Search Results (80,054)

To accurately understand and investigate carbon fluxes in cropland ecosystems, this study adopted a machine learning ensemble model for estimation. Focusing on the Jinzhou station of the ChinaFLUX, we integrated eddy covariance carbon flux observations with multi-source satellite remote sensing data to construct a machine learning-based cropland carbon flux estimation model. For environmental driver selection, a strategy combining correlation analysis with ecological mechanism understanding was employed to screen LST, NDVI, and NDMI as model input variables, effectively avoiding multicollinearity issues. Using footprint-weighted integrated data from 2005 to 2014 for model training and validation, a Stacking ensemble model was constructed with the RF model serving as the meta-learner to stack the predictions of RF, CART, and GBM. The ensemble model further reduced the prediction error (RMSE = 39.82), maintaining an R² > 0.9 in most years and effectively improving predictive performance during anomalous years where single models underperformed. Based on these findings, the model was applied to analyze the spatiotemporal evolution of NEE in Jinzhou croplands from 2005 to 2014. The analysis revealed that while the region functioned overall as a carbon sink, it exhibited significant spatiotemporal heterogeneity. Spatially, the distribution followed a pattern of “strong intensity in the northeast and center, and weak intensity in the northwest and southwest.” Temporally, the sink intensity underwent significant interannual oscillations characterized by a “strengthening–weakening–re-strengthening–declining” trajectory. The high-precision prediction method proposed in this study is of great significance for revealing spatiotemporal variations in carbon sources/sinks, guiding green agricultural development, and supporting relevant policy formulation. Full article

Waterfront recreational spaces, as key urban ecological resources, are distinctive in their scarcity and ecological fragility. Their sustainable revitalization requires evidence-based spatial planning and design. The analysis of the vitality of waterfront recreational spaces, which are characterized by the interaction between space and experience, essentially explores how human, water, and the city can coexist and thrive together. Based on the dual characteristics of vitality, this study presents a space–experience interactive evaluation system for waterfront recreational places that incorporates multi-source data. The vitality evaluation results can then be cross-validated with intuitive representations of vitality quantified using pedestrian flow data. Furthermore, this can be used to accurately calibrate the vitality gradient, identify and analyze the anomalous units, and provide insight into influencing factors and underlying mechanisms of vitality. The empirical investigation of the waterfront recreational area of Suzhou Jinji Lake Scenic Area (JLSA) demonstrates that this method can accurately identify spatial vitality distributions and effectively characterize the key elements of vitality zones at different levels. It can precisely decode the vitality of waterfront recreational spaces, providing fresh perspectives on understanding the space–experience interaction in waterfront recreational spaces and directing actions for enhancing vitality. In addition to serving as a supplement to existing research, it provides a flexible, scalable evaluation framework for a variety of waterfront contexts, supports the implementation of human-centered urban design, and offers theoretical and practical support for the sustainable development of waterfront areas. Full article

Objectives: Dysphagia is a major complication of acquired brain injury (ABI) in children; however, its trajectory and prognostic indicators remain insufficiently characterized. This study aimed to identify predictors of dysphagia and its recovery following pediatric ABI. Methods: This retrospective study included all children admitted with ABI to tertiary pediatric rehabilitation center between 2014 and 2017. Data were collected from electronic medical records. Results: One hundred children aged 2:00–17:11 years were included; 61% had dysphagia at admission. Participants with dysphagia received speech–language pathology (SLP) treatment, with a recovery rate of 78.68%. Treatment duration was significantly shorter among children who recovered (36 days) compared with those who did not (136 days; p < 0.001). Dysphagia at admission was associated with mechanical ventilation, duration of unconsciousness, duration of acute hospitalization, CNS tumor etiology, cranial nerve impairment (V, IX, X, XII), voice and speech impairments, and cognitive and behavioral impairments. Logistic regression showed that reduced consciousness, cranial nerve impairment, voice disorders, and CNS tumors explained 70.6% of dysphagia likelihood. Non-recovery was associated with unconsciousness, enteral feeding, hypoglossal injury, and dysphagia severity at admission. Level of consciousness at admission explained 33.7% of recovery likelihood. Conclusions: Dysphagia was highly prevalent among children with ABI. Recovery rates following SLP treatment were high and were associated with level of consciousness at admission to rehabilitation. Full article

Small combustion installations (SCIs) burning solid fuels remain a major source of particulate matter (PM) emissions responsible for winter smog episodes in many European regions. This study aimed to develop and validate low-cost, micro-scale electrostatic precipitators (ESPs) suitable for retrofitting residential SCIs, and to quantify their PM removal performance under both controlled laboratory conditions and real-life field operation. Two ESP variants were designed and prototyped: (i) a tubular in-line ESP for installation at the boiler flue outlet and (ii) a disk (chimney-bypass) ESP mounted at the chimney outlet, with low energy demand. PM concentrations upstream and downstream of the ESPs were measured using standardized gravimetric, isokinetic sampling with recalculation to reference conditions, and the overall dedusting efficiency was determined from inlet/outlet concentrations. Laboratory testing showed that the micro-scale ESPs can achieve high dedusting efficiencies of approximately 90% under stabilized nominal-load operation. Field trials of the disk ESP in households and small residential buildings confirmed robust performance, with dedusting efficiencies of 70–82% under unsupervised user operation. In most cases, outlet PM concentrations were reduced below applicable Ecodesign thresholds. The results confirm that micro-scale ESPs are a technically feasible and effective “end-of-pipe” option for reducing short-stack PM emissions from solid-fuel heating, offering immediate air quality benefits where appliance replacement or fuel switching is limited by cost or practical constraints. This paper discusses the latest advancements in reducing PM emissions from SCIs. It introduces a prototype design for two types of micro-scale electrostatic precipitators (ESPs) that can be integrated into SCIs that burn solid fuels. The proposed technical solution utilizes an electrostatic method to effectively remove PM from flue gases. An established industrial technology has been adapted to meet the specific technical, economic, and safety needs of residential applications. The paper compares two design variants with a novel self-cleaning mechanism through laboratory testing and presents results from field trials. Findings confirm ESPs can substantially reduce PM emissions from SCIs. Full article

Background: The structural integrity of the abdominal wall is critically dependent on the organization of aponeurotic tissue, a dense collagen-rich connective structure responsible for directional force transmission. While the clinical relevance of the aponeurosis is well recognized in abdominal wall reconstruction, its nano-scale structural organization remains insufficiently characterized. Atomic force microscopy (AFM) provides a suitable approach for investigating surface morphology and nano-architectural features of biological tissues. Methods: Human aponeurotic tissue samples were analyzed using atomic force microscopy operated in contact-mode deflection and topography imaging. Two-dimensional and three-dimensional surface topographies were acquired at the micrometer scale to assess nano-architectural organization. Areal surface roughness parameters (Sa, Sq, Sp, Sv, Sy) were calculated to quantify morphological heterogeneity. AFM deflection imaging was used to evaluate relative spatial variations in deflection imaging contrast under the applied scanning conditions across collagen-dense and interfibrillar regions. Results: AFM analysis revealed a well-organized fibrillar architecture with preferential orientation, consistent with the anisotropic organization of aponeurotic connective tissue. Deflection images demonstrated spatial heterogeneity in deflection contrast at the scanned scale, reflecting variations in the tip–sample interaction signal between collagen-dense and interfibrillar regions. Surface topography showed a continuous morphology with moderate height variations and smooth transitions between structural elements. Roughness parameters reflected a compact extracellular matrix organization within the scanned areas, without features suggestive of surface disruption. Conclusions: Atomic force microscopy enables detailed nano-scale structural characterization of human aponeurotic tissue and reveals spatial heterogeneity in deflection imaging contrast under specific contact-mode scanning conditions. These findings provide a baseline nano-scale descriptive reference dataset for macroscopically normal aponeurotic tissue, supporting future comparative investigations without implying validated mechanical differences or direct tissue–implant interaction analysis within the present study. Full article

Electromagnetic compatibility (EMC) diagnostics for high-density through-silicon via (TSV)-based chips face significant challenges due to complex three-dimensional electromagnetic coupling and inefficient source reconstruction workflows. This paper proposes a universal contribution-driven dipole preprocessing technique tailored for dipole array-based source reconstruction methods, addressing the critical efficiency-accuracy trade-off inherent in traditional approaches. The core innovation is an influence factor-based evaluation-elimination mechanism that extracts effective dipole components aligned with the structural characteristics of TSV-based chips and multilayer printed circuit boards, while eliminating redundant dipoles independently of the downstream source reconstruction algorithm. Validation on a multilayer PCB (1 GHz) and a TSV-based chip (4 GHz) demonstrates that the technique maintains high reconstruction accuracy, with error increase limited to ≤0.2% for the simulated PCB and ≤0.05% for the physically measured TSV-based chip. Computational time is reduced by 28–61% for the PCB and 20–28% for the TSV chip compared to traditional source reconstruction without preprocessing. For TSV-based chips exhibiting complex electromagnetic behavior, the technique delivers consistent performance across different dipole configurations, providing a fast, robust, and universal EMC diagnostic tool for high-density electronic devices. Full article

Background: Acute high-intensity exercise induces transient inflammatory and oxidative stress responses, mediated by redox-sensitive signaling pathways and reflected by elevations in interleukin-6 (IL-6) and lipid peroxidation products. Modulation of these responses through hydration-based redox interventions remains insufficiently characterized at the biochemical level. Objective: This randomized controlled trial investigated whether regular consumption of redox (alkaline) water influences exercise-induced inflammatory and oxidative stress markers in physically active adults. Methods: Forty physically active adults were randomized into an experimental group (EG; n = 20) and consumed redox water subjected to molecular-level modification, yielding alkaline hydrogen-enriched water (pH 9.2–9.4), or a control group (CG; n = 20) that consumed standard water. After eight weeks of intervention, participants performed a standardized maximal aerobic exercise test. Plasma IL-6 and malondialdehyde (MDA) concentrations were measured at baseline and immediately post-exercise. Statistical analyses included two-way repeated measures ANOVA and ANCOVA. Results: A pronounced group × time interaction was observed for IL-6 (F(1,38) = 36.89, p < 0.001). The EG exhibited a significant post-exercise reduction in IL-6, whereas the CG demonstrated a robust increase. A significant group × time interaction was also detected for MDA (F(1,38) = 4.98, p = 0.029), reflecting stable lipid peroxidation levels in the EG and increased levels in the CG; however, baseline-adjusted analyses indicated that post-exercise MDA differences were largely attributable to initial variability. Hematological and coagulation parameters remained within physiological ranges in both groups. Conclusions: Redox water intake was associated with lower immediate post-exercise IL-6 compared with controls after baseline adjustment; however, pronounced baseline imbalance limits causal interpretation and warrants confirmation in larger trials with balanced inflammatory profiles. These findings highlight a potential biochemical mechanism linking hydration redox properties with inflammatory regulation during physical stress. Full article

Background: Inonotus obliquus (Chaga), a medicinal and edible macrofungus abundant in bioactive polyphenols, is a potential source of natural antioxidants and anti-inflammatory agents for functional foods. This study aimed to evaluate the antioxidant capacity of three key polyphenols (osmundacetone [OS], protocatechuic aldehyde [PAH], protocatechuic acid [PA]) from I. obliquus and decipher their anti-inflammatory mechanisms via the MyD88/TLR4/NF-κB pathway in a gout-related model. Methods: Antioxidant activity was assessed by xanthine oxidase (XO) inhibition (IC₅₀), superoxide anion (O₂⁻) scavenging, and structure–activity relationship (SAR) analysis; in a monosodium urate (MSU)-induced acute gout cell model, reactive oxygen species (ROS), nitric oxide (NO), lactate dehydrogenase (LDH), superoxide dismutase (SOD), pro-inflammatory cytokines (TNF-α, IL-1β) were quantified, and MyD88/TLR4/NF-κB pathway proteins were analyzed by Western blot. Results: OS showed the strongest XO inhibition (IC₅₀ = 4.91 mM), followed by PAH (IC₅₀ = 5.92 mM) and PA (IC₅₀ = 26.53 mM); OS exerted dual redox effects by scavenging O₂⁻ and suppressing XO-mediated O₂⁻ generation, with its conjugated C=C-carbonyl system and PAH’s aldehyde group enhancing XO binding. All polyphenols and I. obliquus crude extract significantly reduced ROS, NO, LDH, and cytokines (p < 0.05), increased SOD, and downregulated TLR4, MyD88, and NF-κB expression. Conclusions: I. obliquus-derived polyphenols exhibit obvious antioxidant and xanthine oxidase inhibitory effects, and regulate oxidative stress, pro-inflammatory mediators, and the MyD88/TLR4/NF-κB signaling pathway in monosodium urate-stimulated RAW 264.7 inflammatory macrophages, supporting their development as natural functional food ingredients and potential candidates for gout-related and oxidative stress-associated inflammatory cellular disorders. Full article

Catalytic systems that couple pollutant degradation with hydrogen evolution have attracted significant attention due to their potential to simultaneously address environmental and energy issues. In this study, an S-scheme heterojunction composed of lamellar polymeric carbon nitride (PCN) anchored with a rod-like cerium metal–organic framework (Ce-MOF) was successfully synthesized via a facile one-step oxidation method, enabling efficient visible-light-driven photocatalytic hydrogen evolution and simultaneous tetracycline degradation. The optimized PCN/Ce-MOF composite delivers a hydrogen production rate of 495.7 μmol g⁻¹ h⁻¹ and achieves a tetracycline removal efficiency of 78%. Such excellent performance is attributed to the charge transfer mechanism of the S-scheme heterojunction in the PCN-Ce-MOF composite during the reaction process, while retaining the intrinsic redox capabilities of both materials. Meanwhile, mechanistic studies reveal that tetracycline can effectively capture holes during its efficient degradation, inhibit electron–hole recombination, and promote proton reduction to generate hydrogen. This investigation provides valuable insights for the rational design of S-scheme heterojunction photocatalysts, aiming to achieve efficient and stable photocatalytic hydrogen production and synergistic degradation of organic pollutants. Full article

Background: The choice of mechanical prosthesis for mitral valve replacement (MVR) is critical, yet data comparing long-term outcomes across different valve types are still needed. This study aimed to compare the long-term clinical and echocardiographic outcomes of four distinct mechanical mitral valve prostheses. Methods: We retrospectively analyzed 431 patients who underwent mechanical MVR between 2009 and 2022 with one of four valve types: Carbomedics (n = 112), Bicarbon (n = 176), ATS (n = 89), or On-X (n = 54). A competing risk regression model was used to identify predictors of a composite endpoint (valve thrombosis, reoperation, stroke, pulmonary embolism, and major bleeding), accounting for all-cause mortality. Longitudinal echocardiographic data were analyzed using linear mixed-effects models. Results: The median follow-up was 62 months. The cumulative incidence of the composite endpoint at 10 years was 14% for the On-X valve, 12% for the Bicarbon valve, 9.5% for the Carbomedics valve, and 7% for the ATS valve. After adjusting for confounders, the type of valve prosthesis was not significantly associated with the composite endpoint. Significant predictors of adverse events included coronary artery disease (Sub-distribution Hazard Ratio [SHR] 2.70, p = 0.023), peripheral artery disease (SHR 6.29, p = 0.007), and smaller valve size (SHR 0.87, p = 0.037). No significant difference in overall survival was observed between the groups (log-rank p = 0.904). All valve types were associated with favorable LV remodeling. The Carbomedics group showed the greatest reduction in left ventricular end-diastolic diameter, likely reflecting regression to the mean given the larger baseline ventricular dimensions in this group. Conclusions: The type of mechanical mitral valve did not significantly influence long-term thromboembolic and bleeding events or overall survival. Patient-specific factors and valve size were the primary determinants of adverse outcomes. The observed differences in ventricular remodeling may warrant further investigation. Full article

Background: Vascular calcification (VC) affects up to 90% of patients with end-stage renal disease and increases cardiovascular mortality 3- to 5-fold. Once considered passive mineral deposition, VC is now recognized as an active, toxin-driven process orchestrating vascular smooth muscle cell transdifferentiation, endothelial dysfunction, and matrix remodeling. However, current uremic toxin classifications remain biochemically oriented, providing limited clinical guidance for risk stratification and therapeutic selection. Methods: This comprehensive review reframes uremic toxin-driven VC through an integrated phenotypic lens, synthesizing molecular mechanisms, clinical biomarkers, and therapeutic targets into a unified translational framework. Results: We propose five mechanistic-clinical phenotypes representing distinct biological trajectories of vascular injury. These include (1) inflammatory-oxidative (dominated by indoxyl sulfate, p-cresyl sulfate, NLRP3 inflammasome activation), (2) mineral-metabolic (hyperphosphatemia, FGF23 excess, Klotho deficiency), (3) epigenetic-senescent (histone modifications, microRNA dysregulation, cellular senescence), (4) endocrine cross-talk (vitamin D, PTH, gut-derived metabolites), and (5) integrated toxic continuum (convergence of multiple pathways in advanced disease). A comprehensive biomarker panel spanning inflammatory markers, mineral metabolism parameters, epigenetic indicators, and endocrine-gut metabolites enables phenotypic stratification and therapeutic monitoring. Emerging therapies—including tissue-nonspecific alkaline phosphatase inhibition, ectonucleotide pyrophosphatase/phosphodiesterase 1 enzyme replacement, vitamin K₂ activation, senolytic agents, and SNF472 crystal-growth blockade—are mapped to their optimal phenotypic contexts. Conclusions: This phenotype-oriented paradigm transforms VC from an inevitable complication into a targetable and potentially reversible manifestation of uremic toxicity, establishing a translational foundation for precision-based vascular medicine in chronic kidney disease. The framework enables biomarker-guided patient stratification, rational therapeutic selection, and phenotype-enriched clinical trial design. Full article

To address the current research gap where studies on the failure mechanisms of fissured tunnels mainly focus on single tunnels with insufficient research on double tunnels, and to provide a scientific basis for disaster prevention and control of the Jinan Tunnel on Jinan Ring Expressway, this study investigates the mechanical behavior and failure characteristics of tunnel structures containing fissure–hole composite systems using experimental tests and numerical simulations. The crack initiation, propagation, and coalescence mechanisms are systematically analyzed to provide engineering references for tunnel design and stability assessment. Sand-based 3D printing technology was used to fabricate double-tunnel models with prefabricated fissures of different inclination angles α. Uniaxial compression tests were conducted, and crack evolution was monitored using DIC technology. Meanwhile, numerical simulation verification was performed based on the parallel bond (PB) model of the Discrete Element Method (PFC). The results show that the mechanical response of sand-based 3D-printed models conforms to the brittle characteristics of engineering rock masses. For models without fissures, cracks are preferentially initiated at the top and bottom of the tunnels. For models with fissures, the peak strength is the highest when α = 30° and 60°, and the lowest when α = 45° and 90°. As the fissure inclination angle increases, the tensile stress concentration shifts from the top and bottom of the tunnels and the middle of the fissure to the two ends of the fissure. The numerical simulation results are consistent with the experimental results and can accurately reproduce crack evolution. This study verifies the effectiveness of combining sand-based 3D printing with discrete element simulation, providing a reference for fissure prevention and control as well as operation and maintenance optimization of similar double-tunnel projects. Full article

Fatigue behaviors in asphalt mixtures are influenced by multiple factors, including strain level, strain waveform, and temperature, as well as rest periods. This complexity makes the analysis and interpretation of fatigue data particularly challenging. Dissipated energy (DE) is effective for developing unified fatigue models that characterize asphalt mixture behavior across varying temperatures and strain levels. However, its applicability requires further validation across a broader range of loading scenarios, especially those involving diverse strain waveforms and rest periods. This research aimed to apply the dissipated energy method to analyze fatigue behaviors of asphalt mixture subjected to extended combinations of strain waveforms and temperatures, as well as rest periods. It was found that strain waveform significantly impacts DE values and the rate of DE variation in asphalt mixtures, which contributes to differences in fatigue life at varying strain waveforms. The initial DE (IDE) indicator establishes a distinct correlation with the fatigue life of the asphalt mixture, unaffected by strain waveforms or strain levels. However, this IDE-fatigue life relationship is influenced by rest periods and temperatures. Longer rest periods shift the IDE-fatigue life curve toward a higher fatigue life, indicating improved performance. Through IDE analysis, a generalized model was formulated to represent IDE-fatigue life relationships across broad strain waveforms and strain levels, as well as rest periods, facilitating fatigue life prediction under changing conditions. This research provides valuable insights into the fatigue characteristics and underlying mechanisms of asphalt mixtures from an energy perspective. Full article

Hexavalent chromium (Cr(VI)) is a high-priority environmental pollutant due to its strong oxidizing properties, which cause DNA damage and other severe health effects. Conventional detection methods are often costly and lack real-time monitoring capabilities, creating a strong demand for cost-effective, real-time biosensors that meet industrial requirements. In this study, we developed a novel biosensor for continuous Cr(VI) monitoring using a single-chamber microbial fuel cell (MFC). The biological element is an engineered Escherichia coli strain (ChrA-ChrB-E. coli), constructed by introducing Cr(VI)-resistant (ChrA) and Cr(VI)-reducing (ChrB) genes. The presence of Cr(VI) affects bacterial metabolism and electron transfer within the MFC, generating a measurable signal proportional to the contaminant’s concentration. The biosensor demonstrated robust performance and characteristics. The recombinant strain retained functional activity after 450 days of storage at −20 °C. The system exhibited high sensitivity and excellent linearity (R² ≥ 0.999) across a broad Cr(VI) concentration range of 0.015–200 mg/L. During continuous monitoring of chrome tanning and electroplating wastewater, measurements deviated by less than 2.33% from the standard diphenylcarbazide (DPC) method; electroplating deviation was further reduced to −0.69% with EDTA pretreatment. In fishery water, the deviation was higher (−7.12%) due to dissolved oxygen (DO) interference but was reduced to −0.75% after mechanical stirring to remove DO. The biofilm bacterial community remained highly stable over six months in both wastewater types, with the inoculated ChrA-ChrB-E. coli strain maintaining dominance (>99.6%). These results substantiate the feasibility of using this biosensor for continuous, online, real-time detection of Cr(VI) in actual wastewater environments. Full article

This paper presents a minimally intrusive experimental methodology for identifying and modeling power losses in the electric powertrain of a battery electric vehicle, including the inverter, electric motor and speed reducer. Measurements are performed on a roller test bench equipped with an eddy current brake, using two complementary approaches to determine the mechanical power at the wheel: (i) a direct measurement based on an onboard rotary torque sensor integrated into a driveshaft; (ii) an indirect estimation derived from brake power measurements corrected for bench losses and tire longitudinal slip. The two approaches are systematically compared in order to quantify the accuracy loss associated with brake-based measurements and to identify the operating conditions under which they can reliably substitute direct torque measurements. The experimental results show that brake-based estimations provide acceptable accuracy at moderate–high torque levels, while significant deviations occur at low torque. Based on the experimental dataset, an overall power loss model is identified using a polynomial function of motor torque and speed. Two fitting strategies are investigated: an unconstrained least-squares approach, allowing all coefficients to vary freely, and a constrained formulation enforcing physically admissible (non-negative) loss terms; while the unconstrained method slightly improves the numerical fit, it may lead to non-physical coefficients and invalid efficiency predictions. In contrast, the constrained approach preserves physical interpretability and ensures consistent loss and efficiency maps. Finally, a step-by-step practical guide is provided to facilitate the implementation of the proposed methodology for powertrain loss identification on electric vehicles without extensive mechanical disassembly. Full article