Search Results (593)

Let $K\subset {\mathbb{R}}^n$ be a bounded convex body. We prove a lattice-averaging formula that gives upper bounds for the number of unit balls required to cover K. If the Voronoi cell P of a lattice is contained in the Euclidean unit ball, then some translate and rotation of the lattice produces a covering whose size is at most a linear combination of the intrinsic volumes of K; the coefficients are determined by the intrinsic volumes of P. The proof averages the number of Voronoi cells meeting K over one fundamental cell and over $SO\left(n\right)$. For the regular hexagonal lattice in ${\mathbb{R}}^2$, the formula reproduces the classical planar Blaschke bound. For the cubic lattice, it gives a closed-form estimate in every dimension $n\ge 2$. In ${\mathbb{R}}^3$, explicit computations for the cubic, face-centered cubic, and body-centered cubic Voronoi cells show that the body-centered cubic lattice has the smallest coefficientwise bound among these three lattices. In ${\mathbb{R}}^4$, the intrinsic volumes of the $A_4^{\ast }$ permutohedron are computed from its graphical-zonotope representation, leading to a sharper bound than for the cubic lattice. Full article

Background: Intraoperative hypotension during major abdominal surgery is common and can result from changes in preload, afterload, or myocardial contractility. Recognising the underlying cause is essential for targeted haemodynamic management. Arterial dP/dt_max has been proposed as a surrogate marker for ventricular systolic function, but its behaviour during fluid and vasopressor administration under general anaesthesia remains not fully understood. This study evaluated changes in radial arterial dP/dt_max following protocol-guided fluid administration and norepinephrine boluses during intraoperative hypotension. Methods: This prospective observational study involved 88 adult patients undergoing elective major abdominal surgery with continuous radial arterial waveform monitoring. Hypotensive episodes were defined as a mean arterial pressure <65 mmHg persisting for at least 60 s and were managed according to a predefined algorithm based on stroke volume variation and dynamic arterial elastance. The primary outcome was the change in arterial dP/dt_max from baseline to 5 min after fluid administration. Linear mixed-effects models were used to account for repeated intervention episodes within patients. Results: A total of 502 protocol-guided intervention episodes contributed by 76 patients were included in the primary analysis: 228 fluid-treated episodes and 274 norepinephrine-treated episodes. Estimated mean arterial dP/dt_max increased from 517 mmHg·s⁻¹ (95% CI 477–557) at baseline to 631 mmHg·s⁻¹ (95% CI 591–671) at 5 min during fluid-treated episodes and from 575 mmHg·s⁻¹ (95% CI 536–615) to 647 mmHg·s⁻¹ (95% CI 608–686) during norepinephrine-treated episodes (both p < 0.001). A significant intervention-condition-by-time interaction was observed (F = 5.55, p = 0.019), indicating that temporal evolution of arterial dP/dt_max differed between the two algorithm-defined haemodynamic conditions. Conclusions: Radial arterial dP/dt_max increased after both fluid administration and norepinephrine, confirming its sensitivity to haemodynamic loading conditions. It should therefore be interpreted as an integrated haemodynamic variable influenced by ventricular performance, preload, and arterial properties rather than as a direct measure of intrinsic myocardial contractility. Full article

Large volumes of solid waste are produced by the winemaking sector, which could be utilised as adsorbents to retain contaminants, providing a beneficial approach in terms of economic recovery and sustainability. The adsorption of nitrate onto biochar produced from grape pomace has not received enough attention, even though biochar-based materials have been thoroughly studied for water treatment applications. This study aims to fill the knowledge gap by assessing a low-cost mildly carbonized biochar derived from winery residues for nitrate retention and optimising the nitrate retention procedures by comprehensive physicochemical characterisation. The mildly carbonized biochar prepared from grape pomace collected from the Dealu Mare wine region (Romania) was characterized using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM–EDX), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), and thermogravimetric and derivative thermogravimetric (TGA/DTG) analyses. Results revealed a structure enriched with oxygen-containing functional groups that promote nitrate retention through combined physical adsorption and electrostatic interactions. Surface analyses after adsorption confirmed the successful immobilization of nitrate species on the biochar matrix. The adsorption performance was improved by Response Surface Methodology (RSM) method using a Central Composite Design (CCD), studying the influences of the following parameters: solution pH, adsorbent weight, nitrate concentration and time. Among all variables, pH was identified as the dominant factor controlling adsorption efficiency, reflecting the key role of surface charge interactions. The optimized conditions (175 mg/L nitrate, pH 6, 0.3 g adsorbent dosage, and 94 min contact time) resulted in a maximum nitrate removal efficiency (RE) of 86.69%, while the predictive model exhibited excellent accuracy (R²_adj = 0.985). The findings demonstrate that mildly carbonized grape pomace biochar can achieve competitive nitrate removal without chemical surface modification, offering a more sustainable and economically attractive alternative to conventionally biochars. The research highlights that selecting feedstock and utilizing intrinsic surface functionality can create efficient nitrate adsorbents from agro-industrial residues. Full article

This study investigates the direct tensile mechanical behavior of cement mortar plates reinforced with a galvanized steel mesh and randomly incorporated alkali-resistant glass fibers. An experimental program was executed using direct tensile tests on thin mortar specimens containing fiber volumetric fractions of 0%, 4%, 6%, 8%, and 10% relative to the cement volume. To rigorously characterize the mechanical response, the study quantified the apparent initial stiffness, 0.2% offset stress, ultimate tensile strength, and post-offset energy absorption capacity. Results indicate that increasing alkali-resistant glass-fiber content systematically modified the global tensile response of the composite system. At 10% glass-fiber content, the mean crosshead-derived apparent initial tensile stiffness was 10.43 times that of the reference group without glass fibers. The characteristic stress determined using the adopted 0.2% offset criterion and the ultimate tensile strength increased by 154.5% and 74.1%, respectively, while the apparent post-offset energy absorption increased by 68.4%. Because strain was derived from crosshead displacement, the apparent stiffness and energy-absorption parameters represent the global specimen–grip–machine response rather than intrinsic material properties. The experimental results exhibited acceptable repeatability, although the apparent tensile stiffness showed greater variability than the strength-related parameters. These findings support the continued development of the investigated composite configuration for thin cementitious elements requiring improved tensile response and damage tolerance. Full article

Synthetic media are digital artifacts (image, video, audio, text, or multimodal content) that are wholly or partly generated or materially manipulated by artificial intelligence (AI), particularly by deep-learning models. In consequence, their form, source, identity signal, or evidentiary relation to recorded events becomes partly or wholly artificial. A deepfake is the best-known subclass: AI-generated or AI-manipulated image, audio, or video content (including audio-only voice clones and still images) that realistically depicts an existing or fictitious person, object, place, or event and could falsely appear to be authentic. Contemporary scholarly and legal usage defines deepfakes by their technological origin and their capacity to deceive rather than by the creator’s intent, so disclosed and beneficial applications (accessibility, dubbing, entertainment, and research) are synthetic media as well. They are distinguished from cheapfakes (or shallowfakes), which achieve deception through conventional, non-AI editing such as selective cropping, slowing, or recontextualization. The social significance of synthetic media is not intrinsic but depends on consent, context, disclosure, and distribution, and on the institutional conditions under which audiences judge authenticity across the expanding volume of AI-generated content (AIGC) in the digital society. Full article

Prostate cancer (PC) is one of the most common cancers in men globally and there is an urgent need for new immune-based approaches because many traditional therapies, including chemotherapy, radiotherapy, and anti-androgens, have limitations. Due to their distinct physicochemical and biological features, gold nanoparticles (AuNPs) are emerging as a potential nanoplatform for the development of strategies in prostate cancer therapy. These features include tunable size, shape, and surface plasmon resonance (SPR) and high surface-to-volume ratio, which result in enhanced drug loading, targeted delivery and improved bioavailability. In addition, AuNPs can also be functionalized for active targeting to promote selective accumulation in tumors while minimizing systemic toxicity. In addition, the intrinsic optical and photothermal properties of these nanoparticles allow them to serve for PTT, radiosensitization and multimodal imaging, i.e., CT (computed tomography) and photoacoustic imaging. These have shown potential in pre-clinical and clinical evaluation but face issues with long-term toxicity, biodistribution and large-scale manufacturing. In this review, we summarize the organizing features, functional properties, therapeutic activities and translational potentials of AuNPs in prostate cancer treatment, with emphasis on their contributions towards precision nanomedicine. Full article

This systematic review aimed to evaluate whether cross-sectional geometry is associated with cyclic fatigue resistance of nickel–titanium (NiTi) endodontic instruments and to identify the geometric and materials-related features most frequently associated with improved fatigue performance. The protocol was prospectively registered on the Open Science Framework (OSF). PubMed, Scopus, Embase, Web of Science, and WorldCat were searched in April 2026 in accordance with PRISMA 2020. Eligible studies were comparative in vitro investigations that explicitly evaluated cross-sectional geometry or a related geometric parameter as a prespecified study factor and reported quantitative cyclic fatigue outcomes. Of 107 screened records, 66 full-text reports were assessed and 23 studies were included in the qualitative synthesis. Twenty-two studies had a medium risk of bias and one had a low risk of bias according to the Quality Assessment Tool for In Vitro Studies (QUIN). Cyclic fatigue resistance was most often reported as time to fracture or number of cycles to failure. Instruments with reduced metal mass, smaller core volume, lower cross-sectional area, and greater flexibility tended to demonstrate higher fatigue resistance in curved canals. S-shaped and double-S-shaped cross-sections were most consistently associated with favorable outcomes; however, this association is more plausibly related to reduced bending stiffness and canal-wall contact forces than to increased intrinsic material fatigue strength. Flat-side designs did not show a consistent advantage. The evidence was limited by heterogeneous testing protocols and residual confounding by alloy, heat treatment, taper, manufacturing, surface condition, and kinematics. No meta-analysis or quantitative dimensional correlation was feasible because testing conditions and detailed geometric parameters were inconsistently reported. Full article

Conventional methods of plant distance and volume measurements are limited by low efficiency, limited spatial coverage, and high measurement error. LiDAR and RGB-D imaging offer cost-effective, precise, and non-destructive techniques for plant distance and volume measurements. This study aimed to measure cabbage height, volume, and distance using LiDAR and RGB-D imaging. The sensors were mounted on a 1.6 kW electric field scouting platform (EFSP) for data collection. Point cloud (PCD) data were collected using LiDAR, whereas data processing, visualization, and measurements were done using commercial software and open-source programming scripts. A total of 20 cabbage plants were analyzed. LiDAR data processing included data frame screening, outlier removal, denoising, voxelization, and generation of 3D PCD density maps. Depth image processing included importing raw data and metadata shaping using intrinsic camera parameters, visualization, extraction of depth points, and pixel-level measurements of distances and volume. RGB image processing involved image conversion, segmentation, normalization, binary masking, mask cleaning, region extraction of cabbages, separation of ROI and preparation of contours, Delaunay triangulation and convex hull preparation, ROI overlay, bounding box preparation, sharing boundary between two boxes, conversion to pixel distances, and for visualization, plant height, volume measurements, and center to center distance measurement for measuring the plant distance. LiDAR demonstrated higher measurement accuracy for cabbage plant height, circumferential volume (geometric canopy volume), and plant distance, followed by RGB-D imaging, while RGB imagery showed comparatively lower performance under the study field conditions. Overall, LiDAR and RGB-D imaging provided reliable and non-destructive approaches for cabbage geometric characterization under field conditions, although accurately capturing complex plant geometry remains challenging. Positive and negative values of bias represent the over- and under-estimated results, respectively. Future studies should include larger and more diverse plant datasets exhibiting diversified size, shape, and geometric structure to further improve the robustness and general applicability of the proposed sensing approaches. Full article

Background: Right-to-left shunting through a patent foramen ovale (PFO) is an underrecognized yet potentially reversible cause of refractory hypoxemia, particularly in patients with right ventricular dysfunction. This case report describes heart-rate-dependent right-to-left shunting through a PFO causing refractory hypoxemia in a patient with inflammatory cardiomyopathy and severe right ventricular dysfunction, presumably arising from biventricular output mismatch. Case Presentation: We report the case of a 41-year-old male with inflammatory cardiomyopathy and a recently implanted single-chamber pacemaker (VVI mode, lower rate limit 50 bpm), admitted for decompensated heart failure. After initial clinical improvement with guideline-directed therapy, the patient’s intrinsic heart rate declined, and ventricular pacing at 50 bpm became the dominant rhythm. He subsequently developed refractory hypoxemia unresponsive to mechanical ventilation. Systematic hemodynamic assessment was performed using transthoracic echocardiography and thoracic electrical bioimpedance (TEB) monitoring at different pacing rates. Results: Echocardiographic evaluation revealed dynamic interatrial shunting through a PFO with the following characteristics: left-to-right at a pacing rate of 80 bpm and right-to-left at 50 bpm. Hemodynamic and echocardiographic data suggested that bradycardia induced biventricular output mismatch—left ventricular outflow tract velocity–time integral (VTI) increased by approximately 38% (from 17.5 cm to 24.1 cm), whereas right ventricular outflow tract VTI increased by only approximately 4% (13.3 cm vs. 13.8 cm). This mismatch likely resulted in relative elevation of right atrial pressure, thereby driving right-to-left shunting through the PFO. Increasing the pacing rate to 80 bpm reversed the shunt direction, normalized oxygenation, and facilitated successful extubation. Conclusions: This case suggests that in patients with severe right ventricular dysfunction, bradycardia may induce biventricular output mismatch with substantially greater left than right ventricular stroke volume augmentation, and presumably relative elevation of right atrial pressure, potentially leading to dynamic right-to-left shunting through a PFO. For such patients with unexplained hypoxemia, the possibility of dynamic PFO shunting should be considered. Appropriately increasing the pacing rate may help restore biventricular output matching, reverse shunt direction, and improve oxygenation; individualized heart rate management strategies warrant clinical consideration. Full article

LiDAR (Light Detection and Ranging) and RGB-D camera imaging have emerged as essential tools in agricultural applications, particularly for plant size and distance measurements, enabling non-destructive, cost-effective, and precise estimation. The objective of this study was to measure the plant canopy dimensions and distance between apples using commercial LiDAR, and an RGB-D camera with a speed sprayer platform was used to determine whether LiDAR provides a higher measurement accuracy under field conditions. Data were collected in an apple orchard in Muju, Republic of Korea. Commercial 3D LiDAR, a terminal box, an RGB-D camera, a microcontroller, a power supply, and individual display monitors were integrated into a customized data acquisition (DAQ) box for LiDAR point cloud (PCD), RGB, and depth imagery data collection. Commercial software was used for data acquisition, data conversion (pcap to PCD), segmentation of regions of interest (ROI), and pre-processing of data. PCD processing and measurement consisted of data frame selection, data conversion, outlier removal, downsampling, denoising, ground point removal by filtering, voxelization, and density map generation using an open access programming language script. Depth image processing included importing raw data, shaping metadata using intrinsic camera parameters, visualizing depth images, extracting depth points, and measuring the plant canopy at the pixel level. RGB image analysis involved grayscale conversion, thresholding, segmentation of ROI, contour preparation, noise removal, and binary masking for eliminating the background. Estimated results were compared to measured results. LiDAR measurements showed the closest agreement with the measured results for plant height, canopy volume, plant spacing, and row distance, outperforming both RGB and depth imaging. Under field conditions, plant spacing and row distance were estimated with accuracies of 97.5% and 94.7%, respectively, exhibiting higher measurement accuracies than RGB and depth imagery data results. Despite some discrepancies due to complex plant geometry and dynamic data collection, the results support data collection strategies critical for precision horticulture. Full article

Slag splashing protection is the dominant technology for extending refractory lining service life and enhancing production efficiency in basic oxygen furnace (BOF) steelmaking. However, the intrinsic mechanism of gas-slag-steel multiphase coupled splashing remains poorly understood, and existing numerical methods suffer from prohibitive computational costs and inaccurate characterization of interfacial momentum transfer and multiphase interactions. This study establishes a fully coupled three-dimensional numerical model integrating Volume of Fluid (VOF)–Discrete Particle Method (DPM) bidirectional phase transition, adaptive mesh refinement (AMR), and Eulerian Wall Film Model (EWFM), and the multiphase flow simulation in this study adopts constant thermophysical parameters of molten steel and slag at the industrial splashing temperature of 1650 °C. Taking the Blowing Number (N_B) as the core similarity criterion, a 1:10 scaled geometric model of a 50-ton industrial BOF is employed to systematically investigate the regulatory effects of top-blowing flow rate, lance height, and N_B on droplet splashing behavior and wall liquid film evolution. The model is validated against mercury-glycerol cold model experimental data, with a relative error of less than 3% in total splashing mass prediction. Results demonstrate that increasing N_B significantly enhances splashing intensity. Under optimal conditions (200 mm lance height, 11.76 Nm³/h flow rate, N_B = 9.30), the wall liquid film fully covers the middle-upper furnace wall with a uniform thickness of 0.8–1.2 mm. N_B dominates jet momentum distribution: high N_B forms a deep-penetrating four-lobed impact cavity, remarkably improving droplet axial momentum and residence time. Molten steel droplets concentrate at 3–4 mm, while slag droplets shift to 2–4 mm at high flow rates of 11.76 Nm³/h, with maximum slag droplet production at N_B = 6.99. This work provides reliable theoretical support for industrial BOF slag-splashing process optimization. Full article

Semiconductor-based photocatalytic water splitting is a promising pathway for sustainable hydrogen production; however, the reported performance depends not only on the intrinsic properties of the photocatalyst but also on reactor configuration and operating conditions. This systematic technical review examines the interplay between nanostructured semiconductor photocatalysts and the principal engineering variables governing photocatalytic hydrogen evolution. Particular attention is given to particle size, morphology, surface area, defect density, heterojunction design, cocatalyst incorporation, aggregation, and catalyst immobilization, as well as their interaction with reactor geometry, optical path length, photon distribution, catalyst loading, working volume, pH, sacrificial agents, mixing, thermal control, gas purging, and product quantification. The reviewed evidence indicates that these material and reactor parameters jointly determine light absorption, charge-carrier separation and transfer, suspension turbidity, mass transport, catalyst recovery, stability, and the measured hydrogen evolution rate. Batch slurry reactors remain the most widely used laboratory configuration, whereas annular, flat-panel, microreactor, fixed-bed, continuous-flow, and photofluidized systems offer specific advantages for photon utilization, catalyst reuse, product removal, and scale-up. The review also emphasizes the need to distinguish overall water splitting from sacrificial-agent-assisted hydrogen evolution. Standardized reporting of photocatalyst properties, irradiance, spectral distribution, illuminated area, reactor dimensions, reaction atmosphere, and gas-analysis procedures is essential to improve reproducibility and enable reliable comparisons among nanostructured photocatalytic systems. Full article

The inferior electronic conductivity, sluggish bulk Li⁺ transport, and Jahn–Teller distortion intrinsic to Mn³⁺ collectively impede the practical application of LiMn_0.6Fe_0.4PO₄ (LMFP) as a high-performance cathode for lithium-ion batteries. Herein, a series of W-doped Li(Mn_0.6Fe_0.4)_1−xW_xPO₄/C (x = 0, 0.005, 0.010, 0.015) cathode materials were synthesized via spray-drying combined with carbothermal reduction. Rietveld refinement indicated decreases in the fitted lattice parameters and unit-cell volume with increasing nominal W content, and no crystalline secondary phases were detected within the laboratory XRD detection limit. Although the structural evolution is consistent with W incorporation, direct determination of the occupation site requires further local structural characterization. X-ray photoelectron spectroscopy indicated that the detectable near-surface W species are predominantly present as W⁶⁺, and the semi-quantitative Mn 2p peak-area fitting showed that the fitted relative Mn³⁺ contribution decreased from 70.4% in LMFP-0 to 58.3% in LMFP-2. The optimal composition (LMFP-2, x = 0.010) delivers an initial discharge capacity of 160.2 mAh g⁻¹ at 0.1 C, retains 98.1% capacity after 100 cycles at 1 C, and achieves 126.3 mAh g⁻¹ at 5 C. Electrochemical impedance spectroscopy reveals that LMFP-2 possesses the lowest charge-transfer resistance (195.4 Ω) and the highest Li⁺ diffusion coefficient (5.3 × 10⁻¹⁵ cm² s⁻¹). These improvements may be attributed to the synergistic effects of enhanced bulk electronic conductivity, accelerated Li⁺ diffusion kinetics, and improved structural stability induced by moderate W incorporation. This work establishes W doping as a viable compositional engineering strategy for olivine-based cathode materials. Full article

The escalating accumulation of microplastics (MPs) in marine ecosystems presents a critical environmental crisis. However, current monitoring efforts rely heavily on labor-intensive, contamination-prone, and time-consuming laboratory analyses. While these conventional off-chip methods provide high accuracy, they inherently lack the throughput and autonomy required for continuous, real-time oceanic surveillance. To bridge this technological gap, microfluidic technologies (Lab-on-a-Chip) provide a viable route towards miniaturized, reagent-free in situ detection with reduced sample volumes and continuous operation capability. This review examines the transition from benchtop to field-deployable platforms and organizes the available microfluidic approaches for MP analysis into a structured overview. We examine on-chip sample manipulation and complementary separation techniques, such as acoustophoresis, dielectrophoresis, and optical tweezers, which are essential for isolating target particles from complex environmental matrices and overcoming intrinsic microfluidic challenges. Following sample preparation, we provide a comprehensive evaluation of state-of-the-art optical and spectroscopic identification methods optimized for continuous flow detection. Finally, we address current analytical limitations and discuss how the integration of machine learning with dynamic spectral libraries could enable autonomous, field-deployed monitoring networks for long-term MP surveillance. Full article

This study proposes and validates a unified geometry-based capacitance model for four representative silicon detector architectures: planar, 3D trench electrode, 3D spherical electrode, and silicon drift detector (SDD). Closed-form analytical expressions explicitly relate capacitance to key geometric parameters—anode radius, depletion thickness, electrode depth, and electrode spacing—and the resulting geometric scaling laws are rigorously verified by combining physical modeling, TCAD simulation, and experimental measurement. A central finding is that for highly symmetric structures, capacitance is governed almost exclusively by the radius of the collecting anode and is essentially independent of the overall detector volume, thereby defining an ideal low-capacitance limit. For the SDD, a hemispherical capacitor approximation accurately captures this anode-dominated behavior, and measurements on prototypes together with independent literature data confirm that the total capacitance can be decomposed into an intrinsic geometric component and a parasitic contribution. This work provides a unified framework and direct cross-structure design guidelines for minimizing capacitance toward ultra-low-noise, high-performance silicon detectors. Full article