Search Results (108)

A series of reduced Schiff base ligands derived from salicylaldehyde (1) and methoxybenzylamines (2a–c) were prepared and used to prepare three copper(II) complexes, 5a (2-methoxyderivative), 5b (3-methoxyderivative), and 5c (4-methoxyderivative). They were characterized by spectral methods and X-ray crystallography. The complexes showed DNA cleavage activity, with 30% cleavage at 3 × 10⁻³ M and up to 94.5% at 5 × 10⁻³ M. Absorption titration studies with ct-DNA and EB-DNA displacement methods revealed strong binding of the prepared complexes, with complexes 5b and 5c favored. Viscosity measurements and thermal degradation of DNA studies indicate DNA groove binding. All complexes exhibit a moderately strong binding affinity to serum albumin. The complexes performed very well in the resazurin assay monitoring mitochondrial activity, with significant cytotoxic effects (around 95% already at 1 × 10⁻⁴ M). The MTT assay confirmed the complexes’ cytotoxicity against cancer cell lines (A549, HepG2) compared with HEL fibroblasts. All complexes showed remarkable selectivity for HepG2 cells, with selectivity indices (HEL vs. HepG2) up to 3.05 for complex 5a, and complex 5b achieved the lowest IC₅₀ (33.0 ± 5.3 μM) against HepG2 cells. From a regioisomerism perspective, complex 5a outperformed the others in DNA cleavage; complex 5b, with the 3-methoxy group, showed the most interesting cytotoxicity results, and both complexes 5b and 5c showed good DNA-binding properties. Full article

Particle-reinforced metal matrix composites, wherein preform pore structure dominates liquid infiltration behavior and final composite quality, are essential for high-performance industries. Conventional empirical models predict pore characteristics for bimodal preforms based on ideal particle stacking assumptions yet ignore real compression-induced microstructural changes including particle contact compaction and particle fracture, yielding systematic deviations from actual pore characteristics. This study adopted high-resolution 3D X-ray micro-computed tomography (μ-CT) to quantify such discrepancies for bimodal SiC_p preforms across six coarse-to-fine particle ratios (0–100%). Three-dimensional pore network models were extracted to quantify key characteristics including areal porosity, surface area, and pore/throat dimensions. The results demonstrated that the average areal porosity fell to a minimum at a 67% coarse fraction then rose, while the pore distribution homogeneity steadily declined. Additionally, μ-CT measurements revealed that particle contact compactness reduced the particle surface area per unit volume at coarse fractions below 25% whereas particle fracture increased it at fractions above 25%, deviating significantly from empirical predictions. Larger coarse particle fractions reduced pore/throat quantities but increased their average size and volume. Beyond using established pore network extraction, this work distinguishes these two competing micro mechanisms and provides reasonable datasets to support bimodal preform optimization for composite manufacturing. Full article

Quantitative characterization of cement hydration microstructures from X-ray micro-computed tomography (μCT) images is fundamental to understanding hydration mechanisms and developing data-driven cement materials. However, existing deep learning approaches rely heavily on manually annotated datasets, limiting scalability and reproducibility. This study presents a physics-guided artificial intelligence framework for automated characterization of cement hydration microstructures using μCT imaging. A multi-Otsu thresholding strategy, guided by the physical relationship between X-ray attenuation and material density, was developed to automatically generate pixel-level pseudo-labels representing pore space, hydration products, and unhydrated cement. The proposed workflow produced a curated dataset comprising 7638 labeled μCT images extracted from 28 volumetric regions of interest spanning multiple hydration ages, Blaine fineness levels, and water-to-cement ratios. The pseudo-labeled dataset was used to train and evaluate three semantic segmentation architectures: U-Net, Attention U-Net, and U-Net++. All models achieved excellent segmentation performance, with mean Dice coefficients exceeding 0.94, while the baseline U-Net achieved the highest overall accuracy (Dice = 0.9454, IoU = 0.8982). Quantitative analysis of the segmented microstructures successfully captured the expected temporal evolution of pore space, hydration products, and unhydrated cement. ROI-level statistical analysis showed that hydration age, Blaine fineness, and water-to-cement ratio influenced morphological descriptors across the three microstructural phases, revealing systematic differences in microstructural evolution. The proposed framework reduces reliance on manual pixel-level annotation while enabling reproducible and scalable characterization of cement hydration microstructures. These findings provide a foundation for automated μCT-based cement characterization and future materials informatics applications. Full article

Three-dimensional images of multiphase natural and engineered materials obtained by X-ray micro-computed tomography require quantitative processing methods that can describe not only phase volume but also connectivity, spatial heterogeneity, and anisotropy. In this article, X-ray micro-computed tomography is abbreviated as X-$\mu$CT. Scalar descriptors such as fractal dimension, Betti numbers, Euler characteristic, and Minkowski functionals provide compact phase-level summaries of segmented X-$\mu$CT data, but they do not encode where structural heterogeneity occurs, whether connectivity is directionally spanning, how finite sample boundaries affect topological measurements, or how surface-normal orientation is distributed. We propose a unified methodological framework that extends scalar topological and Minkowski-functional analysis of segmented multiphase 3D images by adding cut-response analysis, including its boundary-sensitivity interpretation, directional connectivity and orientation descriptors, and the rank-two surface Minkowski tensor $W_1^{0,2}$. The framework is demonstrated on a previously published segmented geological X-$\mu$CT volume used as a benchmark multiphase geometry with four X-ray-density phases and on synthetic validation geometries with analytically known topology. The results show that the proposed extensions reveal spatial sensitivity, boundary-to-boundary connectivity, and surface fabric that are not captured by scalar phase-level invariants alone. The proposed framework can be used to analyze segmented 3D images of multiphase geological, porous, composite, and engineered samples, thereby expanding quantitative knowledge about their internal structure beyond scalar phase-level descriptors. Full article

Soil contamination by heavy metals and organic pollutants presents significant challenges to the global environment and public health. However, a lack of micro-scale understanding of the pollution process hinders efforts to remediate and enhance soil quality. Synchrotron-based X-ray imaging and spectroscopy techniques are powerful tools in revealing complex interactions within heterogeneous soil systems. This review systematically explores recent advances in soil research that deepen our knowledge on the chemical states, spatial distribution, and dynamic interactions of heavy metals and organic contaminants via synchrotron-based techniques (e.g., micro-XRF imaging, FTIR, SR-μCT). It highlights the potential of these methods to characterize composition, aggregate structure, and microbial activity within soil matrices with high spatial and temporal resolution, in situ, and with element-specific analysis. Additionally, a forward-looking perspective outlines key research directions to leverage these advantages and develop more effective and sustainable soil restoration strategies. We hope this work emphasizes the role of synchrotron science in field-scale soil applications and inspires future, mechanism-driven, evidence-based soil remediation efforts. Full article

The structural integrity of nuclear graphite is paramount for the lifespan of High-Temperature Gas-Cooled Reactors. The nuclear graphite components operate under extreme conditions involving high temperature, pressure, and intense neutron irradiation, leading to complex service behavior that is difficult to characterize only by experimental methods. This study employs the finite element method (FEM) to assess component stress and failure risk. The ManUMAT simulation method was first validated against irradiation data for Gilsocarbon graphite from an Advanced Gas-Cooled Reactor and was subsequently applied to stress–strain analysis of the nuclear graphite bricks in the HTR-PM side reflector layer. The 3D micropore structure of nuclear graphite was obtained via X-μCT and reconstructed in Avizo to establish an FEM model based on the actual pore geometry. Simulations of nuclear graphite over a 30 full-power-year service period predicted a significant contraction on the core-side and minimal thermal expansion on the out-side driven by the neutron doses. This research establishes a finite element framework that extends the ManUMAT approach by integrating a realistic pore structure model, thereby providing a foundation for quantifying the microstructural effects on macroscopic performance. Full article

Lacustrine shale oil in the Chang 7 Member of the Ordos Basin is controlled by a multi-scale pore–throat system in which oil occurrence, spontaneous imbibition, and pore-structure evolution are tightly coupled. In this study, nitrogen adsorption and micro-computed tomography (μCT) were employed to characterize pore-size distribution and connectivity, whereas nuclear magnetic resonance (NMR) T₂ relaxation was utilized to classify oil occurrence states, and X-ray diffraction (XRD) and total organic carbon (TOC) analyses were performed to determine mineralogical and organic compositions. Spontaneous imbibition experiments were conducted at 60 °C and subsequently extended to temperature–pressure sequence tests. The Chang 7 shale exhibits a stratified pore system in which micropores, mesopores, and macropores jointly define a three-tier “micropore adsorption–mesopore confinement–macropore mobility” pattern. As pore size and connectivity increase, the equilibrium imbibed mass and initial imbibition rate both rise, while enhanced wettability (contact angle decreasing from 81.2° to 58.7°) further strengthens capillary uptake. Temperature elevation promotes imbibition, whereas increasing confining pressure suppresses it, revealing a “thermal enhancement–pressure suppression” behavior. μCT-based network analysis shows that imbibition activates previously ineffective pore–throat elements, increasing coordination number and connectivity and reducing tortuosity, which collectively represents a capillary-driven structural reconfiguration of the pore network. When connectivity exceeds a threshold of about 0.70, the flow regime shifts from interface-dominated to channel-dominated. Building on these observations, a multi-scalecoupling framework and a three-stage synergistic mechanism of “pore-throat activation–energy conversion–structural reconstruction” are established. These results provide a quantitative basis for predicting imbibition efficiency and optimizing capillary-driven development strategies in deep shale oil reservoirs. Full article

Micro-computed tomography ($\mu$CT) and X-ray Fluorescence (XRF) were used to investigate a Polymetallic Nodule (PN) from the North-Western Pacific abyssal plain to gather more information concerning the environmental changes that could be reflected by the PN’s internal structure. Despite its small size, for example, an ovoid measured 48 × 38 mm, the $\mu$CT revealed the presence of four concentric layers with varying thicknesses and opacities to X-rays, all developed around a fragment of a tooth, most likely belonging to a Lamniformes shark. The same micro-tomograph, functioning as an XRF spectrometer, allowed for the determination of the mass fractions of Mn and Fe in the first two external layers. To estimate the PN age, a model that considers PN growth rate proportional to the ratio of Mn to the square of Fe mass fractions was used, and, by extrapolating it to the entire PN, its age was estimated at 1.56 ± 0.22 Ma, i.e., Early Pleistocene. Therefore, the correlated use of $\mu$CT and FRX, two noninvasive methods, allowed to highlight a shark tooth fragment as being the PN nucleus as well as determine its absolute age. Full article

Urbanization generates large quantities of arsenic-contaminated excavated soils that pose environmental risks due to arsenic volatilization during high-temperature sintering processes. While these soils have potential for recycling into construction materials, their reuse is hindered by arsenic release. This study demonstrated calcium hydroxide (Ca(OH)₂) as a highly effective additive for suppressing arsenic volatilization during soil sintering, while simultaneously improving material properties. Through comprehensive characterization using inductively coupled plasma-mass spectrometry (ICP-MS), scanning electron microscopy (SEM) and X-ray microtomography (μCT), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), results demonstrated that Ca(OH)₂ addition (0.5–2 wt.%) reduces arsenic volatilization by 57% through formation of thermally stable calcium arsenate (Ca₃(AsO₄)₂). Ca(OH)₂ acted via two mechanisms: (a) chemical immobilization through Ca-As-O compound formation, (b) physical encapsulation in a calcium-aluminosilicate matrix during liquid-phase sintering, and (c) pH buffering that maintains arsenic in less volatile forms. Optimal performance was achieved at 0.5% Ca(OH)₂, yielding 9.14 MPa compressive strength (29% increase) with minimal arsenic leaching (<110 ppb). Microstructural analysis showed Ca(OH)₂ promoted densification while higher doses increased porosity. This work provides a practical solution for safe reuse of arsenic-contaminated soils, addressing both environmental concerns and material performance requirements for construction applications. Full article

Amidst environmental concerns regarding the use of petroleum-based materials, wood and wood-based products are among the key players in the pursuit of green construction practices. However, environmental degradation of these materials remains a concern during structural design, particularly for outdoor applications. Borrowed from anatomy to preserve human body parts, this study applies and assesses a technique called ‘plastination’ as a new means for moisture management of Western Red Cedar (WRC). Specifically, the proposed technique includes acetone dehydration of WRC, followed by SS-151 silicone vacuum-assisted impregnation and silicone curing. To evaluate the method’s effectiveness, Micro X-ray Computed Tomography (μCT), Fourier Transform Infrared (FTIR) Spectroscopy, Thermogravimetric Analysis (TGA), and static water contact angle measurements were employed. Tensile testing was also performed to quantify the treatment’s effect on WRC’s mechanical properties under moisture conditioning. μCT confirmed an impregnation depth of 21.5%, while FTIR and TGA results showed reduced moisture retention (3.6 wt%) in plastinated WRC due to the absence of hydroxyl groups. Mechanical testing revealed enhanced deformability in treated samples without compromising tensile strength. Upon moisture conditioning, plastinated WRC retained its tensile properties and showed 59% lower moisture absorption and 15% lower weight as compared to conditioned virgin samples. Full article

Schiff base ligands prepared from salicylaldehyde and 2-, 3- and 4-methoxybenzylamine were used to prepare copper(II) complexes, characterized by spectral methods, elemental analysis and X-ray crystallography in the case of complex 4a derived from 2-methoxybenzylamine. The DNA cleavage activity of the prepared complexes was exceptional, with best activities of over 95% one-strand cleavage for 4c at 3 mM and full double-strand cleavage for complex 4a at 5 mM. Absorption titration studies with ct-DNA revealed good binding constants (at 10⁵ M⁻¹) with a decrease of up to 56% light absorption. Meanwhile, the EB–DNA displacement method and viscosity studies revealed groove binding as a possible binding mode. For BSA binding studies, all three complexes showed K_BSA values in the optimal range for reversible BSA binding (10⁴ M⁻¹). The copper(II) complexes showed significant cytotoxic effects (67–96% at 1 mM) in mitochondrial activity monitoring assays. Cytotoxicity was confirmed against cancer cell lines (A549 and HepG2) and HEL cells. The complexes 4a and 4c exhibited high activity against HepG2 cancer cells (IC50 < 22 μM), comparable to cisplatin. The radical scavenging activity was determined by the INT method with the best IC50 for 4c (189 ± 11 μM). Overall, complexes 4a and 4c with a methoxy group in the ortho and para positions show high potential in most determined activities, but mainly as DNA cleavers and as cytotoxic agents with selectivity against HepG2 cells. Full article

In this study, we demonstrated that lrp6a, a co-receptor in the Wnt signaling pathway, is essential for proper median fin formation and somitogenesis in goldfish. We analyzed the gene’s sequence features and expression patterns in both wen-type and egg-type goldfish, uncovering distinct tissue-specific expression differences between the two varieties. To explore the functional role of lrp6a, we performed CRISPR/Cas9-mediated gene knockout using eight designed single-guide RNAs (sgRNAs), of which four showed effective targeting. Three high-efficiency sgRNAs were selected and co-injected into embryos to achieve complete gene disruption. Morphological assessments and X-ray microtomography (μCT) imaging of the resulting mutants revealed various abnormalities, including defects in the dorsal, caudal, and anal fins, as well as skeletal deformities near the caudal peduncle. These results confirm that lrp6a plays a key role in median fin development and axial patterning, offering new insights into the genetic regulation of fin formation in teleost fish. Full article

MgO–C refractory materials were developed by incorporating different ratios of alumina/titania nano-additives which were synthesized chemically. Their physical and mechanical properties, oxidation resistance, slag wettability, bulk density, apparent porosity, cold crushing strength, oxidation index, and closed porosity were tested, evaluated, and compared using conventional techniques as well as X-ray micro-computed tomography (µCT). This investigation indicated a slight degradation of physical properties and mechanical strengthening which was stronger for samples with increased alumina content. Oxidation and corrosion extent were tested both with X-ray tomography and conventional methods. The first method allowed for the calculation of the oxidation index, the detection of closed porosity, and an improved analysis of the internal corrosion, avoiding the sectioning of the materials. This result confirms the supremacy of the first technique. On the contrary, although conventional methods such as the Archimedes procedure cannot detect close porosity, they provide more accurate measurements of the physical properties of refractories. This study shows that conventional methods exhibit superiority in investigations of the pore structures of refractories for pore sizes in the range 1–2 μm, while the use of the μCT system is limited for pore sizes equal to or larger than 20 μm. Full article

Apatite pastes derived from eggshell waste (BAp) were implanted onto the calvarial bone of rats, and bone formation was evaluated using X-ray μ-computed tomography (CT) and histological evaluation. BAp was mixed with distilled water to prepare a paste. Monoclinic hydroxyapatite of mineral resources (HAp) was used as a control. A 5 mm diameter PTFE (polytetrafluoroethylene) tube was filled with apatite pastes and implanted in the calvarial bone of 9-week-old Sprague Dawley rats for 8 weeks. A larger radiopaque area, similar to that of native bone, was observed in the BAp paste-implanted specimens than that of HAp paste. The bone mineral density (BMD) value of the BAp paste was significantly higher than that of the HAp paste (p < 0.05). In the histological evaluation, new bone formation was noticed from the calvarial side for both apatite specimens, and HAp remained in the PTFE unlike BAp. The bone mass (BM) value of the BAp paste was significantly higher than that of the HAp paste (p < 0.05). SEM and XRD analyses revealed that BAp was microcrystalline and poorly crystalline. The promotion of new bone formation may contribute to the crystallinity and Mg content of BAp. BAp was found to be useful as a bone regeneration material. Full article

Ultra-high-performance fiber-reinforced concrete (UHPFRC) exhibits exceptional tensile properties, but its tensile strength is highly dependent on fiber distribution, orientation, and count, making accurate strength estimation challenging. This study introduces a novel approach in which tensile strength estimation is achieved by analyzing fiber characteristics at predicted cracking locations using deep learning. Using X-ray computed tomography (CT) and image analysis techniques, the fiber orientation factor (μ₀) and average efficiency factor ((μ₁)⁻) were determined at predicted cracking locations. A deep learning model (YOLOv11) was trained to identify regions with a defective distribution, achieving a mean Average Precision (mAP@0.5) of 0.87, demonstrating its high reliability in predicting cracking locations. The overall cracking location prediction success rate was 73% for strain-hardening specimens. The estimated tensile strength was then compared with uniaxial tensile test (UTT) results, revealing an average experiment-estimation error of 5.72% and an average theory-estimation error of 3.34% for strain-hardening specimens, whereas strain-softening specimens exhibited significantly higher errors, with an average experiment-estimation error of 43.09% and an average theory-estimation error of 15.73%. These findings highlight the strong correlation between fiber count, cracking behavior, and tensile strength in UHPFRC, offering a trustworthy, non-destructive framework for estimating tensile performance in UHPFRC elements. Full article