Search Results (456)

Graphene has promise as a channel connecting separate units of large-scale spintronic circuits owing to its outstanding theoretical spin transport properties. However, spin transport properties of experimental devices consistently fall short of theoretical estimates due to impacts from the substrate, electrodes, or defects in the graphene itself. In this study, we fabricate both traditional non-local spin valves (NLSVs) and novel hybrid drift-diffusion spin valves (HDDSVs) to explore the impact of charge current and AC spin injection efficiency on spin transport. HDDSVs feature channel branches that allow investigation of charge-based spin drift enhancement compared to diffusion-only configurations. We investigate the modulation of spin transport through hybrid drift-diffusion, observing a decrease in spin signal by 11% for channels with a 45° branch angle, and a 21% increase in spin signal for 135° branch angle channels. We then fabricate symmetrical 90° channel branch angle devices, which do not produce consistent spin transport modulation in drift diffusion mode. These findings highlight the role of carrier drift in enhancing or suppressing spin transport, depending on channel geometry and injection configuration. Overall, our work demonstrates a promising approach to optimizing spin transport in graphene devices by leveraging hybrid drift-diffusion effects without requiring additional DC current sources. Full article

This study develops a thermo-mechanical damage (TMD) model for predicting damage evolution in heterogeneous rock materials after heat treatment. The TMD model employs a Weibull distribution to characterize the spatial heterogeneity of the mechanical properties of rock materials and develops a framework that incorporates thermal effects into a nonlocal gradient damage model, thereby overcoming the mesh dependency issue inherent in homogeneous local damage models. The model is validated by numerical simulations of a notched cruciform specimen subjected to combined mechanical and thermal loading, confirming its capability in thermo-mechanical coupled scenarios. Sensitivity analysis shows increased material heterogeneity promotes localized, X-shaped shear-dominated failure patterns, while lower heterogeneity produces more diffuse, network-like damage distributions. Furthermore, the results demonstrate that thermal loading induces micro-damage that progressively spreads throughout the specimen, resulting in a significant reduction in both overall stiffness and critical strength; this effect becomes increasingly pronounced at higher heating temperatures. These findings demonstrate the model’s ability to predict the mechanical behavior of heterogeneous rock materials under thermal loading, offering valuable insights for safety assessments in high-temperature geotechnical engineering applications. Full article

We propose a universal framework for understanding system evolution based on structural complexity, offering a directional signature that applies across physical, chemical, and biological domains. Unlike entropy, which is constrained by its definition in closed, equilibrium systems, we introduce Kolmogorov Complexity (KC) and Fractal Dimension (FD) as quantifiable, scalable metrics that capture the emergence of organized complexity in open, non-equilibrium systems. We examine two major classes of systems: (1) living systems, revisiting Schrödinger’s insight that biological growth may locally reduce entropy while increasing structural order, and (2) irreversible natural processes such as oxidation, diffusion, and material aging. We formalize a Universal Law: expressed as a non-decreasing function Ω(t) = α·KC(t) + β·FD(t), which parallels the Second Law of Thermodynamics but tracks the rise in algorithmic and geometric complexity. This framework integrates principles from complexity science, providing a robust, mathematically grounded lens for describing the directional evolution of systems across scales-from crystals to cognition. Full article

Diffusion-weighted magnetic resonance (DWMR) images were acquired using a custom-designed, 3D-printed breast-mimicking phantom. The smoothing factor of the non-local means (NLM) algorithm was then optimized for noise reduction. Phantoms were fabricated using polylactic acid, polyethylene terephthalate, and various concentrations of polyvinylpyrrolidone. DWMR images were obtained across b-values ranging from zero to 2000 s/mm². Based on image contrast, the NLM algorithm was applied to the b = 1000 s/mm² image, testing smoothing factors from 0.001 to 0.150. The NLM algorithm’s performance was quantitatively evaluated using a single DWMR image acquired from this custom phantom. At the optimized smoothing factor, the signal-to-noise ratio (SNR) improved from 96.87 ± 3.42 to 215.81 ± 4.18, and the contrast-to-noise ratio (CNR) from 43.63 ± 2.97 to 131.98 ± 3.56, representing 2.22-fold and 3.02-fold enhancements, respectively. No formal statistical tests were conducted as the analysis was based on a single acquisition. The optimized NLM algorithm also outperformed conventional denoising methods—median, Wiener, and total variation—in both noise suppression and contrast preservation. These findings suggest that the NLM algorithm with optimized parameters is likely to be more effective than existing approaches for enhancing breast DWMR image quality. However, further validation using in vivo patient datasets is essential to confirm its diagnostic utility and clinical generalizability because of the absence of tissue heterogeneity, motion, and physiological noise in the phantom environment. Full article

This paper investigates the dispersion of atmospheric pollutants in urban environments using a fractional-order convection–diffusion-reaction model with dynamic line sources associated with vehicle traffic. The model includes Caputo fractional time derivatives and Riesz fractional space derivatives to account for memory effects and non-local transport phenomena characteristic of complex urban air flows. Vehicle trajectories are generated stochastically on the road network graph using Dijkstra’s algorithm, and each moving vehicle acts as a mobile line source of pollutant emissions. To reflect the daily variability of emissions, a time-dependent modulation function determined by unknown parameters is included in the source composition. These parameters are inferred by solving an inverse problem using synthetic concentration measurements from several fixed observation points throughout the area. The study presents two main contributions. Firstly, a detailed numerical analysis of how fractional derivatives affect pollutant dispersion under realistic time-varying mobile source conditions, and secondly, an evaluation of the performance of the proposed parameter estimation method for reconstructing time-varying emission rates. The results show that fractional-order models provide increased flexibility for representing anomalous transport and retention effects, and the proposed method allows for reliable recovery of emission dynamics from sparse measurements. Full article

Background/Objectives: Veillonella species are Gram-negative, non-motile, non-fermentative, obligate anaerobic cocci. They are typically considered commensals of the oral cavity, respiratory tract, genitourinary tract, and gastrointestinal tract. It may be a rare cause of dental infections and discitis/spondylodiscitis. Methods: We report the case of an 80-year-old patient diagnosed with discitis caused by Veillonella parvula, isolated from blood. In addition, we performed a comprehensive literature review summarizing all reported cases of discitis or spondylodiscitis caused by Veillonella species. Results: In our case, antimicrobial susceptibility testing was performed using the Kirby–Bauer disc diffusion method. Based on the results, the patient was treated with amoxicillin/clavulanate, which led to a favourable clinical outcome. A review of the literature revealed that, to date, only 14 cases of spondylodiscitis or discitis caused by Veillonella spp. have been reported. Potential risk factors for Veillonella spp. bacteremia were identified in only 9 cases. The most commonly affected site was the lumbar or lumbosacral spine. Magnetic resonance imaging was consistently regarded as the diagnostic gold standard. Most patients presented with localized pain. The overall therapeutic approach generally consisted of an initial course of intravenous antibiotics, typically ceftriaxone administered either as monotherapy or in combination with metronidazole, followed by an oral regimen with amoxicillin/clavulanate, given alone or alongside metronidazole. Conclusions: Spondylodiscitis due to V. parvula remains extremely rare. Although antimicrobial susceptibility patterns remain heterogeneous, beta-lactams, particularly amoxicillin/clavulanate, appear effective in most cases, and treatment regimens typically involve an initial intravenous phase followed by oral therapy. Full article

Primary cutaneous lymphomas (PCLs), including cutaneous T-cell lymphomas (CTCL) and primary cutaneous B-cell lymphomas (PCBCL), are a diverse group of non-Hodgkin lymphomas that primarily affect the skin. Radiotherapy (RT) plays a pivotal role in the treatment of these lymphomas, particularly for localized disease, due to its ability to deliver precise, skin-directed treatment. Mycosis fungoides (MF) and Sézary syndrome (SS), the most common subtypes of CTCL, often require skin-directed therapies such as electron beam therapy and superficial brachytherapy to manage localized lesions. Electron beam therapy, including total skin electron beam therapy (TSEBT), has been utilized for decades, offering high response rates but with the risk of cumulative skin toxicity. Recently, low-dose radiotherapy (LDRT) has gained attention as an effective alternative that reduces toxicity while maintaining durable responses. Superficial brachytherapy is another modality that delivers radiation through custom molds, allowing for homogeneous dosing over complex anatomical areas like the face. Both teleradiotherapy and brachytherapy have demonstrated high complete response rates, with low recurrence rates observed when higher doses are used. In the context of primary cutaneous B-cell lymphomas, such as primary cutaneous marginal zone lymphoma (PCMZL) and primary cutaneous follicle center lymphoma (PCFCL), radiotherapy also offers excellent local control, particularly for indolent subtypes. However, more aggressive subtypes, such as diffuse large B-cell lymphoma, leg type (PCDLBCL-LT), may require systemic therapies in addition to radiation. Overall, teleradiotherapy and brachytherapy are essential components of the therapeutic arsenal for primary cutaneous lymphomas, offering effective disease control with manageable toxicity, while ongoing research focuses on optimizing treatment strategies and exploring novel combinations with systemic therapies. Full article

Background: Temporomandibular joint (TMJ) injections and arthrocentesis are commonly used minimally invasive methods for treating temporomandibular disorders (TMDs). Although considered safe, they can cause neurological complications. The aim of this systematic review was to synthesize all identified evidence for neurological adverse events following intra-articular TMJ interventions. Methods: This review was based on a systematic search with BASE, DOAJ, PubMed, SciELO, and Semantic Scholar on 28 May 2025. It included primary studies involving patients diagnosed with TMDs who underwent intra-articular injections into the TMJ or were treated with arthrocentesis, and in whom neurological adverse effects associated with the intra-articular intervention were reported. Studies reporting non-specific symptoms or unrelated systemic conditions were excluded. The risk of bias was assessed using the Joanna Briggs Institute’s critical appraisal tools. Results were presented in summary tables. Results: The search yielded five eligible studies comprising 319 patients, of whom 320 neurological adverse events were reported. Included studies comprised a randomized controlled trial, two retrospective studies, and two case reports. Four studies had a low risk of bias, and one had a moderate risk of bias according to the Joanna Briggs Institute appraisal tools. The proportion of patients affected ranged from 14% to 65% depending on the study design and intervention type. The most common adverse event was transient facial nerve (cranial nerve VII) paralysis, mainly involving the temporal and zygomatic branches. Less commonly reported complications involved the trigeminal nerve branches (V1, V3). There is also a single case of epidural hematoma with palsy of the oculomotor nerve (III). Most symptoms resolved spontaneously within a few hours to a few days. The use of local anesthesia and large volumes of irrigation (60 mL) during arthrocentesis increases the risk of complications. Attempts to explain the mechanisms of complications include local anesthetic diffusion, compression neuropraxia due to lavage fluid leakage, and corticosteroid neurotoxicity. One of the limitations of the study is the scarcity of data. Conclusions: Although most adverse events are mild and reversible, these findings highlight that precise, real-time guided injection and careful control of lavage volumes can minimize extra-articular spread of anesthetics or fluids, thereby reducing the likelihood of neurological complications. This study received no funding. PROSPERO ID number: CRD420251088170. Full article

Background: Seminoma is the most common subtype of testicular germ cell tumors in young men; however, the contribution of tumor-associated macrophages (TAMs) to disease progression remains insufficiently understood. This study aimed to quantitatively and phenotypically characterize CD68⁺ and CD163⁺ TAMs in non-metastatic seminomas (pT1N0M0 and pT2N0M0). Methods: This retrospective, multicenter, cohort, observational, analytical study was conducted from 1 January 2015 to 1 January 2025 at two branches of the National Medical Research Radiological Center of the Ministry of Health of the Russian Federation: the A. Tsyb Medical Radiological Research Center and the P. Hertsen Moscow Oncology Research Institute. Archived paraffin-embedded tumor samples from 96 patients and 21 samples of normal testicular tissue were analyzed using immunohistochemistry and digital morphometric analysis with QuPath software to assess macrophage density and spatial distribution. Results: Compared to normal testicular tissue, seminomas demonstrated more than a 10-fold increase in CD68⁺ TAMs and over a 100-fold increase in CD163⁺ TAMs. CD68⁺ cells predominantly localized to peripheral tumor regions, while CD163⁺ cells formed diffuse clusters in central tumor zones and around peripheral vessels. No statistically significant differences in CD68⁺ cell density were found between pT1 and pT2 stages. However, pT2 tumors showed a trend toward higher CD163⁺ TAMs density, suggesting increased M2 polarization with advancing tumor stage. Conclusions: These findings highlight the spatial and phenotypic heterogeneity of TAMs in seminoma and indicate a shift toward an immunosuppressive tumor microenvironment during local progression. Future studies should assess macrophage polarization and progression-free survival to evaluate their potential as prognostic biomarkers and therapeutic targets in seminoma. Full article

Mechanical and contractile forces in the vascular wall regulate smooth muscle cell migration. We previously demonstrated the presence of C3 complement products in atherosclerotic lesions of human aortas and showed that that C3-derived fragments promote key cellular processes, such as actin cytoskeleton organization and cell migration, in lipid-loaded human vascular smooth muscle cells (hVSMCs). In the present study, we aimed to investigate gene expression profiles related to cytoskeletal remodeling and cell adhesion in migrating hVSMCs with a particular focus on modulatory effect of the C3 complement pathway on these processes. We analyzed gene expression in migrating and non-migrating hVSMCs using real-time PCR and in silico network analysis. Additionally, we investigated cytoskeletal remodeling through Western blotting and confocal microscopy. PCR profiling revealed 30 genes with significantly altered expression in migrating hVSMCs compared to non-migrating control cells. In silico analysis identified six of these genes—PXN, AKT1, RHOA, VCL, CTNNB1, and FN1—as being associated with cytoskeletal remodeling and focal adhesion, with PXN occupying a central position in the interaction network. PXN expression was reduced at both the transcript and protein levels and showed altered subcellular localization in migrating lipid-loaded hVSMCs. Protein–protein interaction analysis using STRING predicted an association between PXN and the integrin complex αMβ2 (comprising ITGAM (CD11b) and ITGB2 (CD18)), which functions as receptors for the iC3b complement fragment. Confocal imaging of cell adhesion structures revealed that lipid-loaded hVSMCs stimulated with iC3b displayed a more diffuse PXN distribution and significantly increased PXN–F-actin colocalization in active cytoplasmic regions compared to lipid-loaded control cells. PXN–F-actin colocalization increased from 1.26% to 19.68%. Subcellular fractionation further confirmed enhanced PXN enrichment in the membrane fraction, with no significant changes observed in the cytosolic or cytoskeletal compartments. In conclusion, iC3b-mediated molecular signaling in lipid-loaded hVSMCs alters PXN distribution and enhances cytoskeletal remodeling, revealing novel molecular interactions in vascular remodeling and the progression of atherosclerotic lesions. Full article

We aimed to establish non-invasive diagnostic models comparable to pathology testing and explore reliable digital imaging biomarkers to classify diffuse large B-cell lymphoma (DLBCL) and invasive ductal carcinoma (IDC). Our study enrolled 386 breast nodules from 279 patients with DLBCL and IDC, which were pathologically confirmed and underwent ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) examination. Patients from two centers were separated into internal and external cohorts. Notably, we introduced 2.5D deep learning and machine learning to extract features, develop models, and discover biomarkers. Performances were assessed using the area under curve (AUC) and confusion matrix. Additionally, the Shapley additive explanation (SHAP) and local interpretable model-agnostic explanations (LIME) techniques were employed to interpret the model. On the internal cohort, the optimal model PT_TDC_SVM achieved an accuracy of 0.980 (95% confidence interval (CI): 0.957–0.991) and an AUC of 0.992 (95% CI: 0.946–0.998), surpassing the other models. On the external cohort, the accuracy was 0.975 (95% CI: 0.913–0.993) and the AUC was 0.996 (95% CI: 0.972–0.999). The optimal imaging biomarker PET_LBP-2D_gldm_DependenceEntropy demonstrated an average accuracy of 0.923/0.937 on internal/external testing. Our study presented an innovative automated model for DLBCL and IDC, identifying reliable digital imaging biomarkers with significant potential. Full article

Non-uniform corrosion cracking in reinforced concrete buildings constitutes a fundamental difficulty resulting in durability failure. This work develops a microscopic-scale multi-species electrochemical phase field model to tackle this issue. The model comprehensively examines the spatiotemporal coupling mechanisms of the full “corrosion-rust swelling-cracking” process by integrating electrochemical reaction kinetics, multi-ion transport processes, and a unified phase field fracture theory. The model uses local corrosion current density as the primary variable to accurately measure the dynamic interactions among electrochemical processes, ion transport, and rust product precipitation. It incorporates phase field method simulations of fracture initiation and propagation in concrete, establishing a bidirectional link between rust swelling stress and crack development. Experimental validation confirms that the model’s predictions about cracking duration, crack shape, and ion concentration distribution align well with empirical data, substantiating the efficacy of local corrosion current density as an indicator of electrochemical reaction rate. Parametric studies were performed to examine the effects of interface transition zone strength, oxygen diffusion coefficient, protective layer thickness, reinforcing bar diameter, and reinforcing bar configuration on cracking patterns. This model’s multi-physics field coupling framework, influenced by dynamic corrosion current density, facilitates cross-field interactions, offering sophisticated theoretical tools and technical support for the quantitative analysis, durability evaluation, and protective design of corrosion-induced cracking in reinforced concrete structures. Full article

Blast-furnace staves serve as critical protective components in ironmaking, requiring synergistic optimization of slag-coating behavior and self-protection capability to extend furnace lifespan and reduce energy consumption. Traditional integer-order heat transfer models, constrained by assumptions of homogeneous materials and instantaneous heat conduction, fail to accurately capture the cross-scale thermal memory effects and non-local diffusion characteristics in multiphase heterogeneous blast-furnace systems, leading to substantial inaccuracies in predicting dynamic slag-layer evolution. This review synthesizes recent advancements across three interlinked dimensions: first, analyzing design principles of zonal staves and how refractory material properties influence slag-layer formation, proposing a “high thermal conductivity–low thermal expansion” material matching strategy to mitigate thermal stress cracks through optimized synergy; second, developing a mechanistic model by introducing the Caputo fractional derivative to construct a non-Fourier heat-transfer framework (i.e., a heat-transfer model that accounts for thermal memory effects and non-local diffusion, beyond the instantaneous heat conduction assumption of Fourier’s law), which effectively describes fractal heat flow in micro-porous structures and interfacial thermal relaxation, addressing limitations of conventional models; and finally, integrating industrial case studies to validate the improved prediction accuracy of the fractional-order model and exploring collaborative optimization of cooling intensity and slag-layer thickness, with prospects for multiscale interfacial regulation technologies in long-life, low-carbon stave designs. Full article

Copper alloys are critical heat sink materials for fusion reactor divertors due to their high thermal conductivity (TC) and strength, yet their performance under extreme particle bombardment and heat fluxes in future tokamaks requires enhancement. While neutron-induced transmutation helium affects the properties of copper, the atomistic mechanisms linking helium bubble size to thermal transport remain unclear. This study employs non-equilibrium molecular dynamics (NEMD) simulations to isolate the effect of bubble diameter (10, 20, 30, 40 Å) on TC in copper, maintaining a constant He-to-vacancy ratio of 2.5. Results demonstrate that larger bubbles significantly impair TC. This reduction correlates with increased Kapitza thermal resistance and pronounced lattice distortion from outward helium diffusion, intensifying phonon scattering. Phonon density of states (PDOS) analysis reveals diminished low-frequency peaks and an elevated high-frequency peak for bubbles >30 Å, confirming phonon confinement and localized vibrational modes. The PDOS overlap factor decreases with bubble size, directly linking microstructural evolution to thermal resistance. These findings elucidate the size-dependent mechanisms of helium bubble impacts on thermal transport in copper divertor materials. Full article

We present the results of a detailed spectroscopic analysis of the double-lined spectroscopic binary system $\alpha$ Equulei. High-resolution spectra obtained with the SOPHIE spectrograph at various orbital phases were used to disentangle the composite spectra into individual components using the spectral line deconvolution (SLD) iterative technique. The atmospheric parameters of each component were refined with the SME (spectroscopy made easy) package and further validated by following methods: SED (spectral energy distribution), the independence of the abundance of individual Fe i–ii lines on the reduced equivalent width and ionisation potential, and fitting with the hydrogen line profiles. Our accurate abundance analysis uses a hybrid technique for spectrum synthesis. This is based on classical model atmospheres that are calculated under the assumption of local thermodynamic equilibrium (LTE), together with non-LTE (NLTE) line formation. This is used for 15 out of the 25 species from C to Nd that were investigated. The primary giant component (G7-type) exhibits a typical abundance pattern for normal stars, with elements from He to Fe matching solar values and neutron-capture elements showing overabundances up to 0.5 dex. In contrast, the secondary dwarf component displays characteristics of an early stage Am star. The observed abundance differences imply distinct diffusion processes in their atmospheres. Our results support the scenario in which chemical peculiarities in Am stars develop during the main sequence and may decrease as the stars evolve toward the subgiant branch. Full article