Search Results (528)

Background: Heart rate variability (HRV) is a well-established marker of autonomic nervous system (ANS) activity. It is also an important tool for investigating cardiovascular and neurological health. Changes in HRV have been associated with epilepsy and sudden unexpected death in epilepsy (SUDEP), conditions in which autonomic dysregulation is believed to play a significant role. HRV is traditionally measured using electrocardiography (ECG) under standardized laboratory conditions. Recently, however, wearable devices such as the Empatica E4 wristband have emerged as promising tools for continuous, noninvasive HRV monitoring in real-life, ambulatory, and clinical settings where laboratory infrastructure may be lacking. Methods: We evaluated the validity and clinical utility of the Empatica E4 wristband in two cohorts. In the first cohort of healthy controls (n = 29), we compared HRV measures obtained with the E4 against those obtained with a gold-standard laboratory ECG device under seated rest and metronomic breathing conditions. In persons with epilepsy (PWE, n = 42), we assessed HRV across wake and sleep states, as well as during exposure to sodium channel blockers. This was done to determine whether the device could detect physiologically and clinically meaningful changes in autonomic nervous system (ANS) function. Results: In healthy participants, the Empatica E4 provided heart rate (HR), root mean square of successive R-R intervals (RMSSD), and standard deviation of all interbeat intervals (SDNN) values that were strongly correlated with laboratory measurements. Both devices detected the expected increase in RMSSD during metronomic breathing; however, the E4 consistently reported higher absolute values than the ECG. In patients with epilepsy (PWE), the E4 reliably captured parasympathetic activation during sleep and detected a significant reduction in heart rate variability (HRV) in patients taking sodium channel blockers, demonstrating its sensitivity to clinically relevant autonomic changes. Conclusions: The Empatica E4 wristband is valid for measuring HRV in research and clinical contexts. It can detect modulations of ANS activity that are physiologically meaningful. While HRV metrics were robust, other signals, such as electrodermal activity and temperature, were less reliable. These results highlight the potential of wearable devices as practical alternatives to laboratory-based autonomic testing, especially in emergency and resource-limited settings, and emphasize their importance in epilepsy care risk assessment. Full article

Background/Objectives: Transcatheter aortic valve implantation (TAVI) is a standard treatment for severe aortic stenosis, especially in older adults and high-risk patients. However, many TAVI candidates have osteopenia or osteoporosis, indicated by low bone mineral density (BMD), which is linked to frailty and adverse outcomes. Although prior research suggests an association with poor clinical outcomes, data remain limited. We investigated the impact of osteopenia on TAVI outcomes, hypothesizing that a lower BMD is associated with poor perioperative outcomes and decreased long-term survival. Methods: In this single-center retrospective study, we analyzed data from 411 patients who underwent TAVI at Yamaguchi University Hospital from 2014 to 2024. Clinical and survival data were collected, and Cox regression analysis was used to identify independent predictors of mortality. Preoperative BMD was measured using computed tomography, defining osteopenia as <135 Hounsfield units at L1. Patients were categorized as having mild, moderate, or severe osteopenia. Results: Early clinical outcomes and procedural success were similar; however, patients with osteopenia had longer intensive care unit stays (p = 0.04) and higher late cardiac mortality (p < 0.001). Six-year survival was 36.2% and 88.1% in patients with and without osteopenia, respectively (p < 0.0001). Cox regression analysis revealed osteopenia as a mortality risk factor (hazard ratio: 6.75, 95% confidence interval: 2.96–15.38, p < 0.0001). Severe osteopenia was associated with the poorest outcomes. Conclusions: Osteopenia is an independent predictor of poor long-term survival after TAVI. These findings underscore the importance of comprehensive risk assessment, suggesting that targeted interventions may improve outcomes. Full article

An accelerometer mounting technique has large implications on the frequency range and accuracy of the measurement, with stiffness and the mass relative to the monitored structure as the primary concerns. The International Organization for Standardization (ISO) gives an extensive list in 5348:2021, detailing mounting methods, and provides recommendations for testing mounts that are not specifically defined. In the nuclear industry on the laboratory scale, there is a need for vibration measurements for predictive maintenance and process monitoring that are nondestructive and capable of working in high-temperature environments. Commercial adhesive products with easy application and removal were tested as nondestructive methods, while quick mounts to a commonly used aluminum frame were tested as nondestructive and have potential applicability in high-temperature environments. The sinusoidal excitation method was used, measuring frequencies from 50 Hz to 10 kHz in one-third octave band intervals, utilizing three accelerometers and comparing the results to those obtained with the stud-mounting method. Using the lowest ±3 dB threshold across each accelerometer, foam dots and poster strips were not successful, and foam tapes were accurate up to 2000 Hz, hose clamps and zip ties up to 800 Hz, and a custom 3D printed mount up to 1000 Hz. Knowing the limitations of each mounting technique allows for accurate measurements within the appropriate range. Full article

Background/Objectives: Beetroot supplementation is a rich source of inorganic nitrate and has been proposed to enhance nitric oxide bioavailability and support cardiovascular recovery after exercise. This study aimed to evaluate the effects of beetroot supplementation on post-exercise cardiovascular and autonomic recovery in postmenopausal women. Methods: A systematic review and meta-analysis were conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Searches were performed in PubMed, Scopus, and Web of Science databases from inception to July 2025. Ten trials involving postmenopausal women were included. Outcomes assessed included cardiovascular measures (blood pressure and vascular function), autonomic parameters derived from heart rate variability (HRV)—specifically the root mean square of successive differences (RMSSD), the standard deviation of normal-to-normal intervals (SDNN), and high-frequency power (HF)—as well as physical performance (peak oxygen uptake [VO_2peak or VO_2max] and functional fitness tests). Four independent reviewers extracted data, assessed risk of bias, and evaluated the certainty of evidence using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Results: Pooled analyses from two trials (n = 54) revealed a statistically significant improvement in RMSSD with beetroot supplementation (mean difference: 6.68 ms; 95% CI: 0.86 to 12.50; p = 0.02), suggesting enhanced parasympathetic reactivation after exercise. No significant effects were detected for HF (mean difference: 61.75 ms²; 95% CI: −70.92 to 194.43; p = 0.36) or SDNN (mean difference: 6.20 ms; 95% CI: −9.69 to 22.09; p = 0.44). Substantial to considerable heterogeneity was identified across outcomes (I² = 73–86%). Certainty of evidence was rated moderate for RMSSD, low for SDNN, and very low for HF. Conclusions: Beetroot supplementation may enhance post-exercise autonomic recovery in postmenopausal women, primarily through improvements in RMSSD. However, further trials with standardized protocols, larger samples, and longer intervention durations are required to clarify its impact on broader HRV domains, cardiovascular function, and clinical outcomes. Full article

An exposed sedimentary succession, ca 115 m of a total of 1000 m, from the Eastern Carpathian foredeep was, for the first time, analyzed using facies analysis and scale- and time-independent sequence stratigraphy methods to reveal the depositional environment and its cyclic sedimentation. The outcropping deposits, belonging to the Șomuz Formation, dated on the basis of molluscs, foraminifera, and ostracods, are uppermost Volhynian (upper Serravalian). The three recurrent facies associations we have distinguished indicate a storm-dominated shoreface–offshore transition environment. Five-decametre-thick high-frequency sequences (HFS1–5), at most of 4th order, bounded by maximum regressive surfaces, were defined in the studied interval. The maximum thickness of the Volhynian deposits in the area, known both from well sites and outcrops, allowed us to estimate the sedimentation rate at ca 1.5 m/kyr. The fossil content shows that the entire sedimentary succession was deposited in very shallow to shallow water during the whole Volhynian (12.65 - ca 12.01 Ma). The time interval we studied was estimated at ca 75 kyr, so the average time of one HFS is ca 15 kyr. At this scale, considering that both high subsidence and Eastern Paratethys sea-level rise added to accommodation, the sediment supply must have been the main control of cyclic sedimentation, which, in turn, must have been controlled by precession climatic changes in the source area. The estimated time of an HFS is shorter than a precession cycle, but better dating might support or refute this hypothesis. This paper may awaken the interest of the owners of better data, especially from subsurface (seismic, well logs), to complete the data from natural exposures. Full article

The subject of this paper is the computational homogenisation and identification of heterogeneous materials in the form of auxetic structures made of materials with nonlinear characteristics. It is assumed that some of the material and topological parameters of the auxetic structures are uncertain and are modelled as interval numbers. Directed interval arithmetic is used to minimise the width of the resulting intervals. The finite element method is employed to solve the boundary value problem, and artificial neural network response surfaces are utilised to reduce the computational effort. In order to solve the identification task, the Pareto approach is adopted, and a multi-objective evolutionary algorithm is used as the global optimisation method. The results obtained from computational homogenisation under uncertainty demonstrate the efficacy of the proposed methodology in capturing material behaviour, thereby underscoring the significance of incorporating uncertainty into material properties. The identification results demonstrate the successful identification of material parameters at the microscopic scale from macroscopic data involving the interval description of the process of deformation of auxetic structures in a nonlinear regime. Full article

Background/Objectives: Human leukocyte antigens (HLAs) are major determinants of successful allogeneic hematopoietic stem cell transplantation (allo-HSCT). Their alleles are closely linked to outcomes, even in HLA-identical sibling donor (ISD) HSCT. This retrospective study analyzed the impact of HLA alleles on HLA-ISD HSCT outcomes in Omani patients. Methods: Data were collected for a heterogenous cohort of patients registered at the Sultan Qaboos University Hospital (SQUH), who underwent HLA-ISD HSCT from 2012 to 2022 (n = 153). HSCT outcomes, namely acute GVHD (aGVHD), chronic GVHD (cGVHD), chimerism status (complete or mixed) at 6 to 12 months after HSCT, neutrophil and platelet engraftment time, and patient five-year overall survival, were included. Low-resolution HLA-typing records were collected for five HLA loci: HLA-A, B, C, DRB1 and DQB1. GVHD and chimerism were analyzed by logistic regression analysis. Platelet and neutrophil engraftment times were assessed by Mann–Whitney tests. Patient overall survival was evaluated by the Kaplan–Meier model and Log-rank testing. At a 95% confidence interval, the p-value threshold was corrected using Bonferroni correction. Results: The incidence rates of aGVHD and cGVHD from all grades were 16% and 15%, respectively. Although no association between HLA alleles or any of the investigated outcomes was identified, survival curve analyses indicated a significant protective effect of HLA-DQB1*05 (p = 0.01). Patients carrying this allele had a better-estimated 5-year overall survival (90%) than did DQB1*05 negative patients (68%). Conclusions: This study suggests that HLA-DQB1*05 in the Omani population could have an impact on overall survival and might be a predictive biomarker. Further studies on a larger scale in other regional populations are needed to validate our findings and explore the underlying mechanism. Full article

Background: As we age, our autonomic function declines, resulting in altered autonomic balance during postural transitions. These changes can affect the dynamic interplay between sympathetic and parasympathetic modulation, compromising short-term compensatory responses to active standing. Objectives: This study aimed to compare heart rate variability (HRV) at baseline, cardiac parasympathetic modulation (CPM), and cardiac baroreflex gain (CRG) between younger adults (YA) and older adults (OA) following active standing orthostatic stress. A secondary objective was to analyze the incidence of orthostatic intolerance (OI) symptoms. Methods: Participants (n = 76) completed sit-to-stand and lie-to-stand maneuvers with continuous beat-to-beat blood pressure and heart rate (HR, electrocardiogram). HRV at baseline was analyzed in both time and frequency domains. CPM was measured by the HR 30:15 ratio on standing. CBG was determined as the ratio of HR and SBP changes (ΔHR/ΔSBP) at specific phase time points (30 s, 60 s, 180 s, and 420 s). Results: At baseline, OA showed reduced Standard Deviation of RR intervals (SDRR), Root Mean Square of Successive Differences (RMSSD), low-frequency (LF), and high-frequency (HF) power, and elevated LF/HF ratio (all p < 0.05), indicating a shift toward sympathetic dominance. During active standing orthostatic stress, OA demonstrated a lower HR30:15 ratio and CBG in later phases (phases 2–4) (all p < 0.05). Also, OA reported more symptoms (14%) of OI than YA (0%) (p = 0.041). Conclusions: These findings indicate that older adults have impaired autonomic function characterized by reduced HRV, CPM and CBG responses. These impairments lead to diminished autonomic regulation under active-standing orthostatic stress and a higher incidence of OI symptoms. Full article

Objectives: The primary objective was to compare the usage of Hazardous Materials (HazMat) Protective Personal Equipment (PPE) and ordinary PPE when performing basic and advanced health care support maneuvers in a prehospital setting, evaluating the effectiveness of several procedures, defined as the mean success rate of each. The secondary objective was to evaluate the presence of a learning effect, with improvements in the success rate and/or procedure timing. Methods: This was a prospective within-subjects (repeated-measures) study conducted on Emergency Medical Services (EMS) responders within their Chemical-Biological-Radiological-Nuclear-Explosive (CBRNe) training institutional programme. Volunteers performed a trial sequence of eight lifesaving procedures four times. During the first trial sequence, they wore standard clothing; during the three successive trials, they wore full HazMat PPE equipment. The primary outcomes were changes in success rate and time interval across the four trials. Results: A total of 146 EMS responders volunteered for the experiment. Procedure success rates remained high overall, with the most notable initial drop observed for video-assisted intubation (≈−10%). The only statistically significant delay in the first HazMat trial compared with baseline was for intravenous access (median +30 s; p < 0.001). In the two successive HazMat trials, success rates and timings improved, with median values coming close to baseline. However, only 61% of participants completed the entire drill due to tolerance limits of the equipment. Conclusions: HazMat PPE, while physically and ergonomically demanding, has minimal impact on most lifesaving procedures, though it may reduce intubation success and delay intravenous access. Tolerance to prolonged use is a key limitation, but dexterity improves rapidly with brief practice. EMS responders can benefit from continuous training practice, while manufacturers could explore ergonomic and tolerance improvements in their PPE equipment. Full article

Background/Objectives: This study aimed to identify specific endoscopic findings associated with the development of GC following successful H. pylori eradication. Methods: This prospective multicenter observational study included patients who underwent annual surveillance endoscopy after successful H. pylori eradication therapy between September 2013 and June 2019. Endoscopic findings were evaluated one year after eradication therapy and analyzed using the Kyoto Classification of Gastritis to identify factors associated with GC development. Results: A total of 465 patients were included, including 49 patients with GC and 416 patients without GC. At the initial endoscopic assessment (median, 0.96 years post-eradication), emergence of map-like redness and invisible regular arrangement of collecting venule (RAC) as independent predictors of GC (map-like redness: hazard ratio [HR], 2.561; 95% confidence interval [CI], 1.362–4.572; p = 0.003; invisible RAC: HR, 3.131; 95% CI, 1.078–9.091; p = 0.036). Patients with map-like redness or invisible RAC showed a significantly higher incidence of GC than those without map-like redness or invisible RAC (p < 0.001 and p < 0.001, respectively). Notably, map-like redness and visible RAC appeared in 13% and 28.4% of cases within the first year after eradication, respectively. Conclusions: Map-like redness and invisible RAC were identified as independent predictors of GC following H. pylori eradication and may serve as early predictive indicators, appearing within one year of successful eradication. This finding underscores the importance of early surveillance endoscopy in identifying patients at elevated risk for GC. Full article

Background: Ectopic pregnancy (EP) is a serious condition often treated with methotrexate. Letrozole, a safer aromatase inhibitor, may offer an effective alternative. This study presents a meta-analysis comparing the efficacy and safety of single-agent letrozole versus methotrexate for EP management. Methods: A systematic review and meta-analysis were conducted following PRISMA guidelines. Six sources of information underwent screening until 12 June 2025. Risk of bias and evidence certainty of evidence were assessed. Primary outcome was treatment success rate. Results were presented as mean difference (MD) or risk ratio (RR) along with a 95% confidence interval (CI) using a random-effects model. Results: Six studies (three randomized controlled trials and three nonrandomized prospective cohort studies) comprising seven arms and 260 patients (letrozole = 130, methotrexate = 130) were included. Almost all studies (n = 5) had overall moderate or high risk. Treatment success rates were comparable between groups (n = 7 arms; RR = 1.05; 95% CI: [0.94, 1.17]; p = 0.40). Letrozole was associated with significantly lower β-hCG levels on day 4 (n = 5 arms; MD = −95 mIU/mL; 95% CI: [−189.7, −0.91]; p = 0.048), day 7 (n = 5 arms; MD = −86.24 mIU/mL; 95% CI: [−143.1, −29.36]; p < 0.001), and day 14 (n = 3 arms; MD = −9.15 mIU/mL; 95% CI: [−17.24, −1.06]; p = 0.03); however, the differences were not clinically meaningful. Letrozole showed a better safety profile with higher platelet counts and lower liver enzymes. AMH levels were similar between groups. Most analyses were consistent, though secondary outcomes were less stable. Overall evidence certainty was rated ‘very low’ due to seriousness of risk of bias and imprecision. Conclusions: While letrozole shows comparable efficacy to methotrexate and a potentially better safety profile in the management of EP, the certainty of evidence is ‘very low’ due to risk of bias and imprecision. Therefore, these findings should be interpreted with caution, and further high-quality studies are urgently needed to confirm the results. Full article

Background: HIV drug resistance (DR) mutations can compromise antiretroviral therapy (ART) success among children living with HIV (CLHIV). We conducted a secondary analysis using data from a randomized control trial for ART monitoring among CLHIV in Kisumu County, Kenya from 2019 to 2023, to assess clinical, psychosocial, and structural factors associated with HIV DR. Methods: 704 CLHIV were followed for 12+ months, with characteristics captured at enrollment and follow-up visits in the “parent” randomized-controlled-trial (of point-of-care plasma viral load testing and for viremias ≥ 1000 copies/mL HIV genotyping for DR vs. standard-of-care) and an observational “extension” substudy (of participants on a dolutegravir-containing ART with genotyping performed on viremic specimens ≥ 200 copies/mL). A multivariate modified Poisson regression model was used to analyze factors associated with sequences yielding a Stanford HIVDR database DR penalty score (DR-PS) ≥ 30 to a nucleos(t)ides and/or non-nucleoside reverse transcriptase inhibitor, protease inhibitor (PI), and/or integrase inhibitor (INSTI). Results: Among 113 (16.1%) participants who underwent genotyping, 93 (82.3%) had a DR-PS ≥ 30. DR-PS ≥ 30 were associated with age 1–5 years (adjusted risk ratio (ARR) = 1.84; 95% confidence interval (CI): 1.07, 3.14), history of viremia ≥ 1000 copies/mL (ARR = 4.18; 95% CI: 2.77, 6.31), prescription of a PI- (ARR = 6.05; 95% CI: 3.43, 10.68) or INSTI-containing regimen (ARR = 1.83; 95% CI: 1.08, 3.11), poor adherence to ART (ARR = 1.91; 95% CI: 1.32, 2.76), lack of caregiver confidence in ART administration (ARR = 1.89; 95% CI: 1.11, 3.22), and mid-sized clinic populations (ARR = 0.55; 95% CI: 0.33, 0.92). Conclusion: Addressing social factors associated with DR-PS ≥ 30 may improve ART success among CLHIV. Full article

Background/Objectives: This meta-analytical review assesses the relationship between effect size and replication success in genetic studies of athletic performance, focusing on the ACTN3 and ACE polymorphisms across power- and endurance-based sports. The analysis revealed substantial heterogeneity in reported effect sizes (overall I² = 72.3%), indicating considerable variability between studies, likely influenced by differences in population genetics, study design, and sample size. Methods: For ACTN3, the pooled effect sizes were 1.40 (95% CI: 1.18–1.65) for power sports and 1.35 (95% CI: 1.12–1.58) for endurance sports. Although the difference between these estimates is small, it reached statistical significance (p = 0.0237), reflecting the large sample size, but it remains of limited practical and clinical significance. For the ACE polymorphism, effect sizes were similar in both endurance (ES = 1.22, 95% CI: 1.05–1.41) and power sports (ES = 1.20, 95% CI: 1.03–1.43), with overlapping confidence intervals, indicating no meaningful difference in association strength between sport types. Effect sizes were calculated as odds ratios (OR) with 95% confidence intervals for case–control designs, with standardized conversion protocols applied for alternative study designs reporting standardized mean differences or regression coefficients. Results: Publication bias was detected, particularly in smaller studies on ACTN3 and power sports (Egger’s test p = 0.007). The pooled effect of ACTN3 in power sports (OR 1.40, 95% CI: 1.18–1.65, 95% PI: 0.89–2.20) was adjusted to OR 1.32 (95% CI: 1.15–1.51) following trim-and-fill publication bias correction. The high degree of heterogeneity (I² = 72.3%) cautions against overgeneralization of the pooled results and highlights the need for careful interpretation, robust replication studies, and standardized methodologies. Conclusions: The findings emphasize that, while genetic markers such as ACTN3 and ACE are statistically associated with athletic performance, the magnitude of these associations is modest and should be interpreted conservatively. Methodological differences and publication bias continue to limit the reliability of the evidence. Future research should prioritize large, well-powered, and methodologically consistent studies—ideally genome-wide approaches—to better account for the polygenic and multifactorial nature of elite athletic ability. Full article

The deep carbonate reservoirs in the Yingzhong Block of the Qaidam Basin exhibit strong vertical heterogeneity and complex natural fracture development. Conventional fracability evaluation methods struggle to accurately characterize formation features, thereby affecting the stimulation effectiveness. To enhance the evaluation accuracy of fracturing sweet spot intervals, automatic mineral scanning equipment is employed to obtain formation micro-physical property parameters at continuous depths. Considering the temperature-pressure coupling effect under deep conditions, a rock mechanics computational model based on mineral composition was established to derive macroscopic mechanical parameters such as brittleness index and in situ stress. Based on a combined algorithm of the improved Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Analytic Hierarchy Process (AHP), a fracturing sweet spot prediction model integrating micro- and macro-multi-factors is established, and sweet spot index levels are classified. The research results indicate that the rock mechanics computational model demonstrates high accuracy, the calculated macroscopic parameters are reliable, and the fracturing sweet spot index model can fracability and meticulously evaluate the characteristics of deep carbonate formations. The fracturing sweet spots can be classified into three levels: Level I with an index higher than 0.50, Level II with an index between 0.35 and 0.50, and Level III with an index lower than 0.35. After using this method for layer selection, the fracture pressure decreases by 11.6%, and the sand addition success rate increases by 24%. Applying this method to guide the optimization of fracturing intervals demonstrates good on-site practical value, providing an important reference for identifying fracturing sweet spots in deep carbonate reservoirs. Full article

Background/Objectives: Heart rate variability (HRV) is a reliable, non-invasive marker of autonomic nervous system function and is often impaired in individuals with metabolic syndrome (MetS). Physical exercise has emerged as an effective strategy to improve autonomic modulation; however, the comparative effects of different training modalities on HRV in individuals with MetS remain unclear. This systematic review and meta-analysis aimed to evaluate the impact of various exercise interventions on HRV and to identify which training types yield the most significant improvements. Methods: A systematic search was conducted in PubMed and Scopus up to April 2025. Eligible studies (n = 16) included adults with obesity and MetS (n = 752) who underwent structured exercise interventions with HRV assessments pre- and post-intervention. Standardized mean differences were calculated using random effects models. Subgroup analyses were performed based on training modality (endurance training [ET], resistance training [RT], high-intensity interval training [HIIT], and concurrent training [CT]). Results: Sixteen studies of moderate to high quality were included, with eleven studies eligible for meta-analysis. ET and HIIT significantly improved time-domain indices (Root mean square of differences of successive R-R intervals —rMSSD—, Standard deviation of the R-R interval series —SDNN—) and frequency-domain parameters (high-frequency —HF—), suggesting enhanced parasympathetic activity. RT showed inconsistent effects, while CT improved long-term HF and total power (TP). Non-linear indices were the least reported due to insufficient data. Conclusions: Physical exercise—particularly ET and HIIT—appears to enhance cardiac autonomic modulation in individuals with obesity and MetS. These findings support incorporating targeted training strategies into clinical practice to optimize cardiovascular health in these populations. Full article