Search Results (1,204)

Multi-terminal HVDC transmission lines contain a T-zone, where no explicit line boundary element exists. Conventional traveling-wave (TW) protection schemes mainly identify faults by utilizing the attenuation characteristics of TWs caused by transmission lines and boundary elements. Therefore, their performance is sensitive to transition resistance and sampling frequency, and they cannot be directly applied to fault identification in the T-zone. To address this issue, this paper proposes a single-ended directional protection scheme based on the normalized covariance of line-mode backward TWs. The proposed method constructs the protection criterion according to the overall waveform variation in line-mode backward TWs. It does not rely on boundary-effect-induced wave attenuation or the extraction of specific high- or low-frequency components. Fault regions are identified using only local measurements collected by the protection devices installed on both sides of the T-zone, and the fault pole is determined by the bipolar voltage ratio. A ±500 kV three-terminal MMC-based multi-terminal DC system is established in PSCAD to evaluate the proposed scheme. Simulation results show that the proposed method identifies the fault region within a 0.5 ms data window. It can tolerate transition resistances up to 300 Ω and 40 dB Gaussian white noise. The proposed scheme features fast operation, low computational complexity, and high robustness. Full article

Magnesium–yttrium (Mg–Y) alloys are promising biodegradable orthopedic implant materials because of their mechanical compatibility with bone tissue; however, their degradation rate in physiological environments requires further control. In this study, the surfaces of gravity-cast Mg–3.5Y alloy were treated with micro-arc oxidation (MAO) in Na₂SiO₃-based electrolytes supplemented with diammonium hydrogen phosphate ((NH₄)₂HPO₄), eggshell powder, or a mixture of both, to form corrosion-resistant ceramic coatings containing calcium and phosphates. The MAO process utilized a bipolar pulsed DC power supply for 8 min, and the resulting coating characteristics were analyzed via FESEM, EDS, XRD, Vickers microhardness, electrochemical test (potentiodynamic polarization), and simulated body fluid immersion tests. Cross-sectional SEM and EDS revealed that all MAO-treated samples contain Mg, Na, O, Si, and elements derived from the electrolyte additives. Electrolytes containing diammonium hydrogen phosphate not only produced thicker films but also facilitated the deposition of calcium-related species derived from eggshells; in contrast, the deposition of calcium is limited when only eggshell powder is added to the electrolyte. X-ray diffraction analysis confirms the formation of MgO, Mg₂SiO₄, and calcium-containing compounds within the coating. Energy-dispersive X-ray spectroscopy spectrum further verified the presence of these compounds in the deposited films. Electrochemical tests in simulated body fluid revealed that the electrolyte containing only diammonium hydrogen phosphate yields the highest open-circuit potential and corrosion current; further immersion tests demonstrate better corrosion resistance. Overall, the results show that combining diammonium hydrogen phosphate with eggshell-derived calcium compounds can be an effective method for producing multifunctional MAO coatings on Mg–Y alloys. For microhardness, adding diammonium hydrogen phosphate and eggshell to Na₂SiO₃-based MAO electrolytes yields a harder coating, whereas Na₂SiO₃-based electrolytes with only diammonium hydrogen phosphate would lead to a better corrosion-resistant coating. These differences are caused by differences in composition and microstructure in the deposited films. This study offers a viable production method for application in biodegradable materials. Full article

Background/Objectives: Bipolar depression impairs psychosocial functioning, cognition, and quality of life. Evidence regarding adjunctive exercise remains limited. This pilot study evaluated the clinical and biological effects of adjunctive exercise in patients with bipolar depression. Methods: In this multicenter cluster-randomized controlled trial, 26 hospitalized patients were assigned by facility to treatment as usual plus supervised exercise (TAU + Ex) or supervised stretching (TAU + SC) for 6 weeks. Twenty-four completed the study (TAU + Ex, n = 14; TAU + SC, n = 10). Clinical outcomes and plasma tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-1β, IL-2, brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor-A (VEGF-A) were assessed at baseline and week 6. The trial was registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR; UMIN000045877; registered on 1 December 2021). Results: FAST and QIDS-SR scores improved significantly in both the exercise and stretching groups after the 6-week intervention, but no significant group × time interactions were observed. No significant group, time, or group × time effects were observed for any plasma biomarker. Before correction for multiple comparisons, nominal correlations were observed between changes in IL-1β and FAST, BDNF and FAST, and VEGF-A and Spotter performance. None remained statistically significant after Benjamini–Hochberg FDR correction. Conclusions: Adjunctive exercise therapy was not superior to active stretching. The exploratory biomarker–outcome correlations did not remain significant after correction for multiple comparisons and should be considered hypothesis-generating. Larger, adequately powered randomized controlled trials are warranted. Full article

Bipolar disorder is characterized by marked circadian and metabolic vulnerability, but direct evidence linking the timing of food intake to its course remains sparse. This structured narrative review examines chrono-nutritional disruption, including irregular meal timing, nocturnal eating, prolonged or inconsistent fasting, eating-window variability, and eating jet lag, as a potential behavioral correlate and mechanistic contributor to bipolar instability. PubMed/MEDLINE, Scopus, and Web of Science were searched for literature published from January 2000 to 30 June 2026, supplemented by predefined foundational studies. Evidence was organized as direct bipolar-specific, indirect human, or translational/preclinical. The strongest direct findings are cross-sectional associations involving night eating, eveningness, sleep disturbance, and functioning; bipolar-specific longitudinal and completed interventional evidence remains insufficient. Indirect human and experimental studies suggest that biologically mistimed eating can alter peripheral-clock entrainment, glucose–insulin regulation, cortisol rhythmicity, mitochondrial function, inflammatory signaling, and gut microbial rhythms. On this basis, we propose a hypothesis-generating chrono-metabolic model in which food timing may interact bidirectionally with sleep, mood state, medication effects, and metabolic health. Routine attention to nutritionally adequate and feasible meal regularity may be considered within broader monitoring of social rhythms, but it has not been shown independently to prevent relapse or improve mood outcomes. Time-restricted eating is investigational in bipolar disorder and should be evaluated only in carefully monitored research or specialist contexts. Prospective within-person studies and adequately powered trials are required before chrono-nutritional strategies can be regarded as evidence-based bipolar interventions. Full article

This study examined direct and indirect associations of Machiavellianism, narcissism, psychopathy, and sadism with suicidal ideation through depression, anxiety, and stress in psychiatric patients. A cross-sectional sample of 210 patients completed the Short Dark Tetrad (SD4), Depression Anxiety Stress Scales-21 (DASS-21), and Suicidal Ideation Attributes Scale (SIDAS). Regression paths were estimated using robust maximum likelihood, whereas indirect effects were evaluated using 10,000 bootstrap resamples. Because 92 participants (43.8%) had SIDAS = 0, two-part sensitivity analyses separated the occurrence from the severity of suicidal ideation; additional analyses excluded the two smallest diagnostic groups. Depression, stress, and anxiety correlated with SIDAS (r = 0.560, 0.509, and 0.466, respectively). The sadism–stress–SIDAS indirect effect was significant in the primary model (B = 0.147; 95% bootstrap CI [0.037, 0.291]), after covariate adjustment (B = 0.126; 95% bootstrap CI [0.016, 0.266]), and after excluding psychotic and bipolar groups (B = 0.115; 95% CI [0.006, 0.259]). In two-part analyses, depression was associated with SIDAS occurrence, whereas stress and sadism were associated with severity among participants with SIDAS > 0. The findings support a stress-related indirect association between sadism and suicidal ideation, but causal interpretation is not warranted. Full article

To enhance the corrosion resistance, adhesion strength, and electrical conductivity of bipolar plates for proton exchange membrane fuel cells (PEMFCs), a duplex surface treatment comprising plasma nitriding (PN) followed by arc ion plating of a TiN coating was applied to 316L stainless steel. The duplex coating exhibited a bilayer structure with a TiN top layer (~1.3 μm) and a nitrided diffusion layer (~9.2 μm). Compared with a single TiN coating, it showed superior corrosion resistance in both cathode and anode environments, with corrosion current densities of 0.069 and 0.422 μA·cm⁻², respectively, and maintained stable performance over 10,000 s of potentiostatic polarization. Its interfacial contact resistance at 140 N·cm⁻² was 7.84 mΩ·cm², below the Department of Energy (DOE) 2025 target of 10 mΩ·cm². The water contact angle also increased, benefiting water management. The nitrided interlayer substantially enhanced the adhesion strength of the TiN coating. These findings confirm that the sequential combination of plasma nitriding and TiN coating is an effective strategy for improving the corrosion resistance, electrical conductivity, and adhesion of stainless steel bipolar plates for PEMFC applications. Full article

Sleep architecture alterations have been shown in major psychiatric disorders, but the contribution of demographic factors to between-study heterogeneity remains insufficiently characterized. This study reports a transdiagnostic systematic review and meta-regression of case-control polysomnographic studies comparing schizophrenia, bipolar disorder, and unipolar depression with healthy controls. The factors age and sex as possible moderators across harmonized case-control polysomnographic studies have been analyzed. Eligible studies reported diagnostic criteria, treatment status, age, and sex. Because the UD literature encompassed developmentally distinct populations, pediatric/adolescent and adult studies were analyzed separately. Standardized mean differences were synthesized using random-effects models with REML estimation. Univariable mixed-effects meta-regressions assessed study-level mean age and sex composition as moderators within each diagnostic group. Study-level mean age and sex composition significantly moderated delta sleep effect sizes in drug-naive schizophrenia, while study-level mean age significantly moderated REM time in drug-free schizophrenia. In bipolar disorder, study-level mean age moderated REM sleep time effect sizes during mania, whereas sex composition moderated delta sleep and REM density effect sizes. In UD, study-level mean age moderated total sleep time, and sex composition moderated wake after sleep onset only in pediatric/adolescent studies, whereas no significant moderation was observed in adult samples. No significant moderator effects were identified during bipolar depression. Overall, demographic composition explained only a modest proportion of between-study heterogeneity. Interpretation is limited by the ecological nature of study-level meta-regression and residual study heterogeneity. Full article

Lithium remains the gold-standard maintenance treatment for bipolar disorder (BD) and is distinguished by its unique anti-suicidal and neuroprotective properties. Beyond its established psychiatric efficacy, growing evidence suggests that lithium may modulate fundamental mechanisms of biological aging. In parallel, cellular senescence has emerged as a central process linking oxidative stress, chronic inflammation, mitochondrial dysfunction, and impaired cellular resilience with neurodegeneration and psychiatric disease. Notably, BD is increasingly associated with features of accelerated aging, including telomere shortening, increased inflammatory burden, and structural brain changes consistent with premature brain aging. In this review, we discuss current evidence supporting lithium as a potential senostatic agent in the central nervous system. Experimental studies indicate that lithium attenuates several hallmarks of cellular senescence and promotes cellular resilience under conditions of oxidative, inflammatory, and genotoxic stress. These effects appear to involve coordinated modulation of neuroinflammatory signaling, mitochondrial function, oxidative stress responses, genomic stability, and neurotrophic pathways. Clinical findings further suggest that chronic lithium treatment may be associated with preserved telomere length and attenuated biological brain aging in BD. Collectively, the available data support a model in which lithium acts not only as a mood stabilizer but also as a broader regulator of aging-associated processes relevant to neuropsychiatric and neurodegenerative disorders. Although the senomodulatory effects of lithium appear context- and cell-type-dependent, its established clinical use and pleiotropic biological actions make it a promising candidate for translational senotherapeutic research. Full article

This proposed study presents an in-situ experimental approach for investigating anode-side water dynamics through detailed analysis of pressure-drop data measured across multiple segments of bipolar plate flow channels. A theoretical model was first developed to predict pressure-drop profiles and liquid-water distribution in parallel multiphase flow channels. Based on the model, a bipolar plate with integrated multi-point pressure sensors was designed to enable real-time, spatially resolved monitoring of gas–liquid dynamics and provide advanced diagnostic capabilities. The proposed system was successfully implemented in a single Proton Exchange Membrane Fuel Cell (PEMFC) with an active area of 282 cm², which allows accurate identification of the timing and location of flooding events during operation. Experimental results showed that inadequate water management can cause flooding under steady-state conditions, while water accumulation is more prominent during startup and load-reduction processes. Additionally, the effects of reactant flow rate, humidity, and circulating water temperature on water distribution within the channels were systematically evaluated. Based on these findings, a closed-loop diagnostic and control framework is proposed by enabling dynamic adjustment of operating parameters according to pressure-drop characteristics for real-time optimization of water management and improved fuel cell performance. Full article

Citric acid-based leaching is gaining attention as an environmentally friendly alternative to conventional sulfuric acid-based processes for recycling spent lithium-ion batteries (LIBs), but it generates sodium citrate (Na₃Cit)-rich wastewater that is difficult to treat using conventional technologies. Bipolar membrane (BM) electrodialysis (BMED), particularly a two-compartment BM/cation-exchange membrane (CEM) configuration, offers a simple and energy-efficient solution for simultaneously recovering acids and bases from such wastewater without external reagents, enabling a closed-loop resource-circulation approach that remains largely unexplored for this specific waste stream. This system was applied to treat Na₃Cit wastewater generated from citric acid-based spent LIB leaching, and the recovery feasibility and process performance of citric acid and NaOH were evaluated. The effects of feed concentration, current density, initial base concentration, and initial base volume on NaOH recovery, current efficiency, and energy consumption were investigated. Under the optimal conditions (1.00 M Na₃Cit, 300 A/m², 0.1 M NaOH, 1.25 L), a NaOH recovery of 93.93%, current efficiency of 92.55%, and energy consumption of 0.65 kWh/kg were achieved. This study demonstrates that Na₃Cit wastewater can be treated via BMED without external reagents, yielding high-purity NaOH, whereas the recovered acid stream contains residual unreacted Na₃Cit, and its direct reuse in the leaching process requires further verification. These findings provide a fundamental basis for developing BMED-based resource-circular processes. Full article

Background/Objective: Advances in cardiac computed tomography (CT) now allow high-resolution, three-dimensional reconstruction of the left atrium, enabling precise quantification of left atrial wall thickness (LAWT). However, the relationship between LAWT and electrophysiological properties, particularly as assessed by high-density bipolar voltage mapping, remains poorly defined. The objective was to evaluate left atrial structural remodeling in atrial fibrillation (AF) by integrating three-dimensional CT-derived LAWT maps with high-density bipolar voltage mapping, and to assess the relationship between structural remodeling and electrophysiological changes across AF phenotypes. Methods: In this single-center observational study, 60 patients (30 with paroxysmal AF and 30 with persistent AF) undergoing their first AF ablation were enrolled. Pre-procedural cardiac CT scans were analysed using a validated artificial intelligence (AI)-based method to generate three-dimensional LAWT maps. The left atrium was segmented into five regions (lateral, anterior, septal, posterior, and roof) excluding the pulmonary veins and left atrial appendage. High-density bipolar voltage maps were acquired using the CARTO system and a multipolar catheter. Global and regional LAWT and bipolar voltage values were compared between AF phenotypes. The association between global LAWT and bipolar voltage was assessed at the patient level using Pearson’s correlation coefficient, whereas regional comparisons and associations between LAWT and bipolar voltage were evaluated using linear mixed-effects models accounting for repeated measurements within patients. Results: Patients with persistent AF showed larger left atrial volume (119 ± 26 vs. 102 ± 31 mL; p = 0.024) and a trend toward greater CT-derived LAWT, with significant differences observed in selected atrial regions. Overall mean bipolar voltage and LAWT were 1.86 ± 0.59 mV and 1.45 ± 0.32 mm, respectively. No meaningful linear association was observed between these parameters (global Pearson r = −0.018), a finding that persisted across regions and AF phenotypes. No clinical factors were significantly associated with global LAWT, although heart failure and persistent AF showed a trend toward greater global wall thickness. Conclusions: Compared with paroxysmal AF, persistent AF was associated with a tendency toward increased left atrial wall thickness, consistent with more advanced structural remodeling. The lack of a meaningful correlation between wall thickness and bipolar voltage suggests that LAWT provides complementary structural information beyond electroanatomical mapping. Full article

Water dissociation (WD) at the internal junction of bipolar membranes (BPMs) is the key process enabling acid/base generation under reverse bias, yet the physical origin of its strong enhancement remains debated. In our previous work, we proposed a power-dissipation model in which WD is enhanced by an intense electric field through local power dissipation by autoprotolysis ions. Here, we experimentally validate this model using three commercial BPMs under acid/base and neutral salt conditions and extend it to high current density by incorporating finite water supply to the BPM junction. Under acid/base conditions, two BPMs showed strong field-dominated quadratic behavior, while a catalyst-containing BPM displayed a predominantly linear response, indicating that heterogeneous interfacial catalysis can mask the purely field-driven signature. In neutral $N{a}_{2}S{O}_4$, all three BPMs exhibited excellent quadratic fits, confirming that the predicted $J_{WD}\propto U_j^2$ behavior is robust. The fitted prefactor varied with membrane type and electrolyte configuration, reflecting differences in hydration, junction thickness, transport behavior, and catalysis effect. The model was extended at higher current density to include finite diffusive water supply to the junction. The resulting saturation law links the intrinsic quadratic WD current $J_{\mathrm{W}\mathrm{D}}$ to a water-transport-limited current $J_{\mathrm{l}\mathrm{i}\mathrm{m},2}$, and predicts an inflection point at $J_{\mathrm{W}\mathrm{D},\mathrm{i}\mathrm{n}\mathrm{f}} = 0.25 J_{\mathrm{l}\mathrm{i}\mathrm{m},2}$. Full article

This work constitutes Part III of a comprehensive three-part study that critically reviews techniques for the indirect extraction of the thermal resistance in bipolar transistors using simple DC current/voltage measurements. While Part I focused on thermometer-based methods and Part II examined approaches relying on intersection points between characteristics, this paper mainly investigates techniques exploiting the base current. Their accuracy is assessed by applying them to DC electrothermal characteristics obtained through circuit simulations of an in-house transistor model incorporating nonlinear thermal effects and comparing the extracted thermal resistance data with the formulation embedded in the model. An InGaP/GaAs HBT and a Si/SiGe HBT for high-frequency applications are considered as case studies. The analysis highlights the accuracy, advantages, and limitations of the examined approaches, discussing the impact of theoretical approximations and physical mechanisms. In addition, the analytical method proposed by Menozzi et al. is critically evaluated within the same simulation framework. Overall, the results show that none of the examined techniques provides a universally applicable, straightforward, and robust extraction procedure, since each involves theoretical assumptions and/or practical constraints that restrict its range of validity, numerical robustness, or ease of application. Finally, the findings from all three parts of this study are summarized, and practical guidelines are provided to support the selection and correct application of extraction techniques. Full article

Background: Migraine is a leading cause of disability worldwide and is frequently associated with psychiatric comorbidities that may influence pain perception and treatment response. Anti-CGRP monoclonal antibodies represent an effective preventive treatment, although response variability remains poorly understood, particularly in patients with complex neuropsychiatric profiles. Case Presentation: We report the case of a 49-year-old woman with migraine with a previously chronic course and psychiatric comorbidity, including bipolar disorder and obsessive–compulsive disorder, treated with galcanezumab. The clinical course was characterized by an “on-off-on” pattern, with marked worsening after treatment discontinuation and subsequent improvement after treatment reintroduction. Results: The patient presented with severe emotional distress (BDI-II = 59; STAI = 77–80), a very high self-reported burden of central sensitization-related symptoms (CSI = 100/100) and reduced performance on cognitive screening measures (MoCA = 19/30; BCSE = 18/58). MMPI-3 findings indicated a high level of self-reported psychological distress; however, substantial elevations in symptom-validity indicators required cautious interpretation of the substantive scales. Conclusions: This case illustrates that complex neuropsychiatric comorbidity and psychotropic polypharmacotherapy did not preclude an apparent clinical benefit from galcanezumab. Treatment discontinuation and reintroduction were temporally associated with worsening and subsequent improvement in headache frequency, although causality cannot be established from a single uncontrolled observation. The case also highlights the potential value of coordinated neurological and psychiatric monitoring in patients with migraine and complex neuropsychiatric profiles. Full article

The limitations of conventional inorganic electrodes call for organic alternatives for advanced energy storage. Metal–covalent organic frameworks (MCOFs) integrate the metal active sites of metal–organic frameworks (MOFs) with the high chemical stability imparted by strong covalent bonds in covalent organic frameworks (COFs) while retaining the high specific surface area and tunable porosity of both material classes. Among these, MCOFs constructed from porphyrin and phthalocyanine building units have emerged as a research hotspot in electrochemical energy storage owing to their inherent 18π-conjugated macrocyclic electronic systems, well-defined M–N₄ coordination sites, and potential bipolar charge storage characteristics. This review systematically summarizes recent advances in this class of materials. First, from the perspective of metal center introduction timing, three core synthetic strategies—pre-metallation, simultaneous metallation, and post-metallation—are categorized and evaluated in terms of coordination precision, synthetic efficiency, and scalability potential. Second, the regulatory effects of two-dimensional layered and three-dimensional interpenetrated structures on charge transport pathways and structural stability are elucidated. Subsequently, the applications of porphyrin/phthalocyanine-based MCOFs in lithium-based batteries, zinc-based batteries, sodium/potassium-ion batteries, and supercapacitors are reviewed in detail, with emphasis on the key roles of metal active sites in catalytic conversion, chemical anchoring/confinement, interface stabilization, and pseudocapacitive contribution. Finally, future directions to address key performance and mechanistic bottlenecks are discussed. This review aims to provide a systematic reference for the rational design and energy storage applications of high-performance porphyrin/phthalocyanine-based MCOFs. Full article