Search Results (5,354)

This work presents a method to encapsulate plant extracts within a binary polysaccharide carrier and to characterize the physicochemical and rheological performance of the resulting biocomposites in the context of food use. Using a starch/psyllium matrix, extracts from Sambucus nigra (SN), Aronia melanocarpa (AM), and Echinacea purpurea (EP) were effectively protected and incorporated through a stepwise workflow encompassing matrix preparation, encapsulation, structural verification, and functional assessment. SEM revealed a porous network containing uniformly distributed, extract-loaded spherical structures (~800–1500 nm), while FTIR supported the presence of hydrogen bonding and hydrophobic interactions that contributed to system stability. The prepared nanoemulsions showed shear-thinning (pseudoplastic) behavior, indicating favorable processing characteristics, whereas most physicochemical and bioactivity measurements were performed on lyophilized composites. The dried materials preserved extract-specific color signatures (ΔE > 5) and exhibited distinct thermal responses: AM produced a pronounced plasticizing effect (Tg reduced by >20 °C), while the incorporation of extracts generally delayed thermal degradation, consistent with polyphenol–starch interactions. Phase-transition behavior was also altered, with melting peaks suppressed for SN and AM and melting temperatures lowered for EP. Surface analysis indicated increased hydrophobicity and a reduced polar component of surface free energy, suggesting improved moisture barrier potential. Antioxidant capacity closely tracked total phenolic content (r > 0.94), with caffeic acid contributing strongly, particularly in EP-based systems. Antimicrobial activity depended on extract type (broad-spectrum for EP, selective for SN, minimal for AM), and the comparatively higher sensitivity of Gram-negative bacteria points to improved phenolic availability and membrane interactions upon encapsulation. Collectively, these results highlight the starch/psyllium matrix as a flexible platform for stabilizing plant extracts while enabling tunable functional attributes for functional food applications. Full article

Sleeper voids, or hanging sleepers, in ballasted railway tracks threaten structural safety and serviceability. This study proposes a physics-guided quantitative ground-penetrating radar (GPR) framework for detecting hanging sleepers using high-frequency antennas ($f\ge 1.5$ GHz). The framework integrates signal post-processing, sleeper-region localization, time-domain peak searching with polarity consideration, and continuous wavelet transform (CWT) as auxiliary verification. By exploiting the physical geometric relationship between the sleeper and ballast interfaces, the method quantitatively estimates their elevation difference and identifies hanging sleepers according to engineering criteria. Spatial continuity constraints are further introduced to reduce false detections. Validation through gprMax simulations and field experiments demonstrates effective detection and severity assessments, providing a physically interpretable solution for automated railway inspection. Full article

Mechanical properties of lead-free hybrid perovskites have attracted growing interest because of their significance in future eco-friendly optoelectronic applications. However, there are very limited studies about the intrinsic elastic properties and high-pressure structural evolution of hybrid perovskites, and the fundamental structure–mechanical property relationships are insufficiently understood. Here, we report the elastic behavior of a three-dimensional (3D) hybrid organic–inorganic perovskite, (DABCO)RbBr₃ (DABCO = triethylenediammonium), and confirm the processability through processing with chiral metasurfaces and the generation of circular dichroism. Our in situ high-pressure synchrotron X-ray diffraction experiments demonstrate that this crystal does not start to amorphize until 2.3 GPa. Density functional theory calculations reveal that its E, G and v range between 20.73 and 27.93 GPa, 8.21 and 11.62 GPa and 0.18–0.39, respectively. Additionally, due to the low elastic moduli and polar crystal structure, we fabricate a device of (DABCO)RbBr₃ composite film, which shows favorable performance for piezoelectric energy harvesting. This work utilizes (DABCO)RbBr₃ to open up new avenues for applications in manufacturing and energy harvesting. Full article

Different components of the cytoskeleton are very important determinants of brain development. They orchestrate multiple cellular processes involved in all phases of cerebral cortex development. In this review, we summarize current knowledge on the components of the cytoskeleton—microtubules, actin filaments, and intermediate filaments—and their roles in cortical development. We provide a detailed analysis of how cytoskeleton molecules control neuronal progenitor proliferation, neuronal migration, polarization, axon and dendrite specification and outgrowth, and synaptogenesis. We further examine how pathogenic variants in genes encoding cytoskeletal proteins or their regulators disrupt particular steps of neurogenesis and contribute to major neurodevelopmental disorders (NDDs). Focusing on NDDs such as microcephaly, lissencephaly, corpus callosum agenesis, and synaptopathies, we discuss consequences of cytoskeletal dysfunctions causing altered cellular behavior and clinical phenotypes. By linking molecular defects to developmental and phenotypic consequences, this review highlights the cytoskeleton as a central element in neurodevelopmental pathologies and underscores its potential as a target for future therapeutic strategies. Full article

As the process node is scaled down, the spin-transfer-torque magnetic random-access memory (STT-MRAM) exhibits higher memory density than the static random-access memory (SRAM), making it one of the more promising successors of the low-level on-chip cache memory. However, the low read margin (RM) of the magnetic tunnel junction (MTJ) in STT-MRAM can limit the achievable read accuracy. We implemented 2-bit channel quantization for error-correcting code (ECC) schemes and explored the trade-offs between improved read accuracy and factors such as circuit area, power consumption, and latency. The proposed quantization scheme consists of a sensing amplifier-based 2-bit quantizer and MTJ resistor-based soft-decision thresholds. Compared to 1-bit channel quantization using the Bose–Chaudhuri–Hocquenghem (BCH) code, the proposed 2-bit quantization architecture achieves a fourfold reduction in frame error rate (FER) from $8.0\times {10}^{-4}$ to $2.0\times {10}^{-4}$ when paired with polar codes and successive cancellation (SC) decoding. Additionally, this approach results in decoding complexity that is only 1/13th of that required for BCH at a 0.7 code rate. Full article

The paper suggests a model-dependent theoretical framework for designing optimal ranking algorithms to achieve desirable macroscopic opinion configurations. We consider an opinion formation process in which agents communicate through stochastic pairwise interactions, with the outcomes of these interactions being a function of the interacting agents’ opinions and individual attributes (types). For the model, we write a mean-field approximation (MFA)—a coarse-grained nonlinear ordinary differential equation—which accommodates network modularity and assortativity, agents’ activity heterogeneity, and the curation of a ranking system that can prohibit interactions with opinion- and type-dependent probabilities. Upon MFA, we formulate a control problem for dynamically adjusting the ranking algorithm’s parameters. The existence of a solution is proved, and certain properties of optimal controllers are derived. For the case of a two-element opinion alphabet, we obtain a solution to the control problem using finite-difference schemes. This solution holds for any number of agent types and does not depend on external factors, such as the influence of social bots. Numerical tests corroborate our findings and also enable us to investigate the control problem for high-dimension opinion spaces, wherein we consider two primary scenarios: depolarization of an initially polarized society and nudging a social system towards a fixed endpoint of an opinion spectrum. Full article

The spin relaxation rate of Xe isotopes is a key characteristic of nuclear magnetic resonance gyroscopes (NMRGs). A pump-induced biphasic relaxation (PBR) model is proposed to describe the pump dependence of the transverse relaxation rate of ¹²⁹Xe nuclear spin. The distribution of electron polarization is theoretically analyzed based on the Bloch–Torrey equations and the volume-averaged polarization is evaluated through NMR frequency shift measurements. Experimental results confirm the theoretical quadratic dependence between Γ and $P_{Rb}$ with a high fitting accuracy (R² = 0.9969). The predicted linear (R² > 0.9966) and hyperbolic (R² > 0.9942) regimes of Γ versus pump power are also observed. Validation across different pump power conditions shows agreement between the model and measurements, with an average relative deviation of 0.2169%. The multi-stage process of nuclear spin relaxation is quantified, thereby providing a robust validation for the PBR model. Full article

Molybdenum (Mo) is currently considered as a potential diffusion barrier material for copper (Cu) interconnects, and these interconnect structures are generally processed using the technique of chemical mechanical planarization (CMP). While a limited number of publications on Mo CMP are presently available, the considerations for mitigating CMP-induced galvanic corrosion of Mo have remained largely underexplored. Using a model CMP system in pH-neutral slurries of citric acid with silica abrasives, the present work demonstrates how Mo barrier lines in contact with Cu wires in the CMP environment can develop CMP defects of galvanic corrosion. Including imidazole in the slurry considerably reduces the galvanic current of this corrosion process. The mechanisms of galvanic inhibition and material removal are examined by employing strategic tribo-electrochemical measurements. Open-circuit potential and potentiodynamic polarization measurements performed under surface abrasion aid the characterization of CMP-enabling surface reactions. The slurry’s surface chemistry initiates the primary modes of material wear for CMP, and corrosion-induced propagation of subsurface wear mostly governs the measured material removal rates for both Mo and Cu. Although the Cu:Mo selectivity of material removal is affected as the galvanic corrosion of Mo is suppressed, this effect can be controlled by varying the slurry content of imidazole. Full article

Conventional deposition techniques hinder the integration of high-performance lead-free piezoelectric thick films on silicon substrates due to slow growth kinetics and complex processing. Herein, dense, crack–free Ba(Zr_xTi_1−x)O₃ (BZT, x = 0–0.10) thick films (~2 μm) were fabricated via aerosol deposition (AD) followed by annealing, forming a nanocrystalline microstructure with an average grain size of ~78 nm. Compositional tuning showed optimal electromechanical performance at x = 0.03, attributed to the coexistence of tetragonal and orthorhombic phases near room temperature that reduce the phase transformation energy barrier. The optimized BZT films exhibit excellent electrical properties: saturation polarization of 31.3 μC/cm², relative permittivity of 430, dielectric tunability figure of merit (FOM) of 155, and a large transverse piezoelectric coefficient |e_31, f| of 1.01 C/m²—comparable to textured magnetron–sputtered BaTiO₃ films but with higher deposition efficiency. This work provides a high-throughput route for fabricating piezoelectric thick films, highlighting the potential of compositionally engineered AD–processed BZT in lead-free MEMS applications. Full article

The primary objective of this study is to develop a specialized deep learning framework specifically adapted for the unique physical characteristics of neurovascular Optical Coherence Tomography (OCT) imaging. Although Polyp-PVT, originally designed for polyp segmentation, shows promise for OCT analysis, it faces limitations in neurovascular applications. The default RGB input wastes resources on duplicated grayscale data, while its fixed-scale fusion struggles with vascular curvature variations. Furthermore, the attention mechanism fails to capture radial vessel patterns, and geometric constraints limit thin boundary detection. To address these challenges, we propose Brain-OCT-PVT with key innovations: a single-channel input stem reducing parameters by two-thirds; a Radial Intensity Module (RIM) using polar transforms and angular convolution to model annular structures; and a Deformable Cross-scale Fusion Module (D-CFM) with learnable offsets. The Boundary-aware Attention Module (BAM) combines Laplace edge detection with Swin-Transformer for sub-pixel consistency. A specialized loss function combines Dice Similarity Coefficient (Dice), BoundaryIoU on 2-pixel dilated edges, and Focal Tversky to handle extreme class imbalance. Evaluation on 13 clinical cases achieves a Dice score of 95.06% and an 95% Hausdorff Distance (HD95) of 0.269 mm, demonstrating superior performance compared to existing approaches. Full article

Metasurface is a kind of artificial structure which can efficiently control the amplitude, phase, frequency, and polarization of the light field. Metasurface polarization holographic encryption is a holographic encryption technology with the polarization state as a key, which has been widely concerned in recent years with advantages such as sub-wavelength pixels, precision adjustment, and high security factor. In this paper, the design and optimization of the unit structure of metasurface have been carried out, and the clear double-channel holographic image reproduction and good encryption effects have been realized afterwards. The results show that the relatively good polarization holographic encryption can be achieved by employing the designed Si nanorods with the length of 148 nm and width of 55 nm, respectively, which have been beforehand grown on SiO₂ substrates. Note that the periodic angle deflection around the Z axis was adopted by using the dual-channel optical rotation incidence with the wavelength of 632.8 nm. It has been theoretically demonstrated that information transmittance loss should be less and the image restoration effect should be satisfactory. A novel encryption method has also been proposed for the optical information processing and optical encryption, and the huge application potential of our theme has been revealed as the next-generation optical control platform in the near future. Full article

In the framework of Harmony, the 10th ESA Earth Explorer mission, this paper presents a general methodology to optimize the formation parameters relevant to the single-pass, cross-track interferometry (XTI) configuration. The proposed method considers the requested height sensitivity and the maximum allowable temporal lag and derives the formation parameters for an optimal coverage over different ranges of latitudes by leveraging the relative eccentricity and inclination vector formalism. Our approach addresses the problem of interferometric coherence through the wavenumber support alignment method which is able to take into account the specific geometry of XTI in Harmony, which is a long-baseline multistatic configuration with large squint angles. The analysis is completed by an estimate of the propellant budget, required to maintain the optimized formation, which can be used as a further trade-off parameter within the mission design process. The results indicate that the passively stable helix configuration (with relative eccentricity and inclination phase angles set to 90°) provides a robust solution at equatorial and mid-latitude regions with perpendicular baselines up to the order of 1 km and temporal lag below 10 ms. Conversely, for high-latitude and polar regions, two alternative strategies are identified, revealing a trade-off between enhanced interferometric performance and increased formation maintenance requirements. For polar regions, a first strategy adopts relative eccentric and phase angles of 10°, achieving satisfactory performance across most latitudes, whereas an alternative approach retains the value of 90° and optimizes the formation specifically for high latitudes. These two options result in distinct station-keeping demands since the former strategy requires a $\Delta \mathrm{V}$ budget about two orders of magnitude higher, while the latter remains within a $\Delta \mathrm{V}$ range that is typical for missions of the considered class. Full article

We describe the formation of LIPSS by fs laser irradiation on polished titanium or steel samples, from which polymer replicas can be produced. The irradiation of inclined samples allows a variation in the periodicity of the LIPSS in a range between about 500 and 1000 nm, depending on the angle of incidence and the orientation of the laser polarization relative to the plane of incidence, either parallel (p-polarization) or perpendicular (s-polarization). For p-polarization, a second larger-size LIPSS feature with periodicities between about 1300 and 2200 nm is observed at medium angles. LIPSS lines are oriented perpendicular to the light polarization, except for s-polarization on steel samples, where a rotation of up to 35° is observed. In a two-step process, the LIPSS are replicated in polymers. We investigate the attachment of Schwann cells and fibroblasts seeded thereon, which show no direct dependence on the variation in the LIPSS periodicities. Full article

Polar Stratospheric Clouds (PSC) have been observed by the lidar observatory at Concordia station since 2014. The Concordia lidar is one of a few primary lidar stations in Antarctica of the Network for the Detection of Atmospheric Composition Change (NDACC). The lidar system was deployed at McMurdo from 2004 to 2010 and has been upgraded before its installation at Concordia. Concordia station is one of the most favourable locations for the observation of polar stratospheric clouds, due to the limited cloud cover by tropospheric clouds and the ubiquitous presence of PSCs throughout the Antarctic winter. The PSCs observations have been synchronized with the overpasses of satellite borne lidars, CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) on the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) satellite from 2014 to June 2023, and the Atmospheric Lidar (ATLID) on the EarthCARE (Earth, Cloud, Aerosol and Radiation Explorer) mission since September 2024. A modified v2 algorithm, used for the detection and classification of PSCs as observed by CALIOP, has been used to determine detection limits and classification criteria. This facilitates comparison with CALIOP PSC profiles during quasi-coincident overpasses of the CALIPSO with respect to Concordia station. A local PSC climatology has been produced, with typically more than 150 profiles per PSC season. Considerable inter-annual variations have been observed, mostly depending on the local temperature. The data have been used to infer a decadal trend of PSC occurrences, although the large inter-annual variability renders such an approach difficult. The occurrences of the different PSC types show a strong correlation with the local temperature and depend on the formation processes and the formation temperatures of the different PSCs. Full article

The effect of Mn addition on the structural, dielectric, ferroelectric, and mechanical properties of Bi_0.5Na_0.5TiO₃ (BNT) and 0.94(Bi_0.5Na_0.5TiO₃)–0.06(BaTiO₃) (BNT–BT) ceramics was systematically investigated under identical processing conditions. Powders were calcined at 750 °C for 2 h and 900 °C for 2 h, followed by sintering at 1060 °C for 5 h. Mn contents of 0.5 and 5 mol% were selected to represent low-level substitution and near-saturation regimes. XRD confirmed single-phase perovskite formation within laboratory detection limits, while Raman spectroscopy revealed Mn-induced lattice distortions. Low Mn addition (0.5 mol%) enhanced densification and improved remanent polarization in BNT–BT (Pr = 33.5 μC/cm²). In contrast, 5 mol% Mn promoted grain coarsening, increased porosity, and reduced functional performance. Mechanical properties evaluated using two-parameter Weibull statistics showed composition-dependent variations in characteristic hardness and elastic modulus. The results demonstrate that Mn-doping effects depend strongly on both dopant concentration and host-lattice structural state, distinguishing beneficial substitution from defect-saturation behavior in lead-free BNT-based ceramics. Full article