracy (R² > 0.95) in validation. This research provides an optimized rheological modeling approach and a robust prediction tool for HTHP drilling fluids, supporting safer and more efficient deep and ultra-deep drilling operations. Full article

Background and Objectives: This study aimed to evaluate the association between relationship dynamics as measured by dyadic adjustment and factors such as erectile function and lower urinary tract symptoms, adjusting for relevant clinical characteristics. Materials and Methods: This cross-sectional study collected data from 94 males in relationships of at least 6 months and with a prostate volume equal to or higher than 30 cc. Lower urinary tract symptoms, erectile function, and relationship dynamics were assessed with the International Prostate Symptom Score (I-PSS), International Index of Erectile Function (IIEF), Dyadic Adjustment Scale (DAS). Results: We found significant positive correlations between DAS affective expressions (AEs) and erectile dysfunction duration; between IIEF general satisfaction and DAS dyadic adjustment (DA), dyadic consensus (DC), and dyadic cohesion (DH); and between prostate width and DAS DA and DC (all ρ ≈ 0.2–0.3, p < 0.05). Further multiple regression analyses adjusting for age, prostate width, and comorbidities showed that the associations between IIEF general satisfaction and DAS DA (p = 0.013) and DH (p = 0.008) remained significant, while the relationship with DAS DC (p = 0.051) was borderline. Conclusions: Our findings highlight that general sexual satisfaction, as measured with the IIEF, had a small but independent association with higher affective expressions, dyadic cohesion, and dyadic consensus in couples, which are key domains of dyadic adjustment, regardless of relationship duration, prostate width, and comorbidities. These results emphasize the importance of considering sexual satisfaction in the context of relationship quality and, therefore, involving the female partner in the assessment and treatment of erectile dysfunction. Full article

This study addresses the problems of poor dynamic stability, high vibration coupling, and inefficient energy use in large-farm manure handling machines. A profiling wheel-based multi-disciplinary approach is proposed in the study. With the rocker arm prototype, double-ball heads, and a hydraulic damping system, a parametric design is built that includes vibration and energy consumption. The simulation results in EDEM2022 and ANSYS2022 prove the structure viability and motion compensation capability, while NSGA-II optimizes the damping parameters (k₁ = 380 kN/m, C = 1200 Ns/m). The results show a 14.7% σ_Fc reduction, 14.3% α_RMS decrease, resonance avoidance (14–18 Hz), Δx (horizontal offset of the frame) < 5 mm, 18% power loss to 12.5%, and 62% stability improvement. The new research includes constructing a dynamic model by combining the Hertz contact theory with the modal decoupling method, while interacting with an automatic algorithm of adaptive damping and a mechanical-hydraulic-control-oriented optimization platform. Future work could integrate lightweight materials and multi-machine collaboration for smarter, greener manure cleaning. Full article

Background/Objectives: G protein-coupled receptors (GPCRs) can promote ligand-biased signaling, yet the mechanisms that promote bias are not well understood. We have shown that C-C Chemokine Ligand 19 (CCL19) and CCL21 promote ligand-biased internalization and signaling of C-C Chemokine Receptor 7 (CCR7) in T cells. The roles of GPCR kinases (GRKs) in regulating biased CCR7 internalization and biased signaling in T cells are unclear. GRK2 is a serine/threonine kinase that phosphorylates GPCRs in response to ligand binding and is recruited to the plasma membrane via its C-terminal pleckstrin homology domain to phosphatidylinositol 4,5-bisphosphate (PIP₂). Methods: Human embryonic kidney cells (HEK293) transfected to express wild-type and mutant GRK2 and human CCR7, human T cell lines harboring heterozygous deletions of GRK2, and naïve primary T cells from GRK2 heterozygous (GRK2^+/−) or GRK2^f/f CD4-Cre mice were used to examine the effects of GRK2 on ligand-induced CCR7 signaling in T cells. We used flow cytometry to assay the effect of GRK2 on CCR7 internalization, Fluorescence Resonance Energy Transfer (FRET) to define the effect of GRK2 on CCR7 activation of Gα_i isoforms and transwell migration assays to examine the effect of GRK2 on chemotaxis. Since chemotaxis via CCR7 is mediated by phospholipase Cγ1 (PLCγ1), Western blot assays were used to measure the effect of GRK2 during downstream signaling via phosphorylation of PLCγ1. Results: We found that following CCL19 binding, GRK2 promoted kinase-dependent CCR7 recruitment of arrestin-3, rapid CCR7 internalization and Gα_i3 recruitment to CCR7. In contrast, following binding of CCL21 to CCR7, GRK2 slowed CCR7 internalization, induced recruitment of Gα_i2 to the activated receptor_, and promoted chemotaxis. Since we have shown that CCL21 promotes chemotaxis via PLCγ1, we examined the effect of GRK2 on PLCγ1 activation and found that GRK2 had no effect on CCL21-mediated PLCγ1 phosphorylation. Conclusions: GRK2 promotes differential signaling downstream of CCR7 activation by CCL19 and CCL21 and provides a model for biased signaling downstream of a GPCR driven by GRK2. Full article

The photocatalytic conversion of CO₂ into value-added hydrocarbons offers a sustainable route for mitigating carbon emissions. In this study, we synthesized MoSe₂/g-C₃N₄ heterostructured composites through a hydrothermal method and used these composites in the photocatalytic reduction of CO₂ in the presence of ultraviolet radiation. Photoluminescence characterization, photocurrent analysis, and electrochemical impedance spectroscopy confirmed improved charge separation and interfacial transfer as a result of the composites’ heterojunction structure. The MoSe₂/10 wt% g-C₃N₄ composite exhibited a CH₄ production rate of 1.38 μmol g⁻¹ h⁻¹ and a CO₂ consumption rate of 2.22 μmol g⁻¹ h⁻¹, which are 4.2 and 3.1 times, respectively, higher than those of pure MoSe₂. Gas chromatography revealed the selective formation of C₁–C₅ hydrocarbons, with minimal oxygenated by-products. Band structure analysis conducted through ultraviolet photoelectron spectroscopy and ultraviolet–visible/near-infrared spectroscopy confirmed the proposed charge transfer pathway and enhanced C–C coupling efficiency. Overall, these results demonstrate the potential of the as-prepared heterojunction composites for highly selective CO₂-to-CH₄ conversion under mild conditions, with CH₄ as the dominant product (80%) among the generated hydrocarbons. Full article

Oxidative stress is a major contributor to skin aging and related disorders. This study comparatively evaluated the bioefficacy of Schinus terebinthifolius Raddi leaf extracts prepared using three extraction techniques: conventional extraction (CE), accelerated solvent extraction (ASE), and pulsed electric field (PEF) extraction, with 50% (v/v) ethanol and water as green solvents. Among all tested conditions, the CE-derived extract (C-4), obtained with 50% (v/v) ethanol for 120 min, exhibited the highest extraction yield (29.7%). It also showed the highest total phenolic (668.56 ± 11.52 mg gallic acid equivalent (GAE)/g dry material (DM)) and flavonoid content (2629.92 ± 112.61 mg quercetin equivalent (QE)/100 g DM), and potent antioxidant activity against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical (12,645.50 ± 60.31 µmol Trolox equivalent (TE)/g DM) and oxygen radical absorbance capacity assay (ORAC: 7180.27 ± 101.79 µM TE/100 g DM). Liquid Chromatography coupled with Mass Spectrometry (LC-MS) analysis revealed a diverse phytochemical profile rich in polyphenols, including gallic acid, p-coumaric acid, rutin, rosmarinic acid, caffeic acid, and epicatechin. Cellular assays in hydrogen peroxide (H₂O₂)-induced HaCaT keratinocytes demonstrated that C-4 extract significantly enhanced cell viability and upregulated endogenous antioxidant genes (superoxide dismutase (SOD1), catalase (CAT), glutathione peroxidase (GPX)), with effects comparable to established antioxidants such as epigallocatechin gallate (EGCG) and ascorbic acid. These findings highlight the influence of extraction parameters on phytochemical yield and biological activity, supporting the potential application of CE-derived S. terebinthifolius extracts as effective, sustainable ingredients for cosmeceutical formulations targeting oxidative stress-mediated skin aging. Full article

Supercritical CO₂ (ScCO₂) injection has emerged as a promising method to enhance shale gas recovery while simultaneously achieving CO₂ sequestration. This research investigates how ScCO₂ interacts with water and shale rock, altering the pore structure characteristics of shale reservoirs. The study examines shale samples from three marine shale formations in southern China under varying thermal and pressure regimes simulating burial conditions at 1000 m (45 °C and 10 MPa) and 2000 m (80 °C and 20 MPa). The research employs multiple analytical techniques including XRD for mineral composition analysis, MICP, N₂GA, and CO₂GA for comprehensive pore characterization, FE–SEM for visual observation of mineral and pore changes, and multifractal theory to analyze pore structure heterogeneity and connectivity. Key findings indicate that ScCO₂–water–shale interactions lead to dissolution of minerals such as kaolinite, calcite, dolomite, and chlorite, and as the reaction proceeds, substantial secondary mineral precipitation occurs, with these changes being more pronounced under 2000 m simulation conditions. Mineral dissolution and precipitation cause changes in pore structure parameters of different pore sizes, with macropores showing increased PV and decreased SSA, mesopores showing decreased PV and SSA, and micropores showing insignificant changes. Moreover, mineral precipitation effects are stronger than dissolution effects. These changes in pore structure parameters lead to alterations in multifractal parameters, with mineral precipitation reducing pore connectivity and consequently enhancing pore heterogeneity. Correlation analysis further revealed that H and D₋₁₀−D₁₀ exhibit a significant negative correlation, confirming that reduced connectivity corresponds to stronger heterogeneity, while mineral composition strongly controls the multifractal responses of macropores and mesopores, with micropores mainly undergoing morphological changes. However, these changes in micropores are mainly manifested as modifications of internal space. Siliceous shale samples exhibit stronger structural stability compared to argillaceous shale, which is attributed to the mechanical strength of the quartz framework. By integrating multifractal theory with multi–scale pore characterization, this study achieves a unified quantification of shale pore heterogeneity and connectivity under ScCO₂–water interactions at reservoir–representative pressure–temperature conditions. This novelty not only advances the methodological framework but also provides critical support for understanding CO₂–enhanced shale gas recovery mechanisms and CO₂ geological sequestration in depleted shale gas reservoirs, highlighting the complex coupling between geochemical reactions and pore structure evolution. Full article

In this study, the impact resistance of WUF-B steel frame beam–column joints under fire was investigated using ABAQUS finite element software through a sequential thermal–mechanical coupling approach. By integrating a room-temperature impact model with a single-sided fire field applied to the lower flange of the steel beam, the multi-parameter influence mechanisms—including temperature (150–750 °C), fire area distribution, and impact momentum—were systematically analyzed. Results indicate that elevated temperatures significantly degrade structural impact resistance. At 750 °C, the peak impact force decreases by 73.3% compared to room temperature, while the mid-span bending moment increases by 63.3%. When the fire zone is near the impact point, localized thermal softening further reduces the peak impact force. Under constant impact energy, lower momentum (i.e., higher velocity) accelerates the rebound of the falling mass, revealing the role of momentum transfer efficiency in governing the transient response of high-temperature structures. Additionally, an analytical prediction model based on Timoshenko beam theory and thermo-mechanical stiffness degradation is developed. By introducing a segmented temperature reduction function, the model significantly enhances the accuracy of mid-span displacement predictions for steel structures under fire. Full article

The objective of this study was to investigate the influence of additive manufacturing parameters, specifically using laser powder bed fusion (LPBF), and surface finishing methods on the corrosion rate and behavior of maraging steel M350 components. Samples were fabricated via LPBF employing varying laser powers (80 W, 100 W, and 120 W) and subsequently subjected to mechanical polishing. Corrosion performance was evaluated through 450 h immersion tests in a 3.5% aqueous NaCl solution and potentiodynamic polarization measurements. Microstructural characterization and surface topography assessments were performed using optical microscopy, scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), and profilometry. The results demonstrate a strong influence of temperature, manufacturing parameters, and polishing on corrosion processes. At room temperature, higher laser power reduced corrosion rates due to better powder consolidation and lower porosity, whereas at 45 °C, the trend reversed, with the highest corrosion rates observed for samples produced at 120 W. Mechanical polishing significantly reduced surface roughness (Ra from ~7–10 μm to ~0.6–1 μm) but did not improve corrosion resistance; in some cases, it increased corrosion rates, likely due to stress redistribution and exposure of subsurface defects. Potentiodynamic tests confirmed that higher laser power reduced corrosion current density for unpolished surfaces, but polishing increased current density at 80 W more than twofold. The findings indicate that optimizing LPBF process parameters is crucial for improving the corrosion resistance of M350 steel. High laser power (≥120 W) is beneficial at ambient conditions, while lower powers (80–100 W) perform better at elevated temperatures. Mechanical polishing alone is insufficient for enhancing resistance and should be combined with stress-relief and porosity-reduction treatments. These results provide guidelines for tailoring additive manufacturing strategies to ensure reliable performance of M350 steel in chloride-rich environments. Full article

This study presents a plant-fabricated nanoparticle system of zirconia (ZrO₂) using Sonchus asper plant extract, compared with conventionally synthesized ZrO_2, for their efficacy in Cr(VI) removal from aqueous solutions. The nanoparticles were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) for elemental composition, Fourier-transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) analysis. The plant-fabricated ZrO₂ exhibited mesoporosity and enhanced surface functionality, attributed to bioactive compounds from Sonchus asper, which improved adsorption performance via increased surface area and residual organic functional groups. Batch adsorption experiments showed that Cr(VI) removal was optimized at 100 mg/L Cr(VI), 300 mg/L adsorbent dosage, pH 5, and 30 min reaction time at 25 °C. Adsorption followed the Langmuir isotherm and pseudo-second-order kinetics models. According to Langmuir model fitting, the maximum adsorption capacity (qmax) reached 142.24 mg/g for PF-ZrO₂ NPs and 133.11 mg/g for conventional ZrO₂ NPs, indicating the superior adsorption performance of the green-synthesized material. This work highlights the sustainable potential of plant-fabricated ZrO₂ nanoparticles as cost-effective and environmentally friendly nano-adsorbents for heavy metal remediation, contributing to the achievement of UN SDG No. 6 by providing clean water solutions. Full article

Vanadium–titanium magnetite (VTM) is an iron ore abundantly available in China. The dominant utilization route is blast furnace smelting; however, Ti in the ore deteriorates sinter strength, making it urgent to clarify Fe-Ti-Ca interactions during sintering. In this work, single-phase FeTiO₃ and Fe₂TiO₄ were synthesized and each paired with CaO to fabricate diffusion couples. The couples were heated at 1200 °C for 30, 60, 90, and 120 min to investigate their interdiffusion behaviors and microstructure recombination mechanisms. The results show that, at 1200 °C, solid-state diffusion—not interfacial reaction—controls mass transfer in both FeTiO₃-CaO and Fe₂TiO₄-CaO systems. Distinct Fe-rich and Ti-rich sublayers appear within the reaction zone, and banded CaTiO₃ forms adjacent to the FeTiO₃/Fe₂TiO₄ matrices. The interdiffusion coefficients were determined to be 4.08 × 10⁻¹⁰ cm²·s⁻¹ and 7.81 × 10⁻¹⁰ cm²·s⁻¹, and the growth of the reaction layer follows a parabolic law, which can be expressed as x² = 2 × 1.562 × 10⁻⁹ t and x² = 2 × 0.8159 × 10⁻⁹ t, respectively. The coefficients of determination exceed 0.90, indicating reliable regression fits. Full article

During the last decade, artificial intelligence (AI) has enabled key technological innovations within the modern dementia and frailty healthcare and prevention landscape. This has boosted the impact of technology in the clinical setting, enabling earlier diagnosis with improved specificity and sensitivity, leading to accurate and time-efficient support that has driven the development of preventative interventions minimizing the risk and rate of progression. Background/Objectives: The rapid ageing of the European population places a substantial strain on the current healthcare system and imposes several challenges. COMFORTage is the joint effort of medical experts (i.e., neurologists, psychiatrists, neuropsychologists, nurses, and memory clinics), social scientists and humanists, technical experts (i.e., data scientists, AI experts, and robotic experts), digital innovation hubs (DIHs), and living labs (LLs) to establish a pan-European framework for community-based, integrated, and people-centric prevention, monitoring, and progression-managing solutions for dementia and frailty. Its main goal is to introduce an integrated and digitally enabled framework that will facilitate the provision of personalized and integrated care prevention and intervention strategies on dementia and frailty, by piloting novel technologies and producing quantified evidence on the impact to individuals’ wellbeing and quality of life. Methods: A robust and comprehensive design approach adopted through this framework provides the guidelines, tools, and methodologies necessary to empower stakeholders by enhancing their health and digital literacy. The integration of the initial information from 13 pilots across 8 European countries demonstrates the scalability and adaptability of this approach across diverse healthcare systems. Through a systematic analysis, it aims to streamline healthcare processes, reduce health inequalities in modern communities, and foster healthy and active ageing by leveraging evidence-based insights and real-world implementations across multiple regions. Results: Emerging technologies are integrated with societal and clinical innovations, as well as with advanced and evidence-based care models, toward the introduction of a comprehensive global coordination framework that: (a) improves individuals’ adherence to risk mitigation and prevention strategies; (b) delivers targeted and personalized recommendations; (c) supports societal, lifestyle, and behavioral changes; (d) empowers individuals toward their health and digital literacy; and (e) fosters inclusiveness and promotes equality of access to health and care services. Conclusions: The proposed framework is designed to enable earlier diagnosis and improved prognosis coupled with personalized prevention interventions. It capitalizes on the integration of technical, clinical, and social innovations and is deployed in 13 real-world pilots to empirically assess its potential impact, ensuring robust validation across diverse healthcare settings. Full article

The increasing demand for functional beverages sparked greater interest in health-promoting craft drinks, highlighting the need to optimize production parameters and assess their stability. This study aimed to develop, optimize, and characterize a grape juice-flavored naturally carbonated water kefir, evaluating its sensory qualities, physicochemical and microbiological stability. Fermentation conditions (F1) were optimized using Central Composite Rotational Design, leading to the selection of 24 h at 30 °C with (6.5% w/v) brown sugar, ensuring efficient pH reduction to safe levels. Sensory analysis selected grape juice as the flavoring agent, and a mixture design coupled with the desirability function determined the optimal formulation as 50% kefired water, 46.4% grape juice, and 3.6% water, resulting in high overall sensory desirability. During 42 days of refrigerated storage (4 °C), the beverage exhibited progressive sugar consumption from residual metabolic activity, a dynamic antioxidant profile characterized by increases in total phenolic compounds and FRAP activity, stability in ABTS activity, and decline in DPPH activity. Lactic acid bacteria counts remained stable during storage, while acetic acid bacteria and yeast populations decreased. Furthermore, pH (~3.30) and alcohol content (~1.86 °GL) remained stable, although the latter requires clear labeling in compliance with regulations for similar fermented beverages. Full article

The rapid increase in global warming requires that sustainable energy choices aimed at achieving net-zero greenhouse gas emissions be implemented as soon as possible. This objective, emerging from the European Green Deal and the UN Climate Action, could be achieved by using clean and efficient energy sources such as hydrogen produced from nuclear power. “Renewable” hydrogen plays a fundamental role in decarbonizing both the energy-intensive industrial and transport sectors while addressing the global increase in energy consumption. In recent years, several strategies for hydrogen production have been proposed; however, nuclear energy seems to be the most promising for applications that could go beyond the sole production of electricity. In particular, nuclear advanced reactors that operate at very high temperatures (VHTR) and are characterized by coolant outlet temperatures ranging between 550 and 1000 °C seem the most suitable for this purpose. This paper describes the potential use of nuclear energy in coordinated and coupled configurations to support clean hydrogen production. Operating conditions, energy requirements, and thermodynamic performance are described. Moreover, gaps that require additional technology and regulatory developments are outlined. The intermediate heat exchanger, which is the key component for the integration of nuclear hybrid energy systems, was studied by varying the thermal power to determine physical parameters needed for the feasibility study. The latter, consisting of the comparative cost evaluation of some nuclear hydrogen production methods, was carried out using the HEEP code developed by the IAEA. Preliminary results are presented and discussed. Full article