Search Results (3,035)

Background: Sleep deprivation is one of the major public health and performance risk factors, with documented effects on vigilance, executive function, emotional regulation, and safety-critical behaviour. This review examines how event-related potentials (ERPs)—which provide millisecond-level resolution of cognitive processing stages—can clarify which neural processes are most affected by sleep loss, from early sensory encoding to later evaluative and control-related stages. Materials and Methods: This study was conducted as a systematic review of human studies on sleep deprivation and ERPs. Eligible studies included human participants, focused primarily on acute/total sleep deprivation, and reported ERP outcomes (e.g., amplitude, latency, topography, or related event-locked EEG measures). Searches were performed in major biomedical/psychology databases using sleep deprivation and ERP terms, with additional forward/backward citation searching. Data was extracted in a structured format (participant characteristics, deprivation protocol, ERP methods, behavioural outcomes, ERP findings, and recovery/countermeasure effects). Due to substantial heterogeneity in paradigms, protocols, and ERP methods, findings were synthesised narratively rather than meta-analysed. Risk of bias was assessed with RoB 2 and ROBINS-I. Results: The search identified 854 records, of which 82 studies were included following deduplication, screening, full-text review, and citation chasing. Samples were typically small, highly selected, and dominated by healthy young adults, with frequent attrition related to prolonged wakefulness and EEG data-quality constraints. Across studies, sleep deprivation produced stage-specific and task-dependent ERP effects rather than a single uniform pattern. The most consistent findings involved mid-to-late components. These components typically showed prolonged latency and reduced amplitude. In some cases, amplitude increases were observed and interpreted as compensatory recruitment. Early sensory/pre-attentive components (e.g., P1/N1/MMN/P50) were often relatively preserved, but showed selective vulnerability, including latency slowing, reduced filtering/gating, or decreased phase locking. A recurring observation was a behaviour–ERP dissociation, where ERP abnormalities were detectable even when behavioural impairment was modest, indicating covert neural inefficiency or compensation. Recovery sleep, naps, and countermeasures (e.g., modafinil, caffeine) produced partial, component-specific recovery, with amplitude and latency often recovering at different rates. Conclusions: The evidence indicates that sleep deprivation primarily disrupts higher-order, late-stage, and temporally coordinated neural processing, while earlier sensory processing is often preserved but becomes slower and less stable. Among ERP markers, the P300/P3 family is the most robust and informative signature of sleep loss effects and recovery. ERPs are therefore a sensitive tool for detecting neural dysfunction and compensation under sleep deprivation, including changes that may precede overt behavioural decline. Future research must improve the generalisability and reproducibility of ERP findings by employing larger, more diverse samples, alongside more standardised methodological, recording, and reporting practices. Full article

In Argentina, a high incidence of EBV-associated lymphomas was demonstrated in young children. Natural killer (NK) cells, particularly, IFN-γ-producing CD56bright NK cells, have been reported to play a key role in asymptomatic EBV infection in children, restricting viral-mediated transformation. In order to analyze NK cell characteristics in children with primary and persistent EBV infection, along with EBV+ Hodgkin lymphoma (HL) from Argentina, a cohort of EBV-infected pediatric patients was analyzed. A scarcity of CD56+ cells, as an indirect marker of NK cells, across all tonsillar samples and pediatric classical Hodgkin lymphoma cases was observed, with no significant differences according to EBV status. In primary infection, CD56+ cells showed a positive correlation with IFNγ+ cells, suggesting a role in early antiviral responses. Flow cytometry revealed an increased proportion of CD56bright NK cells in EBV-infected children, particularly in cases expressing latency II/III antigens. A significantly higher IFN-γ production was observed in CD56bright cells in children with primary infection compared with healthy carriers, along with an inverse correlation between IFN-γ production and CD56bright cells in healthy carriers. These findings suggest that NK cells may contribute to immune control predominantly during primary infection, whereas their role appears limited in healthy carriers and in EBV-associated Hodgkin lymphoma. Full article

Background/Objective: Persistent dry mouth, associated with poor oral health and lower quality of life (QoL), affects approximately 20% of adults in the global population. Indicating a potential role in nutrition, Camellia sinensis tea leaves contain bioactive compounds that may help prevent and manage dry mouth. This review aimed to evaluate the effects of different tea types on salivary flow rate (SFR), salivary pH, and QoL in healthy and at-risk patients and patients with hyposalivation or xerostomia. Methods: A systematic review without meta-analysis (SWiM) was conducted. Pre-defined inclusion and exclusion criteria were applied to databases: PubMed, Scopus, Web of Science, and the Cochrane Library. Results: Eighteen studies met the eligibility criteria for inclusion in the review. Over 50% of studies investigated either black or green tea, with most conducted in healthy young adults (67%) and predominantly among females. Fifteen of the studies reported that tea intervention improved at least one outcome of interest. In general, green tea improved SFR and salivary pH more consistently than black, oolong, or matcha tea, particularly in at-risk populations and patients diagnosed with xerostomia. Conclusions: Tea consumption, particularly of green and black tea, showed a transient enhancement of salivary flow, pH, and QoL, offering a low-cost non-pharmacological approach to supporting oral health. Definitive recommendations were limited by heterogeneity in study interventions and outcome measurements, small sample sizes, and incomplete reporting of study details. However, tea’s potential as an adjunct for the prevention and management of dry mouth warrants further study in larger, well-designed studies that employ standardized protocols. Full article

Background/Objectives: Shear wave elastography (SWE) may provide an objective method for quantifying piriformis muscle stiffness, but its clinical and research use requires evidence that the measurement procedure is reliable. This study aimed to determine the intra- and inter-examiner reliability of a standardized SWE protocol for assessing piriformis muscle stiffness and to provide measurement error thresholds for clinical interpretation. Methods: Twenty-one healthy volunteers were assessed bilaterally by two examiners with different levels of ultrasound experience. The piriformis muscle was identified in the long axis beneath the gluteus maximus, and SWE images were acquired using a standardized protocol. Each side was measured twice by each examiner, resulting in 168 ultrasound images. Reliability was analyzed using side-specific observations (n = 42). Intraclass correlation coefficients (ICCs), standard errors of measurement (SEMs) and minimal detectable changes (MDCs) were calculated for shear modulus and shear wave speed. Results: Inter-examiner reliability was good for single measurements, with ICCs of 0.872 for shear modulus and 0.813 for shear wave speed. When the average of two measurements was used, ICCs were similar, reaching 0.876 and 0.832, respectively. Inter-examiner MDC values ranged from 6.1 to 6.2 kPa for shear modulus and from 0.37 to 0.39 m/s for shear wave speed. Intra-examiner reliability was excellent for both examiners, with ICCs ranging from 0.938 to 0.979. Test–retest MDC values ranged from 2.7 to 3.3 kPa for shear modulus and from 0.19 to 0.22 m/s for shear wave speed. Conclusions: SWE provides good inter-examiner and excellent intra-examiner reliability for assessing piriformis muscle stiffness using a standardized acquisition protocol. Longitudinal assessments should preferably be performed by the same examiner, and changes should be interpreted in relation to SEM and MDC values, particularly in multi-examiner settings where absolute measurement error is larger. These thresholds reflect measurement error and should not be interpreted as evidence of diagnostic validity or responsiveness to treatment. Full article

Background/Objectives: Angiogenic T (Tang) cells support endothelial repair and vascular homeostasis. This cross-sectional study compared circulating Tang cell levels in young adults with T1DM vs. healthy controls, and assessed associations between Tang cells and continuous glucose monitoring (CGM) metrics. Methods: Sixty-five young adults with T1DM and 55 healthy controls were enrolled at the University of Campania “Luigi Vanvitelli,” Naples, Italy. Clinical and biochemical data were collected. Tang cells (CD3⁺CD31⁺CD184⁺) were quantified by flow cytometry as absolute counts and percentage of CD3⁺ T cells. In T1DM, CGM metrics from the preceding 14 days were analyzed, including time in range (TIR), time above range (TAR), and time below range (TBR). Results: Individuals with T1DM had higher fasting glucose and HbA1c than controls. Total CD3⁺ T cell counts were lower in T1DM. Tang cells were significantly reduced in T1DM both as absolute number and percentage (21% [10–31] vs. 48% [39–62]; p < 0.001). In multivariable analyses, Tang cell percentage was positively associated with TIR and inversely associated with HbA1c and TAR. Conclusions: Young adults with T1DM exhibit significantly reduced circulating Tang cells. Associations with CGM metrics support a link between real-world glucose control and endothelial vascular health. Full article

Background/Objectives: The oscillatory dynamics underlying stage-specific processing in working memory (WM) remain incompletely characterized, particularly under varying memory loads. We examined the load-dependent modulation of theta (4–7 Hz), lower alpha (8–10 Hz), and upper alpha (11–13 Hz) absolute power during encoding, maintenance, and retrieval using quantitative EEG in a modified Sternberg task that temporally dissociates these stages. Methods: Forty-five healthy young adults performed trials with memory sets of three, five, or six uppercase consonants, followed by a lowercase probe. EEG data were analyzed using cluster-based permutation testing, and brain–behavior relationships were assessed using regression models. Results: Fronto-central theta power increased with memory load and was significantly higher during retrieval than during encoding or maintenance. Greater theta power during retrieval predicted faster reaction times in the three-letter condition. Alpha oscillations showed robust stage effects. Lower alpha power was higher during maintenance than retrieval across loads and exhibited a load effect during maintenance (three > six letters) in occipital regions. Upper alpha power was consistently maximal during maintenance across all loads, involving bilateral fronto-central, parietal, and occipital regions. Critically, under moderate load (five letters), higher upper alpha power predicted a greater probability of correct responses across task stages. Conclusions: These findings demonstrate a functional dissociation between oscillatory bands across temporally separated WM stages: theta activity was retrieval-dominant and associated with response speed, whereas alpha, particularly upper alpha, was maintenance-dominant and supported accuracy under increased mnemonic demand. Full article

Background: High-heeled footwear is widely used by women, yet its systemic influence on spatiotemporal gait parameters, pelvic kinematics, and propulsion across a range of heel heights remains incompletely characterised. This study aimed to quantify gait changes across four footwear conditions and assess the contribution of anthropometric characteristics to observed gait variability. Methods: A within-subject repeated-measures study was conducted with 75 healthy young adult women (mean age 24.3 years, BMI 21.3 kg/m²) assessed barefoot, in ballerina flats, 8 cm heels, and 12 cm heels using the G-WALK inertial measurement system (BTS Bioengineering). Thirty gait parameters were analysed using the Friedman test with Bonferroni-corrected Wilcoxon post hoc comparisons (α_adj = 0.0083), Spearman rank correlations, multiple linear regression, and Kruskal–Wallis tertile analysis. Results: Footwear significantly affected 22 of 30 parameters. Walking speed was higher in all shod conditions than barefoot (up to +9.2%), driven entirely by stride elongation with cadence unchanged, indicating a general effect of footwear rather than heel elevation specifically. Stride length peaked at 8 cm heel (+8.9% vs. barefoot) and declined at 12 cm. Gait symmetry decreased progressively with heel height. Ballerina shoes produced a distinctively dynamic temporal profile—shortest stance duration, lowest double support, and highest single support time—significantly different from both barefoot and heeled conditions. The propulsion index increased height-dependently with heel height, rising 23.3% from barefoot (8.20) to 12 cm heel (10.11; p < 0.001). Pelvic obliquity symmetry was disrupted at 12 cm heel, while tilt symmetry was unaffected. Anthropometric analysis identified 110/600 significant Spearman correlations (23 surviving Benjamini–Hochberg FDR correction) and 29/120 significant regression models (14 surviving FDR); age, body weight, and shoe size were the most consistent predictors, most reliably in the barefoot condition. Conclusions: Heel height exerts condition-specific effects on gait biomechanics. Ballerina shoes produce a gait pattern distinct from both barefoot and heeled walking. Propulsion demand increases height dependently with heel elevation. Because participants walked in their own footwear, the observed effects reflect the combined characteristics of each shoe type rather than heel elevation in isolation. Anthropometric characteristics—particularly age, body weight, and shoe size—are modestly associated with footwear–gait responses and may inform future biomechanical research, although clinical application requires confirmation in standardised-footwear studies and clinical populations. Full article

Background/Objectives: Pressotherapy is a method of controlled compression using special cuffs designed to improve lymphatic and blood circulation and support aesthetic treatments and therapies. The available literature lacks evidence of the effects of these treatments on skin parameters in healthy, untrained women. It was hypothesized that a series of pressotherapy treatments would positively impact skin firmness, hydration, friction resistance, and transepidermal water loss (TEWL). Methods: The study involved 15 healthy women aged 20–26 years who underwent a series of 10 pressotherapy treatments on the lower limbs (preliminary study, without a separate control group). The effects of the therapy were assessed by measuring skin hydration, transepidermal water loss (TEWL), elasticity, and resistance to friction, with measurements taken in standardized conditions before, during, and after the treatment cycle. Results: The study did not observe significant changes in skin hydration (Chi-square = 0.48; p = 0.923; Kendall’s W = 0.016) (CI 95% 6.07–16.22), transepidermal water loss (TEWL) (Chi-square = 6.24; p = 0.100; Kendall’s W = 0.208) (CI 95% 2.29–14.37) and skin friction coefficient (Chi-square = 6.27; p = 0.099; Kendall’s W = 0.209) (CI 95% 0.06–1.52), while analysis of elasticity and firmness parameters showed a significant improvement in selected biomechanical indicators (R0 (Chi-square = 13.32; p = 0.004; Kendall’s W = 0.440), R3 (Chi-square = 12.39; p = 0.006; Kendall’s W = 0.413), R8 (Chi-square = 9.00; p = 0.029; Kendall’s W = 0.300), Q1 (Chi-square = 11.64; p = 0.008; Kendall’s W = 0.388), Q2 (Chi-square = 7.54; p = 0.050; Kendall’s W = 0.251) (CI 95% 0.01–0.17)). Conclusions: A series of pressotherapy treatments on the lower limbs of young women may affect skin elasticity (selected parameters) but may not have a significant impact on skin hydration, transepidermal water loss (TEWL), or skin resistance to friction. Full article

Background: Cardiovascular disease (CVD) is the leading cause of global mortality, necessitating its early detection. Carotid intima-media thickness (CIMT) is a validated biomarker of CVD. In Saudi Arabia (SA), population-specific CIMT data for young adults are lacking. This pilot study aimed to generate single-institution preliminary CIMT data using the Butterfly iQ+ handheld ultrasound device (HHUD) and identify CVD risks. Methods: A cross-sectional observational study was conducted on 63 medical students. CIMT was measured bilaterally on common carotid artery (CCA), using the Butterfly iQ+ HHUD. Data on sex, age, ethnicity, BMI, mean arterial pressure (MAP), family history, and dietary habits were collected and analysed using t-tests, one-way ANOVA, Chi-square tests, Spearman’s rho (ρ) correlation, and stepwise multiple linear regression. Results: Mean age was 19.19 ± 1.89 years, and mean BMI was 24.93 ± 4.72 kg/m². Mean CIMT was 0.053 ± 0.006 cm. Males demonstrated thicker right CIMT (0.055 cm; 95% CI: 0.053–0.058 cm) than females (0.051 cm; 95% CI: 0.048–0.053 cm; mean difference: 0.005 cm, 95% CI: 0.001–0.008 cm; p = 0.012) and higher mean CIMT (0.0548 vs. 0.0513 cm; mean difference: 0.004 cm, 95% CI: 0.000–0.007 cm; p = 0.031). Height (ρ = 0.266; p = 0.035) and weight (ρ = 0.320; p = 0.011) correlated with right CIMT. Stepwise regression identified sex as the sole independent predictor (R² = 0.105; F = 6.541; p = 0.013). Conclusions: This pilot study establishes preliminary single-institution CIMT data for young healthy medical students at a single university in Riyadh, Saudi Arabia. Sex, height, and body weight are key early determinants of carotid wall thickness. The Butterfly iQ+ HHUD is a feasible point-of-care tool for CIMT measurement, supporting community-based CVD screening in the region. Full article

Background: The methodology of slow-paced breathing (SPB) to optimize cardiorespiratory function requires further refinement. The aim of this study was to identify the methodological ranges of resonance breathing frequencies during SPB in healthy young adults with optimal and suboptimal spirometric indices. Methods: Twenty-eight healthy Indian students living in the Arctic Russian region (age 21–24 years; 20 males, 8 females) underwent spirometry and 2 min HRV recordings at 6 time points: baseline (spontaneous breathing) and SPB periods of 9–13 s with biofeedback. Results: Participants were divided into Group 1 (FEV1 ≥ 80% predicted, n = 13) and Group 2 (FEV1 < 80% predicted, n = 15). At baseline, Group 2 showed reduced overall HRV, lower vagal activity, a higher stress index and lower baroreflex power (by LFmx) vs. Group 1. During SPB, Group 1 exhibited more significant vagal enhancement, peaking at 9–10 s breathing periods. Group 2 showed delayed, wave-like responses with peak effects at 9 s and/or 12–13 s. Conclusions: SPB frequency depends on the level of FEV1: 9–10 s periods in individuals with FEV1 ≥ 80% predicted, and 9 s and/or 12–13 s periods (delayed effect) in those with FEV1 < 80% predicted, which may be due to cardiorespiratory strain under uncomfortable climatic conditions. Full article

Background: Dietary behaviours in young athletes are shaped by multiple behavioural, social, and environmental influences, which may contribute to the coexistence of healthy and unhealthy eating patterns. This study aimed to explore factors associated with fast-food consumption frequency and adherence to the Mediterranean diet (MD) among young football athletes. Methods: A cross-sectional study was conducted among 94 male football players aged 10–16 years from a Portuguese football club. Adherence to the MD was assessed using the Mediterranean Diet Quality Index for Children and Adolescents (KIDMED) index. Fast-food consumption patterns and food-choice motivations were evaluated through a structured questionnaire. Anthropometric measurements were obtained using standardised procedures. Correlation, linear regression, and ordinal regression analyses were performed. Results: Most participants demonstrated high adherence to the MD (96.8%), with a median KIDMED score of 12.0 (IQR: 10.0–13.0). Although 88.3% of participants reported consuming fast food, intake frequency was generally low, with 67.0% reporting consumption never or only once per month. Higher fast-food consumption frequency was associated with lower fruit and vegetable intake and higher consumption of sweets and pastries. No significant associations were observed between fast-food consumption frequency and overall MD adherence, Body Mass Index z-score, or fat mass percentage. Higher health-related motivation scores were associated with lower odds of more frequent fast-food consumption (OR = 0.248; p = 0.021), whereas greater decision autonomy regarding restaurant choice was associated with higher consumption frequency (OR = 4.036; p = 0.010). Conclusions: Young football athletes showed high adherence to the Mediterranean diet despite the presence of fast-food consumption, suggesting that healthy and unhealthy dietary behaviours may coexist within the same population. Behavioural factors, particularly health motivations and food-choice autonomy, appear to influence fast-food consumption independently of overall diet quality and anthropometric status. Full article

Joint-position sense (JPS) performance depends on the integration of sensory input from different mechanoreceptors, whose contribution may vary according to the protocol. Research on the influence of individual factors (sex, limb dominance and physical activity) on ankle JPS remains scarce or inconclusive. This study aimed to investigate the influence of individual and protocol-related factors on the ankle JPS of young healthy adults. Fifty individuals participated in this cross-sectional study. Ankle JPS was assessed by active repositioning toward three target angles: 10° dorsiflexion and 10°/20° plantarflexion. All procedures were video-recorded and analyzed using Kinovea. Absolute (AAE) and relative angular errors (RAE) were calculated. The International Physical Activity Questionnaire was used to assess physical activity level. There were no significant differences in AAE regarding sex, dominance or physical activity level (p > 0.05). Mean AAE values ranged between 0.5° and 0.7°, with no significant differences between the tested angles (p > 0.05). RAE analysis revealed a tendency toward overestimation of joint position. In young healthy adults, ankle JPS appears to be independent of sex, limb dominance, physical activity level, or tested target angles. Furthermore, these individuals seem to present AAE values below 1°. This information may help to identify those with proprioceptive deficits and monitor intervention outcomes. Full article

Salinity stress remains a major bottleneck for agriculture in arid regions. While Opuntia ficus-indica is known for its resilience, its young cladodes maintain a misleadingly healthy visual appearance and stable biomass even under heavy saline pressure, making traditional vegetation indices and standard statistics unreliable for early diagnosis. The objective of this study was to develop a non-destructive phenotyping framework for the early detection of latent salinity stress in young Opuntia cladodes. Controlled experiments were conducted using hyperspectral data cubes (400–1000 nm) acquired from plants exposed to six distinct salinity levels ranging from 2 to 21 dS m⁻¹. Our methodology integrates these high-dimensional spatial–spectral data with a tailor-made 3D Convolutional Neural Network (3D-CNN). Seven physiological vegetation indices—NDVI, PRI, WI, PSRI, MCARI, SIPI, and NDRE were extracted to track sub-clinical shifts and processed as a volumetric depth dimension within the network to preserve spatial–spectral integrity. The optimized 3D-CNN framework achieved a validation accuracy of 99.7% and a weighted F1-score of 99.1%, delivering 100% precision at critical stress thresholds (13 and 21 dS m⁻¹). Spatial confidence maps (Softmax > 0.95) further confirmed the high reliability of the diagnostic output. Requiring a training duration of approximately 8 s, this framework provides a robust basis for precision early-warning irrigation systems to sustain Opuntia cultivation in challenging environments. Full article

High-intensity interval training (HIIT) is an efficient exercise strategy capable of eliciting acute cardiovascular and metabolic responses. Blood flow restriction (BFR) and normobaric hypoxia (NH) have been proposed as exposures to intensify physiological stress during exercise; however, comparative evidence between both strategies remains limited. The aim of this study was to compare acute physiological responses in HIIT protocols performed under BFR and NH in apparently healthy young men. Eight volunteers completed two HIIT sessions in this fixed-order within-subject repeated-measures study: one with BFR and one with NH (simulated altitude: 3536 m above sea level; FiO₂ ≈ 13.5%). Blood glucose, peripheral oxygen saturation (SpO₂), heart rate, and blood pressure were repeatedly measured during the exercise protocol. After Bayesian analysis, no evidence of differences in glycemic response was observed, while heart rate and diastolic blood pressure responses appeared broadly comparable between conditions. However, SpO₂ was consistently lower during NH, whereas systolic blood pressure values were higher under BFR. Although both BFR and NH induced acute physiological responses characteristic of HIIT, distinct physiological profiles were observed. NH was associated with greater systemic hypoxemic stress, whereas BFR showed higher systolic pressor responses. Full article

Background/Objectives: We hypothesized that orally ingested 1,5-anhydro-D-mannitol (AM) would be absorbed from the gut but poorly metabolized, and it may have low fermentability by gut microbiota based on the breath hydrogen test. Methods: We used a dual-model approach in this study. In animal experiments, AM was administered orally to male Wistar rats. In a randomized, three-way crossover trial (UMIN000054040), 15 healthy young adults consumed a single 5 g dose of AM, mannose, or fructooligosaccharide (FOS). Primary outcome was breath hydrogen concentrations; secondary outcomes included plasma AM, blood glucose concentration, and urinary AM excretion. Results: After ingestion of 5 g AM in humans, the 14 h area under the curve for breath hydrogen excretion was markedly lower after AM than that after FOS ingestion (p < 0.05). Plasma AM peaked at 1 h, whereas blood glucose remained unchanged from baseline. Approximately 30% of ingested AM was excreted unchanged in urine within 24 h. Results of animal experiments were similar to those in humans. Fecal excretion in AM was confirmed to be minimal, accounting for ~1% of the administered dose within 24 h in rats. Conclusions: These findings indicate that AM is potentially a low-energy carbohydrate. Full article