Search Results (586)

Anomaly detection models trained exclusively on healthy data are widely used in wind turbine condition monitoring because failure data are scarce, heterogeneous, and often unavailable. However, these models produce anomaly indicators that are sensitive not only to fault-related degradation but also to normal operational variability, transient disturbances, and changes in loading conditions. As a result, the practical behavior of an alarm system depends not only on the anomaly detection model but also on the decision rule used to activate and maintain alarm states. This study presents a decision-oriented evaluation of persistence-based alarm confirmation in wind turbine anomaly detection. Four representative techniques are analyzed within a unified framework: Isolation Forest, One-Class Support Vector Machine, Referenced Moving Window Principal Component Analysis using Q-statistic and percentage component weight indicators, and Autoencoder-based reconstruction error. The evaluation combines controlled OpenFAST simulations of rotor unbalance under different severity and noise conditions with an industrial SCADA case study involving a documented main bearing fault. Results show that temporal persistence strongly shapes alarm outcomes across methods and datasets. Low persistence values favor early detection but promote alarms from isolated threshold exceedances, whereas moderate persistence substantially reduces false positives while preserving detection capability in severe and well-observable faults. Excessive persistence increases detection latency and missed detections, particularly for weak, intermittent, or slowly evolving fault signatures. These findings indicate that persistence-based alarm confirmation should be treated as an explicit decision-level configuration variable, rather than as a fixed post-processing or alarm-state heuristic, when designing anomaly detection systems for wind turbine condition monitoring. Full article

Background: Prolonged intermittent fasting is associated with metabolic and immune adaptation; however, the extent to which transcriptional immune responses translate into systemic inflammatory changes, and how these processes relate to autophagy, senescence-associated signaling, and inflammasome regulation, remains incompletely understood. Methods: This study represents a secondary integrative analysis of a previously characterized cohort of healthy young men undergoing Ramadan fasting. Longitudinal data across four time points (T1–T4) were re-analyzed, integrating targeted mRNA profiling of autophagy-, senescence-, and inflammasome-related genes with circulating cytokines and clinical parameters. Baseline-stratified regression and exploratory clustering were applied to assess inter-individual variability. Results: Fasting was associated with modest reductions in body weight (−1.78 ± 1.44 kg, FDR < 0.001) and BMI (−0.56 ± 0.47 kg/m², FDR < 0.001), without hemodynamic instability. Autophagy-related transcripts (ULK1, ATG5) were upregulated, while senescence markers showed divergent regulation (p53↑, p21↓). Inflammasome-related genes (NLRP3, IL1B) increased at the transcriptional level; however, circulating IL-1β and IL-6 remained stable and TNFα decreased (FDR < 0.001), indicating dissociation between transcriptional priming and systemic cytokine output. ΔNLRP3 was inversely associated with baseline expression (β = −1.88, R² = 0.31, p = 0.0056), suggesting baseline-dependent transcriptional responsiveness. Responses followed a continuous spectrum rather than discrete subtypes. Conclusions: Prolonged intermittent fasting is associated with coordinated immunometabolic remodeling characterized by transcriptional changes in autophagy-, senescence-, and inflammasome-related pathways, without systemic inflammatory escalation. Inflammasome-related responses appear baseline-dependent, suggesting graded immunological responsiveness rather than a uniform activation. These findings are hypothesis-generating and support the interpretation of fasting as a graded immunometabolic modulator rather than a uniform pro-inflammatory stimulus within the limitations of a secondary exploratory analysis. Full article

Background: Serum uric acid (UA) is increasingly recognized as a cardiovascular (CV) risk factor, with evidence suggesting that CV risk may occur at levels below conventional hyperuricemia thresholds. However, real-world comparative data on the effects of dietary interventions on UA are limited. Objective: The primary objective of this study was to compare the effects of a very low-calorie ketogenic diet (VLCKD), intermittent fasting (IF), and standard dietary advice (free diet, FD) on UA levels and UA-defined CV risk in hypertensive postmenopausal women. Methods: In this prospective, single-center, real-world clinical study, 43 women with essential hypertension and obesity underwent dietary interventions. UA levels were assessed at baseline and after 6 months. Hyperuricemia was defined using both the conventional threshold (≥6.0 mg/dL) and the CV risk-oriented Uric Acid Right for Heart Health (URRAH) cut-off (≥4.7 mg/dL). Analyses included paired tests and ANCOVA adjusted for baseline UA. Results: At baseline, over half of participants exceeded the URRAH threshold. Only VLCKD significantly reduced UA levels (−1.23 mg/dL; p < 0.001), remaining independently associated after adjustment (β = −0.95 mg/dL; p = 0.007). URRAH-defined CV risk decreased significantly only in the VLCKD group (55.6% to 22.2%), with one-third transitioning to lower risk. Conclusions: VLCKD significantly reduced UA levels and UA-defined CV risk, supporting its role as a potentially effective lifestyle intervention in this population. Full article

Slip ring–brush assemblies are widely used in satellite mechanisms to transmit power and signals across rotating interfaces. Under authentic space environments—vacuum, radiation-dominated thermal exchange, and long-duration operation—the coupled effects of mechanical contact dynamics, electrical conduction, intermittent separation, and arcing can accelerate wear and degrade reliability. This paper presents a surface-resolved multiphysics model for multi-track slip rings with staggered brushes. The ring surface is discretized on a circumferential–axial grid and endowed with correlated 3D roughness, enabling interference-based asperity contact. Brush normal dynamics (mass–spring–damper) convert runout and micro-vibration into normal-force ripple and separation events. Electrical conduction is modeled by a parallel admittance network combining pressure-dependent micro-contact conduction and an event-based arc channel activated by separation, opening velocity, and current density with stochastic ignition. A 2D thermal model with ADI integration accounts for Joule/friction heating, radiative cooling, and optional hub conduction. Wear evolves via an Archard-type mechanical term and an arc-energy-driven erosive term. A FAST–MACRO multiscale scheme (20 s FAST, 100 h MACRO with periodic recalibration) enables tractable long-horizon wear prediction while preserving arc statistics. Baseline simulations for a 28 V bus demonstrate rare but nonzero arc activity and predict spatially non-uniform wear at the micrometer scale after 100 h. Full article

Intermittent fasting (IF) has emerged as a popular dietary intervention with potential metabolic and endocrine benefits. However, its effects on sexual function and reproductive health remain incompletely understood. This comprehensive review synthesizes current evidence from human clinical trials and animal studies examining the impact of various IF protocols—including time-restricted eating (TRE), alternate-day fasting (ADF), and Ramadan fasting—on male and female sexual function, reproductive hormones, and fertility outcomes. In males, limited human data suggest preserved erectile function but reduced sexual desire during Ramadan fasting, with neutral effects on testosterone in obese adults undergoing TRE. Animal studies demonstrate context-dependent effects, with IF protecting against high-fat diet-induced reproductive dysfunction while potentially impairing spermatogenesis under prolonged energy restriction. In females, IF shows promise for improving hyperandrogenism and menstrual regularity in polycystic ovary syndrome (PCOS), mediated by enhanced insulin sensitivity and reduced free androgen index. However, direct measurements of female sexual function domains (libido, arousal, lubrication, orgasm) are largely absent from the literature. Mechanistic pathways involve modulation of the hypothalamic–pituitary–gonadal (HPG) axis, insulin–adipokine signaling, sex hormone-binding globulin (SHBG), and oxidative stress pathways. Evidence quality is limited by small sample sizes, heterogeneous protocols, short follow-up periods, and predominance of animal data. While IF may offer reproductive benefits in metabolically compromised populations, particularly women with PCOS, caution is warranted in young, lean, or energy-deficient individuals. Future research should employ standardized IF protocols, validated sexual function instruments, and long-term fertility endpoints to establish evidence-based clinical recommendations. Full article

Background: Intermittent fasting (IF) is a popular dietary strategy for improving weight and cardiometabolic health. However, its effectiveness and potential risks across different adult age trajectories remain unclear. This systematic review and meta-analysis evaluated the age-specific effects of IF on body composition and cardiometabolic markers. Methods: Following PRISMA 2020 guidelines, PubMed, Scopus, and Web of Science were searched for randomized controlled trials (RCTs) up to September 2025. Participants were stratified into three cohorts: <30 years, 30–44 years, and ≥45 years. Random-effects meta-analyses and leave-one-out sensitivity analyses were conducted on body composition, lipid profiles, glycemic markers, and blood pressure. Additionally, a conservative methodological sensitivity analysis (imputed correlation r = 0.5) and subgroup analyses by fasting modality (TRF vs. intermittent energy restriction) were performed. Risk of bias was assessed using the RoB 2 tool. Results: Analysis of 28 RCTs (N = 1833) demonstrated that IF significantly reduced body weight and BMI across all age groups. Notably, subgroup analyses revealed comparable physiological responses between TRF and intermittent energy restriction modalities. Cardiometabolic adaptations were highly age-dependent. Young adults exhibited significant reductions in fasting insulin and HOMA-IR, alongside a robust reduction in fat mass. However, a significant loss of fat-free mass (FFM) was observed in both young and older cohorts. While middle-aged and older adults experienced the most pronounced improvements in triglycerides, systolic blood pressure, and insulin sensitivity, our conservative sensitivity analysis unmasked a significant elevation in low-density lipoprotein cholesterol (LDL-C) in this group, mirroring the robust LDL-C increase observed in young adults. Early middle-aged adults exhibited highly variable responses with no significant overall improvements in cardiometabolic parameters. Conclusions: IF is an effective weight-management tool, but elicits distinct, age-specific metabolic trajectories. While middle-aged and older adults derive pronounced cardiometabolic benefits, they face critical risks of lean mass depletion, necessitating a combined “IF+” strategy (adequate protein and resistance training). Crucially, the age-specific risk of LDL-C elevation dictates a mandate for vigilant lipid monitoring. Given that the certainty of evidence was rated as low to very low per GRADE criteria, these age-specific patterns should be interpreted as hypothesis-generating, warranting validation in future large-scale trials. Full article

Driven by the dual-carbon goals, the high-proportion integration of distributed renewable energy into distribution networks poses significant challenges to operational flexibility due to the inherent intermittency and uncertainty of renewable sources. While direct control of flexible resources is possible, it often entails high costs and lacks mechanisms to incentivize proactive participation. This paper investigates the flexible optimal operation of distribution networks with the active participation of aggregated user-side flexible resources. A two-layer day-ahead optimization framework is proposed. At the lower layer, user-side flexible resource participants employ a deep learning-based intelligent decision-making model to formulate their clearing strategies rapidly, eliminating the need for detailed physical models and iterative calculations. At the upper layer, the distribution network operator (DNO) establishes a multi-objective optimization model that simultaneously minimizes comprehensive operational costs and the net load fluctuation rate to enhance flexibility. The model coordinates distributed generation, energy storage, and user-side resources via a time-of-use pricing mechanism. The fast non-dominated sorting genetic algorithm (NSGA-II) is adopted to obtain the Pareto-optimal set, from which the optimal solution is selected using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Case studies on a modified IEEE 33-bus distribution system demonstrate that the proposed method effectively guides the demand response of user-side resources. The results confirm significant improvements in the economic operation of the distribution network, along with enhanced flexibility evidenced by increased net load adequacy and a reduced net load fluctuation rate, thereby improving the system’s accommodation capability for renewable energy. Full article

Background/Objectives: Diabetic retinopathy (DR) is the most common microvascular complication of diabetes and a significant cause of severe visual impairment. Intermittent fasting (IF) has demonstrated metabolic benefits. We investigated the association between IF and DR risk in individuals with prediabetes and diabetes. Methods: This retrospective cohort study included participants of the Korean National Health and Nutrition Examination Survey 2017–2018 aged ≥40 years who were diagnosed with diabetes or prediabetes who had fundus photography and dietary pattern data. Participants were allocated to the IF (fasting for 24 h or skipping breakfast or dinner) and regular diet groups. Demographic, dietary pattern and clinical data, including DR prevalence, were compared between the groups. Multiple logistic regression assessed the association between IF and DR risk. Results: Of 922 participants, 831 followed a regular diet while 91 practiced IF. The participants in the IF group were significantly younger and more obese, had higher fat intake, and showed a lower prevalence of DR than those in the regular diet group (8.8% vs. 20.6%, p = 0.010). After adjusting for multiple covariates, including demographics, comorbidities, health behaviors, biochemical parameters, and nutritional intake profiles, IF was associated with a 70% reduced risk of DR (OR 0.30, 95% CI 0.12–0.65, p = 0.005). This association did not differ across subgroups (all p for interaction > 0.05). Conclusions: IF was significantly associated with reduced DR risk in this study. Further studies are needed to validate the effectiveness of IF as a dietary intervention for DR. Full article

Background/Objectives: Intermittent fasting (IF) has been widely investigated for its metabolic effects, including improvements in insulin sensitivity, lipid metabolism, and inflammatory markers. However, its psychological and experiential dimensions remain comparatively underexplored. The present narrative review examines IF within a psychobiological framework, integrating evidence from metabolic science, neuroendocrinology, and affective neuroscience to explore its potential impact on emotional regulation and interoceptive processes. Methods: A structured narrative literature search was conducted across PubMed, Scopus, and Google Scholar, focusing on studies published between 2010 and 2025. Eligible studies included human and relevant animal research addressing metabolic, hormonal, interoceptive, and psychological responses to IF. Evidence was synthesized thematically to identify convergent mechanisms linking metabolic adaptations to emotional and regulatory outcomes. Results: Available literature suggests that IF is associated with a metabolic shift toward lipid utilization, characterized by increased ketone body production, particularly β-hydroxybutyrate. These adaptations appear to be accompanied by modulation of neuroendocrine pathways and may influence central nervous system functioning through mechanisms potentially related to neuroinflammation, mitochondrial efficiency, and synaptic plasticity. Emerging evidence further suggests that IF may modulate BDNF signaling and gut–brain axis activity, although direct causal pathways in humans remain to be established. At the psychological level, IF is associated with heterogeneous emotional outcomes: structured fasting protocols have been linked to modest improvements in perceived stress and mood in metabolically healthy individuals, whereas irritability, anxiety, or behavioral rigidity may emerge in those with pre-existing psychological vulnerabilities. Individual differences in interoceptive sensitivity, emotion regulation strategies, and moderating biological factors—including sex, circadian timing, and habitual physical activity—appear to influence these responses. Conclusions: Overall, IF may be conceptualized as a context-dependent psychobiological stressor whose effects extend beyond metabolic regulation to include interoceptive and emotional processes. These effects appear bidirectional, potentially promoting psychological resilience in some individuals while increasing the risk of affective destabilization or maladaptive behaviors in others. Current evidence remains limited by a lack of integrative and longitudinal studies combining metabolic and psychological measures. Future research adopting multidisciplinary approaches is needed to clarify the mechanisms underlying individual variability and to better define the potential benefits and risks of IF in both clinical and non-clinical populations. Full article

Background/Objectives: Intermittent fasting (IF) has gained increasing attention as a nutritional strategy to improve metabolic health, body composition, and disease-related outcomes. However, its effects are often interpreted as broadly uniform, despite growing evidence that biological sex may modulate fasting responses. This narrative review examines sex-specific differences in the physiological, endocrine, clinical, and psychosocial effects of IF in women and men. Methods: We conducted a narrative synthesis of human and preclinical evidence addressing IF protocols, mechanisms, benefits, adverse effects, and sex-related differences. Particular attention was given to substrate metabolism, hormonal regulation, neuroendocrine sensitivity, energy availability, exercise performance, chronic disease management, aging-related outcomes, and psychological or behavioral responses. Results: The available literature suggests that women and men share several beneficial responses to IF, including improvements in body composition and cardiometabolic markers, but may differ in the magnitude, tolerability, and mechanistic basis of these effects. Women appear to show greater sensitivity of reproductive and neuroendocrine function to energetic stress, particularly under conditions of low energy availability, high exercise load, or reproductive vulnerability. In contrast, men may exhibit preserved functional outcomes despite measurable endocrine adaptations, including changes in testosterone dynamics. Across both sexes, responses vary according to fasting protocol, nutritional adequacy, baseline metabolic status, life stage, and clinical context. Conclusions: Current evidence supports a sex-informed and context-specific interpretation of IF rather than universally applicable fasting prescriptions. Direct sex-comparative studies remain scarce, and many conclusions are inferred from parallel male and female studies. Future research should integrate sex as a core biological variable in precision nutrition and fasting-based interventions. Full article

This article presents a low ripple, high voltage-conversion-ratio (VCR = 6), two-stage step-up converter intended for power-burst applications. The first boost stage raises the battery voltage to a maximum of 35 V, while the subsequent low dropout regulator (LDO) stage suppresses the ripple of the final output. Unlike conventional structures in which control circuits operate above a ground-referenced rail, the proposed shunt-current-reusing technique places most of the control circuits within a narrow floating dropout region (V_DROP) between the boost output (V_BST) and the LDO output (V_OUT), thereby achieving nearly 100% current efficiency through current recycling. Adaptive adjustment of V_DROP (0.5 V at light load and 0.65 V at heavy load) balances output ripple against the loss of the LDO stage. Consequently, the proposed converter achieves both high efficiency (>85%) and low ripple (<2 mV) over a load range from 200 μA to 100 mA, with a peak efficiency of 90.4% at a 20 mA load. Hysteretic control of the boost stage combined with the high bandwidth (BW = 1.2 MHz) of the LDO stage yields a fast transient response (<20 μs). The proposed techniques address the requirements of applications that demand high intermittent power bursts (>1 W) at high supply voltage (>20 V) while maintaining low quiescent current consumption under most load conditions (<10 mA), as exemplified by light detection and ranging (LiDAR), haptic sensors, and micro electromechanical system (MEMS) drivers. Full article

Intermittent fasting confers protection in diverse diseases through various mechanisms, including the clearance of senescent and pathogenic cells, modulation of tissue inflammation and enhancement of stem/progenitor cell niche and functionality. Our previous study demonstrated the beneficial impact of alternate-day fasting (ADF) on xerostomia and sialadenitis, along with an improvement in salivary gland ductal compartments, where salivary gland progenitor cells reside, in non-obese diabetic mice, a spontaneous model of Sjögren’s syndrome (SS). In the present study, we induced SS-associated hyposalivation in KRT5^CreERT2; R26^tdTomato lineage tracing mice by immunizing them with submandibular gland proteins from wild-type C57BL/6 mice. ADF alleviated salivary gland hypofunction, which was accompanied by decreased expression of the senescent cell marker p16^INK4a, reduced protein levels of anti-apoptotic proteins BCL-2, BCL-XL, and MCL-1, and attenuated NLRP3 inflammasome activity in the submandibular glands, particularly within the ductal compartments, of this inducible model. Furthermore, immunofluorescence staining of submandibular gland sections revealed the expression of the acinar cell marker aquaporin 5 in a small subset of Keratin 5⁺ cells in 2 of 9 mice that were subjected to ADF, whereas no such cells were detected in the control mice. Taken together, these findings indicate that ADF favorably modulates the salivary gland progenitor cell niche, potentially by promoting apoptosis-mediated senescent cell clearance, suppressing NLRP3 inflammasome signaling, and promoting Keratin 5⁺ progenitor cell-derived acinar cell replenishment, thereby contributing to the structural and functional restoration of damaged salivary glands in autoimmune exocrinopathy. Full article

Obesity is currently recognized as a chronic and multifactorial disease. According to epidemiological data released by the World Health Organization in 2022, more than 2.5 billion adults were overweight and more than 890 million were affected by obesity. The aim of this narrative review is to clarify what leads to overweight and obesity, to explain the concept of energy balance, to address the limited effectiveness of dietary products marketed for weight reduction, to examine commonly promoted nutritional strategies for weight loss and to challenge claims of their superiority. The most recent, robust, and high-quality evidence available on the topic was selected, with particular emphasis on systematic reviews and meta-analyses. Overweight and obesity are characterized by an excessive accumulation of fat mass. At the basis of excessive adipose tissue accumulation lies a persistent positive energy balance. Energy balance is generally considered a central physiological determinant of body weight regulation. Approaches that do not explicitly incorporate this principle may be associated with variable or unsustained outcomes. Available evidence suggests that, when an equivalent caloric deficit is achieved, differences in the timing of energy intake or in dietary patterns—such as intermittent fasting or low-carbohydrate diets—are not consistently associated with greater weight loss compared with other guideline-based dietary strategies. Some supplements supporting weight loss, in selected cases, may offer marginal support; however, based on the current state of scientific knowledge, no product represents an effective shortcut for weight loss. Full article

Background/Objective: Intermittent fasting (IF) shows promise for metabolic and mental health benefits, but evidence in older adults remains limited. This study systematically evaluated the safety and effectiveness of IF in adults aged ≥60 years, comparing different protocols using network meta-analysis. Methods: Systematic review and network meta-analysis following Cochrane and PRISMA guidelines were conducted, producing a literature search until June 2025 across PubMed, Scopus, and ScienceDirect databases, with inclusion criteria comprising randomized controlled trials, clinical trials, and observational studies evaluating IF in adults ≥60 years. Network meta-analysis compared time-restricted eating (TRE), IF 5:2 method, Islamic Sunnah fasting (ISF), Healthy Living Diet and usual diet. The NMA was conducted exclusively using randomized controlled trials (RCTs; n = 7); pre–post trials and observational studies were included solely in the narrative systematic review component and did not contribute to any pooled NMA estimates. Observational data contributed exclusively to the narrative synthesis. Results: Thirty-one studies were included; seven RCTs were eligible for network meta-analysis. ISF and TRE 16:8 were most effective for weight (ISF: −2.36 kg; TRE 16:8: −1.92 kg) and BMI reduction (−0.81 and −1.01 kg/m²) without lean mass loss. Findings on cardiometabolic parameters, mental health, and cognitive function are based on the narrative synthesis of individual studies. Long-term structured IF was associated with improvements in standardized cognitive performance assessed via validated instruments. However, very restrictive eating windows (≤10 h) and prolonged fasting (>12.38 h) were associated with adverse outcomes, including lower cognitive scores and 58% increased cardiovascular mortality. Conclusions: TRE 16:8 and ISF showed the strongest comparative evidence for weight reduction in the RCT-based NMA, with acceptable short-term safety profiles in the included trials. In the narrative review, these protocols were associated with clinically meaningful improvements in body weight, metabolic markers, and blood pressure while generally preserving lean muscle mass in older adults. The cardiovascular mortality risk associated with very restrictive eating windows may emphasize the importance of moderate fasting approaches in this vulnerable population. Further long-term research is needed to confirm optimal protocols and identify at-risk subgroups. Full article