Search Results (45,794)

Distinguishing Active from Inactive Tuberculosis (TB) on Chest X-rays presents a clinical challenge due to overlapping radiological signs. This study introduces Vision Mamba CGSM, a deep learning framework integrating a State Space Model (SSM) backbone with a Context-Guided Slot Mixing (CGSM) module. The SSM captures global anatomical context, while the CGSM module isolates subtle pathological features by applying localized spatial attention. We validated the model using a hierarchical diagnostic scheme covering Normal, Pneumonia, Active TB, and Inactive TB. Experimental evaluations demonstrate an accuracy of 92.96% and a Youden Index of 79.55% on the independent test set. In the specific binary classification of Active vs. Inactive TB, the model recorded a specificity of 97.04%, outperforming standard baseline architectures including ResNet152 and ViT-B. Additional validations on external datasets confirm the consistent generalization of the proposed feature extraction mechanism. Full article

This comparative study investigates binder-free binary WC-TiC and ternary WC-TiC-TaC carbide ceramics as alternatives to cobalt-bonded hard materials. Equimolar compositions were processed via high-energy ball milling (HEBM) and consolidated by spark plasma sintering (SPS) at 1700–2100 °C. X-ray diffraction analysis (XRD) revealed fundamentally different homogenization kinetics: the ternary system achieved a complete single-phase structure at 2000 °C, 100 °C earlier than the binary system. This acceleration correlates with finer initial particle size (2–5 μm vs. 3–10 μm) and near-stoichiometric TaC, facilitating interdiffusion. Lattice parameter evolution confirmed the formation of (W,Ti)C and (W,Ti,Ta)C substitutional solid solutions. Mechanical characterization showed contrasting behaviors: binary WC-TiC exhibits maximum hardness at 1900 °C (1793 HV30, fracture toughness 5.07 MPa·m^1/2), while ternary WC-TiC-TaC peaks at 1700–1800 °C (1947–1782 HV30) with higher toughness (max 5.42 MPa·m^1/2). Optimal processing windows with acceptable property uniformity are 1800–1900 °C (binary) and 1700–1900 °C (ternary). The binary system offers superior toughness and stability; the ternary system enables faster processing and higher initial hardness, defining distinct application domains. Full article

To enhance the early-age properties of steel slag cement mortar and promote the resource utilization of metallurgical solid waste, in this study, nano-SiO₂ (KH-NS) was modified using a KH550 silane coupling agent. The hydration kinetics and microstructure evolution were systematically analyzed by means of a macroscopic performance test (setting time and compressive strength) and multi-scale microscopic characterization (characterized by Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, X-ray Diffraction, Thermogravimetry-Differential Thermal Analysis, and isothermal calorimetry). The influence mechanism of its content on the early performance of the steel slag cement system was systematically studied. Research findings indicate that at a given dosage, increasing the proportion of KH-NS results in a shorter setting time for steel slag mortar. When the KH-NS dosage reaches 1.5%, the initial and final setting times of steel slag mortar decrease by 24.21% and 21.20%, respectively. The addition of KH-NS effectively enhances the compressive strength of mortar, with a particularly pronounced effect on early strength prior to 14 h of curing. At a KH-NS dosage of 1.5%, the onset of the accelerated phase of hydration heat release in steel slag cement mortar is advanced by 2.5 h. Mechanistic studies indicate that KH-NS accelerates cement hydration by promoting C₃S dissolution and C-S-H gel nucleation through interactions between surface silanol groups (Si-OH) and amino groups (-NH₂). Furthermore, KH-NS refines the pore structure via a micro-aggregate filling effect, reducing the number of harmful pores and improving the pore size distribution. KH-NS continuously consumes Ca(OH)₂ through pozzolanic reactions to generate C-S-H, with its reactivity increasing with higher dosage. Research confirms that KH-NS significantly enhances the early strength and density of steel slag mortar, providing both theoretical justification and technical support for developing low-carbon building materials based on solid waste with high dosage. Full article

Cu₂ZnSn(S,Se)₄ (CZTSSe) is a candidate thin-film photovoltaic material; however, its performance is restricted by innate defect-induced nonradiative recombination. Low-concentration Ge doping has been identified as an efficient way to mitigate these defects, but the selenization temperature remains an important process parameter that governs the structure and optoelectronic characteristics of CZTSSe absorbers. In the present work, low-concentration Ge-doped Cu₂ZnSn_0.95Ge_0.05S₄ (CZTGS) precursor films were synthesized through a green, n-butylammonium butyrate-based solution approach. The effects of the selenization temperature (530–570 °C) on the microstructure, composition, and photovoltaic performance of Cu₂ZnSn_0.95Ge_0.05(S,Se)₄ (CZTGSSe) films and devices were comprehensively investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectrometer (EDS), atomic force microscopy (AFM) were performed to comprehensively characterize the synthesized samples, and the results suggested that the selenization temperature dramatically altered the film grain growth, crystallinity, elemental retention and surface roughness. Specifically, the film that underwent selenization at 550 °C presented the best crystallinity, which was accompanied by large-scale even grains, efficient Ge⁴⁺ addition to the kesterite lattice and the lowest surface roughness. These better properties in terms of structure and composition resulted in the lowest carrier transport resistance (R_s = 8.6 Ω∙cm²), improved recombination resistance (R_j = 5.9 kΩ∙cm²), inhibited nonradiative recombination, and prolonged carrier lifetime (τ_EIS = 35.8 μs). Therefore, the resulting CZTGSSe thin-film solar cell had an 8.69% better power conversion efficiency (PCE), while its open-circuit voltage (V_OC) was 0.42 V, the fill factor (FF) was 55.51%, and the short-circuit current density (J_SC) was 37.71 mA·cm^–2. Our results elucidate the mechanism by which the selenization temperature regulates low-concentration Ge-doped kesterite devices and provide more insights into the optimization of processes for cost-effective, high-performance, and green thin-film solar cells. Full article

The present study investigates the co-crystallization process of rivaroxaban (RIV), a poorly water-soluble potent oral anticoagulant, with niacinamide (NIA), a highly soluble and pharmaceutically acceptable co-crystal former, in two different molar ratios (1:1 and 1:2). The aim was to enhance the physicochemical and biopharmaceutical properties of rivaroxaban such as dissolution rate and aqueous solubility, by forming stable co-crystals through a solvent evaporation technique. The resulting co-crystals (RIV-NIA, 1:1 co-crystallization compound, F1 and RIV-NIA, 1:2 co-crystallization compound, F3) were characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD) and thermal analysis, which confirmed the formation of a new rivaroxaban–niacinamide co-crystalline phase. In vitro dissolution studies confirmed a significant enhancement in the dissolution rate of the two obtained co-crystals. These findings suggest that stoichiometric variation plays an important role in co-crystal performance and in improving solubility compared with the pure drug. Also, the obtained results suggest that niacinamide is an effective coformer for improving the dissolution and physicochemical properties of rivaroxaban. Full article

Hydrogen embrittlement is known to adversely affect the mechanical properties of low-carbon steels used for pipelines and pressure vessels, leading to accelerated crack growth and lowered fracture toughness. To overcome the limitations of surface-based analysis, this study employs X-ray micro-computed tomography (µ-CT) to provide a comprehensive 3D evaluation of the crack evolution. This approach is used to assess hydrogen-assisted crack growth in P355NH compact tension samples from previous fracture mechanical tests and enables a precise quantification of the internal crack path and the crack tip opening angle (CTOA) across the entire specimen thickness as well as the local damage morphology. By integrating these spatial parameters, a deeper understanding of the impact of hydrogen on local fracture mechanisms is achieved, revealing insights that have remained hidden in previous two-dimensional microscopy observations. For instance, µ-CT results clearly demonstrate that the hydrogen-assisted crack propagation is associated with increased void formation and secondary cracking in vicinity of the crack tip. However, it is proposed that the results are superimposed with continuous hydrogen desorption, which implies a need for in situ charging during mechanical loading and an analysis of the hydrogen concentration profile. Both will be the scope of further studies. Full article

This study uses a process-based technical approach combining X-ray radiography, visible and raking-light examination, and cross-modal image comparison to assess the construction logic of a Cubist-period painting associated with Pablo Picasso. Across the X-ray dataset, the painting shows orientation-dependent structural coherence, hierarchically organized planning seams with mechanically sensible terminations, and a multistage base-layer construction that remains interpretable under grayscale inversion and rotation. Visible and raking-light images reveal physically incised inscriptions, names, places, and numerals with later paint settling into grooves and, in some areas, bridging over them, establishing a clear sequence in which inscriptions precede overpainting. Reduced color and polarity-inversion checks confirm that these features are carried by luminance and surface relief rather than color artifacts. Together, these converging lines of evidence support an interpretation of a multi-campaign, orientation-aware construction process consistent with documented working methods from Picasso’s relevant period and difficult to replicate by superficial imitation. Full article

Background: The key parameters determining the bioavailability of an active pharmaceutical ingredient are its solubility/dissolution rate in physiological fluids and permeability across biological membranes. Highly accurate in vitro prediction of bioavailability is a key issue that typically arises during the development of new drug formulations and the improvement of existing ones. Objectives: The objective of the present work is to study the dissolution/release and permeation of olanzapine (OLZ) from two- and three-component solid dispersions (SDs) with sulfobutylether-β-cyclodextrin (SBE-β-CD) and several pharmaceutical adjuvants as solubilizing agents. Methods: Solid dispersions were prepared by mechanical grinding and characterized with X-ray Phase analysis (PXRD), Fourier Transform Infrared (FTIR) and Raman spectroscopy, Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM). Results: Raman spectroscopy was shown to be the best for revealing the interactions of OLZ with SBE-β-CD and γ-aminobutyric acid (GABA) in the three-component SD. The kinetic dependences of OLZ release and diffusion through the cellulose membrane were thoroughly described by quantitative parameters and classified according to the drug release mechanism. Significant improvement of release rate, OLZ concentration, and permeation with SDs compared to the pure OLZ was demonstrated. Conclusions: It was shown that the selected dispersions were stable when stored under normal conditions but underwent changes upon exposure to elevated temperature and humidity. The nature of these changes was determined by the properties of the components and their mutual interactions. Full article

Medical image segmentation represents a fundamental task in medical image analysis, serving as a critical component for accurate diagnosis, treatment planning, and disease monitoring. The emergence of Denoising Diffusion Probabilistic Models (DDPMs) has revolutionized the landscape of generative modeling and recently gained significant attention in medical image analysis. This comprehensive review examines the current state of the art in diffusion models for medical image segmentation, covering theoretical foundations, methodological innovations, computational efficiency strategies, and clinical applications. We analyze recent advances in latent diffusion frameworks, transformer-based architectures, and ambiguous segmentation modeling while addressing the practical challenges of implementing these models in clinical environments. The review encompasses applications across multiple medical imaging modalities including Magnetic Resonance Imaging (MRI), Computed Tomography (CT), ultrasound, and X-ray imaging, providing insights into performance achievements and identifying future research directions. Through systematic analysis of publications mostly from 2019 to 2025, we demonstrate that diffusion models have achieved remarkable progress in addressing fundamental challenges including data scarcity, inter-observer variability, and uncertainty quantification. Notable achievements include inference time being reduced from 91.23 s to 0.34 s for echocardiogram segmentation (LDSeg, Echo dataset), DSC scores up to 0.96 for knee cartilage MRI segmentation, and a +13.87% DSC improvement over baseline methods for breast ultrasound segmentation. This review serves as a comprehensive resource for researchers and clinicians interested in leveraging diffusion models for medical image segmentation, providing a roadmap for future research and clinical translation. Full article

Excessive accumulation of copper ions (Cu²⁺) in the environment and biological systems poses severe risks to ecological balance and human health, necessitating accurate detection and monitoring of Cu²⁺. Schiff base derivatives with favorable optical properties provide an efficient strategy for copper ion recognition. In this paper, fluorescent probe L (5-methyl-2-hydroxybenzaldehyde-(7-diethylaminocoumarin-3-formyl) hydrazone) was synthesized through a three-step reaction using 4-diethylaminosalicylaldehyde and diethyl malonate as starting materials. The structure of probe L was confirmed by melting point analysis, infrared spectroscopy, and nuclear magnetic resonance. Single-crystal X-ray analysis revealed that probe L crystallized into a triclinic lattice with space group $P_1^{-}$. Optical investigations, including UV–Vis spectroscopy, fluorescence spectroscopy, and aggregation-induced emission studies, demonstrated highly sensitive and selective fluorescence “turn-off” behavior of probe L towards Cu²⁺ ions in DMSO, with negligible interference from other metal ions. Job’s plot and crystallographic analysis revealed a 1:1 binding stoichiometry between probe L and Cu²⁺, forming the complex [Cu(L)]. Fluorescence titration experiments revealed a binding constant (K_b) of 5.2 × 10⁶ L/mol and a detection limit of 7.8 × 10⁻⁷ mol/L, indicating excellent sensitivity. These results suggest that probe L has considerable promise for Cu²⁺ detection in aqueous environments, with potential applications in environmental monitoring and public health protection. Full article

The development of cementitious materials with multifunctional performance is increasingly important to address environmental demands and durability requirements in modern infrastructure. This study investigates calcium sulfoaluminate (CSA) cement partially substituted with blast furnace slag (BFS), fly ash (FA), and TiO₂ nanoparticles, aiming to combine sustainability with photocatalytic self-cleaning functionality. Phase analysis by X-ray diffraction confirmed the formation of characteristic CSA hydration products, including ettringite, ye’elimite, anhydrite, and calcite, indicating that partial substitution did not disrupt the primary hydration mechanisms. Microstructural observations revealed that the incorporation of BFS, FA, and TiO₂ induced noticeable morphological changes, with increased porosity and microstructural heterogeneity at higher replacement levels. Mechanical testing showed that moderate BFS contents of 5 to 10 wt% enhanced compressive strength in reference mixtures, while systems containing TiO₂ exhibited slightly lower strength values and increased dispersion, particularly at elevated slag contents. The photocatalytic performance, evaluated through Rhodamine B degradation under solar irradiation, demonstrated a marked improvement for TiO₂-containing samples, reaching degradation efficiencies of up to 80%, in contrast to negligible activity in unmodified systems. These results confirm that the combined use of industrial by-products and photocatalytic nanoparticles in CSA-based matrices represents a viable strategy for producing sustainable cementitious materials with added environmental functionality, without compromising fundamental structural performance. Full article

A novel cyanide-free gold electroplating bath was developed with 2-hydroxyphosphonoacetic acid (HPAA) as the core complexing agent in this work. Scanning electron microscopy (SEM) observations demonstrate that the obtained gold electrodeposits possess a smooth and compact surface morphology. The crystal structure of the gold electrodeposits was characterized via X-ray diffraction (XRD), and the coating–substrate adhesion was systematically evaluated through scratch tests. Molecular dynamics (MD) simulations were performed to investigate the adsorption interaction between HPAA and metal (Au/Ni) surfaces. The MD simulation results show that all the studied phosphonate-containing derivatives can strongly adsorb on the gold surface and exert a significant inhibitory effect on the electroreduction of gold ions during electrodeposition. Cyclic voltammetry (CV) and other electrochemical tests reveal that the cathodic reduction peak potential of gold shifts significantly negatively after the addition of phosphonate-based organic additives, which effectively enhances the cathodic polarization of gold deposition, delays the gold nucleation rate, and refines the grain size of electrodeposits, ultimately yielding gold electrodeposits with a denser and smoother surface. Owing to its environmental benignity, excellent process stability and superior coating performance, this cyanide-free gold electroplating system exhibits broad application prospects in the field of modern green surface engineering. Full article

The purpose of this study is the exploration of the catalytic performance of a ZSM-5 zeolite produced from iron-rich fly ash, without any additional iron loading, in removing paracetamol via a heterogenous Fenton reaction. The structural and textural characterization by powder X-ray diffraction and N₂ adsorption isotherms showed that a pure ZSM-5 phase was synthesized, but lower crystallinity and textural parameters were obtained when compared with commercial ZSM-5. The XPS analysis revealed significant amounts of iron and yttrium, which enhanced the electronic properties of the samples’ surface when compared with iron-impregnated commercial ZSM-5. The catalytic reaction was followed through UV-spectroscopy and kinetic models were applied to the data; the best fit was obtained for a pseudo-first-order model. All fly ash-based zeolites showed increased paracetamol removal when compared with commercial iron-loaded ZSM-5, which may be attributed to the more disordered structure, able to accommodate large paracetamol species (dimers). On the other hand, the effect of yttrium on the electronic properties of iron sites may increase the ^●OH radical formation, thus increasing the paracetamol removal rate, despite the progressive drop on paracetamol removal upon regeneration–reuse cycles due to Fe leaching. Full article

Titanium dioxide (TiO₂) is a versatile material that exhibits a high refractive index, strong light-scattering capability, effective UV-absorption, wide band gap semiconductor behavior (3.0–3.2 eV), and excellent chemical stability. Owing to this unique combination of properties, TiO₂ is widely used in applications such as cosmetic and healthcare products, architectural and automotive coatings, and photocatalytic degradation of environmental pollutants. In photocatalytic applications, the crystal structure, phase composition and electronic properties of TiO₂ play a critical role in determining its performance. In the present study, TiO₂ nanotubes were synthesized by anodization of Ti° coatings deposited via a semi-industrial arc-PVD process. A post-anodization heat treatment was carried out at 430 °C for 1 h to promote the formation of the anatase phase within the TiO₂ nanotube structures. The structural characterization of the synthesized film was performed using X-ray diffraction (XRD) and Rietveld refinement. This methodology enabled the identification of the formed oxide phases, structure, and crystalline, confirming the formation of mixed oxides in the coating. To address the difficulty of refinement of these crystalline phases, the Le Bail method was applied. This refinement strategy allowed the identification of the crystalline phases that are present in the Ti_xO_y coating, including a hexagonal structure characteristic of α-Ti (space group P63/mmc, No. 194), the tetragonal anatase TiO₂ (space group I41/amd, No. 141) phase, and the trigonal Ti₂O₃ phase (space group R-3/c No. 167). Key crystallographic parameters such as lattice constants, bond lengths and angles, crystallite sizes, unit cell distortion and electron density were systematically evaluated for each phase. In addition, the Wyckoff positions and interatomic distances of the constitutive atoms were calculated, providing a comprehensive description of the TiO₂+Ti₂O₃/Ti° crystallographic system. The topographic and surface oxidation states were recorded by using profilometry and X-ray photoelectron spectroscopy, respectively. Full article

Water-based drill cuttings generated during onshore natural gas development are complex solid wastes that may pose environmental risks if improperly managed. This study evaluates the feasibility of reutilizing water-based drill cuttings as pavement base materials after stabilization using a novel composite stabilizer composed of cement, stabilizer liquid agent, and water-reducing powder (CLP stabilizer). Mix proportion optimization was conducted through compaction and 7-day unconfined compressive strength tests, followed by evaluation of road performance, including strength, compressive rebound modulus, water stability, and temperature shrinkage, with stabilized powder stabilized soil as a control. Microstructural characteristics were analyzed using X-ray diffraction and scanning electron microscopy, and environmental safety was assessed through heavy metal leaching tests and background soil investigation. The results show that the optimal mixture ratio of curing agent (5% cement + 2% liquid stabilizer + 8% superplasticizer powder) satisfies the strength requirement for pre-drilling road bases, exhibiting superior performance compared to the control group. When the stabilizer dosage reaches 9%, the 7-day unconfined compressive strength achieves a maximum of 3.38 MPa, representing a 51% increase over the control group. At a stabilizer dosage of 12%, the splitting tensile strength reaches a peak value of 0.901 MPa, showing a 60.3% improvement. These results indicate enhanced deformation resistance, water stability, and reduced temperature shrinkage rates. Microstructural analysis indicates that the formation of calcium silicate hydrate (C-S-H) gel and ettringite (AFt phase) leads to a denser structure and enhanced durability. Heavy metal concentrations comply with relevant standards, demonstrating controllable environmental risks and supporting sustainable pavement base application. Full article