Search Results (17,821)

Drug-induced liver injury (DILI) remains a major cause of acute liver failure and drug withdrawal from the market. Recently developed three-dimensional (3D) hepatic in vitro systems exhibit improved functionality and drug sensitivity compared with conventional two-dimensional cultures. These 3D models range from simple physiologic-like culture systems to advanced bioreactors with dynamic flow to provide sufficient nutrients and consistent drug exposure. However, whether dynamic perfusion improves sensitivity and reproducibility of hepatotoxicity testing remains unclear. Here, we developed a tailor-made perfusion platform to support volumetric bioprinted hepatic constructs for hepatotoxicity testing. The constructs consist of intrahepatic cholangiocyte organoids (ICOs) differentiated towards hepatocyte lineage and embedded in a gelatin methacryloyl bioresin. For toxicity evaluation, the hepatocyte-like ICO constructs were exposed to prolonged subtoxic acetaminophen treatment (10 mM, 7 days). The perfusion system effectively maintained and enhanced hepatocyte differentiation, evidenced by upregulated hepatic markers under perfused conditions compared to static controls. Testing of acetaminophen hepatotoxicity revealed that the perfused constructs displayed elevated cellular injury, with markedly higher liver injury markers relative to controls. Collectively, this study demonstrates the successful application of perfusion-based 3D model culture and highlights its potential as a more physiological platform for hepatotoxicity risk assessment in drug discovery and regenerative medicine. Full article

Background/Objectives: Retractile testis has traditionally been considered a benign physiological variant, managed conservatively with observation until puberty. However, recent evidence suggests that retractility may predispose individuals to acquired cryptorchidism and complications such as torsion, testicular atrophy, and impaired fertility. This review aims to synthesize the current literature on the clinical features, natural history, complications, and management of retractile testes, and to evaluate whether conservative management remains appropriate. Methods: A structured narrative review was performed. PubMed (MEDLINE), Embase, Scopus, and the Cochrane Library were searched from database inception to 15 December 2025, and screening was reported using a PRISMA-style flow diagram. To our knowledge, this is the first review focusing exclusively on the retractile testis in the pediatric population, with a primary emphasis on management and treatment. Results: Prevalence among school-aged boys ranges from 1.2% to 3.9%. Reported progression rates to acquired cryptorchidism and orchiopexy vary widely, from 2% to 50%, with risk factors including inelastic spermatic cord, ipsilateral hernia, and younger age at presentation. Histological and sonographic studies demonstrate reduced testicular volume, seminiferous tubule degeneration, and impaired spermatogenesis, paralleling congenital cryptorchidism. Short-term complications include acute torsion, with abnormal gubernacular attachment and patent processus vaginalis frequently observed intraoperatively. Evidence for malignancy risk remains inconclusive. Conclusions: The available evidence, drawn largely from retrospective and observational studies, suggests possible associations between retractility and short- and long-term outcomes such as acute torsion, testicular atrophy, and impaired fertility, whereas an independent link with testicular malignancy remains unproven. This evidence is not yet sufficient to establish causation, and current professional-society guidelines continue to favor surveillance for the true retractile testis, reserving orchiopexy for documented ascent or other defined indications. Pending prospective data, these findings support structured, guideline-consistent follow-up, so that boys in whom ascent or atrophy develops are identified promptly. Full article

Rapid urbanization has intensified two critical urban challenges: the urban heat island effect and stormwater runoff. This study evaluates the pilot-level field performance of a low-tortuosity permeable pavement (LTPP) system in potentially contributing to improved thermal regulation and hydraulic functionality. The system comprises a reduced-tortuosity upper block incorporated with bottom ash (BA) as a recycled fine aggregate and an underlying storage unit connected through an interlocking configuration, enabling direct infiltration while reducing clogging susceptibility and improving resistance to settlement and displacement. Field tests included thermal imaging, water-spraying infiltration-storage and vehicle-loading observations, and theoretical storage analysis. Initially, conventional permeable pavement (PP) dry surface temperature was measured at 44.2 °C, whereas the LTPP system already exhibited a lower temperature of 42.4 °C. During the evaporative stage after wetting, the LTPP system showed a lower temperature recovery rate, with a 2.91% increase between 90 and 120 min compared with 3.60% for conventional permeable pavement, indicating improved surface-temperature regulation. The storage calculations approximated that the LTPP system could theoretically buffer the simulated 15.63 mm/h rainfall by 6.65 to 7.32 h. It was also determined using historical rainfall data that the LTPP system, especially when provided with an outlet or drainage system, could effectively accommodate short- to medium-duration rainfall. Water-spraying tests confirmed rapid infiltration and subsurface storage, while vehicle-loading observations showed no noticeable displacement or settlement. These findings highlight the potential of a multifunctional permeable pavement design strategy that combines low-tortuosity flow paths, functional recycled aggregate selection, and subsurface storage for surface-temperature regulation and stormwater management. Full article

Dielectric Barrier Discharge (DBD) plasma actuators have shown considerable potential for aerodynamic flow control over fixed wings and helicopter rotors. However, their application to small unmanned aerial vehicle (UAV) propellers operating at high rotational speeds remains largely unexplored. This study experimentally investigates the effectiveness of leading-edge AC-DBD plasma actuators in improving the aerodynamic performance of rotating UAV propellers under hovering conditions. A custom-built experimental test stand was developed to measure thrust, rotational speed, and motor power consumption while supplying high voltage to the rotating blades through high-speed slip rings. A series of 3D-printed propellers with different blade pitch angles was tested at rotational speeds up to 4000 rpm. The results showed negligible performance changes for low-pitch propellers, whereas significant improvements were observed under separated-flow conditions. At nearly constant rotational speed and thrust, plasma actuation reduced the propeller power coefficient by up to 7.66%, resulting in a maximum 9.42% increase in Figure of Merit (FoM). The greatest benefits were obtained for intermediate blade pitch angles, while no measurable improvement was observed under severe separation conditions. These findings demonstrate that plasma actuation is most effective within an intermediate separated-flow regime and highlight its potential as a lightweight active flow-control technology for electrically powered UAVs. Full article

The durability of dental restorations against erosive and staining challenges is crucial for long-term clinical success. Therefore, this in vitro study aimed to investigate the combined effects of sequential simulated gastric acid exposure, coffee immersion, and different cleaning procedures on the surface roughness and color stability of four contemporary flowable resin composites with different filler and matrix characteristics. Ninety-six disk-shaped specimens were fabricated from four resin composites: Omnichroma Flow, G-ænial Universal Injectable, Universal Flo, and EverX Flow. Baseline surface roughness and color coordinates were recorded. Specimens were immersed in 0.06 M hydrochloric acid for 48 h to simulate gastric acid exposure and subsequently immersed in coffee solution for 24 h to simulate staining. Color measurements were performed at baseline, after sequential gastric acid–coffee exposure, and after cleaning procedures. ΔE₀ was calculated between baseline and post-exposure values, whereas ΔE₁ was calculated between post-exposure and post-cleaning values. Specimens were then allocated to three cleaning subgroups: toothbrushing (BR), water flosser (WF) and mouthrinse (MR). Final surface roughness and color changes were evaluated. Data were analyzed using mixed and factorial ANOVA tests. Sequential gastric acid–coffee exposure significantly increased surface roughness in all materials. Omnichroma Flow showed the lowest roughness values, whereas G-ænial Universal Injectable demonstrated the highest post-treatment roughness, particularly after toothbrushing. Toothbrushing generally caused greater roughness increases than other cleaning procedures. Material type significantly affected color stability, with Universal Flo showing the greatest discoloration and Omnichroma Flow the lowest color change. Surface roughness and color stability were significantly influenced by sequential gastric acid–coffee exposure and cleaning procedures in a material-dependent manner. Full article

Optimizing fuel injector geometry represents a critical pathway toward cleaner and more efficient diesel combustion. This study presents a comprehensive numerical investigation of the influence of the dual-hole nozzle injection angle on the primary atomization behavior and spray hydrodynamics of high-pressure diesel jets. The present analysis is deliberately restricted to cold-flow, near-nozzle primary breakup under isothermal conditions (293.15 K) so that the hydrodynamic and aerodynamic breakup mechanisms can be isolated in the immediate vicinity of the orifice before evaporation and combustion occur. Two-dimensional simulations are conducted using an Eulerian Volume-of-Fluid (VOF) framework with finite element discretization, three injection-angle configurations (0°, 5°, and 10°) under realistic engine conditions (injection pressure: 138 MPa; chamber pressure: 2.32 MPa; nozzle diameter: 100 µm). The numerical model was validated against the experimental and computational benchmark data of Ménard et al., showing reasonable qualitative agreement in jet morphology, although the 2D nature of the model leads to an exaggerated accumulation of liquid at the spray tip compared to the 3D reference. The validation therefore supports the qualitative trends and the relative angular comparison, but the absolute quantitative predictions remain subject to this 2D structural limitation. Results reveal that the injection angle exerts a decisive influence on the competition between axial momentum and radial dispersion. The neutral 0° configuration yields an overly concentrated jet with limited interfacial destabilization and poor air entrainment, whereas the 10° angle produces excessive radial spreading at the expense of axial penetration depth. By contrast, the 5° convergence angle provides the best trade-off among the three tested configurations under the studied conditions, promoting enhanced Rayleigh–Plateau instability growth, earlier ligament formation, and finer droplet generation—favorable to a more homogeneous air–fuel mixture. These findings provide quantitative guidance for dual-hole injector geometry design and demonstrate the suitability of high-fidelity VOF-based methods for resolving complex two-phase atomization phenomena relevant to low-emission diesel engine design. Quantitatively, the peak axial velocity is reached at the nozzle exit for all configurations; relative to the 0° baseline, the 5° convergence angle increases the fuel–air interfacial spreading by about 141% while retaining roughly 90% of its axial penetration at the monitoring positions P₁–P₃, whereas the 10° case loses about 26% of axial penetration for a comparable radial spread. Full article

Deep learning surrogate models trained with mean-squared-error loss produce statistically accurate but physically unconstrained flood predictions: water may flow uphill, appear spontaneously, or smooth over street-level corridors. In this work, a physics-informed training framework is developed for CNN-LSTM models that predict urban flood depths at 15 min intervals over a $128\times 128$ spatial grid. Three differentiable penalty terms are embedded directly into the loss function: (i) a gravity loss that penalizes depth increases against the water-surface-elevation gradient, (ii) a continuity loss enforcing local mass conservation with rainfall-adaptive thresholds, and (iii) a topography-aware false-alarm penalty modulated by the topographic wetness index (TWI). The framework is evaluated on the Norfolk, Virginia, flood dataset spanning two major storm events (August 2017 and September 2022) comprising 300 samples, with all variants trained on identical splits and robustness assessed over repeated random splits and leave-one-storm-out tests. A road-proximal evaluation restricted to a TWI-derived street mask quantifies street-level skill. The physics-constrained model achieves near-zero gravity violations (∼10⁻⁶) and the highest street-channel recall (0.77 ± 0.09 versus 0.44 ± 0.10 for the unconstrained baseline), the capability most relevant to downstream traffic routing, and its recall advantage more than doubles on a held-out storm, while a uniform false-alarm variant attains 16% lower mean absolute error but suppresses street recall to 0.25. The proposed TWI-modulated penalty reconciles this trade-off: it improves upon the uniform variant on every metric measured, recovering 60% higher street recall at the lowest MAE among all constrained variants and the best street-level F1 score. These results expose a fundamental tension between aggregate pixel-level error metrics and application-specific physical plausibility, and demonstrate that terrain-aware loss modulation offers a principled resolution. Full article

Mountainous pumped-storage upper reservoirs are commonly affected by high reservoir water levels, adjacent low valleys, fractured rock masses, and local fault-fracture zones, which complicate leakage pathway identification and leakage prediction. This study investigates a two-valley connected mountainous pumped-storage upper reservoir in northwestern China. Groundwater observations, packer tests, analytical calculations, and three-dimensional groundwater flow modeling were integrated to analyze the permeability structure of the reservoir basin, potential leakage pathways, and leakage discharge after impoundment. The results show that the reservoir rock mass is dominated by very weakly to weakly permeable rocks, whereas local moderately permeable zones may form leakage pathways together with dam abutments, ridge saddles, and fault-fracture zones. The summed analytical leakage discharge of the identified pathways was 3069.80 m³/d. Under the normal reservoir water level of 1895 m, the summed analytical leakage discharge of the identified pathways was 3069.80 m³/d, whereas the three-dimensional numerical model predicted a total leakage discharge of 2661.81 m³/d. Both methods indicate that dam foundations and abutments, the western ridge saddle of Reservoir B, and surrounding fault-fracture zones are the main leakage-prone zones. These results suggest that seepage-control boundary determination for similar mountainous upper reservoirs should consider the spatial association among dam-site areas, local permeable zones, ridge saddles, adjacent low valleys, and fault-fracture zones. Full article

Reliable assessment of polycarboxylate ether (PCE)–binder combinations requires predictive models whose interpolation performance is distinguished from their performance when an entire formulation is absent from training. This study examined 616 cement–fly ash pastes prepared using twenty-two in-house PCE formulations, four fly ash replacement levels (0, 15, 30, and 45 wt%), seven PCE dosages (0.50–2.00 wt% of binder), and a fixed water-to-binder ratio of 0.35. Marsh funnel flow time was measured for all mixtures, whereas mini-slump measurements were available for 252 mixtures comprising nine PCE formulations. Ten regression algorithms were evaluated using 3 × 5-fold repeated cross-validation and nine non-algebraically redundant input variables. XGBoost achieved R² = 0.946 ± 0.027 and RMSE = 8.40 s for flow time, and R² = 0.778 ± 0.061 and RMSE = 0.471 cm for mini-slump. These random-resampling results describe interpolation among formulations represented in the training folds. When each PCE chemistry was withheld in turn, the mean R² was 0.865 ± 0.198 for flow time and 0.034 ± 0.530 for mini-slump. Performance also decreased when the boundary fly ash levels were withheld. SHAP and permutation analyses identified PCE dose and fly ash replacement as the strongest predictors, while the formulation-level descriptors made smaller contributions. These findings represent associations learned from the present dataset and do not constitute direct evidence of adsorption or dispersion mechanisms. At a nominal 90% level, split-conformal intervals achieved empirical coverages of 85.5% for flow time—moderately below the nominal level, within finite-sample binomial fluctuation—and 90.2% for mini-slump on a random test partition; across fifty repeated train–calibration–test splits, the mean coverages were 89.4 ± 3.6% and 90.1 ± 5.8%. The flow-time model is suitable for preliminary screening within the investigated factor ranges, whereas the mini-slump model should be restricted to interpolation among the sampled formulations. Full article

Background/Objectives: Compression therapy serves as first-line conservative management for low-flow vascular malformations and Klippel–Trénaunay syndrome (KTS). However, ready-made garments are frequently ill-fitting for patients with limb overgrowth, asymmetry, deformity, or heterogeneous body habitus. Custom-made compression elastic garments offer an individualized solution, yet systematic data across diverse clinical entities remain scarce. This study evaluated objective and subjective outcomes of custom-made compression garments across vascular anomalies and edematous disorders in a multi-institutional real-world setting. Methods: A retrospective observational case series was conducted between May 2023 and September 2025 at four institutions: a tertiary medical center, a pediatric specialty hospital, a corporate hospital, and a corporate clinic. Patients who received custom-made compression elastic garments for vascular anomalies, edema, varicose veins, post-traumatic or post-burn venous stasis, or postoperative conditions were included. Objective outcome (limb circumference change) and subjective outcome (patient satisfaction) were analyzed. Results: A total of 191 patients who received custom-made garments were described (117 females, 61.3%; 74 males, 38.7%; mean age 36.3 years; median 22 years; range 1–96 years). The age distribution was bimodal, with 91 patients (47.6%) aged 0–19 years and 50 patients (26.2%) aged ≥70 years. The tertiary center and pediatric hospital treated vascular anomaly patients exclusively (n = 102), while the corporate hospital and clinic primarily served adult and elderly edematous disorder patients (n = 88; one additional vascular anomaly case was managed at the corporate hospital). Quantitative paired outcome analysis was feasible in the subgroups with complete paired data: 20 vascular anomaly patients (objective outcome) and 20 edematous disorder patients (subjective outcome). In the vascular anomaly subgroup (n = 20), the affected limb showed a significantly greater circumference reduction at the ankle’s narrowest point (median −2 mm, IQR −4.2 to 0.0) compared with the unaffected contralateral limb (median +0.5 mm, IQR −0.2 to +1.0; Wilcoxon signed-rank test T = 4; p < 0.001; effect size r = 0.83). In the edematous disorder subgroup (n = 20), patient satisfaction scores improved significantly from a median of 3 (IQR 2.0–4.0) to 4 (IQR 3.0–6.0) after garment use (Wilcoxon signed-rank test T = 0; p < 0.001; effect size r = 0.83). Representative cases illustrated pediatric vascular anomaly (Case A, vascular malformation; Case C, KTS) and adult edematous disorder (Case B, chronic lower limb edema) presentations and outcomes. Conclusions: Custom-made compression elastic garments were feasible and well tolerated across a broad real-world spectrum of vascular anomalies and edematous disorders. In the analyzed subgroups, a measurable reduction in affected-limb circumference was observed in pediatric vascular anomaly patients, and patient satisfaction improved in adult and elderly edematous disorder patients. Because each subgroup was evaluated with only one outcome domain and no head-to-head comparison of measures was performed, these findings should be regarded as hypothesis-generating. We propose that outcome measures may need to be tailored to disease background and age, a hypothesis that warrants testing in prospective studies capturing both objective and subjective endpoints across all patient groups. Full article

Denitrifying bioreactors are edge-of-field best management practices used to reduce excess nutrients in agricultural drainage. Traditional systems rely on woodchips as both a carbon source and microbial habitat, but woodchip-only bioreactors often exhibit limited nitrate removal, particularly under low temperatures and high flow conditions. This study evaluated nitrogen removal in a multimedia bioreactor under varying environmental conditions. A non-ideal, continuous stirred-tank model was applied to estimate nitrogen removal rates and nitrate removal efficiencies in mesoscale reactors containing walnut-shell biochar, Brotex, and woodchips. Two configurations—woodchip–biochar with and without Brotex—were tested at 4 h and 12 h hydraulic residence times (HRTs) and temperatures from 6 °C to 14.5 °C. Nitrate removal was consistently higher in the non-Brotex treatments. At low temperature, average removal was 15.3% (3.21 g m⁻³ d⁻¹) and 50.5% (3.66 g m⁻³ d⁻¹) for 4 h and 12 h HRTs, respectively. Removal improved at higher temperatures, reaching 54.2% (4.77 g m⁻³ d⁻¹) and 79.7% (7.86 g m⁻³ d⁻¹). These results exceeded many nitrate removal values reported for woodchip-only systems in the literature under similar temperature and hydraulic residence time conditions, indicating that alternative media can enhance performance across a range of flow and temperature conditions, supporting broader application in diverse climates. Full article

Software-Defined Networking (SDN) centralizes control logic, improving programmability but exposing the controller to volumetric and low-rate Distributed Denial of Service (DDoS) attacks. Entropy-based detectors often raise late alarms or require significant traffic distribution changes, while machine-learning approaches impose high training and inference overhead. To address these issues, this work proposes a Statistical Mean Renyi Entropy (SMRE)-based early-warning system that amplifies micro-level disturbances in flow randomness using a tunable sensitivity weight (μ). The formulation enhances responsiveness to entropy deviations without adding computational complexity, enabling O(n) single-pass execution per monitoring window. The method was implemented on a Mininet testbed (nine switches, 64 hosts, POX controller with the L3_learning module) with mixed benign traffic and hping3/Scapy-generated UDP and TCP flood attack traffic at intensities ranging from 10 to 75%. Experimental results demonstrate that SMRE detects early-stage attacks with 94.7–98.1% accuracy, 0.8–2.3% false positive rate, and 6.5–14 ms detection latency, outperforming Shannon and classical Renyi entropy detectors. ROC analysis (AUC ≈ 0.99) and paired t-tests (p < 0.01) confirm statistical significance. Resource profiling shows negligible CPU and memory overhead, supporting real-time deployment. By eliminating model training and ensuring robust early detection, SMRE offers a lightweight and practical detection mechanism for SDN environments, whose applicability to cloud, edge, and IoT deployments will be further substantiated through validation on real traffic traces and multi-controller architectures. Full article

To investigate the dynamic response of marine risers under multi-parameter coupling effects, physical model tests of marine risers are designed and performed in this study. The tested parameters consist of structural parameters (materials, boundary condition and top tension) and environmental flow parameters (flow velocity, wave height and wave period). Three riser specimens including aluminum tube (Al), polymethyl methacrylate tube (PMMA) and unplasticized polyvinyl chloride tube (UPVC) are adopted to qualitatively simulate metallic risers and composite risers with distinct stiffness differences. A total of 216 sets of vibration test data are acquired from the indoor flume experiments. Based on experimental data, the individual effects of various parameters on the vibration amplitude and dominant frequency of risers are first analyzed via single-factor comparative tests. Subsequently, an XGBoost machine learning model is established to predict the cross-flow vibration amplitude of risers; stratified sampling and 5 × 5-fold cross-validation are utilized to optimize model hyperparameters. The model achieved a high goodness-of-fit of R² = 0.9296 during the development phase (training and internal validation), demonstrating favorable prediction accuracy. Finally, the SHAP interpretability method is introduced to quantify the contribution weights of individual parameters as well as the interaction mechanisms under multi-parameter coupling. Both single-parameter and multi-parameter analyses are performed, with representative results such as material = −3.965 and flow velocity = 2.085. The results indicate that the riser vibration amplitude exhibits a prominent negative correlation with material properties, boundary conditions, and top tension, while showing a positive correlation with flow velocity, wave height, and wave period. Full article

The overhead ground wire (OGW) may fracture at the suspension clamp under short-circuit faults, posing a serious threat to the safe operation of transmission lines. However, the dominant damage mechanism—whether Joule heating or arc discharge—remains unclear. This study investigates a 110 kV OGW breakage accident through combined experimental and numerical approaches. Fracture analysis using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) revealed composite damage featuring both melting and tensile necking, with no fatigue characteristics. A real-scale short-circuit test platform was constructed, which, for the first time, directly captured intense arc discharge phenomena inside the suspension clamp during current flow. A multi-physics finite element model was then developed to decouple and quantify the thermal contributions of Joule heating and arc heating. Results show that Joule heating alone raises the local temperature to only 49.27 °C—far below the melting points of aluminum (660 °C) and steel (1450 °C). In contrast, arc heating elevates the temperature to over 26,000 °C locally, causing rapid melting of aluminum strands and heating of the steel core above 1450 °C within milliseconds. This extreme heat reduces the effective load-bearing cross-section and tensile strength, ultimately leading to fracture under normal operating tension. The findings demonstrate that arc discharge, rather than Joule heating, is the decisive factor in such failures. This study provides a quantitative theoretical basis for fault protection and hardware design optimization of overhead transmission lines. Full article

The explosive growth of artificial intelligence workloads has triggered unprecedented data center construction, yet environmental assessment remains focused on operational energy efficiency. This paper introduces DC-WLC3O, a framework that simultaneously optimizes three objectives across the full data center lifecycle: whole-life cost, whole-life carbon, and material circularity index. The framework integrates cradle-to-cradle lifecycle assessment with dynamic material flow analysis, employing a four-layer analytical stack: Monte Carlo simulation with Latin Hypercube Sampling and Iman–Conover rank correlation; NSGA-III tri-objective Pareto optimization; Sobol’ variance-based global sensitivity analysis; and Many-Objective Robust Decision Making (MORDM). The framework evaluates 192 design configurations for a 30 MW hyperscale facility under three carbon pricing scenarios. Results reveal a carbon rebound paradox: operational carbon dominates grid-dependent configurations (96.2%), but low-carbon energy produces an 8.5× inversion (Welch’s t = 22.2, p < 10⁻³⁹). Sobol’ analysis confirms energy strategy dominates carbon outcomes (S1 = 0.87). MORDM identifies on-site renewable energy with a full circular economy strategy as unconditionally robust (R = 0.056, stable across 94.2% of weight permutations). The cost–circularity correlation is negative (rho = -0.488, p < 10⁻¹²), overturning the assumption that circular strategies increase lifecycle costs. A post hoc stress test confirms this finding is robust to moderate perturbations in renewable LCOE (+71%), with stability declining to ≈80% under worst-case capital cost assumptions and to ≈61% when generation degradation and battery replacement are jointly considered. Full article