Search Results (3,985)

Hydrogen trapping at carbide/matrix interfaces is important for improving the resistance of steels to hydrogen embrittlement. In this work, the segregation behavior of hydrogen at the coherent α-Fe/V₄C₃ interface was investigated by first-principles calculations. Representative hydrogen sites were considered systematically, including interstitial sites in the near-interface region, interfacial sites, and carbon-vacancy sites in V₄C₃. All of the sites examined are energetically favorable for hydrogen trapping, but the carbon vacancy inside V₄C₃ exhibits the strongest trapping tendency. Charge density, Bader charge, and density-of-states analyses indicate that hydrogen at this site gains more electrons and forms stronger interactions with neighboring V atoms, leading to enhanced stability. The behavior of H₂ at the internal carbon vacancy was also evaluated. After structural relaxation, the H₂ molecule dissociated into two separate H atoms, indicating that hydrogen is more stably trapped in atomic rather than molecular form. These findings reveal the crucial role of carbon vacancies in regulating hydrogen trapping at the α-Fe/V₄C₃ interface and provide atomic-scale insight into the hydrogen trapping mechanism of vanadium carbide precipitates in steels. Full article

Background: Microstructural abnormalities of the corpus callosum (CC) are a consistent finding in schizophrenia, yet conventional diffusion tensor imaging (DTI) metrics provide limited biological specificity. Neurite orientation dispersion and density imaging (NODDI) can disentangle the neurite density index (NDI) and the orientation dispersion index (ODI), providing indirect, model-based markers of white matter microstructure in vivo. Methods: We applied NODDI to diffusion-weighted MRI data in patients with first-episode schizophrenia (FES) and matched healthy controls (HCs). The CC was used as a mask and subdivided into the genu (GCC), body (BCC), and splenium (SCC). Group differences in z-scores of the NDI and ODI were assessed using voxel-wise statistics within the CC and region of interest (ROI) analyses in the GCC, BCC, and SCC, controlling for age and sex. Associations between NODDI metrics and clinical symptoms were examined using the Positive and Negative Syndrome Scale (PANSS). Results: FES patients showed a significantly increased ODI in portions of the GCC, BCC, and SCC, as well as region-specific NDI alterations, with decreased NDI in parts of the SCC and increased NDI in sub-regions of the GCC/BCC (voxel-wise p < 0.05, FWE-corrected). ROI analyses confirmed a significant reduction in NDI z-scores in the SCC in FES patients compared with HCs (p = 0.009), whereas the ODI z-scores in the SCC did not differ significantly between groups (p = 0.124). Despite the absence of group-level ODI differences in the SCC, the SCC ODI was positively correlated with PANSS negative symptom scores in FES patients (r = 0.554, p = 0.002) and was also positively correlated with PANSS total scores in FES (r = 0.457, p = 0.014). This association remained significant in the region of the SCC after regressing out NDI from ODI (residual z_ODI), which was correlated with PANSS negative scores (r = 0.503, p = 0.006) and PANSS total scores (r = 0.474, p = 0.011), and the ODI/NDI ratio in the SCC was also correlated with negative symptom severity (r = 0.457, p = 0.014). Conclusions: Our findings suggest that, in the SCC, negative symptoms in schizophrenia are linked to altered neurite orientation dispersion under conditions of reduced neurite density. The dissociation between group-level NDI and ODI effects and their distinct relationship with psychopathology highlights the value of composite microstructural indices (e.g., residual z_ODI, ODI/NDI) for capturing clinically relevant white matter abnormalities. Full article

Background: Rhythmic knowledge enables the precise timing of actions in dynamic environments. Although rhythm learning has been extensively studied, it remains debated whether such learning arises primarily from the perceptual encoding of rhythmic inputs or from the repetitive execution of periodic actions. Methods: To address this question, we developed a temporal-rhythm serial reaction time (TR-SRT) paradigm that dissociates rhythmic structures in perceptual inputs from the timing of motor responses. Across three experiments, participants learned rhythms under visuomotor (Experiment 1, N = 27), visual-only (Experiment 2, N = 26), or motor-only (Experiment 3, N = 26) conditions while electroencephalography was recorded. Results: Behavioral learning slopes revealed robust rhythm learning in both the visuomotor and visual-only conditions, whereas no learning emerged when rhythmic structure was confined to motor timing alone. Post-learning awareness tests further indicated that the acquired rhythmic knowledge was predominantly implicit. Consistently, global (whole-brain) theta-band magnitude (4.8–5.2 Hz) was enhanced only in the conditions that supported rhythm learning. Conclusions: These findings indicate that rhythm learning depends primarily on perceptual temporal structure rather than the repetition of rhythmic actions and identify increased global theta oscillations as a neural signature of this perceptually driven and largely implicit learning process. Full article

Rational design of smart nanogels for drug delivery requires molecular-level understanding of how structural evolution and drug–carrier interactions couple under multiple stimuli. Here, pH/temperature dual-responsive P(NIPAM-co-AAc) nanogels containing 0–20 mol% AAc were investigated by combining all-atom molecular dynamics simulations with in vitro ibuprofen (IBU) release experiments under acidic (pH 2.75) and weakly basic (pH 7.4) conditions at 298 and 310 K. The simulations identified CA-5-L-298 as the most retained system, with the lowest IBU diffusion coefficient (0.92 × 10⁻⁷ cm² s⁻¹) and no dissociated molecules under the adopted criterion, whereas CA-15-H-310 showed the highest diffusivity (8.61 × 10⁻⁷ cm² s⁻¹) and dissociated fraction (22%). Consistently, in the urea-free release experiments, CA-15-H-310 exhibited the highest 24 h cumulative release (69.4%), while CA-5-L-298 remained among the low-release systems (35.9%). Pore analysis, hydrogen-bond statistics, MM/PBSA calculations, and urea-competition experiments together support the view that IBU release is influenced by both mesh steric sieving and polymer–drug affinity switching, and correlation analysis provides quantitative support for linking the MD descriptors with the experimental release behavior. Overall, the simulations reproduce the qualitative trends in the experiments and provide a molecular-level framework for rationalizing the observed release behavior in dual-responsive nanogels. Full article

Plasma-assisted ammonia (NH₃) decomposition is a promising strategy for hydrogen production. However, reactor geometry remains a key factor limiting its hydrogen yield per energy input (${\mathrm{Y}}_{{\mathrm{H}}_2}$). This study systematically investigates H₂ production in outer-dielectric (OD), inner-dielectric (ID), and double-dielectric (DD) coaxial DBD reactors. The results show that the ammonia decomposition performance of OD- and ID-coaxial DBDs is significantly higher than that of the DD-coaxial DBD. OD- and ID-coaxial DBDs generate abundant micro-discharge pulses, enabling effective discharge energy deposition at lower peak voltages. Consequently, the reduced electric fields E/N are maintained within the optimal kinetic window for NH₃ dissociation and H₂ production. Moreover, by balancing residence time and energy density, the 8 cm length electrode achieves a peak ${\mathrm{Y}}_{{\mathrm{H}}_2}$ of 1.22–1.24 gH₂/kWh in the OD-coaxial DBD. For the ID-coaxial DBD, a 1 mm dielectric thickness yields a maximum capacitance of 86 pF, achieving a peak ${\mathrm{Y}}_{{\mathrm{H}}_2}$ of ~1.35 gH₂/kWh at the optimum E/N. In contrast, the DD-coaxial DBD exhibits the lowest ${\mathrm{Y}}_{{\mathrm{H}}_2}$ (≤0.82 gH₂/kWh) with minimal temperature rise. This is caused by the reduced current pulse numbers and the deviation of E/N from the optimal range with elevated operating voltages. This work provides guidance for the optimization of DBD reactors in plasma-assisted NH₃ decomposition for efficient H₂ production. Full article

To address the challenges of inefficient depolymerization and undesirable condensation side reactions of lignin in lignocellulosic biomass, this study employed an ethanolamine pyruvate protic ionic liquid (EAP) pretreatment system to achieve selective separation of lignin from eucalyptus while simultaneously enabling its in situ structural activation. Under optimized conditions (pyruvate-to-ethanolamine mole ratio of 1:3, 120 °C, 40 min), the EAP system afforded a lignin separation yield of 79.0 ± 0.6%, with dissolution yields of cellulose and hemicellulose of 9.6 ± 0.3% and 11.2 ± 0.4%, respectively. According to 2D-HSQC NMR and ³¹P NMR analyses, the relative content of β-O-4 ether linkages in the isolated lignin decreased from 18.4 ± 0.4% to 14.2 ± 0.3% after EAP treatment. The total phenolic hydroxyl content reached 2.26 ± 0.08 mmol/g, and the syringyl-to-guaiacyl (S/G) ratio declined from 1.72 ± 0.04 to 0.71 ± 0.03. Based on these observations, it is proposed that the ethanolamine component facilitates the dissociation of the lignin network through hydrogen bonding and stabilizes reactive intermediates, while the pyruvate component participates in the cleavage of β-O-4 ether linkages and the removal of methoxy groups via proton catalysis and nucleophilic attack. Compared with the ethanolamine and ethanolamine acetate systems, EAP pretreatment yielded lignin of higher purity (98.4 ± 0.3%) under milder conditions, and the isolated lignin exhibited stronger antioxidant activity (IC₅₀ = 0.17 ± 0.02 mg/mL). This work offers insights into the development of pretreatment systems that combine efficient separation with structural preservation of lignin. Full article

Background: Optimism bias is the tendency to expect more positive and fewer negative events for themselves versus for others. However, it remains unclear whether the valence focus of this bias depends on how events unfold (i.e., through autonomous choice vs. external imposition). This study used behavioral and ERP measures to investigate how the event source modulates the valence focus of optimism bias. Methods: Thirty participants completed a 2 (event source: autonomous choice vs. external imposition) × 2 (valence: positive events vs. negative events) × 2 (target: self vs. other) task while an EEG was recorded. The late positive potential (LPP) was analyzed as a neural index of self-relevance. Results: Behaviorally, autonomous choice preserved optimism bias for positive events (self > other, p = 0.023), whereas external imposition induced it for negative events (self < other, p = 0.006). Under autonomous choice, the LPP mirrored this pattern (enhanced for self-positive events, p = 0.038). Under external imposition, the LPP showed only a valence-general self-bias (main effect of target, p = 0.014). Conclusions: These preliminary findings suggest that event sources may influence the valence focus of optimism bias. Under autonomous choice, the bias is positive-focused. Under external imposition, it shifts to negative-focused. This dissociation between behavioral and neural patterns is consistent with dual patterns in optimism bias expression, though further research is needed. Full article

Saxitoxin (STX) is one of the most potent natural neurotoxins known and is the only marine toxin to be declared a chemical weapon. In both marine and freshwater systems filter feeding organisms can accumulate saxitoxin and human consumption of toxin-contaminated food can result in paralytic shellfish poisoning. Here we highlight for the first time a functional cell-based assay for the detection of STX on an automated patch clamp (APC) system. We demonstrate that a human embryonic kidney (HEK) cell line expressing human Nav1.6 can rapidly and sensitively detect the presence of a range of sodium ion channel blockers including STX. The use of neutralising monoclonal antibody GT13-A and/or saxiphilin was found to confer specificity to the assay by being able to dissociate between STX (along with closely related analogues) and tetrodotoxin. Finally, the application of the functional assay for the detection of STX in complex samples was evaluated during an international exercise led by the Organisation for the Prohibition of Chemical Weapons (OPCW). The neutralisation of STX activity in blinded samples enabled the indirect detection of the toxin in the relevant samples and provided an alternative orthogonal technique to corroborate the findings of liquid chromatography–mass spectrometry (LC-MS). Collectively this work demonstrates the significant potential for functional assays in the analysis of samples suspected of being contaminated with STX and related sodium ion channel targeting toxins; complementing traditional direct identification methods such as high-performance liquid chromatography with fluorescence detection (HPLC-FLD), LC-MS or enzyme-linked immunosorbent assay (ELISA). Full article

A diagnosis of acute leukemia (AL) represents a sudden, life-threatening event that places family caregivers (FCs) at high risk for traumatic stress. While traumatic stress symptoms have been documented among FCs later in the cancer trajectory, little is known about how these responses unfold during the immediate peri-diagnostic period, when acute stress disorder (ASD) may emerge, and early intervention could be most impactful. We conducted a qualitative study using a constructivist grounded theory approach to examine early traumatic stress responses among FCs of adults and children with newly diagnosed AL. Semi-structured interviews were conducted with 18 caregivers within the first six months of diagnosis as part of two clinical trials at major cancer centres in Toronto, Canada, and were analyzed iteratively using constant comparative methods. Caregivers described a coherent trajectory of traumatic stress responses across three phases. The anticipatory phase was characterized by prolonged uncertainty, helplessness, and mounting fear during diagnostic investigations. The acute phase, beginning at diagnosis, involved an abrupt shift toward emotional numbing, deliberate avoidance of catastrophic thoughts, and a narrowed focus on immediate tasks, often described as operating on “autopilot.” In the post-acute phase, as patients stabilized and discharge approached, caregivers reported increased emotional access, including grief, anger, and recognition of their own trauma, alongside emerging concerns about long-term caregiving and life disruption. These findings suggest that FCs of individuals with newly diagnosed AL exhibit a phased pattern of traumatic stress responses, marked by an early, adaptive dissociative coping response followed by delayed emotional processing, underscoring the importance of phase-sensitive psychosocial care in oncology. Full article

Atypical visual attention to aversive or threatening stimuli is a clinically relevant feature of aggressive behavior. However, the developmental dissociation between sustained visual allocation and early orienting remains unclear. This study examined the temporal dynamics of visual attentional biases in a sample of 119 children and adolescents (51 males, 68 females), clinically and behaviorally categorized into aggressive and non-aggressive cohorts. Using a free-viewing paradigm with standardized emotional stimulus pairs selected from the International Affective Picture System (IAPS), eye-tracking analysis focused on first-fixation direction and dwell time. Inferential analyses were conducted using Linear Mixed-Effect Models (LMM) and Generalized Linear Mixed-Effects Models (GLMM). The linear model revealed a significant main effect of behavioral condition: individuals with aggressive traits, regardless of their stage of development, showed greater sustained visual allocation toward negative stimuli. In contrast, the GLMM for first-fixation direction identified a significant age-by-condition interaction, indicating that early orienting differences were more clearly expressed in the aggressive adolescent cohort. These findings suggest that sustained visual preference for negative content may represent a relatively stable correlate of aggressive traits, whereas early orienting differences may vary across developmental stages. Together, these two temporal eye-tracking measures may provide complementary information for future computational approaches to aggression screening. In conclusion, these two temporal oculomotor dimensions may provide a useful feature space for future machine-learning pipelines and may serve as complementary candidate markers for comparing computational predictions against clinically established ground truth in aggression screening research. Full article

As a strategically important metal, vanadium (V) plays a crucial role in resource security, and its efficient extraction is therefore of great significance. Traditional sodium roasting processes suffer from gaseous pollutant emissions and high costs, while calcification roasting–acid leaching has emerged as an alternative due to its environmental friendliness and economic viability. This study focuses on VTS (mainly composed of FeV₂O₄ and Fe₂SiO₄), systematically optimizing the calcification roasting–hydrochloric acid leaching process and investigating its reaction mechanism. By comparing the Gibbs free energy changes of reaction products and the acid leaching process with different additives using DFT calculations, calcium oxide was selected as the optimal calcifying agent. Experimental results show that CaO significantly promotes the transformation of FeV₂O₄ into soluble calcium vanadate and preferentially reacts with SiO₂ to inhibit vanadate encapsulation, creating a structural basis for the selective dissolution of V. Under optimal process conditions, the leaching efficiency of V can reach 94.23%. Furthermore, density functional theory (DFT) calculations substantiate that the inherently weak bonding in Ca₂V₂O₇ facilitates its effortless dissociation during the acid leaching phase. The Douglas hierarchical decision-making method is further adopted for secondary economic potential, and this proposed method has the lowest investment risk. This study provides an experimental and theoretical basis for the efficient and clean extraction of vanadium. Full article

Bluetongue virus (BTV), the prototype of the genus Orbivirus, infects livestock, causing high morbidity and mortality and impacting global trade. BTV is a non-enveloped, double-capsid virus, composed of seven structural proteins and a genome of 10 double-stranded RNA segments. This manuscript highlights our group’s recent findings on the molecular and structural mechanisms underlying BTV entry and assembly during replication. Viral entry is a stepwise, pH-dependent process. The outermost protein, VP2, attaches to sialic acids and senses the acidic pH of early endosomes, triggering their dissociation. Subsequently, the second outer capsid protein, VP5, undergoes major changes in late endosomes, forming a membrane-penetrating pore that releases the transcriptionally active inner core into the host cytoplasm. Core assembly also proceeds stepwise and requires the accurate packaging of 10 positive-sense RNA segments. These segments form an RNA–RNA interaction network independent of viral proteins, beginning with the smaller segments and guiding the complete genome assortment. The small capsid protein, VP6, interacts with VP3 to facilitate RNA encapsidation. While infectious cores assemble in vitro without non-structural proteins, NS2 is essential for the in vivo formation of viral inclusion bodies via liquid–liquid phase separation, concentrating viral components and promoting genome assembly. These comprehensive characterizations of BTV provide a foundation for future control strategies against related reoviruses. Full article

Cognitive models of depression posit a core role for attentional biases, though empirical evidence remains inconsistent, likely due to variations in task demands. This study utilized eye-tracking to assess attentional patterns in individuals with depressive symptoms during a goal-directed visual search task, specifically dissociating early orienting and late disengagement. Seventy-seven participants, classified into high (HD) and low (LD) depressive-symptom groups based on PHQ-9 scores, completed a “face-in-the-crowd” (FITC) task. The set size (4, 8, or 12 faces) was varied to examine the role of perceptual load. The task involved searching for a single emotional target among neutral distractors (assessing early orienting) and searching for a single neutral target among emotional distractors (assessing late disengagement). Contrary to the negativity-bias hypothesis, the HD group demonstrated what might be interpreted as adaptive attentional regulation. During early orienting (8-face condition), the HD group showed reduced total dwell time on happy targets, suggesting accelerated identification. An attentional bias index (sad minus happy dwell time) correlated positively with depression severity. During late disengagement (8-face condition), the HD group exhibited shorter target fixation latency specifically with sad distractors, indicating facilitated disengagement from negative information. The corresponding bias index correlated negatively with depression levels. Under explicit goal-directed demands, individuals with high depressive symptoms displayed facilitated processing of happy faces and accelerated disengagement from sad faces, rather than an enhanced negativity bias. This pattern tentatively suggests a possible adaptive attentional regulatory mechanism in early depression, although the findings were limited to the 8-face condition and no significant group differences emerged at set sizes 4 or 12. Replication is required before firm conclusions can be drawn. The result underscores the critical influence of task demands and highlights the value of early identification and targeted intervention. Full article

Monoclonal gammopathies of clinical significance (MGCSs) are entities in which a small hematological clone produces a monoclonal immunoglobulin capable of causing organ damage. Neurological involvement remains difficult to diagnose and treat, especially in the context of incidental monoclonal gammopathy of undetermined significance (MGUS)–peripheral neuropathy (PN) associations. We conducted a single-center retrospective study at Fundeni Clinical Institute, Bucharest, from January 2015 to December 2025. The reference population included 300 patients with MGUS. The diagnosis of MGNS was established clinically and/or electrophysiologically, with the exclusion of alternative causes of neuropathy. In total, 35 patients with MGNS were identified (prevalence 11.7%). Neuropathy was more common in IgM MGUS (36.7%) compared to IgG (15%), IgA (14.3%), or light chain MGUS (16.7%), with an increased risk for IgM (OR 3.27, p < 0.001). A total of 88.5% of patients received hematological treatment; neurological response was noted in the majority of treated patients. Mortality was 14.3%, and median OS was not reached. Our findings confirm the dissociation between low clonal load and the severity of organ involvement. IgM MGUS is associated with a significantly increased risk of neuropathy, supporting the need for systematic screening for MGUS in patients with PN and for a multidisciplinary approach. Full article

Background/Objectives: Glypican-1 (GPC1) is a heparan sulfate proteoglycan that plays a critical role in regulating various signaling pathways and tumor development. Overexpression of GPC1 promotes tumor cell proliferation and invasiveness, and is associated with poor clinical outcomes. Therefore, anti-GPC1 monoclonal antibodies (mAbs) have been developed in various modalities for tumor therapy. Methods: We developed novel anti-GPC1 mAbs using a flow cytometry-based high-throughput screening approach, the Cell-Based Immunization and Screening (CBIS) method. Results: A clone G₁Mab-28 (IgG₁, κ) reacted with GPC1-overexpressed Chinese hamster ovary-K1 (CHO/GPC1), but not parental CHO-K1, in flow cytometry. Furthermore, G₁Mab-28 recognizes the endogenous GPC1-expressing human esophageal squamous cell carcinoma KYSE770 cell line. Furthermore, G₁Mab-28 specifically recognized only CHO/GPC1, but not the other GPC family-overexpressed CHO-K1. The dissociation constant values of G₁Mab-28 for CHO/GPC1 and KYSE770 were determined to be 3.3 × 10⁻⁸ M and 4.6 × 10⁻⁹ M, respectively. Moreover, G₁Mab-28 is suitable for Western blotting and immunohistochemistry. Conclusions: G₁Mab-28, established by the CBIS method, is versatile for basic research and is expected to contribute to antibody-based tumor therapy. Full article