Search Results (3,341)

Background/Objectives: Fluoride (F) is widely used in public water fluoridation to prevent dental caries, and an optimal level of F has been linked to improved glucose metabolism in animal models. Per- and polyfluoroalkyl substances (PFAS), including fluorotelomer alcohols (FTOHs), are persistent environmental contaminants with potential effects on pancreatic function. Methods: This in vitro and in vivo study investigated the effects of 8:2 FTOH and F (NaF) on pancreatic β-cells, focusing on Ca²⁺ homeostasis, insulin secretion, and the GPR40 pathway. Results: Results showed that 8:2 FTOH alters Ca²⁺ influx in a dose-dependent, biphasic manner, enhancing it at low doses and inhibiting it at high doses, while F increased Ca²⁺ signaling at high doses. High-dose 8:2 FTOH also downregulated GPR40 protein in βTC-6 pancreatic cells and modulated pathways related to lipid metabolism, endoplasmic reticulum stress, and insulin regulation in the mouse pancreas by proteomic analyses (in vivo). Conclusions: These findings exploratory indicate that both PFAS and F can impact β-cell function through complex mechanisms, potentially affecting Ca²⁺ homeostasis. This work highlights the hormesis effect of F and provides novel insights into the pancreatic effects of environmentally relevant PFAS exposures, emphasizing the need for further mechanistic studies at low, human-relevant doses. Full article

This study evaluates the effects of seven biochemical stimulants, ferulic acid, malic acid, L-carnitine, ergothioneine, magnesium sulfate, trehalose, and betaine, on biomass accumulation, total lipid content, and docosahexaenoic acid (DHA) production in Aurantiochytrium sp. ATCC PRA-276 under controlled fermentation conditions. The compounds were selected based on their reported roles in antioxidant defense, carbon flux regulation, osmoprotection, or methyl group donation, with the aim of assessing whether targeted, non-GMO supplementation could modestly enhance microbial productivity. Compared with the control, supplementation with L-carnitine and ferulic acid resulted in the greatest enhancement of DHA production, increasing DHA concentration by 31.7% and 29.2%, respectively. These treatments were also associated with statistically significant, albeit moderate, increases in total lipid accumulation and biomass production. These responses indicate correlated improvements in overall cellular productivity rather than isolated effects on lipid biosynthesis. DHA concentrations were quantified following lipid extraction and transesterification using GC-based analysis; however, comprehensive fatty acid compositional profiling (e.g., saturated, monounsaturated, and polyunsaturated fatty acid distributions or DHA-to-total lipid ratios) was not performed. Although direct mechanistic assays were not performed, the observed trends are consistent with known biochemical functions related to redox balance, cofactor availability, and stress adaptation. A preliminary cost-efficiency analysis identified malic acid as the most economical stimulant for DHA enhancement, whereas ergothioneine was the least cost-effective despite measurable biological effects. Collectively, these findings demonstrate that biochemical stimulation can provide incremental yet reproducible gains in DHA production and lipid accumulation. This work supports the use of targeted biochemical supplementation as a scalable, non-GMO strategy for microbial omega-3 production and establishes a foundation for future optimization through combinatorial supplementation, multi-omics validation, and process engineering. Full article

Major depressive disorder (MDD) is not reducible to a single neurotransmitter deficit. Current explanations commonly involve monoaminergic dysfunction, hypothalamic–pituitary–adrenal axis dysregulation, immune-inflammatory activation, impaired neuroplasticity and synaptic dysfunction, together with metabolic and neurovascular abnormalities. Lipidomic studies have repeatedly identified glycerophospholipid abnormalities in MDD, but their mechanistic meaning remains unresolved because changes in bulk lipid abundance do not explain how altered lipid metabolism becomes a receptor-level neural signal. This review develops a testable interpretation of the lysophosphatidylcholine (LPC)–autotaxin (ATX)–lysophosphatidic acid (LPA)–LPA receptor (LPAR) axis in which LPC species generated during phospholipid turnover provide ATX substrates, ATX activity determines local LPA generation, LPA production and inactivation shape ligand availability, and LPAR signaling links the lipid product to neural output. This structure shifts the focus from total lipid abundance to matched assessment of lipid species, enzyme activity, anatomical site and receptor subtype. Human studies report lower serum and cerebrospinal fluid (CSF) ATX in MDD, lower CSF LPA 22:6 in MDD and schizophrenia, and negative total LPA findings that caution against biomarker oversimplification. Depression-relevant and broader stress- or anxiety-related experimental studies show that ATX, LPA and LPAR perturbation can affect hippocampal function, synaptic physiology, emotional behavior and stress resilience. The key unresolved issue is whether brain-accessible LPC species, active ATX, locally generated LPA, LPA inactivation capacity and receptor-specific output can be demonstrated within the same MDD-relevant fluid, brain-interface site or neural circuit. Future work should therefore move from fluid-level association toward pathway closure through targeted and spatial lipidomics, anatomical ATX activity mapping, LPA inactivation assays, blood–brain barrier (BBB)/interface analysis, LPAR perturbation and matched circuit or behavioral readouts. Full article

For the impact-resistance evaluation of thermoplastics, the DuPont impact test is widely used to replicate multiaxial stress states inherent in actual product environments. However, conventional evaluation methods remain constrained by probabilistic pass/fail judgments or empirical calculations of absorbed energy. Consequently, quantifying the “material-specific fracture criterion,” which is indispensable for high-fidelity computer-aided engineering (CAE) analysis, persists as an important challenge. While our previous works established the derivation of CES from uniaxial tensile tests, the core originality of this study lies in extending this mechanical framework to the dynamic and multiaxial stress states of the DuPont impact test. By integrating a mathematical model with the probabilistic results of the staircase method, we enable for the first time the quantitative identification of material-specific fracture thresholds directly from standard drop-weight impact configurations. For this study, a novel mechanical model for deformation and fracture behavior in the DuPont impact test is constructed. Then a quantitative evaluation method is proposed for the “Critical Expansion Stress (CES),” a material-specific threshold triggering fracture under multiaxial stress. Specifically, using thermoplastic materials of five types and seven grades (including PP, POM, PS, ABS, and PC), the surface impact energy absorbed per unit volume was calculated via the DuPont impact test using the staircase method, accounting for size effects. Furthermore, microscopic parameters (shear modulus G and critical void volume fraction f0) were identified theoretically based on the mechanical properties obtained from short-beam shear tests. These parameters were integrated into a mathematical model to derive the CES. Comparing the derived CES with the true-stress-based uniaxial tensile strength, which incorporates the necking behavior during large deformations, revealed a distinct correlation governed by their mechanical relation (the 1:3 rule) based on the theoretical definition of hydrostatic stress. For the highly ductile polymer exhibiting significant strain hardening, this correlation holds universally when evaluated at the initial plastic flow stage prior to massive molecular orientation. The proposed method serves as a practical quantitative screening tool for evaluating the surface impact characteristics of plastic materials, providing an accessible framework for identifying material-specific fracture thresholds. Full article

Background: Fasting plasma glucose, glycated hemoglobin (HbA1c), and oral glucose tolerance testing remain central to the diagnosis and monitoring of dysglycemia, but they mainly reflect the average glycemic exposure or discrete time-point measurements and may not capture intraday and interday glucose fluctuations. Glycemic variability (GV) has been associated with oxidative stress, endothelial dysfunction, inflammation, and diabetes-related complications, although much of the evidence derives from experimental, clinical, and diabetes-care settings rather than occupational cohorts. Aim: This narrative review examines the physiological basis, measurement, and potential occupational relevance of GV and continuous glucose monitoring (CGM) in working populations. Methods: Literature was narratively selected from biomedical databases, major guidelines, consensus statements, and occupational-health sources, prioritizing reviews, clinical guidelines, cohort studies, mechanistic studies, and CGM studies. No systematic search, risk-of-bias assessment, or quantitative synthesis was performed. Main findings: CGM is an established technology in selected diabetes-care contexts and provides metrics such as coefficient of variation, time in range, time above range, and time below range. Its use in occupational medicine, however, remains investigational outside selected clinical circumstances. Work-related factors such as shift work, circadian disruption, sleep loss, psychosocial stress, irregular meal timing, sedentary behavior, and variable physical workload may influence glucose regulation, but direct evidence linking these exposures to CGM-measured GV in workers remains limited. Implications: Potential applications include research on occupational determinants of metabolic health, monitoring of workplace lifestyle interventions, and individualized management of workers with diabetes in safety-sensitive roles, provided that consent, confidentiality, clinical follow-up, equity, and data-governance safeguards are ensured. Conclusions: GV assessment may complement traditional metabolic markers in selected occupational-health contexts, but routine CGM-based surveillance of general worker populations is not currently supported by sufficient evidence. Further longitudinal and interventional studies are required. Full article

Personal growth is a central aspect of development and well-being during young adulthood, yet sexually diverse and gender-diverse (SGD; a more inclusive term for LGBTQ+) young adults navigate this process within unique contexts shaped by identity, stress, and varying levels of social support. Despite growing visibility and social recognition of SGD identities in the United States, SGD individuals continue to face prejudice and discrimination, which negatively affects their physical and psychological health. Research indicates that stigmatized and marginalized populations with greater psychosocial resources are better able to cope with identity-related stressors. Yet, scholarship on coping with stigma and discrimination remains largely disconnected from research on social support, personal growth, and thriving within close relationships. The present observational study of SGD young adults (N = 400) examines how identity-affirming support from close others contributes to positive well-being outcomes, specifically personal growth, self-concept clarity, and thriving. Whereas much prior work focuses on how support buffers stress, we examine its role across stressors and opportunities for growth, experienced broadly and in relation to SGD identity. Our findings underscore the critical role that close relationships play in fostering social safety and personal growth for SGD young adults navigating identity development. Full article

Asthma is a prevalent, long-term inflammatory airway condition that is difficult to diagnose and treat because there is no single reliable diagnostic test. Misdiagnosis is therefore common, with rates as high as 73% in juvenile groups and up to 35% in adult populations. This ultimately exacerbates their illness by postponing therapy for some people and administering needless medication to others. Although well-known biomarkers such as blood eosinophils and fractional exhaled nitric oxide, as well as conventional diagnostic techniques such as spirometry, have improved clinical assessment, they are nevertheless constrained in many healthcare settings by limited availability, high cost, and inconsistent use. Furthermore, these indicators primarily reflect type-2 inflammation and are less useful for non-type-2 asthma, highlighting the need for more comprehensive, readily accessible diagnostic techniques. Identifying novel biomarkers of oxidative stress, metabolic alterations, and airway inflammation, including volatile organic compounds and redox-related chemicals, has been the focus of recent studies. These biomarkers offer opportunities for improved disease phenotyping and non-invasive detection. Simultaneously, advances in biosensor technology have enabled highly sensitive platforms to rapidly detect these biomarkers at low concentrations. In particular, optical biosensors are becoming more and more popular due to their ability to do real-time detection without the need for labels and their ease of miniaturization for point-of-care devices. This work summarizes traditional diagnostic tools alongside existing information on asthma phenotypes and clinically important biomarkers, and discusses advanced biosensors ranging from electrochemical to optical systems, including recent developments in nanomaterial-enhanced optical biosensing techniques. The importance of artificial intelligence and smartphone-integrated hardware is also covered, along with the main challenges that need to be overcome for these technologies to become useful clinical tools for asthma diagnosis and monitoring. Full article

This study develops a fractional Jeffreys heat conduction model to describe laser-induced thermoelastic distortions in thin optical materials under ultrafast surface heating. The framework employs three fractional parameters to characterize anomalous thermal transport modes: retarded conduction, accelerated conduction, and transitions between super- and sub-diffusive regimes. Thermo-optic effects are represented through a linear relation between temperature and refractive-index perturbation; however, a full optical-aberration decomposition is not claimed in this work. Numerical results demonstrate that anomalous heat transfer significantly affects temperature localization, heat-flux evolution, stress distributions, and OPD-based thermo-optic indicators in components subjected to ultrafast laser pulses. Quantitative optical indicators, including refractive-index variation, optical path difference, wavefront error, focal-length shift, and thermal-lens distortion, are derived from the computed temperature field to connect the thermal solution directly with thin-lens performance. Simulations combining Maple2024 and MATLAB R2023a quantify the coupled thermoelastic-optical response at picosecond time scales. Full article

Student mental health, stress, and success are interconnected, yet the mechanisms linking them remain insufficiently understood. Drawing on Stress Optimization and Self-Regulated Learning (SRL) theories, this study examined how stress appraisals and learning practices jointly contribute to student mental health and academic functioning in post-secondary students, supporting a view of student success that comprises both feeling well psychosocially and functioning well academically. Using a sample of 226 university students, the study replicated prior work on the predictive roles of coping self-efficacy (CSE) and stress mindset (SM) across indicators of student success, including flourishing mental health, motivation-related challenges, social-emotional challenges, and GPA. It extended this work by testing whether metacognitive monitoring and adaptation, and academic social engagement, mediated these relationships. Results showed that neither CSE nor SM significantly predicted GPA, suggesting that stress appraisals alone may be insufficient to explain academic achievement. However, both CSE and SM significantly predicted flourishing mental health, and CSE was additionally associated with fewer motivation-related and social-emotional challenges. Mediation analyses indicated that metacognitive monitoring partially explained the relationship between CSE and reduced motivation challenges, while academic social engagement mediated relationships between stress appraisals and social-emotional challenges and mental health. Findings underscore the value of integrating psychosocial and educational perspectives in promoting student success. Full article

Teacher job satisfaction is a key component of teacher well-being and educational quality, particularly in early childhood education settings. This study examined how different dimensions of job satisfaction are associated with individual factors (sociodemographic characteristics and meaning at work) and work-related factors (perceived stress, workplace relationships, and satisfaction with training experiences) among Italian early childhood educators and preschool teachers. Participants were 259 professionals working with children aged 0–6 years who completed an online questionnaire assessing meaning at work, teacher stress, support from colleagues, and conflictual workplace relationships. Hierarchical regression analyses showed that Positive Meaning was the strongest and most consistent predictor across all dimensions of job satisfaction. Perceived support from colleagues positively predicted intrinsic, relational, and working conditions satisfaction, whereas conflictual workplace relationships negatively affected relational and working conditions satisfaction. Age, years of teaching experience, and work setting selectively influenced specific dimensions of job satisfaction. Overall, the findings highlight the importance of collaborative workplace climates and meaningful work in promoting teacher well-being in early childhood education contexts, suggesting that interventions should address both individual resources and the quality of workplace relationships. Full article

Marine algal viruses exhibit a high level of diversity, and closely related viruses targeting the same algal host species can stably coexist. Here we report an example of a single virus–host system concealing hidden complexity. We discovered two double stranded (ds) DNA viruses infecting the Arctic picophytoplankter Micromonas polaris coexisting in culture for over a decade. Genomic sequencing of the lysate originally characterized as MpoV-44T revealed that it comprises two distinct prasinoviruses with ~203–204 kb genomes (MpoV-44T.A and MpoV-44T.B), of which conserved regions only accounted for 36% (the nucleotide level). The viruses were subsequently separated and compared at both genomic and phenotypic levels. In dual infection studies using a single host strain under nutrient-replete conditions, MpoV-44T.A outcompeted MpoV-44T.B. Yet MpoV-44T.B-like viruses were more abundant than MpoV-44T.A-like ones in natural Arctic metagenomes. This apparent paradox may be explained by differences in host strain specificity and/or possible resilience to nutrient stress by MpoV-44T.B, which we hypothesize based on genomic data. This work unveils hidden virus diversity, illustrating that the dynamics of viral coexistence are not always easily predictable, and underscores the importance of studying the underlying mechanisms at play. Full article

This exploratory cross-sectional study examined whether pandemic-related family well-being responses differed across North Carolina’s 2021 county economic tiers among 178 Black parents. Survey responses were linked to county tier and included reported stress, emotional symptoms, food hardship, self-rated health, sleep change, work and parenting disruption, and parent–child interaction items. Primary analyses used the Kruskal–Wallis and chi-square tests; within-tier correlations and tier-stratified linear probability models were used for supplementary and descriptive purposes. Respondents across all tiers reported pandemic-related burdens, but most cross-tier comparisons were not statistically significant. One food-hardship item (p = 0.050) and one parent–child interaction item (p = 0.042) met the nominal 0.05 threshold, while one emotional symptom item approached significance (p = 0.074); these isolated findings did not form a consistent cross-domain pattern. The findings indicate that the county-tier classification was useful for organizing place-based comparisons but did not consistently differentiate response patterns in this sample. Larger, longitudinal studies using neighborhood- and household-level measures are needed before tier-specific or causal conclusions can be drawn. Full article

Background/Objectives: Medical Malpractice Stress Syndrome (MMSS) describes the psychological and behavioral consequences of malpractice-related concerns and may contribute to defensive medicine practices. Emergency medicine physicians are particularly vulnerable to medicolegal risk because of the high-acuity and time-sensitive nature of their work. This study aimed to evaluate MMSS awareness, malpractice-related stress, and defensive medicine practices among emergency medicine specialists in Türkiye. Methods: A national cross-sectional web-based survey was conducted among emergency medicine specialists practicing in Türkiye between 1 April and 1 June 2026 and was distributed through professional emergency medicine networks and congress-related channels; because the survey was disseminated through multiple open professional platforms, an exact response rate could not be determined. The questionnaire assessed demographic characteristics, MMSS awareness, malpractice-related experiences and anxiety, and defensive medicine behaviors. Defensive medicine practices were evaluated using the validated Turkish version of the Defensive Medicine Attitude Scale. Associations between malpractice-related anxiety and defensive medicine behaviors were analyzed using Spearman correlation analysis. Results: A total of 128 emergency medicine specialists completed the survey. Malpractice-related anxiety was highly prevalent and frequently influenced professional attitudes and clinical decision-making. Defensive medicine practices were common, with assurance-type behaviors being substantially more frequent than avoidance-type behaviors. Malpractice-related anxiety demonstrated a significant positive correlation with assurance defensive medicine behaviors (r = 0.383, p < 0.001) but not with avoidance behaviors (r = 0.139, p = 0.118). Assurance and avoidance defensive medicine scores were positively correlated (r = 0.575, p < 0.001). Conclusions: MMSS and malpractice-related anxiety are highly prevalent among emergency medicine physicians in Türkiye and are associated with widespread defensive medicine practices. Malpractice-related anxiety appears to primarily promote assurance-type defensive medicine behaviors rather than avoidance behaviors. These findings suggest that medicolegal stress may influence clinical decision-making and contribute to increased healthcare utilization in emergency medicine. Full article

Background/Objectives: Dopamine is well known for its role in reward learning, where phasic activity encodes prediction errors and supports the formation of cue–outcome associations. More recently, dopamine has been implicated in encoding salience, novelty, and aversive events, suggesting a broader function in shaping learning and memory across motivational contexts. However, how accumbal dopamine contributes to the recovery of extinguished fear, a process central to relapse in anxiety and trauma-related disorders, remains unclear. Methods: Here, we examined NAc core dopamine dynamics during shock-induced reinstatement of an extinguished fear memory. Using dLight fiber photometry, we found that a sustained decrease in baseline dopamine marked extinction recall. In contrast, an unexpected reminder footshock prevented this reduction, maintaining dopamine levels near baseline as freezing behavior re-emerged. Results: The reminder shock also evoked a transient dopamine peak, and optogenetic manipulations demonstrated that dopamine signaling during this period bidirectionally modulated reinstatement, with enhancement of dopamine release increasing reinstatement and inhibition of dopamine terminals markedly attenuating it. Together, these results demonstrate that unexpected aversive events reset NAc core dopamine levels and gate the return of extinguished fear. Conclusions: By revealing that accumbal dopamine contributes to fear recovery, this work broadens current models of dopamine function and identifies a neural mechanism through which surprising events may promote relapse of aversive memories in anxiety- and stress-related disorders. Full article

Agaricus bisporus is highly valued for its sensory and nutritional aspects, but it is highly perishable because of its intense postharvest metabolism. In this study, we looked at how white button mushrooms responded to three thermal regimes including constant refrigeration (4 °C), ambient storage (20 °C), and repeated temperature stress (RTS). The investigations were combined with an innovative smart packaging called Store Box (SB). Using an integrated volatilomics approach combining both gas chromatography–mass spectrometry (GC-MS) and proton transfer reaction time of flight mass spectrometry (PTR-ToF-MS), we tracked volatile compounds from intact mushrooms and internal tissues and linked these with weight loss and CO₂ production. According to the results, the SB stabilizes the internal microenvironment by reducing moisture loss and modulating gas exchange through controlled CO₂ buildup. This mechanism attenuated the respiratory surge and significantly delayed the rise of spoilage-related markers like methanethiol, acetaldehyde, and hexanal. At the same time, SB preserved freshness indicators such as 1-octen-3-one and benzaldehyde, which normally fade as mushrooms age. The protective effect was especially clear during thermal fluctuations, where SB acted as a metabolic buffer. Overall, this work offers new insights into the volatilome dynamics of Agaricus bisporus and confirms that smart packaging can help offset the damage caused by temperature instability along the supply chain. Full article