Search Results (731)

The segregation of brittle Laves phases remains a critical bottleneck limiting the performance of additive manufacturing (AM) nickel-based superalloys. While its evolution is governed by complex transient physical fields within the melt pool, a quantitative kinetic correlation between processing parameters and microstructural features is currently lacking. In this study, a high-fidelity multiphysics numerical model was developed to establish a cross-scale mapping logic of “Process-Physical Field-Microstructure” by dissecting the global distribution of temperature gradient (G) and solidification rate (R) along the quasi-steady-state melt pool boundary. It is revealed that increasing the scanning speed synergistically enhances R while compressing G. Beyond driving a transition from oriented columnar dendrites to refined mixed-dendritic structures, this shift effectively blocks the continuous enrichment channels of Nb and Mo elements by compressing the “kinetic time window” for solute redistribution. Consequently, the morphology of the Laves phase is forced to evolve from a continuous interconnected chain-like network into dispersed isolated particles. This research clarifies the kinetic essence of microstructural evolution under non-equilibrium solidification, providing critical physical criteria for the precise intervention of deleterious phases and the regulation of microstructural consistency in high-performance AM components. Full article

Hemispheric asymmetries in the cortical structure and function are well documented, but whether this asymmetry is reflected in the electrophysiological properties of the same neuron type remains unclear, particularly given the many factors that influence action potential (AP) generation. Among these factors, dendritic tree size plays a crucial role in AP generation and in forward and backward propagation, yet it is not well understood whether dendritic size affects spike generation similarly in the two hemispheres. Here, electrophysiological recordings of layer 6a corticothalamic (CT) pyramidal neurons from a mouse’s left and right primary visual cortex were analyzed to examine how apical dendrite integrity influences somatic AP properties. Neurons were divided into four groups based on hemisphere and apical dendrite status (intact vs. truncated), and the AP shape parameters were quantified in response to current stimulation. Intact CT neurons showed similar AP rapidity and width across hemispheres but differed in AP threshold and amplitude. In contrast, a comparison of the intact and truncated neurons within each hemisphere revealed significant and opposing effects of apical dendrite truncation on all AP parameters. These results suggest that the coupling between dendritic morphology and somatic AP generation differs between hemispheres, implying distinct rules for integrating dendritic load in the left and right CT neurons. Full article

Submarine canyon-channel systems play a critical role as potential conduits for warm-water upwelling around Antarctica, potentially influencing ice-sheet stability. Integrating multibeam bathymetry, seismic profiles, and morphometric analysis, this study identifies 29 canyon-channel systems along the Adélie Land margin and reveals clear morphological contrasts between the Adélie Depression and the Adélie Bank. Systems in the Depression are elongated, slightly sinuous, and dendritic, with downstream increases in width-to-depth ratio, whereas those on the Bank are shorter, isolated, and single-branched, with irregular along-thalweg variations. Mann–Whitney U tests show significant differences in sinuosity and thalweg gradient (p < 0.01). These contrasts reflect the combined effects of shelf-slope topography, sediment supply, and ice-sheet dynamics. In the Depression, steep slopes, focused glacial sediment input from the Wilkes Subglacial Basin, and associated progradational wedges and mass transport deposits promote mass failures and turbidity-current incision. Strong correlations among canyon-channel length, width, and depth indicate coherent scaling under concentrated sediment supply. In contrast, gentler slopes and lower sediment input on the Bank produce simpler systems. These results highlight how glaciated-margin canyon morphology records coupled sedimentary and ice-sheet–ocean processes. Full article

Alzheimer’s disease (AD) is increasingly recognized as a disorder not only of cognition but also of motivation and emotional regulation. Apathy and anhedonia often precede memory deficits, implicating early dysfunction in reward-related circuits. This study investigated whether chronic infusion of palmitoylethanolamide (PEA), a lipid-derived PPARα agonist, could restore motivational behavior and dendritic plasticity in the Tg2576 mouse model of AD. The motivational behavior of mice that received sustained-release PEA pellets for 6 months was assessed by using the conditioned place preference (CPP) paradigm. Morphological and molecular analyses were conducted in the entorhinal cortex (EC), dentate gyrus (DG), and prefrontal cortex (PFC). In Tg2576 mice, PEA significantly rescued CPP performance, increased basal dendritic spines in WT mice in the EC, and both basal and apical dendritic expression in EC and DG from Tg2576 mice, and upregulated the expression of both PPAR-α and brain-derived neurotrophic factor (BDNF) in the PFC. Interestingly, the BDNF increase occurred even in the absence of baseline deficits, suggesting a trophic-enhancement effect. These findings suggest that the PEA-PPARα-BDNF axis may be a potential mechanism for restoring motivation and synaptic integrity in an AD-like mouse model. Lipid-based neuromodulation may therefore offer novel therapeutic routes for addressing non-cognitive symptoms and affective circuitopathy in neurodegenerative diseases. Full article

Nickel-based superalloy GH3625 is widely used in extreme environments due to its exceptional high-temperature strength and corrosion resistance; however, optimizing its comprehensive performance through precise microstructural control remains a critical challenge. In this study, the effect of withdrawal rate (10–200 μm/s) on the microstructural evolution, mechanical properties, and corrosion resistance of GH3625 alloy was investigated using a liquid-metal-cooled directional solidification system. The microstructural characteristics, elemental segregation, and phase distributions were systematically analyzed via OM, SEM, and EDS, followed by uniaxial tensile and electrochemical polarization tests. The results show that with increasing withdrawal rate, the solid–liquid interface morphology evolves from cellular to cellular-dendritic and finally to fully dendritic. Correspondingly, the primary dendrite arm spacing decreases from 270.4 μm to 100.2 μm, and the secondary dendrite arm spacing decreases from 66.5 μm to 12.3 μm. The area fraction of the detrimental Laves phase first decreases and then increases, reaching a minimum at 100 μm/s. Correspondingly, the yield strength increases from 282 MPa to 409 MPa, and the corrosion resistance is optimized at 100 μm/s. The microstructure–property relationships are discussed based on second-phase strengthening theory and microstructural refinement. This study provides a theoretical basis and practical process windows for optimizing directional solidification parameters to achieve enhanced mechanical and corrosion performance in GH3625 alloy. Full article

Objectives: To analyze changes in ocular dendritic cells and their correlation with signs of keratitis in patients with herpes simplex stromal keratitis (HSK) using in vivo confocal microscopy (IVCM). Methods: This was a retrospective, cross-sectional, controlled, single-center study. Fifty-nine eyes from 59 patients with HSK and 40 eyes from 40 control subjects were studied. Each patient underwent IVCM and slit-lamp examinations. The density, area, size, and number of dendritic cells (DCs) in the corneas of both groups were analyzed. The severity of HSK was assessed, and the morphology and density of DCs in the cornea in the HSK group, categorized by ocular parameter severity levels, were compared with those in the control group. Results: DC density was significantly greater in patients with HSK than in controls. The DC field and size and the number of branches were also significantly greater in the HSK group. Furthermore, the DC density increased and morphological changes were exacerbated with increasing degree of corneal edema. The DC density was significantly increased and morphological changes were significantly exacerbated in the HSK group compared to the control group, even in those with the mildest cases of HSK. Conclusions: DC density and morphological changes correlate with the degree of corneal edema in patients with HSK. Changes in DC density and morphology can be observed even in mild cases of HSK. IVCM may be a powerful tool for monitoring ocular surface immune responses in patients with HSK, aiding in the clinical diagnosis and management of this disease. Full article

Elucidating the pathophysiological mechanisms of mental disorders remains a critical challenge in psychiatric research. Recent studies have highlighted the potential involvement of cytoskeletal and molecular motor abnormalities in the development of mental disorders such as schizophrenia and autism spectrum disorder (ASD). Although schizophrenia and ASD differ clinically, both disorders are increasingly regarded as neurodevelopmental conditions and share vulnerabilities in synapse formation and neural circuit maturation. This review synthesizes the latest findings on the relationship between cytoskeletal and molecular motor abnormalities and mental disorders. The cytoskeleton, composed of microtubules, actin filaments, and intermediate filaments, along with molecular motors such as kinesins, dyneins, and myosins, plays crucial roles in neurodevelopment, synapse formation, and neurotransmission. In schizophrenia, decreased expression of the microtubule-associated protein MAP2 and abnormalities in the DISC1 gene have been reported, potentially leading to dendritic morphological abnormalities and neurodevelopmental disorders. Additionally, abnormalities in molecular motors such as KIF17 and KIF1A have been implicated in schizophrenia pathophysiology. Myosin Id has been identified as a risk gene for ASD. Furthermore, abnormalities in actin-related proteins such as SHANK3 and CYFIP1 have been shown to cause synaptic dysfunction. These findings suggest that mental disorders arise from complex pathologies involving multiple cytoskeletal and molecular motor-related protein abnormalities. Future research should focus on elucidating the functions of individual proteins and adopting a comprehensive approach that includes glial cells. Advances in this field may deepen our understanding of the pathophysiological mechanisms of mental disorders and potentially lead to the development of novel therapeutic strategies. Full article

The demand for high-energy-density and fast-charging solid-state lithium metal batteries (SSLMBs) often subjects practical devices to internal thermal loads, making high-temperature operation a common operational condition rather than an isolated scenario. To address the interfacial degradation and dendrite growth accelerated by such thermomechanical stresses, we developed a composite gel electrolyte (CGE) by incorporating an optimal concentration of active Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) into a fluoropolymer network. The abundant Lewis acidic sites on the LLZTO surfaces promote competitive solvation decoupling by interacting with anions, thereby modulating the primary solvation sheath of Li⁺. This localized modulation lowers the lithium-ion migration activation energy to 0.248 eV and facilitates a dual-interfacial passivation mechanism. Specifically, a rigid, inorganic-rich solid electrolyte interphase (SEI) forms to suppress morphological instability at the lithium anode, while an organic-dominated cathode electrolyte interphase (CEI) enhances the oxidative stability up to 4.3 V. As a result, symmetric cells demonstrate stable electrodeposition for over 450 h at 80 °C and 0.5 mA cm⁻². Furthermore, NCM811/Li full cells utilizing this CGEs exhibit significantly improved thermal resilience and cycling stability. Full article

Objectives: To assess diurnal changes, topographical differences, and day-to-day repeatability of ocular surface epithelial immune cell (EIC) density and morphology in dry eye disease (DED). Methods: Sixteen participants with moderate-to-severe DED (mean (SE) age 49.4 (4.2) years) underwent in vivo confocal microscopy at three timepoints (day-1 morning and evening and day-2 morning) at six locations: central cornea, inferior whorl, inferior cornea, and temporal cornea, limbus and conjunctiva. Diurnal and topographical variation in EIC density and morphology were analyzed using linear mixed-effects models with adjusted pairwise comparisons. Day-to-day repeatability was assessed using the coefficient of repeatability (CoR) for density and Cohen’s kappa for morphology. Results: EIC density and morphology varied by location (p < 0.001) but not by timepoint at any location (p = 0.59–0.90). Density was highest at the inferior cornea (model-estimated mean: 101.2 (SE: 21.7) cells/mm²) and temporal limbus (104.3 (22.7) cells/mm²), and lowest at the central cornea (26.8 [5.1] cells/mm² and inferior whorl (38.3 [8.2] cells/mm²; all pairwise, p < 0.001). EICs with large bodies were more frequent in conjunctiva (100%), inferior cornea (94%), and temporal cornea (87%), than in central cornea (34%) and whorl (19%) (all p ≤ 0.007). EICs with dendrites, and with long dendrites were similarly distributed (p < 0.001). Bland–Altman analysis showed low mean bias and EIC density was more repeatable at the central (CoR ± 23.8 cells/mm²) and temporal cornea (±27.5 cells/mm²) than the inferior cornea (±47.9 cells/mm²) or temporal conjunctiva (±42.3 cells/mm²). Morphology agreement was substantial to near-perfect (κ = 0.71–0.97). Conclusions: In DED, EIC density and morphology are diurnally stable and maintain topographic distribution patterns similar to healthy eyes. Day-to-day repeatability show location dependent patterns. The study provides feasibility data for using IVCM for EIC metrics in disease monitoring. Full article

Precise control over the physicochemical and biological properties of colloidal particles is essential for the rational design of functional soft materials. In this work, we report a simple and scalable strategy for generating modular dendron particles (MDPs) through the self-assembly of fully characterized small-molecule Bis-MPA dendrons that act as programmable molecular building blocks for colloidal particle formation. By systematically varying three structural domains—the inner functionality, methylene spacer length, and outer connector—we achieve tunable formation of MDPs ranging from nano- to microscale dimensions. Upon solvent evaporation under mild drying conditions, pre-assembled MDPs act as structure-directing seeds that guide the emergence of hierarchical surface morphologies with spiky, scaly, or spherical protrusions, depending on dendron architecture. Importantly, these assemblies exhibit good biocompatibility toward non-tumoral bronchial epithelial (NL-20) cells while displaying selective cytotoxicity toward Neuro-2a neuroblastoma cells, demonstrating that dendron molecular architecture alone can govern particle size, morphology, and biological response without external drug loading. Collectively, these findings highlight modular Bis-MPA dendrons as versatile building blocks for directing particle size, morphology, and biological response through controlled self-assembly and evaporation-driven structuring. Full article

The etiology of autism spectrum disorder (ASD) implicates genetic predispositions and environmental chemicals, such as polybrominated diphenyl ethers (PBDEs). We aimed to identify whether mitochondrial quality control (MQC) was involved in ASD-relevant behavioral changes induced by decabromodiphenyl ether (deca-BDE, BDE-209) and the alleviation by melatonin. Pregnant rats exposed to BDE-209 (50 mg/kg i.g.) were administrated melatonin through drinking water (0.2 mg/mL) during gestation and lactation. Behavioral assessments integrated open-field test, three-chamber social test, and Morris water maze; mitochondrial detections took transmission electron microscopy, immunofluorescence, and homeostasis together; hippocampal molecular network was identified through transcriptomics profiles, combining dendritic morphology analysis after Golgi-Cox staining. Melatonin supplementation attenuated BDE-209-reduced social and cognitive ability, accompanied by improvements in hippocampal synaptic plasticity (dendritic spines, PSD95, SNAP25). Mitochondrial dysfunctions, shown as decreases in complex IV activity, ATP content, and mtDNA copies, plus redox imbalance (ROS/SOD2) and resultant mitochondrial membrane potential disruption and apoptosis, together with fusion/fission dynamic (MFN2/DRP1), biogenesis (SIRT1-PGC1α-TFAM), and mitophagy (SIRT3-FOXO3-PINK1) suppression, were reversed by melatonin partially through SIRT1 (Sirtuin-1)-dependent pathways, as these protections were abolished by inhibitor EX527. This study highlighted the SIRT1–SIRT3 axis in MQC and behavioral effects, providing novel intervention for PBDEs’ neurodevelopmental impairment. Full article

The microstructural evolution and tensile behavior of Inconel 617 welded joints produced by gas tungsten arc welding (GTAW) with ERNiCrCoMo-1 filler were systematically investigated. Detailed microstructural characterization revealed that Cr-rich M₂₃C₆ and Ti-rich MC carbides are the dominant precipitates, while Mo-rich M₆C forms locally along grain boundaries after thermal exposure. The fusion and weld zones exhibit fine dendritic morphologies with uniformly distributed precipitates, resulting in significant strengthening through precipitation and dislocation–pinning mechanisms. Owing to the low heat input and compositional compatibility between the weld and base metals, the heat-affected zone remains extremely narrow and free of compositional transitions. The welded joint attains tensile strengths of 920 MPa at room temperature and 605.5 MPa at 750 °C, corresponding to joint efficiencies of 117% and 121%, respectively, with fracture consistently occurring in the base metal. Deformation analysis shows that plasticity at room temperature is governed by planar slip and dislocation entanglement, whereas deformation twinning predominates at elevated temperatures owing to the reduced stacking-fault energy and the pinning effect of M₂₃C₆ carbides. These results provide key insights into the deformation and strengthening mechanisms controlling the high-temperature performance of GTAW-welded Inconel 617 joints and offer guidance for their application in advanced nuclear and high-temperature energy systems. Full article

Anode-less battery architectures, which eliminate the host anode material, have attracted considerable attention as a promising approach to increase energy density, simplify cell manufacturing, and improve safety in next-generation energy storage systems. This review provides a structured and integrative overview on the current research landscape of anode-less cells, spanning both liquid- and solid-electrolyte technologies. It first introduces the fundamental principles, key advantages, and inherent challenges of the anode-less concept. Advanced characterization techniques, including electrochemical, interfacial, morphological, and operando approaches, are then discussed as essential tools for probing metal plating/stripping behavior and degradation mechanisms. The core of the review examines how system design governs performance, addressing strategies for liquid electrolytes, including current collector design, electrolyte formulation, and deposition control, as well as solid electrolytes, with an emphasis on interfacial engineering, fundamental limitations, and extensions to Na- and K-based batteries. By integrating insights across these systems, the review identifies critical challenges, including unstable solid-electrolyte interphases, dendrite formation, and interfacial contact loss. Finally, a development pyramid is introduced as a conceptual framework linking fundamental research to practical implementation, outlining key priorities from interface control and full-cell compatibility to long-term reliability while also highlighting industrial pathways toward hybrid and fully solid-state anode-less batteries. Full article

A Cu-containing FeCrMnNiAl multi-principal element alloy was processed by laser-based and electron beam-based powder bed fusion (PBF-LB/M and PBF-EB/M) to investigate processing–microstructure–property relationships. In focus were alloy variants with a relatively high Cu content. Two PBF-LB/M scan strategies, employing a Gaussian beam with and without a re-scan with a laser featuring a flat-top profile, were compared to PBF-EB/M processing, followed by heat-treatments between 300 °C and 1000 °C. The phase constitution, elemental partitioning and grain boundary characteristics were analyzed by X-ray diffraction, electron backscatter diffraction and energy-dispersive X-ray spectroscopy. Mechanical behavior was assessed by hardness and tensile testing. Both manufacturing routes promoted the evolution of stable multi-phase microstructures composed of face-centered-cubic (FCC)- and body-centered-cubic (BCC)-type phases across all heat-treatment conditions. PBF-LB/M processing resulted in finer, dendritic microstructures and suppressed formation of a Cu-rich FCC phase due to higher cooling rates, whereas PBF-EB/M promoted the evolution of Cu-rich FCC segregates and equiaxed grain morphologies. Heat-treatment above 700 °C led to recrystallization, accompanied by an increase of the FCC phase fraction, grain coarsening, and recovery. At lower heat-treatment temperatures, the changes in microstructure are different. Here, it is assumed that small, non-clustered Cu-rich precipitates formed at the grain and sub-grain boundaries, although this assumption is only based on the assessment of the mechanical properties. The size of these precipitates is below the resolution limit of the techniques applied for analysis in the present work. Additional structures seen within the Cu-rich areas of PBF-EB/M-manufactured samples treated at lower temperatures also seem to have an influence on the hardness and yield strength. All of the conditions investigated exhibited pronounced brittleness, limiting reliable tensile property evaluation and indicating the need for further optimization of processing strategies and microstructural control for high-Cu-fraction-containing multi-principal element alloys. Full article

In the present study, the electrodeposition of thin Ni–Fe films obtained from aqueous electrolytes containing nickel (II) and iron (II) sulfates and chlorides is investigated. The study particularly emphasizes the influence of electrolyte additives—boric acid, chloride ions, and Na₂EDTA—on the electrochemical behavior, microstructure, and magnetic properties of the deposited layers. Cyclic voltammetry revealed a partial alignment of the reduction potentials of nickel and iron and the suppression of the hydrogen evolution side reaction up to −1 V. Electrodeposition in galvanostatic mode in the range of 0.5 to 1.0 A/dm² allows the formation of layers with iron contents between 20.5 wt. % to 41.4 wt. % and coating thickness from 1.3 to 3.0 µm. SEM and AFM observations demonstrated a pronounced dependence of the surface morphology on the current density, with higher current densities promoting the formation of dendritic structures. X-ray diffraction confirmed the dominance of a face-centered cubic (FCC) Ni-based solid solution, accompanied by minor contributions from non-stoichiometric Fe_1−xO. All the obtained Fe-Ni films have soft magnetic properties. Increasing the current density and the boric acid concentration causes the coercive force and isotropy of the layers to improve. The results demonstrate that thin Ni-Fe films with controlled structure and morphology, with favorable soft ferromagnetic properties suitable for functional applications, could be electrodeposited from complex chloride–sulfate electrolytes by adjusting the current density. Full article