Search Results (1,650)

Objective: To explore radiomic texture features from multi-phase contrast-enhanced CT as potential predictors of microvascular invasion (MVI) in hepatocellular carcinoma (HCC). Materials and Methods: This exploratory single-center study retrospectively analyzed 49 patients (54 HCC lesions) who underwent liver resection between 2018–2022. Radiomic analysis extracted 642 features across arterial, venous, and delayed phases using original and 5 mm-expanded tumor margins. Results: The 20–50 mm lesion subgroup (n = 37) provided the most reliable results, with arterial phase texture homogeneity features achieving AUC 0.772. Features from lesions <20 mm (n = 14, 4 MVI+) showed clear evidence of overfitting and were excluded from primary analyses. Delayed phase features showed preliminary associations (AUC 0.8) in a small LR-3/4 subset (n = 20). Limitations: This hypothesis-generating study has significant limitations including small sample size, single-center design, and lack of correction for multiple comparisons. Conclusions: Multi-phase CT radiomic analysis shows potential for MVI prediction in intermediate-sized HCC lesions, though external validation in larger cohorts is essential before clinical application. Full article

Since mechanical processing can introduce stress in the sample, electrochemical dissolution has been utilized to attain shape accuracy in certain materials. However, this technique is rarely applied to laser-repaired Ni-based single-crystal superalloys. In this work, the transpassive dissolution behaviors of an additive manufacturing-repaired Ni-based single crystal superalloy in a 10% NaNO₃ solution were investigated by comparison with the substrate. A significant disparity in dissolution rates was found between the dendritic and interdendritic regions of the substrate, resulting in a rough surface. Conversely, the dissolution of the dendritic and interdendritic regions in the cladding structure occurred nearly simultaneously, leading to a high-quality, smooth surface. This behavior was attributed to the differences in phase dissolution preferences between the substrate and the cladding structure. It indicates that electrochemical dissolution is a promising method for achieving shape accuracy in laser-clad Ni-based single-crystal superalloys. Full article

Piezoelectric materials are fundamental elements in modern science and technology due to their unique ability to convert mechanical and electrical energy bidirectionally. They are widely employed in sensors, actuators, and energy-harvesting systems. In this work, we investigate the behavior of commercial lead zirconate titanate (PZT) sensors under frequency-mode excitation using a combined approach of impedance spectroscopy and optical interferometry. The impedance spectra reveal distinct resonance–antiresonance features that strongly depend on geometry, while interferometric measurements capture dynamic strain fields through fringe displacement analysis. The strongest deformation occurs near the first kilohertz resonance, directly correlated with the impedance phase, enabling the extraction of an effective piezoelectric constant (~40 pC/N). Moving beyond the linear regime, laser-induced excitation demonstrates optically driven activation of piezoelectric modes, with a frequency-dependent response and nonlinear scaling with optical power, characteristic of coupled pyroelectric–piezoelectric effects. These findings introduce a frequency-mode approach that combines impedance spectroscopy and optical interferometry to simultaneously probe electrical and mechanical responses in a single setup, enabling non-contact, frequency-selective sensing without surface modification or complex optical alignment. Although focused on macroscale ceramic PZTs, the non-contact measurement and activation strategies presented here offer scalable tools for informing the design and analysis of piezoelectric behavior in micro- and nanoscale systems. Such frequency-resolved, optical-access approaches are particularly valuable in the development of next-generation nanosensors, MEMS/NEMS devices, and optoelectronic interfaces where direct electrical probing is challenging or invasive. Full article

(Bi_0.5Na_0.5)TiO₃-based lead-free ferroelectric ceramics are among the most extensively researched energy storage materials today. In this paper, (1 − x)Bi_0.46Sr_0.06Na_0.5TiO_3−xCaTiO₃ ceramics were synthesized through a solid-phase sintering method by synergistically adjusting CaTiO₃ components after introducing Sr²⁺ at the A-site. The XRD patterns revealed that all samples formed a single perovskite solid solution, with the 111 and 200 peaks shifting to higher levels as the CaTiO₃ increased, indicating a gradual decrease in cell volume. The SEM images exhibited dense crystals without any apparent porosity, which were formed by the different components of the ceramics. Through energy storage, dielectric, and charge–discharge performance tests, it was found that with a 10%mol CaTiO₃ addition, the samples obtained a maximum breakdown field strength of 260 kV/cm and corresponding saturation polarization strength of 32.80 μC/cm² and thereby exhibited a reversible energy storage density valued 3.52 J/cm³. In addition, the dielectric constant varied by less than 10% within the temperature range of 63.7 °C to 132.7 °C and presented good frequency (10–250 Hz) stability at 180 kV/cm. Moreover, the ceramics demonstrated a maximum current density reaching 349.58 A/cm² and a maximum power density of 18.90 MW/cm³ for their charge–discharge performance, all of which makes them suitable for pulse system applications. Full article

This article reports on the synthesis and physicochemical characterization of a novel complex ferrite material, LiCr₃.₄Fe₁.₆O₈, prepared via the sol-gel method. X-ray diffraction (XRD) analysis confirmed that the synthesized compound is a single-phase material with a spinel-type structure and cubic symmetry. Raman spectroscopy was employed to investigate the vibrational modes, and the observed peaks corresponding to Fe–O and Cr–O bonds further validated the spinel-like structure of the compound. The microstructure and elemental composition were examined using scanning electron microscopy (SEM). Multiple regions of the LiCr₃.₄Fe₁.₆O₈ crystals were analyzed, revealing a homogeneous phase and providing detailed insight into the morphology and chemical composition of the surface. The synthesized ferrite particles exhibited relatively large dimensions, with sizes measured at approximately 5, 30, 100, and 200 μm. The dielectric behavior was studied to assess the material’s response to an external electric field, demonstrating its capacity for electric charge polarization. Both capacitance and electrical conductivity were found to increase with rising temperature. Electrophysical measurements were conducted using the LCR-800 system over a temperature range of 293–483 K and at frequencies of 1.5 kHz and 10 kHz. An increase in frequency to 10 kHz resulted in a decrease in the dielectric constant (ε) across the entire temperature range. Full article

Advancements in flexible, low-cost, and recyclable alternatives to transparent conductive oxides (TCOs) are critical challenges in the sustainability of third-generation solar cells. This work introduces a copper mesh-based transparent electrode for dye-sensitized solar cells, replacing conventional fluorine doped-tin oxide (FTO)-coated glass to simultaneously reduce spectral reflection losses, enhance mechanical flexibility, and enable material recyclability. Titanium dioxide (TiO₂) photoanodes were synthesized and directly deposited onto the mesh via a single-step, low-energy ball milling process, which eliminates TiO₂ paste preparation and high-temperature annealing while reducing fabrication time from over three hours to 30 min. Structural and surface analyses confirmed the deposition of high-purity anatase-phase TiO₂ with strong adhesion to the mesh branches, enabling improved dye loading and electron injection pathways. Optical studies revealed higher visible light absorption for the copper mesh compared to FTO in the visible range, further enhanced upon TiO₂ and Ru-based dye deposition. Electrochemical measurements showed that TiO₂/Cu mesh electrodes exhibited significantly higher photocurrent densities and faster photo response rates than bare Cu mesh, with dye-sensitized Cu mesh achieving the lowest charge transfer resistance in impedance analysis. Techno–economic and sustainability assessments revealed a decrease of 7.8% in cost and 82% in CO₂ emissions associated with the fabrication of electrodes as compared to conventional TCO electrodes. The synergy between high conductivity, transparency, mechanical durability, and a scalable, recyclable fabrication route positions this architecture as a strong candidate for next-generation dye-sensitized solar modules that are both flexible and sustainable. Full article

As freely available but not yet commercially acquired biomass resource, water care material (WCM) is generated seasonally in the periodic maintenance of surface water bodies and consists of mainly aquatic and/or rural-associated biomass of the water body profile, as well as wood, soil substrate, water or other possible impurities. In addition to other recovery options, such as composting or utilization in biogas production, hydrothermal carbonization (HTC) was selected as a thermochemical process because it is suitable for converting biomass with a high content of carbon into high-quality combustibles. The biomass sample used in this investigation was obtained during a single sampling event from a small stream in the North German lowlands. The material was pretreated by shredding it to a particle size of <0.12 mm. Through a 5 L stirred reactor, hydrothermal treatments were performed under low temperature conditions (200, 220 and 240 °C), residence times (120, 180, 240 min) and solid dry matter of the sample content: 6%. Solid phase was evaluated in terms of calorific value and proximate and ultimate analysis. The results suggested that the hydrothermal carbonization of WCM gave a high heating value of 23.84 MJ/kg for its char after being dried for 24 h at 105 degrees. At the same time, biochar can be used in agriculture to improve soil properties. To understand to what extent the product is suitable for soil amendment, the surface and the nutrient content of the resulting hydrochar were analyzed in detail. As the initial material is rich in fiber contents, process temperatures up to 240 °C have a huge impact on effective particle size. Furthermore, the analysis of selected nutrients, minerals and heavy metals shows the suitability of the produced hydrochar for soils in accordance with current legislation. Full article

This study evaluates the effect of printing orientation on the wear resistance of 3D-printed nylon fabricated via Fused Deposition Modeling (FDM). We conducted abrasive wear resistance tests, thermal analysis, and microstructural characterization using scanning electron microscopy before and after wear testing. The results show that alternating printing directions lead to significantly higher wear. Under a normal load of 130 N, this configuration caused the exposure of up to four layers. At the same time, single-orientation prints exhibit lower material loss and better filament cohesion. DSC analysis reveals that all printed samples, regardless of wear exposure, display dual melting temperatures (T_s1 and T_s2) due to distinct crystalline phase formations. Abrasion decreases the secondary melting temperature (T_s2) and increases enthalpy by up to 144% compared to unprinted nylon, highlighting the thermal history on structural properties. These findings emphasize the critical role of printing configurations in optimizing the tribological performance of 3D-printed nylon for industrial applications. Full article

This study examines binary blends of three types of polyhydroxyalkanoates (PHAs)—poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB)—with a focus on their rheological, thermal, and mechanical behavior. The blends exhibit partial miscibility in both the melt and solid states. Glass transition analysis revealed that semicrystalline/amorphous PHA combinations are fully miscible (single Tg) at amorphous PHA contents below 30 wt%. Above this threshold, a two-phase morphology develops, consisting of crystalline spherulites embedded in an amorphous matrix. When the amorphous PHA content reached ≥30 wt%, the blends could be oriented by stretching, yielding materials that display thermoplastic elastomer (TPE)-like behavior without chemical modification of the base polymers. Thermal and mechanical characterization, supported by X-ray diffraction of samples before and after orientation, confirmed that the elastomeric properties originate from the multiphase architecture formed by crystalline and amorphous domains interconnected through a miscible amorphous fraction. Full article

Monocrystalline silicon, despite its widespread use as a photoelectrode material, is hindered by inherent drawbacks, such as high surface reflectivity, vulnerability to oxide passivation, and instability in aqueous electrolytes. To address these, a micropyramidal texture is fabricated on the silicon surface via wet chemical etching. A heterojunction photoanode was constructed by sequentially depositing NiSe₂ and WO₃ onto the textured silicon using chemical bath deposition, forming NiSe₂/WO₃@SiMPs. The photoanode demonstrates optimal photoelectrochemical performance at a NiSe₂ to WO₃ mass ratio of 9:1. Under simulated solar illumination (AM 1.5 G, 100 mW cm⁻²), it achieves a photocurrent of 5.62 mA cm⁻² at 1.23 V (vs. RHE), and a maximum photocurrent of 13.6 mA cm⁻² at 2.0 V (vs. RHE), markedly outperforming the individual components NiSe₂@SiMPs (8.23 mA cm⁻²) and WO₃@SiMPs (0.95 mA cm⁻²) at 2.0 V (vs. RHE). Electrochemical impedance spectroscopy (EIS) results show a markedly lower charge transfer resistance (Rct) for the NiSe₂/WO₃@SiMPs (8.16 Ω) compared to the single-phase counterparts NiSe₂@SiMPs (121.48 Ω) and WO₃@SiMPs (902.23 Ω), indicating more efficient charge separation. In addition, the photocurrent remains steady for about 10 h without significant degradation. This work presents a promising strategy for improving the photoelectrochemical water splitting efficiency of silicon-based photoelectrodes through rational heterostructure engineering. Full article

Background: The human acellular amniotic membrane (HAAM) is widely used as a decellularized bioscaffold in tissue engineering to promote wound healing, but its clinical application is limited by poor mechanical properties, rapid degradation, and handling difficulties. This study aimed to develop a modified amniotic membrane-based composite material loaded with vascular endothelial growth factor (VEGF) and the Notch signaling inhibitor N-[N-(3,5-difluorophenacetyl)-Lalanylhydrazide]-Sphenylglycine t-butyl ester (DAPT) to enhance wound healing by modulating macrophage polarization and cytokine secretion. Methods: VEGF-loaded gellan gum-hyaluronic acid (GG-HA) hydrogels (VEGF-GG-HA) and DAPT-loaded HAAM (DAPT-HAAM) were prepared and combined to form a novel composite material (VEGF-GG-HA & DAPT-HAAM). The morphology and microstructure of the materials were characterized using scanning electron microscopy. In vitro studies were conducted using the human monocytic cell line (Tohoku Hospital Pediatrics-1, THP-1) to evaluate the effects of the materials on cell viability, cytokine secretion, and protein expression. Assessments included CCK-8 assays, ELISA, quantitative real-time PCR, Western blot analysis, and immunohistochemical staining. Results: The composite material VEGF-GG-HA & DAPT-HAAM exhibited good biocompatibility and significantly promoted THP-1 cell proliferation compared to control and single-component groups. It enhanced the secretion of IL-10, TNF-α, TGF-β, MMP1, and MMP3, while suppressing excessive TGF-β overexpression. The material also modulated macrophage polarization, showing a trend toward anti-inflammatory M2 phenotypes while maintaining pro-inflammatory signals (e.g., TNF-α) for a balanced immune response. Conclusions: The modified amniotic membrane hydrogel composite promotes wound healing through a phased immune response: it modulates macrophage polarization (balancing M1 and M2 phenotypes), enhances cytokine and matrix metalloproteinase secretion, and controls TGF-β levels. These effects contribute to improved vascular remodeling, reduced fibrosis, and prevention of scar formation, demonstrating the potential for enhanced wound management. Full article

The rapid proliferation of electric vehicles (EVs) demands lightweight yet efficient battery thermal management systems (BTMS). The fin-embedded phase-change material energy storage tube (PCM-EST) offers significant potential due to its high thermal energy density and passive operation, but conventional designs face a critical trade-off: enhancing heat transfer typically increases mass, conflicting with EV lightweight requirements. To resolve this conflict, this study proposes a multi-objective surrogate optimization framework integrating computational fluid dynamics (CFD) and Kriging modeling. Fin geometric parameters—number, height, and tube length—were rigorously analyzed via ANSYS (2020 R1) Fluent simulations to quantify their coupled effects on PCM melting/solidification dynamics and structural mass. The results reveal that fin configurations dominate both thermal behavior and weight. An enhanced multi-objective particle swarm optimization (MOPSO) algorithm was then deployed to simultaneously maximize heat transfer and minimize mass, generating a Pareto-optimal solution. The optimized design achieves 8.7% enhancement in heat exchange capability and 0.732 kg mass reduction—outperforming conventional single-parameter designs by 37% in weight savings. This work establishes a systematic methodology for synergistic thermal-structural optimization, advancing high-performance BTMS for sustainable EVs. Full article

Rigid–flexible coupled robots hold significant potential for operating in unstructured environments, but a systematic analysis of their actuation strategies across diverse physical fields is notably lacking in the literature. This review addresses this gap by introducing a novel taxonomy based on field-controlled evolutionary pathways—mechanical → electromagnetic → chemical → biohybrid—and critically examining over 100 seminal studies through a six-dimensional framework encompassing design, dynamics, and performance. We demonstrate that hybrid field integration (e.g., pneumatic-chemical synergy) improves grasping robustness by 40% in cluttered environments compared to single-field systems. Notably, biohybrid actuators, which integrate living cells, exhibit over 90% motion similarity to biological models, while phase-transition materials allow for adaptive stiffness tuning (0.1–5 N·mm⁻¹) in medical applications. Radar chart analysis further reveals fundamental trade-offs between energy efficiency, response speed, and scalability across the various fields. These insights provide a clear roadmap for the development of next-generation robots with embodied intelligence, emphasizing multi-field synergies and bio-inspired adaptability. Full article

Al-Zn-Mg-Cu alloys are widely used as heat-treatable ultra-high-strength materials in aerospace structural applications. While conventional single-stage aging enables high strength, advanced performance demands call for precise microstructural control via multi-stage aging. In this study, we employ a combination of scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) to investigate the microstructural evolution and its correlation with mechanical properties of AA7150 aluminum alloy subjected to two-step aging treatments, following a 6 h pre-aging at 120 °C. Through atomic-scale STEM imaging along the [110]_Al zone axis, we systematically characterize the precipitation behavior of GPII zones, η′ phases, and equilibrium η phases both within the grains and at grain boundaries under varying secondary aging (SA) conditions. Our results reveal that increasing the SA temperature from 140 °C to 180 °C leads to coarsening and reduced number density of intragranular precipitates, while promoting the continuous and coarse precipitation of η phases along grain boundaries, accompanied by a widening of the precipitation-free zone (PFZ). Notably, SA at 160 °C induces the formation of fine, uniformly dispersed nanoscale η′ precipitates in the alloy, as confirmed by XRD phase analysis. Aging at this temperature markedly enhances the mechanical properties, achieving an ultimate tensile strength (UTS) of 613 MPa and a yield strength (YS) of 598 MPa, while presenting an exceptionally broad peak-aging plateau. Owing to this feature, a moderate extension of the SA duration does not reduce strength and can further improve ductility, increasing the elongation (EL) to 14.26%. These results demonstrate a novel two-step heat-treatment strategy that simultaneously achieves ultra-high strength and excellent ductility, highlighting the critical role of advanced electron microscopy in elucidating phase-transformation pathways that inform microstructure-guided alloy design and processing. Full article

Background and Objectives: This study aimed to compare target volumes and organ-at-risk (OAR) doses using five different volume definitions in radiotherapy (RT) planning of patients with glioblastoma multiforme (GBM). Materials and Methods: Rigid image fusion was performed using simulation computed tomography and postoperative magnetic resonance imaging scans of 20 patients with GBM. Volumetric modulated arc therapy (VMAT) plans were generated according to three two-phase protocols—American Brain Tumor Consortium (ABTC), North Central Cancer Treatment Group/Alliance (NCCTG/Alliance), and Radiation Therapy Oncology Group/NRG (RTOG/NRG)—and two single-phase protocols—European Organisation for Research and Treatment of Cancer (EORTC) and European Society for Radiotherapy and Oncology–European Association of Neuro-Oncology (ESTRO/EANO)—each delivering a total dose of 60 Gy. OARs and dose constraints were evaluated. Statistical analysis was performed using the paired sample t-test. Results: The ESTRO/EANO volume had the smallest median PTV overall (p < 0.001). The lowest brain-PTV Dmean in the initial phase was observed in the ABTC group, followed closely by ESTRO/EANO (p < 0.001). Among boost volumes, the ABTC volume was the smallest, and the median brain-PTV Dmean was lowest in the ESTRO/EANO volume. ESTRO/EANO provided the lowest doses for contralateral and ipsilateral cochlea Dmean, brainstem D1cc, and contralateral lens Dmax. Notably, both EORTC and ESTRO/EANO plans maintained OAR doses within acceptable constraints, with ESTRO/EANO achieving the most consistently minimised exposure. Conclusions: Reduced irradiated brain volume, acceptable OAR preservation and practical applicability, the use of ESTRO-EANO and EORTC target volumes in radiotherapy of glioblastoma multiforme may provide dosimetric advantages that require further validation in clinical outcome studies. Full article