Search Results (9,215)

This work investigates the corrosion behavior of 18%Ni high-strength steel (00Ni18Co-8Mo5TiAl, solution-treated at 820 °C for 3 h and aged at 480 °C for 3 h) in NaCl solutions with 1%, 3.5%, and 6% chloride ions, as well as chloride ions’ effect on passive film properties. The corrosion process was systematically studied via chemical immersion tests (GB/T 17897-1999, 144 h, solution-to-sample contact area ratio 20:1) and electrochemical methods, including EIS (frequency range: 100 kHz–0.01 Hz) and Tafel polarization curves (scan rate: 10 mV/min). Passive film evolution was analyzed via Mott–Schottky curves (fixed frequency: 1000 Hz, scanning potential: −1 V to 1 V vs. SCE). Microstructural observations show the steel exhibits pitting corrosion in chloride environments, with corrosion products transforming from loose outer α-FeOOH/γ-FeOOH to dense inner Fe₃O₄/β-FeOOH. These dense products inhibit anodic reactions. Electrochemical results reveal polarization resistance decreases and corrosion current density rises with increasing chloride concentration. Mott–Schottky curves indicate that flat band potential increases from −0.2177 V to −0.1258 V with rising chloride concentration, increasing point defects in the passive film and weakening its self-healing ability. Full article

Proteoglycans are macromolecules consisting of a core protein and one or more glycosaminoglycan side chains. Proteoglycans synthesized by vascular endothelial cells modulate various functions such as anticoagulant activity and vascular permeability. We previously reported that some heavy metals interfere with proteoglycan expression, and that organic–inorganic hybrid molecules, such as metal complexes and organometallic compounds, serve as useful tools to analyze proteoglycan synthesis mechanisms. However, the effects of metal compounds lacking electrophilicity on proteoglycan synthesis remain unclear. Au₂₅(SG)₁₈, a nanoscale gold cluster consisting of a metal core protected by gold–glutathione complexes, exhibits extremely low intramolecular polarity. In this study, we investigated the effect of Au₂₅(SG)₁₈ on proteoglycan synthesis in vascular endothelial cells. Au₂₅(SG)₁₈ accumulated significantly in vascular endothelial cells at low cell density and suppressed the expression of perlecan, a major heparan sulfate proteoglycan in cells, by inactivating ADP-ribosylation factor 6 (Arf6). Additionally, Au₂₅(SG)₁₈ reduced the expression of biglycan, a small dermatan sulfate proteoglycan, in vascular endothelial cells at low cell density; however, the underlying mechanisms remain unclear. Overall, our findings suggest that organic–inorganic hybrid molecules regulate the activity of Arf6-mediated protein transport to the extracellular space and that perlecan is regulated through this mechanism, highlighting the importance of Arf6-mediated extracellular transport for maintaining vascular homeostasis. Full article

A method for the second-harmonic generation (SHG) in optical fibers by exploiting the third-order nonlinearity under an external electric field is proposed. The analysis begins with the electric polarization vector of the SHG, and the analytical solution for the SHG is presented. When fiber birefringence is neglected, a mode-field matching condition is introduced. The nonlinearity-induced shift in propagation constant is provided based on Gaussian approximation. For a specific case, the power of SHG is calculated. The results show that the SHG power scales quadratically with the nonlinear coefficient. Reducing the effective area of the fiber and increasing the nonlinear coefficient can enhance the SHG power by 1–2 orders of magnitude. Since phase matching strongly affects the SHG process, optimizing the fiber design is crucial. Additionally, the polarization state of SHG is shown to have the same as the equivalent optical field of the injected fundamental wave. This work demonstrates potential for distributed sensing of electric fields and lightning events in high-voltage power grids using optical fibers. Full article

Lead-free transparent ferroelectric ceramics with integrated opto-electro-mechanical functionalities are pivotal for next-generation multifunctional devices. In this study, K_0.48Na_0.52NbO₃-xLa₂O₃ (KNN-xLa, x = 0.005 − 0.04) ceramics were fabricated via a conventional solid-state route to investigate the La³⁺-induced multiscale structural evolution and its modulation of optical and electrical properties. La³⁺ substitution drives a critical structural transition from an anisotropic orthorhombic phase (Amm2) to a high-symmetry pseudocubic-like tetragonal phase (P4mm) for x ≥ 0.025, characterized by minimal lattice distortion (c/a = 1.0052). This enhanced structural isotropy, coupled with submicron grain refinement (<1 μm) driven by -mediated solute drag, effectively suppresses light scattering. Consequently, a high-transparency plateau (T₇₈₀ ≈ 53–58%, T₁₇₀₀ ≈ 70–72%) is achieved for 0.025 ≤ x ≤ 0.035. Simultaneously, the system undergoes a crossover from normal ferroelectric (FE) to relaxor (RF) state, governed by an FE–RF boundary at x = 0.015. While x = 0.005 exhibits robust piezoelectricity (d₃₃ ≈ 92 pC/N), the x = 0.015 composition facilitates a transitional polar state with large strain (0.179%) and high polarization (P_m ≈ 33.3 μC/cm², P_r ≈ 15.8 μC/cm²). Piezoresponse force microscopy (PFM) confirms the domain evolution from lamellar macro-domains to speckle-like polar nanoregions (PNRs), elucidating the intrinsic trade-off between optical transparency and piezoelectricity. This work underscores La³⁺ as a potent structural modifier for tailoring phase boundaries and defect chemistry, providing a cost-effective framework for developing high-performance transparent electromechanical materials. Full article

Microglia play a key role in the development of neuroinflammation induced by cerebral ischemia. On the other hand, these cells participate in neurorepair processes. This dual role of microglia stems from the ability to shift their phenotype from pro-inflammatory M1 to protective M2. Histone deacetylase inhibitors (HDACis) are a group of agents that exhibit neuroprotective effects in some models of ischemia, among others, by modulation of signaling pathways that regulate microglial activation. This study aimed to examine the effect of HDACis—sodium butyrate and Givinostat—on polarization of microglia and their potential mechanism of action in a model of ischemia in vitro (oxygen and glucose deprivation, OGD). We examined the expression of pro- and anti-inflammatory markers in the BV2 microglial cell line after OGD and HDACis treatment by qPCR; polarization of microglia by flow cytometry; and the activation/phosphorylation of ERK and AKT in BV2 cells by Western blot and ELISA. Our findings demonstrate a divergent impact of HDACis on the phenotype of microglial cells. Sodium butyrate significantly suppressed the mRNA expression of pro-inflammatory markers (IL-1β, TNF-α, CD86) and increased the level of anti-inflammatory factors in BV2 microglial cells after OGD, whereas Givinostat failed to attenuate these inflammatory responses. Our findings demonstrate that sodium butyrate, but not Givinostat, promotes a shift in microglia toward an anti-inflammatory M2 phenotype under ischemic conditions. This effect is associated with suppression of pro-inflammatory gene expression and activation of the PI3K/AKT signaling pathway. These results identify sodium butyrate as a potential modulator of microglial responses following ischemic injury. Full article

Bacterial infections and the lack of bioactivity of titanium implants and their alloys remain critical challenges for the long-term performance and clinical success of these devices. These issues arise from the undesirable combination of early microbial adhesion and the limited ability of metallic surfaces to form a bioactive interface capable of supporting osseointegration. To address these limitations simultaneously, this study employed electrical discharge machining (EDM), which enables surface topography modification and in situ incorporation of bioactive ions from the dielectric fluid. Ti-6Al-4V ELI surfaces were modified using two dielectric fluids, a fluorine/phosphorus-based solution (DF1-F) and a calcium/phosphorus-based solution (DF2-Ca), under positive and negative polarities. The recast layer was characterized by SEM and EDS, while bioactivity was evaluated through immersion in simulated body fluid (SBF) for up to 21 days. Antibacterial performance was assessed against Staphylococcus aureus at 6 h and 24 h of incubation. The results demonstrated that dielectric composition and polarity strongly influenced ionic incorporation and the structural stability of the modified layers. The DF2-Ca(+) condition exhibited the most favorable bioactive response, with Ca/P ratios closer to hydroxyapatite and surface morphologies typical of mineralized coatings. In antibacterial assays, Ca/P-containing surfaces significantly decreased S. aureus attachment (>80–90%). Overall, EDM with Ca/P-containing dielectrics enables the fabrication of Ti-6Al-4V surfaces with enhanced mineralization capacity and anti-adhesive effects against Gram-positive bacteria, reinforcing their potential for multifunctional biomedical applications. Full article

Background: Diabetic wound healing is hampered by persistent inflammation and excessive neutrophil extracellular traps (NET) formation. Peptidylarginine deiminase 4 (PAD4) is a key enzyme driving this pathology. This study developed a thermosensitive chitosan/β-glycerophosphate hydrogel for the local delivery of a novel PAD4 inhibitor, YJ-2, to promote diabetic wound repair. Methods: A YJ-2-loaded hydrogel (CGY) was synthesized and characterized. In vitro studies used HaCaT cells and macrophages to assess proliferation, migration, NETs (via H3cit), and polarization. Efficacy was evaluated in diabetic C57 mouse wound models. Results: CGY exhibited temperature-sensitive gelation and sustained YJ-2 release. In vitro, YJ-2 inhibited NETs formation, reduced pro-inflammatory markers, promoted HaCaT migration, and induced M2 macrophage polarization. In vivo, CGY treatment significantly accelerated wound closure. Conclusions: Local hydrogel delivery of the PAD4 inhibitor YJ-2 effectively mitigates inflammation and NETs, promoting healing in diabetic wounds. This strategy represents a promising targeted therapy for diabetic wounds. Full article

Microseismic source localization is essential for the early warning of disasters in deep rock mass engineering. Traditional time difference methods require a dense sensor network, which is often impractical in large-scale scenarios with low-density sensor placement. Three-component microseismic sensors offer a promising alternative by utilizing multi-axis sensing, but their application depends on accurate sensor attitude estimation—a challenge due to installation deviations, integration errors, magnetic interference, and ambiguity in P-wave polarization direction. This study proposes an attitude calculation and source localization method based on P-wave polarization analysis. For attitude estimation, a unit vector from the sensor to the event is used as a reference; the P-wave polarization direction is extracted via covariance matrix analysis, and a novel “direction–vector–rotation–matrix cross-optimization” method resolves polarization–vector ambiguity. Multi-event data fusion enhances stability and robustness. For source localization, a “1 three-component + 1 single-component” sensor scheme is introduced, combining distance, azimuth, and distance difference constraints to achieve accurate positioning while substantially reducing hardware and energy costs. Field validation at the Yebatan Hydropower Station shows an average reference vector conversion error of 7.72° and an average localization deviation of 10.72 m compared with a conventional high-precision method, meeting engineering early-warning requirements. The proposed approach provides a cost-effective, efficient technical solution for large-scale microseismic monitoring with low sensor density, supporting sustainable infrastructure development through improved disaster risk management. Full article

Background/Objectives: Fusobacterium nucleatum and Akkermansia muciniphila are key components of the human microbiota, influencing health and disease. F. nucleatum is associated with colorectal cancer (CRC) and poor prognosis through its pro-inflammatory and pro-tumorigenic activity, whereas A. muciniphila is linked to metabolic benefits and anti-inflammatory effects. This study aimed to evaluate the immunomodulatory impact of protein extracts from these bacteria on peripheral T cell responses in healthy individuals and CRC patients. Methods: Peripheral blood mononuclear cells (PBMCs) were exposed to bacterial extracts, individually or in combination, and T cell subsets were analyzed by polychromatic flow cytometry. Results: In healthy donors, F. nucleatum increased Th0, Th2, and Tc9 cell frequencies while reducing Th1, Th1/Th17, and Treg cells. Conversely, A. muciniphila promoted a pro-inflammatory-associated T cell phenotype characterized by higher Th0, Th2, Th17, and Tc17 cells. Combined exposure enhanced Th0, Th17, and Tc17 cells while decreasing Th9 cells. In CRC patients, bacterial extracts induced no significant changes in T cell subsets. Conclusions: These findings indicate that F. nucleatum skews immune responses toward humoral and mucosal defense, whereas A. muciniphila enhances T cell polarization toward subsets usually associated with pro-inflammatory immune responses in healthy subjects. Further studies are needed to clarify their systemic immunological roles and interactions within the tumor microenvironment of CRC. Full article

In vitro oocyte maturation (IVM) is a pivotal process influencing the success of embryo production in laboratory and clinical settings. However, oxidative stress (OS) often compromises oocyte quality during IVM. Antioxidants such as melatonin and epigallocatechin-3-gallate (EGCG) are known to mitigate OS by neutralizing reactive oxygen species (ROS) and bolstering antioxidant defenses. Despite extensive studies on their individual effects, the synergistic impact of melatonin and EGCG remains underexplored. Utilizing a mouse model, this study evaluated their combined effect on oocyte maturation, focusing on nuclear and cytoplasmic development, intracellular ROS, glutathione (GSH) levels, and subsequent embryonic competence. The results demonstrated that melatonin and EGCG significantly enhanced the polar body extrusion rate (p < 0.05), with the combination group achieving the highest rate of 91.96%. Cumulus expansion was observed to improve across all treated groups, with the combination treatment showing the highest cumulus expansion index (CEI) of 3.06. Furthermore, the combination treatment significantly reduced ROS levels and increased GSH content, indicating enhanced antioxidant capacity (p < 0.01). Embryonic development outcomes, including cleavage and blastocyst rates, were markedly higher in the combination group at 75.23% and 53.97%, respectively, demonstrating superior developmental potential (p < 0.01). These findings suggest that the melatonin–EGCG combination offers a novel and effective strategy to combat oxidative damage during IVM, thereby improving oocyte quality and embryonic development potential in mice. Full article

In this paper, an anisotropic object electromagnetic image reconstruction system based on a two-stage multi-frequency extended network is developed by deep learning techniques. We obtain the scattered field information by irradiating the TM different polarization waves to uniaxial objects located in free space. We input the measured single-frequency scattered field into the Deep Residual Convolutional Neural Network (DRCNN) for training and to be further extended to multi-frequency data by the trained model. In the second stage, we feed the multi-frequency data into the Deep Convolutional Encoder–Decoder (DCED) architecture to reconstruct an accurate distribution of the dielectric constants. We focus on EMIS applications using Transverse Magnetic (TM) and Transverse Electric (TE) waves in 2D scenes. Numerical findings confirm that our method can effectively reconstruct high-contrast uniaxial objects under limited information. In addition, the TM/TE scattering from uniaxial anisotropic objects is governed by polarization-dependent Lippmann–Schwinger integral equations, yielding a nonlinear and severely ill-posed inverse operator that couples the dielectric tensor components with multi-frequency field responses. Within this mathematical framework, the proposed two-stage DRCNN–DCED architecture serves as a data-driven approximation to the anisotropic inverse scattering operator, providing improved stability and representational fidelity under limited-aperture measurement constraints. Full article

Background/Objectives: The milk fat globule membrane (MFGM) is a complex structure of polar lipids, gangliosides, and glycoproteins that has demonstrated anti-inflammatory, neuroprotective, and gut-modulatory effects in preclinical and human studies, but its effects on adult psychological outcomes have not been systematically synthesised. Methods: We conducted a systematic literature search across multiple databases using combined relevant keywords and Medical Subject Headings terms, with manual reference checks to ensure comprehensiveness. Of the 35 articles initially identified, 3 randomised controlled trials met the inclusion criteria: adult participants (≥20 years); bovine MFGM supplementation; a placebo or control group; and outcomes measuring stress, anxiety, or depression. A random-effects meta-analysis was performed, calculating standardised mean differences for stress, anxiety, and depression outcomes. Results: MFGM supplementation produced small but statistically significant reductions in stress and anxiety. Effects on depression were non-significant, though directionally favourable. Risk-of-bias assessments were conducted using Cochrane criteria and indicated low concerns across trials. Publication bias was not indicated, but interpretation was limited by the small number of studies. Conclusions: Whilst the evidence for depression is inconclusive, bovine MFGM supplementation may confer modest benefits for stress and anxiety in adults and could be part of a nutritional strategy to support overall mental well-being. Full article

Berberine (BBR), an isoquinoline alkaloid, has a long history of clinical use in treating dysentery. However, its precise mechanism has not been fully elucidated. This study aimed to investigate the intestinal protective mechanisms of BBR against Shigella flexneri (S. flexneri)-induced dysentery in mice. We found that BBR significantly upregulated the intestinal barrier proteins ZO-1, occludin, and E-cadherin, enhancing intestinal mucosal integrity to inhibit S. flexneri invasion. Moreover, BBR effectively attenuated M1 macrophage polarization and restored the Th1/Th17/Treg balance to reduce inflammatory injury upon S. flexneri infection. Specifically, BBR reduced both the populations of Th1 and Th17 cells and their production of inflammatory cytokines IFN-γ and IL-17A. Concurrently, it enhanced Treg cell populations and the secretion of anti-inflammatory cytokines IL-10 and TGF-β1. Additionally, the intestinal protective effect of BBR was further augmented by an increase in secretory IgA (sIgA). Collectively, our findings demonstrate that BBR protects against S. flexneri-induced dysentery by enhancing the intestinal barrier and inflammatory responses, providing support for its clinical use. Full article

Artificial intelligence is reshaping approaches to architectural heritage conservation by enabling a deeper understanding of how people perceive and experience historic built environments. This study employs deep learning and large language models (LLMs) to explore public perceptions of the Qinghefang Historical and Cultural District in Hangzhou, illustrating how AI-driven analytics can inform intelligent heritage management and architectural revitalization. Large-scale public online reviews were processed through BERTopic-based clustering to extract thematic structures of experience, while interpretive synthesis was refined using an LLM to identify core perceptual dimensions including Hangzhou Housing & Residential Choice, Hangzhou Urban Tourism & Culture, Hangzhou Food & Dining, and Qinghefang Culture & Creative. Sentiment polarity and emotional intensity were quantified using a fine-tuned BERT model, revealing distinct affective and perceptual patterns across the district’s architectural and cultural spaces. The results demonstrate that AI-based textual analytics can effectively decode human–heritage interactions, offering actionable insights for data-informed conservation, visitors’ experience optimization, and sustainable management of historic districts. This research contributes to the emerging field of AI-driven innovation in architectural heritage by bridging computational intelligence and heritage conservation practice. Full article

The electrical resistivity and acoustic properties of marine sediments are essential for understanding their physical and mechanical behavior. Over recent decades, significant advancements have been made in both in situ and laboratory measurement techniques, alongside theoretical models, to establish correlations between these geophysical parameters and sediment properties such as porosity, saturation, and consolidation degree. However, a comprehensive comparison of the advantages, limitations, and applicability of different measurement methods remains underexplored, particularly in complex scenarios such as gas hydrate-bearing sediments. This review provides an in-depth synthesis of recent developments in in situ and laboratory testing technologies for assessing the resistivity and acoustic characteristics of marine sediments. Special emphasis is placed on the latest advances in acoustic measurements during gas hydrate formation and decomposition. The review highlights key challenges, including (1) limited vertical resolution in in situ resistivity measurements due to probe geometry; (2) errors arising from electrode polarization and poor soil–electrode contact; and (3) discrepancies in theoretical models linking geophysical parameters to sediment properties. To address these challenges, future research directions are proposed, focusing on optimizing electrode array designs for high-resolution resistivity measurements and developing non-destructive acoustic techniques for deep-sea sediments. This work offers a critical reference for marine geophysics and offshore engineering researchers, aiding the selection and development of testing technologies for effective marine sediment characterization. Full article