Search Results (1,964)

This study includes a comparative analysis of four graphene-based electrochemical sensors used for the detection of melatonin, an endogenous hormone involved in circadian rhythm regulation and associated with various neurological pathologies. The sensors were based on screen-printed electrodes (SPE) modified with graphene (G), graphene modified with gold nanoparticles (AuNPs/G), graphene oxide (GO), and reduced graphene oxide (rGO). Melatonin was extracted from commercially available pharmaceutical products, purified, and characterized using UV-Vis spectroscopy, FTIR spectrometry, and HPLC. The performance of the electrodes was evaluated via cyclic voltammetry, using potassium ferrocyanide and standard melatonin solutions to determine the kinetic characteristics, while square-wave voltammetry was employed to determine the detection and quantification limits. G/SPE showed the best performance, with a detection limit of 0.3424 μM, followed by AuNPs/G/SPE with an LOD of 1.2768 μM. GO/SPE had the poorest performance (LOD 23.1056 μM), and rGO/SPE had an LOD of 5.8503 μM. Testing of sensors on pharmaceuticals showed accurate quantification of melatonin in a complex environment. The results highlight the potential of G/SPE and AuNPs/G/SPE sensors for use in the rapid and accurate detection of melatonin in pharmaceutical and biomedical applications. Full article

Widespread in coastal environments, artificial light at night (ALAN) is suspected to disrupt organisms’ biological rhythms by altering natural light cycles and thus constitutes a growing threat to these ecosystems. This study evaluates the effects of ALAN exposure at low and realistic intensity (~1 lx) on a coastal keystone species, the oyster Crassostrea gigas. The results reveal that ALAN significantly impairs the expression of core circadian clock genes (CgClock and CgBmal1) as well as the valve opening behavior, affecting rhythmic characteristics such as its robustness and daily profile. At the same time, ALAN leads to a decrease in daily shell growth and to a disruption of the gill microbiota, associated with an obliterated day/night difference in microbial alpha diversity. A direct correlation between a decrease in daily rhythm robustness, limitation of shell growth, and some microbial strands is shown, suggesting that biological rhythm disruption caused by ALAN might have harmful physiological consequences in oysters. Full article

The containment of misinformation diffusion on social media is a critical challenge in computational social science. However, prevailing intervention strategies predominantly rely on static topological metrics or time-agnostic learning models, thereby overlooking the profound impact of temporal–demographic heterogeneity. This oversight frequently results in a “spatio-temporal mismatch”, where limited intervention resources are misallocated to structurally central but temporarily inactive nodes, particularly during non-stationary propagation bursts driven by exogenous triggers. To bridge this gap, we propose a Spatio-Temporal Deep Reinforcement Learning (ST-DRL) framework for proactive misinformation defense. By seamlessly integrating continuous trigonometric time encoding with demographic-aware Graph Attention Networks, our model explicitly captures the coupling dynamics between group-specific circadian rhythms and event-driven transmission surges. Extensive simulations on heterogeneous networks demonstrate that ST-DRL achieves a Peak Prevalence Reduction of 93.2%, significantly outperforming static heuristics and approaching the theoretical upper bound of oracle-assisted baselines. Crucially, interpretability analysis reveals that the agent autonomously evolves a “Preemptive Strike” strategy—prioritizing the sanitization of high-risk bridge nodes, such as bots, prior to event onsets—thus establishing a new paradigm for predictive rather than reactive network governance. Full article

Chronotype, an individual’s preferred timing of sleep and activity within a 24 h cycle, significantly influences metabolic health, muscle function, and body composition. This review explores the interplay between circadian rhythms, hormonal fluctuations, and behavioral patterns—such as nutrition timing, physical activity and sleep quality—and their impact on muscle mass, strength, and quality. Evening chronotypes (ETs) are consistently associated with poorer sleep, irregular eating habits, reduced physical activity, and increased risk of obesity, sarcopenia and metabolic disorders compared to morning types (MTs). At the molecular level, disruptions in circadian clock gene expression (e.g., BMAL1, PER2, CRY1) affect protein synthesis, insulin sensitivity, and energy metabolism, contributing to muscle degradation and impaired recovery. The review highlights critical components—targeting chrono-nutrition, sleep quality, and exercise timing—to align lifestyle behaviors with circadian biology, thereby preserving muscle health and improving overall metabolic outcomes. Full article

The circadian cycle regulates metabolism in response to external stimuli, such as light exposure, sleep schedules, and eating patterns. However, misalignment between internal biological rhythms and social demands can compromise food choices, potentially leading to overweight and obesity. This research aimed to assess how a person’s chronotype links to social jet lag (SJL), which in turn would relate to their nutritional status and food consumption patterns as a university student. 617 students from a State University located in the State of Paraná, Brazil, completed a cross-sectional research study that collected sociodemographic information/anthropometrics by means of an online survey. It included self-reported height/weight data and dietary habits. The Munich Chronotype Questionnaire (MCTQ) was utilized to determine each participant’s chronotype classification and SJL calculation. Researchers found that nearly half of the students (49.3%) displayed an Intermediate Chronotype, which is associated with a diet that contained elements of the “Mixed” Diet, meaning there are equal portions of healthy food (Fresh Fruits, Beans, etc.) and unhealthy foods (Sweetened Beverages). The multivariate logistic regression analyses identified age as a significant predictor of obesity risk (OR: 1.15, p < 0.001), while dietary habits such as fruit consumption played a protective role. Additionally, having a breakfast protected them from being classified as obese compared to those who did not eat breakfast (OR = 0.59). Contrary to expectations, late-night supper was not a statistically significant predictor in the adjusted model. Predictors of an Intermediate chronotype included being male and eating morning snacks regularly. The results of this study suggest that students with an intermediate chronotype will predictably have skewed eating patterns, such as skipping breakfast and eating late—both of which affect obesity risks. Nutritional strategies for university students should focus on promoting circadian regularity and optimizing meal timing. Full article

The dramatic shift in human behavior from hunter-gatherer to modern lifestyles has led to a systematic disruption of the human circadian cycle. Contributors include night-shift work, jet lag, and less intuitive but widespread factors, such as exposure to artificial light at night and irregular eating schedules. Circadian disruption is classified as a Group 2A carcinogen by the International Agency for Research on Cancer (IARC). Hepatocellular carcinoma (HCC) is the third most deadly cancer worldwide, with a rising prevalence in Western countries, largely driven by increasing rates of obesity and steatotic liver disease-associated hepatocarcinogenesis. Emerging evidence suggests that circadian disruption plays a significant role in HCC pathogenesis. Several genes involved in metabolism, cell survival, and immunosurveillance are under the control of circadian rhythms. Experimental preclinical data and epidemiological studies have indicated a strong association between circadian disruption and HCC development. Moreover, molecular signatures related to circadian regulation appear to accurately predict the prognosis of patients with HCC. The concept of chronotherapy is also gaining interest, with studies suggesting improved immunotherapy effectiveness when immune checkpoint inhibitors are administered in the morning. This review summarizes the current literature on the impact of circadian disruption on HCC pathogenesis, prognosis, and treatment. Full article

Background/Objectives: Chrononutrition—the temporal organization of food intake relative to circadian rhythms—has emerged as an important factor in cardiometabolic health. While meal timing is typically analyzed as an isolated variable, limited research has examined integrated meal timing patterns, and no study has systematically compared clustering approaches for their identification. This cross-sectional study compared four clustering techniques—traditional (K-means, Hierarchical) and non-traditional (Gaussian Mixture Models (GMM), Spectral)—to identify meal timing patterns from habitual breakfast, lunch, and dinner times. Methods: The sample included 388 Mexican university students (72.8% female). Patterns were characterized using sociodemographic, anthropometric, food intake quality, and chronotype data. Clustering method concordance was assessed via Adjusted Rand Index (ARI). Results: We identified five patterns (Early, Early–Intermediate, Late–Intermediate, Late, and Late with early breakfast). No differences were observed in BMI, waist circumference, or age among clusters. Chronotype aligned with patterns (morning types overrepresented in early clusters). Food intake quality differed significantly, with more early eaters showing healthy intake than late eaters. Concordance across clustering methods was moderate (mean ARI = 0.376), with the highest agreement between the traditional and non-traditional techniques (Hierarchical–Spectral = 0.485 and K-means-GMM = 0.408). Conclusions: These findings suggest that, while traditional and non-traditional clustering techniques did not identify identical patterns, they identified similar core structures, supporting complementary pattern detection across algorithmic families. These results highlight the importance of comparing multiple methods and transparently reporting clustering approaches in chrononutrition research. Future studies should generate meal timing patterns in university students from other contexts and investigate whether these patterns are associated with eating patterns and cardiometabolic outcomes. Full article

Feeding time is a critical but understudied factor influencing nutrient dynamics and overall productivity in aquaponic systems. This study examined the effects of two feeding schedules on growth performance of common carp (Cyprinus carpio L.), hydrochemical parameters, and the growth of lettuce (Lactuca sativa) cultivated in an integrated aquaponic system. Two 60-day trials were conducted over consecutive years under identical greenhouse conditions. Carp were fed either in the morning and early afternoon (T1: 08:00, 11:00, 14:00) or later in the day (T2: 11:00, 14:00, 17:00). Hydrochemical indicators, including dissolved oxygen, turbidity, ammonium ions (NH₄⁺), and nitrates (NO₃⁻), were continuously monitored through online measurement. Carp reared under T2 displayed significantly higher specific growth rate, final body mass, and improved feed conversion ratio (p < 0.05). The T2 variant also showed higher dissolved oxygen levels and lower turbidity compared to T1, indicating enhanced system stability. Although NH₄⁺ concentrations were higher and NO₃⁻ levels lower in T2, these differences did not compromise water quality due to efficient plant nutrient uptake. Lettuce grown under T2 exhibited greater stem and root development and higher biomass accumulation, suggesting improved nitrogen utilization linked to the NH₄⁺/NO₃⁻ ratio and enhanced root oxygenation. Overall, aligning feeding time with fish circadian rhythms improved fish performance, plant growth, and nutrient cycling efficiency. These findings demonstrate that feeding schedule is a key management factor capable of enhancing sustainability and productivity in aquaponic systems. Full article

Background: Obesity and its accompanying complications have an influence on diurnal rhythm, potentially causing cardiometabolic disease. This study explores how weight loss due to bariatric surgery affects circadian rhythm disruptions measurable through wearable heart rate monitors. Methods: A single-center observational study was performed, in which patients who had undergone primary bariatric surgery 3 years ago with telemonitoring of vital parameters using a wireless accelerometer were eligible to participate. A Wilcoxon signed-rank test was conducted to evaluate the delta of, or amount of change in, circadian patterns between the baseline (before) and post-weight-loss peak, nadir, and peak–nadir heart rates. Results: In this cohort of 69 patients, 70% were female, with a median total weight loss of 31.4% towards a median BMI of 28.4 kg/m². Analysis revealed significant changes in peak–nadir excursions post-weight loss. Peak, nadir, and peak–nadir differences showed a significant reduction in values in the post-weight-loss group. No significant correlations between other clinical endpoints and change in peak–nadir excursion were found in the multivariable regression models. Conclusions: In conclusion, this study reveals significant changes in circadian heart rate patterns before and after weight loss due to metabolic surgery. The results could add to the health benefits of bariatric surgery, as it could lower the incidence of diseases associated with changes in diurnal rhythm due to obesity. However, a clear clinical explanation is lacking, as no correlation with total weight loss nor other variables was substantiated. Full article

Background: It is well-known that rotating shift work disrupts the circadian rhythm and sleep quality in nurses. With this study, we aimed to compare subjectively and objectively measured sleep quality in nurses, specifically focusing on any differences that arose in relation to shift work. Methods: This prospective, observational, cross-sectional study was conducted in 2025 in Croatia; a total of 140 nurses participated. Sleep was assessed using the Pittsburgh Sleep Quality Index (PSQI) and FitBit Charge 3 smartwatch, which monitored sleep over an eight-day period. Results: Most nurses rated their sleep as good or very good, but according to the PSQI questionnaire, all participants were classified as poor sleepers (PSQI > 5). Objective smartwatch measurements showed that nurses working only day shifts had higher sleep scores (median 77, IQR 75–80 vs. 73, IQR 68–76; p < 0.001), significantly longer total sleep duration (median 6.4, IQR 6.3–7.1 vs. 5.5, IQR 5.2–6.2 h; p < 0.001), and longer durations of all sleep stages compared with those working rotating shifts. Conclusions: Most nurses subjectively rated their sleep as good or very good; however, according to the PSQI questionnaire results, all were classified as poor sleepers, with no significant difference related to shift work. Objective measurements using the smartwatch indicated that rotating shift work is associated with significantly poorer sleep quality. Full article

This study aimed to elucidate the genetic basis of body-size-related traits in Wanyue Black pigs, including body length, chest circumference, forearm circumference, and hip circumference. Phenotypic data were collected from 139 four-month-old female pigs, and genotyping was performed using a 50K SNP array. After stringent quality control and genotype imputation, approximately 4,697,453 high-quality autosomal variants were retained for subsequent genome-wide association study (GWAS), transcriptome-wide association study (TWAS), and phenome-wide association study (PheWAS). The GWAS identified four genome-wide significant loci, including rs343276492 and rs321308815. TWAS results revealed that the expression level of PTH2R was significantly associated with pituitary-related traits. In addition, selection signal analysis identified multiple genomic regions related to growth, development, and environmental adaptability, which were significantly enriched in pathways such as circadian rhythm regulation and the MAPK signaling pathway. These pathways play critical roles in growth regulation and adaptive evolution in Wanyue Black pigs. Collectively, this study provides valuable candidate genes and potential molecular markers for the genetic improvement and breeding of Wanyue Black pigs. Full article

Oxidative stress is a defining feature of stroke pathology, but the magnitude, timing and impact of redox imbalance are not static. Emerging evidence indicates that physiological contexts, such as aging, metabolic stress, and circadian disruption, continuously reshape oxidative status and determine the brain’s vulnerability to ischemic and reperfusion injury. This review integrates recent insights into how these intrinsic modulators govern the transition from adaptive physiological redox signaling to pathological oxidative stress during stroke. Aging compromises mitochondrial quality control and blunts NRF2-driven antioxidant responses, heightening susceptibility to ROS-driven damage. Metabolic dysfunction, as seen in obesity and diabetes, amplifies oxidative burden through NADPH oxidase activation, lipid peroxidation, and impaired glutathione recycling, further aggravating post-ischemic inflammation. Circadian misalignment, meanwhile, disrupts the rhythmic expression of antioxidant enzymes and metabolic regulators such as BMAL1, REV-ERBα, and SIRT1, constricting the brain’s temporal window of resilience. We highlight convergent signaling hubs, NRF2/KEAP1, SIRT–PGC1α, and AMPK pathways, as integrators of these physiological inputs that collectively calibrate redox homeostasis. Recognizing oxidative stress as a dynamic, context-dependent process reframes it from a static pathological state to a dynamic outcome of systemic and temporal imbalance, offering new opportunities for time-sensitive and metabolism-informed redox interventions in stroke. Full article

Heart rate variability (HRV) comprises several components driven by various internal processes, the least understood of which is the ultra-low frequency (ULF) one. Recently published research has shown that the HRV frequency distribution in this range is bimodal. The main aims of this work were to verify this finding, to determine the basic characteristics of these two components and to analyze their potential physiological couplings. For this purpose, two components within the conventional ULF band (below 4 mHz) were extracted from HRVs of 25 patients with apnea using adaptive variational mode decomposition (AVMD) and continuous wavelet transform (CWT), and then analyzed with the Hilbert transform (HT), Savitzky–Golay filter, and empirical distributions of instantaneous amplitudes and frequencies. These studies have demonstrated the existence of both components in HRVs of all subjects and apnea groups: extremely low frequencies (ELFs) in the range of 0.01–0.4 mHz and narrowed ultra-low frequencies (nULFs) in the range of 0.1–4 mHz. The independence of both components is also shown. Concluding, heart rate variability is separately regulated by circadian rhythms (ELF bound) and ultradian fluctuations (nULF bound), which can be assessed by decomposing HRV, and the obtained components may be helpful to better understand the underlying homeostatic mechanisms, as well as in the long-term monitoring of patients. Full article

Salt stress causes harm to plants through multiple aspects, such as osmotic pressure, ion poisoning, nutrient imbalance, and oxidative damage. Zinc finger proteins harboring two B-box domains, known as double B-box (DBB) proteins, constitute the DBB family. While DBB genes have been implicated in regulating circadian rhythms and stress responses in various plant species, their functions in cotton remain largely unexplored. The present study characterized the DBB gene family across the genomes of Gossypium hirsutum L., Gossypium raimondii L., and Gossypium arboreum L., revealing a complement of 58 members. These DBB genes were assigned to three separate clades based on phylogenetic analysis. Members possessing close phylogenetic relationships have similar conserved protein motifs and gene structures. All DBB proteins were predicted to be nuclear-localized, consistent with their roles as transcription factors. Furthermore, the presence of multiple cis-acting elements related to light, hormone, and stress responses in the promoters implies that GhDBBs are integral to cotton’s environmental stress adaptation. Expression pattern analysis indicated that the expression of GhDBB genes was associated with the plant’s response to multiple abiotic stresses, such as salt, drought, heat (37 °C), and cold (4 °C). The reliability of the expression data was confirmed by qPCR analysis of eight selected GhDBBs. Under 200 mM NaCl, Arabidopsis plants overexpressing GhDBB22 displayed longer roots and healthier true leaves than the wild-type controls. Conversely, VIGS-mediated silencing of GhDBB22 in G. hirsutum led to significantly reduced salt tolerance, accompanied by exacerbated oxidative damage. Taken together, the findings from our integrated genomic and functional analyses provide a foundational understanding of the molecular mechanisms through which proteins encoded by DBB genes are involved in the plant’s response to salt stress. Full article