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Phosgene, as a crucial chemical, is used to produce polymers, agrochemicals, and pharmaceuticals. Herein, we report a mild iron-catalyzed in situ conversion of CCl4 to phosgene, applied to the synthesis of various ureas. Using Fe(acac)3/CCl4 to replace dangerous phosgene offers significant advantages in terms of its safety and easy operation. Given the broad utility of phosgene and the importance of ureas in drugs and functional materials, this method, as a convenient and adaptable approach, holds promise for academic and industrial applications.

Coffee exerts beneficial effects on health, such as suppressing type 2 diabetes, cardiovascular disease, and fatty liver. Coffee also relieves headaches by the caffeine component decreasing blood flow in the cerebral arteries. Caffeine is also used to treat apnea in premature infants, but blood flow in the superior mesenteric artery (SMA) decreases as a side effect. However, whether drinking coffee decreases abdominal blood flows in adults remains uncertain. If drinking coffee decreases SMA blood flow in adults, subsequent blood flows via the portal vein (PV) to the liver might also decrease, which could be a contributor to the beneficial suppression of fatty liver. The present study aimed to clarify hemodynamics in the SMA and PV under fasting conditions after drinking coffee or water in 32 healthy young men (mean age, 21&#x2009;&#xb1;&#x2009;1&#x2009;years). Flow volume decreased on sonography 30&#x2009;min after drinking coffee in the SMA (median -13.4%, interquartile range [IQR] -18.6% to -9.6%; p&#x2009;<&#x2009;0.001) together with an increase in pulsatility index (median 9.0%, IQR -1.1% to 14.5%; p&#x2009;<&#x2009;0.001), and a decrease in PV (median -11.3%, IQR -14.5% to -5.3%; p&#x2009;<&#x2009;0.001). These phenomena were observed 90&#x2009;min after drinking coffee and were particularly prominent in habitual low caffeine consumers, but were largely absent after drinking water. Drinking coffee decreases SMA and PV blood flows in adults.

Vascular endothelial dysfunction plays a critical role in the development of atherosclerosis; however, the mechanisms by which endothelial cells contribute to plaque instability remain incompletely understood. In this study, we performed an integrated analysis of single-cell RNA sequencing (scRNA-seq) and bulk RNA-seq data to characterize endothelial cell heterogeneity associated with carotid plaque instability. Clustering analysis, gene set variation analysis (GSVA), differential gene expression analysis, and KEGG pathway enrichment were conducted to identify key endothelial cell subsets and their functional characteristics. We identified three endothelial cell subsets (subsets 9, 10, and 11) that were significantly enriched in unstable plaques and exhibited upregulation of multiple pro-inflammatory cytokines. Pathway analysis revealed that these subsets were associated with activation of the PI3K - Akt signaling pathway and other inflammation-related pathways. Furthermore, findings were validated in an apolipoprotein E-deficient (ApoE-/-) mouse model, where increased expression of placental growth factor (PGF) and a higher proportion of PGF-positive endothelial cells were observed in atherosclerotic lesions. In conclusion, this study reveals the heterogeneity of endothelial cells in atherosclerotic plaques and identifies pro-inflammatory endothelial subsets potentially associated with plaque instability, providing new insights into the pathogenesis of atherosclerosis.Trial registration: This study was approved by the Experimental Animal Ethics Committee of Guizhou University of Chinese Medicine (approval number: 2,024,010).

Zinc-organic batteries (ZOBs) based on C&#x2550;N compounds arouse great interest due to wide structure, high capacity, and long cycle life. However, activation phenomenon of C&#x2550;N compound is seldom discussed in ZOBs, as well as activation mechanism during charging/discharging. Herein, DPPT (Diphenazine-pyrenetetraimine) with eight C&#x2550;N active sites is first synthesized for ZOBs, delivering ultralong cycling life (45&#xa0;000 cycles) and good rate performance (20 C). Notably, there shows obvious activation process at beginning cycles because of the transformation of DPPT-eight proton into DPPT. In situ experiments and DFT calculations reveal co-participation mechanism of Zn2+ & H+ with optimized structure of 2DPPT-1Zn-14H deriving from 16 discharged products. Impressively, wearable NH3 sensors could be powered by as-fabricated flexible DPPT ZOBs, making it possible from the restriction of traditional power supply. Prospectively, activation mechanism of high-performing DPPT would provide methods for further design of organic structures into ZOBs and offer self-powered energy for wearable sensors.

Consumers often inspect products before making purchase decisions. Some items are selected for their shopping baskets, while others are discarded. Can discarded products influence how the selected set is perceived? We examined this question across two experiments. Participants viewed sequences of grocery products, some included in the shopping basket and some discarded, and were asked to provide a summative estimate of the included set's environmental friendliness after presentation. In Experiment 1, participants had to remember which items to consider for the upcoming judgment, as each item disappeared after presentation. In Experiment 2, each item remained visible after presentation. Discarded green (environmentally friendly) items produced a downshift in perceived environmental friendliness of the included set of items in Experiment 1 (a contrast effect), but an upshift in Experiment 2 (an assimilation effect). Correspondingly, discarded red (environmentally harmful) items produced an upshift in Experiment 1 and a downshift in Experiment 2. These findings show that discarded items can shift judgments of environmental friendliness, but that the direction of this effect depends on whether discarded items are mentally excluded or perceptually integrated with the remaining set.

Single-molecule detection enables precise biomarker quantification, yet conventional endpoint assays suffer from long incubation and nonspecific binding. Kinetic assays resolve these via real-time monitoring of molecular interactions, but their reliance on complex optics has restricted their practical adoption, especially in point-of-care settings where speed, portability, and ease of use are paramount. We present a microlens-assisted platform that enables real-time tracking of single-binding events under conventional bright-field microscopy. An on-chip microlens array amplifies scattering from gold nanoparticle labels, enabling kinetic monitoring with low-magnification optics. Dynamic fingerprints of individual events distinguish specific from nonspecific interactions, achieving wash-free digital biosensing with high sensitivity and specificity. This approach not only preserves the analytical advantages of kinetic profiling but also enables an exceptionally compact and portable optical configuration. Using cardiac troponin I, a time-critical biomarker for acute myocardial infarction, we demonstrate an ultralow detection limit of 0.051 pg mL-1 and validate clinical applicability in undiluted serum samples, paving the way for miniaturized, high-performance biosensors that can deliver laboratory-grade diagnostics at the point of need.

Mental health practitioners assess and treat trauma and dissociation by considering the biopsychosocial factors influencing the symptomatology of clients. In this process, clinicians often default to a prescriptive model that inherently assigns generalized cultural values to certain marginalized groups. Particularly for Latines, clinicians may overaccentuate the cultural value of familismo, the centering of family, for all Latine clients. These cultural values often translate into clinicians' expectations that their Latine clients will cherish their familial relationships in ways that make familismo an asset in treatment. However, for multiply marginalized Latines who endure intersectionality, familismo may not only be a detriment to trauma treatment, but the source of psychological distress itself. In this theoretical article, we center sexual and gender minoritized (SGM) Latines as we reconceptualize familismo as a potentially oppressive cultural value that may additionally be a contributing structural factor to both betrayal trauma exposure and dissociation by way of double-consciousness (du Bois, 1903). We define and briefly review the literature on familismo, intersectionality, and secondary marginalization. We also describe how intersectionality may contribute to dissociation and resistance through the framework of double-consciousness. We use a hypothetical case example to demonstrate the role of double-consciousness in dissociative responses to betrayal and discuss the implications for clinical practice and research.

Childhood maltreatment is widely recognized as a significant risk factor for the development of insecure attachment. However, empirical evidence on the strength and direction of this relationship remains mixed. To address this gap, we conducted two three-level meta-analyses to (a) estimate the overall associations between childhood maltreatment and adult attachment and (b) examine key moderators of these associations. A comprehensive literature search was conducted across five databases. Two three-level meta-analyses were employed to account for the dependence among effect sizes within studies. The analyses comprised 1,304 effect sizes derived from 228 independent samples across 211 studies, with 82,376 participants. Results revealed significant and positive correlations between childhood maltreatment and both attachment anxiety (r&#x2009;=&#x2009;0.23) and avoidance (r&#x2009;=&#x2009;0.20), with stronger associations observed for emotional maltreatment and when multidimensional measurement tools were employed. These findings suggest that adverse caregiving experiences have an enduring impact on attachment across the lifespan. This highlights the importance of implementing policies to reduce the incidence of childhood maltreatment and developing intervention programs to help affected adults rebuild secure attachment bonds.

The stable modulation of the local charge distribution behavior induced by unsaturation sites within photocatalysts continues to pose a significant challenge in the quest to achieve notable enhancements in photocatalytic activity. Herein, we harnessed the hydrogen annealing reduction technique to deliberately introduce oxygen vacancies (OVs) into the BiOCl lattice for constructing the OVs-Bi-O structure, which decreases the valence state of Bi, and diminishes the Bi&#x2500;O coordination, further establishing a charge asymmetric region within the material. This distinctive structural arrangement facilitates the sufficient migration of electrons to adjacent Bi sites that are closely linked to the OVs, significantly promoting the capture capability of electrons, leading to more adsorption and activation of water and oxygen as well as the conversion of reactive oxygen radicals. The engineered OVs-BiOCl variant showcases potential photocatalytic prowess, boasting a satisfactory photocatalytic application than that of its unmodified BiOCl counterpart. Under low-light conditions, this variant impressively achieves a &#x223c;98.1% removal efficiency for RhB, while concurrently achieving an almost complete elimination of E. coli. This finding presents an insightful approach for manipulating unsaturation coordination active sites through the strategic introduction of controllable defects and elucidates the impact of unsaturation coordination on photocatalytic efficiency.

This study aimed to evaluate social appearance anxiety in patients with systemic sclerosis compared with healthy controls and to examine its associations with anxiety, depressive symptoms, health-related quality of life, and disease-related clinical features. This cross-sectional study included 71 patients with systemic sclerosis and 38 healthy controls. Social appearance anxiety was assessed using the Social Appearance Anxiety Scale. Anxiety and depressive symptoms were evaluated using the Hospital Anxiety and Depression Scale, and health-related quality of life was assessed using the Short Form-36. Disease-related variables, including modified Rodnan skin score and EUSTAR disease activity index, were recorded. Patients with systemic sclerosis had higher Social Appearance Anxiety Scale scores than healthy controls [32.0 (21.0-51.5) vs. 19.0 (16.25-34.0); p&#x2009;=&#x2009;0.003]. Anxiety and depressive symptom scores were also higher in patients with systemic sclerosis. In systemic sclerosis, social appearance anxiety correlated positively with anxiety symptoms and negatively with several health-related quality-of-life domains. No significant association was observed between social appearance anxiety and modified Rodnan skin score or EUSTAR disease activity index. Social appearance anxiety is increased in systemic sclerosis and is associated with psychological distress and impaired health-related quality of life rather than conventional disease activity or skin thickness measures. These findings support incorporating psychosocial assessment into routine systemic sclerosis care. Key Points &#x2022;&#xa0;Patients with systemic sclerosis had higher social appearance anxiety than healthy controls. &#x2022;&#xa0;Social appearance anxiety was associated with anxiety symptoms and impaired health-related quality of life. &#x2022;&#xa0;Social appearance anxiety was not significantly associated with skin thickness or EUSTAR disease activity. &#x2022;&#xa0;Psychosocial assessment may provide clinically relevant information in systemic sclerosis care.

Opioid overdose deaths have devastated communities across the USA for over two decades. This study explores how Christian clergy in North Carolina perceive and respond to substance use issues, including opioid misuse. An anonymous online survey of clergy in 24 North Carolina counties was conducted from December 2020 to February 2021 (n&#x2009;=&#x2009;105, response rate 7.6%). Nearly all respondents (98%) reported that their congregations offered at least one form of support for those affected by substance use issues. Over half (58%) reported someone seeking help for substance use in the past year, and clergy noted significant family impacts such as financial hardship, job loss, and overdose. Relative to evangelical Protestant congregations, mainline Protestant congregations were reported as more likely to view addiction as disease rather than sin and to support medication-assisted treatment and syringe exchange. Clergy expressed strong interest in practical resources that are more relational than educational. Limitations include a low response rate, a predominantly white, Christian sample, and pandemic-era timing. Findings highlight opportunities for trust-based partnerships between public health and faith communities that respect theological commitments while building on congregations' existing strengths and practices.

Electromagnetically induced transparency (EIT), arising from quantum interference in coherently driven atomic systems, has inspired a variety of photonic analogues, such as coupled-resonator-induced transparency (CRIT), built on the quantum-state modelling using resonators. Although CRIT serves as a building block for slow light in photonic integrated circuits, recent advances in topological photonics motivate a further generalization of both EIT and CRIT using gauge-field degrees of freedom. Here, we propose generalized CRIT via a spinor representation with dual-channel gauge fields, enabling fully programmable CRIT featuring dynamical spectral engineering. We generalize the traditional EIT framework by introducing a spinor representation of bright- and dark-mode resonances, yielding a unified description of design parameters through universal unitary operations. Implementing a coupled-resonator building block that accesses the entire design space through dual-channel gauge fields, we demonstrate a programmable slow-light band in a one-dimensional CRIT lattice. Together with the practical implementation of a programmable CRIT unit cell on a silicon nitride integrated-photonics platform, our results address urgent needs in optical interconnects, such as tunable delay lines, reconfigurable synchronization, and linear frequency conversion.

Corticosteroids (CSs) are widely prescribed but can induce psychiatric adverse effects (depressive, manic, psychotic, and anxiety symptoms). This systematic review aimed to quantify the association between CS use and psychiatric symptoms and to explore potential moderators across clinical contexts. We conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided systematic review and meta-analysis. MEDLINE and Embase were searched through 10 October, 2025, and 19 hand-searched records were also screened. We included observational studies in medical CS users and excluded sex steroids, neonatal exposure, prescription-only outcomes, purely objective outcomes, sleep/cognition/delirium-focused studies, CS deficiency, withdrawal, and studies confounded by co-medications; randomized controlled trials were excluded by design. Two reviewers screened studies, extracted data, and assessed risk of bias with the Newcastle-Ottawa Scale. Certainty of evidence for each pooled outcome was additionally evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Pairwise meta-analyses pooled standardized mean differences and odds ratios using random-effects models; I2 quantified heterogeneity. The acute phase was operationally defined as &#x2264;&#xa0;8 weeks after CS initiation. An exploratory meta-regression across six studies (seven groups) examined dose, duration, cumulative dose, age, and sex. Seventy-three studies (total N = 3,759,659) were included (22 cross-sectional, 31 cohort, 12 pre-post, 2 case-control, 2 registry, and 4 prospective patient-as-own-control investigations comparing outcomes during on-CS vs off-CS periods). Compared with non-users, CS use was associated with higher depressive symptom scores (standardized mean difference = 0.92, 95% confidence interval [CI] 0.40-1.45; p&#xa0;<&#xa0;0.001;&#xa0;I2 = 89%; seven studies; n = 1403; eight groups). During the operationally defined acute phase (&#x2264;&#xa0;8 weeks after CS initiation), manic symptoms were more frequent than depressive symptoms (six studies; n = 1086; odds ratio = 2.42, 95% CI 1.48-3.97;&#xa0;p&#xa0;<&#xa0;0.001; I2 = 0%). A single-arm meta-analysis estimated psychotic symptoms in 2.4% of CS users (95% CI 0.76-7.26; six studies; n = 1206). Anxiety showed no significant association with CS use (standardized mean difference = 0.13, 95% CI -&#xa0;0.24 to 0.51;&#xa0;p&#xa0;=&#xa0;0.26; I2 = 7%; three studies; n = 1251). Overall study quality (Newcastle-Ottawa Scale) was generally moderate to high, whereas certainty of evidence according to GRADE was generally low to very low across pooled outcomes. The exploratory meta-regression suggested that higher daily dose and older age were associated with greater depressive severity; by contrast, cumulative dose, treatment duration, and sex showed no significant associations, and these moderator findings remain exploratory. Corticosteroid use is associated with more severe depressive symptoms, and manic symptoms may predominate during acute treatment; psychotic reactions are uncommon. Dose and age may modulate depressive severity, but these moderator findings should be interpreted cautiously. Routine monitoring for mood and psychotic changes, especially early after initiation and in higher-dose or older patients, is warranted. Corticosteroids are widely used medicines that control inflammation, yet they can also influence mental health. We analyzed 73 clinical studies of patients taking these drugs for physical illnesses. Overall, people who used corticosteroids reported more signs of depression than those who did not. During the first 8 weeks of treatment, manic episodes&#x2014;characterized by abnormally elevated or irritable mood, decreased need for sleep, racing thoughts, impaired judgment, and sometimes risky behavior&#x2014;were about 2.4 times more frequent than depressive symptoms. Severe reactions such as psychosis affected only a small proportion of patients (approximately 2%). When we looked for possible reasons, an exploratory meta-regression suggested that higher daily corticosteroid doses and older age may be linked to more severe depression, whereas total cumulative dose, treatment duration, and sex were not. These findings should be interpreted cautiously because they are based on a small number of studies and show between-study variability. We found no consistent evidence that corticosteroids raise anxiety. Taken together, these results suggest that clinicians should routinely ask patients about mood changes, especially during the first 8 weeks, and pay particular attention to older adults who are receiving higher daily doses, while balancing any possible mental side effects against the well-established physical benefits of corticosteroid therapy.

Chronic, high-resolution imaging of peripheral nerve injury and regeneration remains a major technical challenge due to the optical inaccessibility of peripheral nerves embedded in soft tissue. Here, we present a broadly applicable approach for longitudinal, high-resolution optical imaging of peripheral nerves in vivo that combines a flexible, optically transparent polydimethylsiloxane (PDMS) window along with multimodal microscopy. The PDMS window is implanted in the skin above the mouse sciatic nerve, providing stable, motion-tolerant optical access for over one month without impairing nerve function. Using confocal, two-photon, and second-harmonic generation microscopy, we simultaneously visualized fluorescently labeled axons and Schwann cells, endogenous collagen, and vasculature with high spatial and temporal resolution. This approach enabled real-time tracking of axonal degeneration and regeneration, Schwann cell dynamics, and extracellular matrix-guided axon pathfinding across multiple nerve injury models. The platform also supports longitudinal imaging of axonal regrowth within a clinically relevant model of nerve transection gap repair. Overall, our method enables new avenues for studying peripheral nerve biology and testing regenerative therapies in vivo.

Extreme stressor-evoked psychophysiological responses are associated with adverse health outcomes. The present study examined the individual and combined influence of exercise and arousal reappraisal on stressor-evoked psychophysiological responses. Participants (N&#x2009;=&#x2009;238) were randomly assigned to one of four groups: control (CTRL), arousal reappraisal only (AR), exercise only (EX), or combined arousal reappraisal and exercise (AR&#x2009;+&#x2009;EX). After completing baseline 1, the assigned experimental condition, recovery, and baseline 2, participants underwent a speech task. Cardiovascular measures were obtained during baselines and the stress task, and state psychological measures were obtained after informed consent and after the stress task. Trait reappraisal was also measured. There were no group differences in stressor-evoked cardiovascular responses. However, despite similar stress intensity ratings across all groups, participants in the AR group interpreted their stress more positively. Additionally, moderation analyses demonstrated that individuals with higher trait reappraisal in the EX and AR&#x2009;+&#x2009;EX groups viewed their physiological arousal as more helpful than individuals in the CTRL group. Arousal reappraisal may improve interpretations of acute stress. Additionally, acute exercise may be most beneficial for reducing negative interpretations of perceived physiological arousal when trait reappraisal levels are high. Future research should explore whether repeated arousal reappraisal and exercise training may promote more adaptive stressor-evoked responses.

Polymerizable deep eutectic electrolytes (PDEEs) have emerged as next-generation electrolytes for electrochemical devices, addressing the leakage risk of traditional DEEs and the safety concerns of flammable ionic liquid electrolytes. However, a significant challenge hindering further development is the scarcity of DEE-based polymers capable of simultaneously balance the electrolyte conductivity, mechanical strength, and stability. Herein, a high-performance poly(DEEs) was engineered by exploiting the synergistic effects of hydrogen bonding and ion-dipole interactions via the incorporation of acrylamide (AM), succinonitrile, LiClO4, and methyl methacrylate (MMA). The solid polymer electrolytes were elaborately designed via in situ copolymerization, facilitating Li+ transport through hydrogen bond interaction with NH2 and C&#x2261;N groups, and utilizing the dual-skeleton framework of AM and MMA to integrate electrochemical and mechanical properties. The optimized poly(DEE-MMA) exhibits a high ionic conductivity of 1.43 mS cm-1, a superior Li+ transference number of 0.83, and excellent tensile strength of 17.8&#xa0;MPa at 298&#xa0;K, enabling the Li||LiFePO4 battery to deliver an impressive lifespan of 120 cycles with 83% capacity retention and the electrochromic device sustains 2000 coloration-bleaching cycles with retaining 80% of the initial optical modulation. These findings provide a novel strategy for high-performance solid polymer electrolytes and demonstrate potential applications in electrochemical devices.

This study examined cortical thickness and appetite-regulating hormones-neuropeptide Y (NPY) and ghrelin-to better understand the neurobiological mechanisms underlying binge eating disorder (BED) and obesity in adolescence. We compared adolescents with BED and obesity, adolescents with obesity without BED, and healthy controls (HCs), and explored the relationships among these measures, BMI, and psychological symptoms. Seventy adolescents (aged 12-18&#x2009;years) were included: 24 adolescents with BED and obesity, 24 adolescents with obesity without BED, and 22 HC. Cortical thickness was measured using 3.0&#x2009;T structural MRI with FreeSurfer-based analysis, and fasting serum levels of NPY and ghrelin were quantified by ELISA. Participants also completed the Eating Attitudes Test-40 (EAT-40), the Eating Disorder Examination Questionnaire (EDE-Q), the Children's Depression Inventory (CDI), and the State-Trait Anxiety Inventory for Children (STAI-C). Both groups with obesity showed significantly elevated NPY levels compared to HCs (p&#x2009;<&#x2009;0.001), with no difference between adolescents with and without BED; fasting total ghrelin levels did not differ across groups. Adolescents with BED exhibited reduced cortical thickness in the right posterior cingulate cortex relative to both comparison groups (p&#x2009;=&#x2009;0.002), while left posterior cingulate thinning was observed in both groups with obesity versus HCs (p&#x2009;=&#x2009;0.004). No significant group differences were found in insular or anterior cingulate thickness. Both groups with obesity showed greater depressive symptoms, disordered eating attitudes, and eating-related psychopathology than HCs. In multiple regression analyses adjusted for diagnostic group membership, higher BMI (&#x3b2;&#x2009;=&#x2009;0.47, p&#x2009;<&#x2009;0.001) and lower left insular cortical thickness (&#x3b2;&#x2009;=&#x2009;-0.45, p&#x2009;=&#x2009;0.031) were independently associated with elevated NPY levels. Findings suggest that elevated NPY levels may represent a shared neurobiological feature of adolescent obesity, whereas reduced right posterior cingulate cortical thickness may be more specifically associated with the diagnosis of BED. These findings contribute to understanding the neurobiological correlates of disordered eating behaviors during adolescence.

Geometric singularities are known to concentrate electric and optical fields, but whether curvature alone can localize thermal energy and thereby influence chemical kinetics remains unresolved. Here, we show experimentally and computationally that nanoscale curvature generates localized thermal fields that directly lower reaction barriers in heterogeneous catalysis. Using &#x3b3;-Al2O3 architectures with systematically varied curvature, nanoneedles, micro-needles, and spheres, while maintaining comparable composition, phase, acidity, and defect states, we observe curvature-dependent temperature localization of up to &#x223c;30 &#xb0;C at nanoneedle tips under identical external heating. In situ infrared thermography confirms hotspot formation, and operando vibrational spectroscopy reveals enhanced water dissociation and increased *CF3 intermediate populations during CF4 decomposition. These effects reduce the apparent activation energy and enable complete CF4 decomposition at 580 &#xb0;C, substantially below that required for lower-curvature structures. The results establish curvature-induced thermal localization as a general physical mechanism linking geometry to interfacial energy density and reaction kinetics, providing a universal design principle for activating strongly bound molecules.

The design of smartwatch antennas confronts two challenges. The forward problem is related to how to reduce the performance degradation caused by the arm effect, while the inverse problem involves how to diminish the electromagnetic exposure of the antenna to the human body, especially for children who are sensitive to radiation. This paper presents a smartwatch antenna featuring a metamaterial protection layer, which satisfies the requirements of 4&#x2009;G communication and Wi-Fi. The smartwatch antenna loaded with the metamaterial layer is fabricated. The electromagnetic exposure dose is simulated, and the reflection coefficient of the antenna is measured when it is worn on the arms of adults and children, respectively. Simulation and measurement results demonstrate that the addition of the metamaterial layer can alleviate the frequency shift; the bandwidth is improved by 8.8%, and the gain is enhanced by 7.8% at most. Furthermore, the peak specific absorption rate (SAR) values in the arms of children and adults decrease by up to 6% and 14%, respectively, conforming to the safety limits stipulated by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The findings indicate that the proposed metamaterial layer with reflective performance can mitigate the reduction in radiation performance caused by the arm and concurrently minimize the radiation dose absorbed by the arm. This presents a viable strategy for electromagnetic radiation protection. Smartwatch antennas face two main challenges: first, The wearer&#x2019;s arm can interfere with antenna performance, and second, the antenna&#x2019;s electromagnetic radiation may affect the human body &#x2013; especially children, who are more sensitive to such exposure. This study introduces an innovative solution using a specially engineered material layer placed between the antenna and the arm. Tests and simulations show that this material layer helps maintain stable signal quality by reducing frequency shifts and improving antenna strength. It also significantly cuts radiation absorption in the arm &#x2013; by up to 6% for children and 14% for adults &#x2013; keeping it within international safety guidelines. In simple terms, this research makes smartwatches work better and safer, offering added protection, particularly for young users.