Search Results (48,417)

Background: Noble gases, such as argon, have been observed to exhibit cytoprotective effects. The non-anesthetic properties, abundance, and cost-effectiveness of argon suggest its clinical potential. While its efficacy in mitigating ischemia–reperfusion injury has been demonstrated in cellular and small animal models, data on its effects in large animals remain limited. This study evaluated the effects of argon inhalation on pulmonary ischemia–reperfusion injury in miniature swine with potential applications in transplantation. Methods: The left bronchial and pulmonary artery and veins were clamped for 90 min, and then the clamps were released to induce lung ischemia–reperfusion injury in 10 CLAWN miniature swine. The argon group (n = 5) inhaled a mixture of 30% oxygen and 70% argon for 360 min, whereas the control group (n = 5) inhaled a mixture of 30% oxygen and 70% nitrogen for an equivalent duration. Lung function was evaluated using chest X-ray, lung biopsies, and blood gas analysis. Results: The PaO₂/FiO₂ ratio significantly decreased in the control group 2 h post-reperfusion (568 ± 12 to 272 ± 39 mmHg), but was better preserved in the argon group (562 ± 17 to 430 ± 48 mmHg). Blood gas from the left pulmonary vein showed a superior PvO₂/FiO₂ ratio in the argon group (331 ± 40 vs. 186 ± 17 mmHg at 2 h; 519 ± 19 vs. 292 ± 33 mmHg at 2 days). Chest X-ray revealed reduced infiltration in the left lung. The lung biopsy histological scores improved in the argon group at 2 h and 2 days. Serum superoxide dismutase analysis and tissue TUNEL assays suggested that antioxidant and anti-apoptotic mechanisms, respectively, were involved. Conclusions: Perioperative argon inhalation attenuates ischemia–reperfusion injury in swine lungs, likely via anti-apoptotic and antioxidant effects. Full article

Installation in sand is sensitive to its evolving pore structure, yet design models rarely update permeability for real-time fabric changes. This study tracks the stress-dependent pore size distribution of coarse sand under laterally constrained compression using high-resolution X-ray nano-CT. Scans taken at six axial stress levels show that the distribution shifts toward smaller radii while keeping its log-normal shape. A single shifting factor, defined as the current median radius normalized by the initial value, captures this translation. The factor decays with axial stress according to a power law, and the exponent as well as the reference pressure are calibrated from void ratio data. The resulting closed-form expression links mean effective stress to pore radius statistics without extra fitting once the compressibility constants are known. This quantitative relation between effective stress and pore size distribution has great potential to be embedded into coupled hydro-mechanical solvers, enabling engineers to refresh hydraulic permeability at every computation step, improving predictions of excess pore pressure and soil resistance during suction anchor penetration for floating wind foundations. Full article

To clarify the organic matter enrichment regularity of Permian shales in the Kaijiang–Liangping Trough, as well as the differential characteristics of their reservoir lithology, mineral assemblage, and nanopore structure—and thereby provide a geological basis for the exploration and development of Permian marine shales in the eastern Sichuan Basin—core samples from different depths of the Wujiaping Formation and Dalong Formation in Well DY-1H were analyzed using a series of micro–nano technical research methods, including whole-rock X-ray diffraction, major/trace element analysis, conventional porosity-permeability measurement, high-pressure mercury intrusion porosimetry, nitrogen adsorption, and field emission scanning electron microscopy. Research finds that the Dalong Formation shale contains Type I organic matter with high abundance, whereas the Wujiaping Formation shale is dominated by Type II₂ organic matter. The Wujiaping Formation experienced stronger terrigenous input and higher weathering intensity, while the Dalong Formation was deposited under persistently anoxic conditions, in contrast to the frequent oxic–anoxic alternations in the Wujiaping Formation. Paleoproductivity indicators suggest higher productivity in the Dalong Formation than in the Wujiaping Formation. Mo/TOC ratios below 4.5 indicate deposition in a strongly restricted water body. Enrichment factors of multiple elements further support the enhanced paleoproductivity of the Dalong Formation. The Dalong Formation shale has higher contents of quartz and carbonate minerals, while the Wujiaping Formation shale has a higher content of clay minerals. The Wujiaping Formation shale is more developed with inorganic micropores, whereas the Dalong Formation shale is characterized by more developed organic nanopores. During the sedimentary period of the Dalong Formation shale, the paleoproductivity was high, the sedimentary waterbody had high reducibility and restriction, and the reservoir was well-developed with nanopores. The Dalong Formation is a more favorable interval for Permian shale gas exploration and development in the Kaijiang–Liangping Trough. Full article

Next-generation space observatories for high-energy gamma-ray astrophysics will increase scientific return using onboard machine learning (ML). This is now possible thanks to today’s low-power, radiation-tolerant processors and artificial intelligence accelerators. This paper provides an overview of current and future ML applications in gamma-ray space missions focused on high-energy transient phenomena. We discuss onboard ML use cases that will be implemented in the future, including real-time event detection and classification (e.g., gamma-ray bursts), and autonomous decision-making, such as rapid repointing to transient events or optimising instrument configuration based on the scientific target or environmental conditions. Full article

Fotis Kontoglou (1895–1965) was a prominent Greek painter and writer, known primarily for revitalizing byzantine painting in the 20th century and being one of the first artist-conservators in Greece active at this period. The current study represents the first systematic attempt to examine seven (7) icons (i.e., ecclesiastical panel paintings) attributed to Kontoglou, currently located in two famous monasteries in Laconia, Greece. The research utilized exclusively non-destructive analytical techniques, namely digital optical microscopy, UV-induced visible fluorescence photography (UVIVF), and portable X-ray fluorescence (p-XRF) spectroscopy, to identify the materials—particularly pigments—employed in the corresponding paintings. The results are interpreted under the light of Kontoglou’s own writings on painting, in particular his “Ekphrasis” painting manual. Preliminary assessments of surface morphology and state of preservation were achieved through macroscopic and microscopic probing, as well as through inspection under ultraviolet light, while further analysis was performed using portable X-ray fluorescence spectroscopy. The results confirm the employment of both traditional and modern synthetic inorganic components, while comparisons with the pigments listed in Kontoglou’s “Ekphrasis” painting manual suggest his persistent use of a rather limited palette of pigments. Nevertheless, despite the fact that the paintings were executed in a small period of time (1954–1956), data revealed notable differentiation between the studied icons, which probably indicates procurement of materials from various sources. Given the scarcity of technical investigations of modern (20th century) paintings, this study is relevant and reveals some interesting hints, which may pertain to the trends of the mid-20th century Greek paint market, like, e.g., the rather limited distribution of Ti-white. Additionally, the current findings contribute considerably towards understanding Kontoglou’s artistic methods during a highly creative period and can be utilized to support future conservation efforts. Ultimately, the current preliminary study sheds light on some methodological aspects of the pertinent research and assists towards establishing a detailed protocol for future studies. Full article

Background: Bone fracture is a partial or complete break in the continuity of a bone, which poses a significant healthcare burden. It is important to discover a novel method to stimulate and speed-up the healing of bone fractures. Aim: This study aimed to investigate the effects and mechanisms of alternating current (AC) in promoting bone fracture healing. Methods: A rabbit bone fracture model was used. X-ray and Micro-CT evaluated fracture healing, while HE staining and immunohistochemistry assessed morphological changes. In vitro, pre-osteoblastic cells were tested with alizarin red S staining and alkaline phosphatase (ALP) activity. RNA-seq analysis explored potential mechanisms. Results: X-ray evaluation showed that alternating current stimulation (ACS) promoted bone formation and shaping by day 14 post-treatment. Micro-CT results revealed significant new bone formation as early as day 3 and day 7 (p < 0.05). HE staining indicated more trabecular bone formation in the ACS group compared to the model group at days 7 and 14. Immunohistochemistry showed higher expression of BMP-2 and VEGF in the ACS group by day 7. In vitro, ACS enhanced osteogenic differentiation, increasing calcified nodule formation and ALP activity. Gene expression analysis demonstrated significant changes in key osteogenic genes, confirmed by multiple immunohistochemical staining. Conclusions: ACS may be a novel method for treating bone fractures more rapidly, significantly relieving the patient’s burden, particularly in the early stages of bone healing. Full article

The performance of ultra-high-purity copper sputtering targets is critical for nanoscale integrated circuit fabrication, yet challenges such as dynamic recovery and recrystallization hinder grain refinement and texture control. In the present work, cryogenic deformation was introduced to address these issues. Through electron backscatter diffraction (EBSD), X-ray diffraction (XRD), and mechanical testing, the microstructure, texture, and mechanical properties of 6N ultra-high-purity copper processed by room-temperature rolling (RTR) and cryorolling (CR) were comparatively investigated. Results reveal that RTR deformation is dominated by slip mechanisms; the RTR sample with 90% reduction exhibits obvious dynamic recrystallization (DRX) and forms a bimodal structure dominated by Copper ({112}⟨111⟩) and S ({123}⟨634⟩) textures. In contrast, CR suppresses thermal activation processes, enabling deformation mechanisms suggestive of twinning activity, leading to ultrafine fibrous structures, while shifting texture components toward Brass ({110}⟨112⟩) and S. Compared to RTR-processed samples, CR-processed samples possess superior mechanical performance. The CR sample with 90% reduction exhibits: a microhardness of 164.60 HV, a yield strength of 385.61 MPa, and a tensile strength of 648.02 MPa, which are, respectively, 33.2%, 91.7%, and 84.6% higher than those of RTR counterparts. Williamson–Hall analysis confirms that the CR sample with 90% reduction achieves finer substructure sizes (~133 nm) and higher stored energy (~22 J·mol⁻¹) by suppressing dynamic recovery, providing a robust driving force for subsequent annealing. This work demonstrates that cryorolling optimizes microstructure and texture through twin-dislocation synergy, providing a fundamental basis for the development of advanced sputtering targets. Full article

The study of the antimatter component in cosmic rays is essential for the understanding of their acceleration and propagation mechanisms, and is one of the most powerful tools for the indirect search of dark matter. Current methods rely on magnetic spectrometers for charge-sign discrimination, but these are not suitable for extending measurements to the TeV region within a short timeframe of a few decades. Since most of present and upcoming high-energy space experiments use large calorimeters, it is crucial to develop an alternative charge-sign discrimination technique that can be integrated with them. The Electron/Positron Space Instrument (EPSI) project, a two-year R&D initiative launched in 2023 with EU recovery funds, aims to address this challenge. The basic idea is to exploit the synchrotron radiation emitted by charged particles moving through Earth’s magnetic field. The simultaneous detection of an electron/positron with an electromagnetic calorimeter and synchrotron photons with an X-ray detector is enough to discriminate between the two particles at the event level. The main challenge is to develop an X-ray detector with a very large active area, high X-ray detection efficiency, and a low-energy detection threshold, compliant with space applications. In this paper, we give an overview of the EPSI project, with a focus on the general idea of the detection principle, the concept of the space instrument, and the design of the X-ray detector. Full article

The optimization of BiVO₄-based structures significantly contributes to the development of a global system towards clean, renewable, and sustainable energies. Enhanced photocatalytic performance has been reported for numerous doped BiVO₄ materials. Bi³⁺-based compounds can be easily doped with rare earth (RE³⁺) ions due to their equal valence and similar ionic radius. This means that RE³⁺ ions could be regarded as active co-catalysts and dopants to enhance the photocatalytic activity of BiVO₄. In this study, a simple microwave-assisted approach was used for preparing nanostructured Bi_1−xEu_xVO₄ (x = 0, 0.03, 0.06, 0.09, and 0.12) samples. Microwave heating at 170 °C yields a bright yellow powder after 10 min of radiation. The materials are characterized through X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet–visible–near-infrared diffuse reflectance spectroscopy (UV-Vis-NIR DRS), photoluminescence spectroscopy (PL), and micro-Raman techniques. The effects of the different Eu³⁺ ion concentrations incorporated into the BiVO₄ matrix on the formation of the monoclinic scheelite (ms-) or tetragonal zircon-type (tz-) BiVO₄ structure, on the photoluminescent intensity, on the decay dynamics of europium emission, and on photocatalytic efficiency in the degradation of Rhodamine B (RhB) were studied in detail. Additionally, microwave chemistry proved to be beneficial in the synthesis of the tz-BiVO₄ nanostructure and Eu³⁺ ion doping, leading to an enhanced luminescent and photocatalytic performance. Full article

In this study, a two-dimensional gamma-ray source localization system using a mesh array of plastic scintillating fibers and an artificial neural network is presented. The system covers a 200 cm by 100 cm area using SCSF-78 multi-cladded fibers. A novel U-shaped fiber topology connects both fiber ends to one side, requiring only two data-acquisition systems. Silicon photomultiplier arrays measure fast time-of-flight under optimized operating conditions to maximize signal yield. An independent artificial neural network model map measured time-of-flight values to spatial coordinates, compensating for systematic non idealities. Performance was validated using a Cesium-137 source at 20 random test positions. The artificial neural network method achieved a mean full-scale error of 4.6%. This demonstrated a 79.34% accuracy improvement over direct theoretical calculation, which had a mean full-scale error of 22.5%. The system showed consistent performance, achieving a two-dimensional standard deviation of 0.492 cm during repeatability assessment. This methodology provides a practical, efficient approach to two-dimensional radiation source localization suitable for real time monitoring and contamination mapping. Full article

To address the challenges of strong heterogeneity and poor crude oil mobility in tight conglomerate reservoirs of the Mahu Oilfield, this study systematically evaluated the effects of different surfactants on wettability alteration, spontaneous imbibition, and relative permeability through high-temperature/high-pressure spontaneous imbibition experiments, online Nuclear Magnetic Resonance (NMR) monitoring, and relative permeability measurements. Core samples from the Jinlong and Madong areas (porosity: 5.98–17.55%; permeability: 0.005–0.148 mD) were characterized alongside X-Ray Diffraction (XRD) data (clay mineral content: 22–35.7%) to compare the performance of anionic, cationic, nonionic, and biosurfactants. The results indicated that the nonionic surfactant AEO-2 (Fatty Alcohol Polyoxyethylene Ether) (0.2% concentration) at 80 °C exhibited optimal performance, achieving the following results: 1. a reduction in wettability contact angles by 80–90° (transitioning from oil-wet to water-wet); 2. a decrease in interfacial tension to 0.64 mN/m; 3. an imbibition recovery rate of 40.14%—5 to 10 percentage points higher than conventional fracturing fluids. NMR data revealed that nanopores (<50 nm) contributed 75.36% of the total recovery, serving as the primary channels for oil mobilization. Relative permeability tests confirmed that AEO-2 reduced residual oil saturation by 6.21–6.38%, significantly improving fluid flow in highly heterogeneous reservoirs. Mechanistic analysis highlighted that the synergy between wettability reversal and interfacial tension reduction was the key driver of recovery enhancement. This study provides a theoretical foundation and practical solutions for the efficient development of tight conglomerate reservoirs. Full article

Geometric inaccuracies in the design of X-ray baggage scanners can lead to significant image artifacts, such as banding and discontinuities, which compromise security screening effectiveness. Although comprehensive commercial solutions are available, constructing a custom X-ray scanner requires the precise alignment of detector arrays. This is a complex and time-consuming process when performed manually. The core of the proposed method is a computational model that calculates the optimal position and orientation for each detector card based on user-defined scanner dimensions and hardware parameters. To validate the geometry created with this method, its performance was compared against flat and arc-shaped geometries. The results demonstrate that the proposed method successfully generates geometries that produce continuous and artifact-free images. The study concludes that the developed software tool provides a robust and practical solution, significantly simplifying the complex task of scanner construction and accelerating the development of reliable, custom X-ray inspection systems. Full article

Background/objectives: The study aimed to present cases of malignant struma ovarii from seven centers in Türkiye and evaluate them within the context of the existing literature. Methods: We retrospectively analyzed clinical data from 17 patients treated at seven centers, focusing on clinical features, surgical management, pathology, thyroid function, adjuvant treatment, and outcomes. Additionally, a literature review including eight studies with 178 patients was conducted. Results: The mean age of patients was 44.7 years, with a mean tumor size of 9.2 cm. Elevated Ca 125 was found in 33.3% of patients, while thyroid function abnormalities and hyperthyroidism signs were rare. Pelvic pain and menstrual irregularities were common presenting symptoms. A total of 16 patients (94.1%) had unilateral tumors. Total abdominal hysterectomy with bilateral salpingo-oophorectomy and unilateral salpingo-oophorectomy were the most frequent surgical approaches. Histopathology predominantly showed classical papillary thyroid carcinoma (13 patients, 76%). All patients were FIGO stage I, with no metastasis. Thyroidectomy was performed in seven patients, identifying two concurrent thyroid cancers. Four patients received adjuvant radioactive iodine therapy. During a median follow-up of 43 months, no deaths and one recurrence were observed. The literature review showed a diagnosis age ranging 43–53 years and papillary thyroid carcinoma as the most common subtype. Thyroidectomy and RAI treatment were selectively applied. Among the reported studies, recurrence occurred in 7 of 76 patients (9.2%), while 5-year disease-free and overall survival rates exceeded 94% and 100%, respectively. BRAF mutations were uncommon. Conclusions: Malignant struma ovarii is a rare tumor with a favorable prognosis when diagnosed early and managed appropriately. Full article

Humidity monitoring is essential in industrial and scientific scenarios, yet remains challenging for compact EMI (electromagnetic interference)-immune sensors with high sensitivity and robust stability. A novel fiber Bragg grating (FBG) humidity sensor was developed, which incorporated LiCl@UIO-66 microfillers within a poly(N-isopropylacrylamide) (PNIPAM) hydrogel matrix. Structural characterization using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared (FTIR) spectroscopy confirms that LiCl is confined or nanodispersed within intact UIO-66, and that interfacial ion–dipole/hydrogen-bonding exists between the composite and water. Systematic variation in coating time (30–720 min) reveals monotonic growth of the total wavelength shift with diminishing returns. A coating time of 4 h was found to yield a wavelength shift of approximately 0.38–0.40 nm, representing about 82% of the maximum shift observed at 12 h, while maintaining good quasi-linearity and favorable kinetics. Calibration demonstrates sensitivities of 6.7 pm/%RH for LiCl@UIO-66_33 and 10.6 pm/%RH for LiCl@UIO-66_51 over ~0–95%RH. Stepwise tests show response times t90 of ≈14 min for both composites, versus ≈30 min for UIO-66 and ≈55 min for neat PNIPAM. Long-term measurements on the 51 wt.% device are stable over the first ~20 days, with only slow drift thereafter, and repeated humidity cycling is reversible. The wavelength decreases monotonically during drying while settling time increases toward low RH. The synergy of hydrogel–MOF–salt underpins high sensitivity, accelerated transport, and practical stability, offering a scalable route to high-performance optical humidity sensing. Full article

In this study, a multiphysics coupling numerical model was developed to investigate the thermal-fluid dynamics and microstructure evolution during the laser metal deposition of AlCoCrFeNi high-entropy alloy (HEA) coatings on 430 stainless steel substrates. The model integrated laser-powder interactions, temperature-dependent material properties, and the coupled effects of buoyancy and Marangoni convection on melt pool dynamics. The simulation results were compared with experimental data to validate the model’s effectiveness. The simulations revealed a strong bidirectional coupling between temperature and flow fields in the molten pool: the temperature distribution governed surface tension gradients that drove Marangoni convection patterns, while the resulting fluid motion dominated heat redistribution and pool morphology. Initially, the Peclet number (Pe_T) remained below 5, indicating conduction-controlled heat transfer with a hemispherical melt pool. As the process progressed, Pe_T exceeded 50 at maximum flow velocities of 2.31 mm/s, transitioning the pool from a circular to an elliptical geometry with peak temperatures reaching 2850 K, where Marangoni convection became the primary heat transfer mechanism. Solidification parameter distributions (G and R) were computed and quantitatively correlated with scanning electron microscopy (SEM)-observed microstructures to elucidate the columnar-to-equiaxed transition (CET). X-ray diffraction (XRD) analysis identified body-centered cubic (BCC), face-centered cubic (FCC), and ordered B2 phases within the coating. The resulting hierarchical microstructure, transitioning from fine equiaxed surface grains to coarse columnar interfacial grains, synergistically enhanced surface properties and established robust metallurgical bonding with the substrate. Full article