Browse Articles

Respiratory pattern change in female and male runners by respiratory tract restriction using a respirator

Respiratory protective equipment, particularly filtering facepiece respirators (FFRs), are increasingly used during physical activity, yet their influence on breathing mechanics remains unclear. This randomized, crossover trial investigated the impact of N95 FFRs on thoracoabdominal breathing patterns during graded treadmill exercise. Twenty competitive runners (10 male, 10 female; 18.9 ± 2.3 years) performed Bruce protocol tests with and without FFRs, while optoelectronic plethysmography quantified the contributions of pulmonary ribcage (RCp), abdominal ribcage (RCa), and abdomen (Ab) to tidal volume. Global ventilatory parameters (tidal volume, breathing frequency, minute ventilation) were unaffected by FFR use. However, compartmental analysis revealed significant alterations in breathing patterns at higher intensities. At 12 and 15 minutes, FFRs reduced RCp contribution (−7.85 ± 2.49%, P = 0.002; −8.41 ± 3.35%, P = 0.012) and increased Ab contribution (+5.97 ± 2.08%, P = 0.004; + 6.51 ± 2.80%, P = 0.020). Across all phases, females demonstrated moderate, but variable RCp dominance (P = 0.052). These findings indicate that while FFRs do not impair overall ventilation in trained runners, they substantially modify the biomechanics of breathing under load, reflecting compensatory adjustments that likely help preserve ventilatory efficiency. The results suggest that well-trained athletes may tolerate acute respiratory stress more effectively than the general population, which has implications for athletic training, rehabilitation, and occupational health where respirator use is required. Trial registration ClinicalTrials.gov NCT07032740

Growth and yield response of sorghum to omission of nutrients under contrasting landscape positions in the semi-arid tropical environment

Quality improvement intervention for school-based support teams for adolescents’ mental health in selected secondary schools in Gauteng: A study protocol

The prevalence of mental health disorders among adolescents poses a significant global health challenge, with approximately one in seven individuals aged 10–19 affected. The limited access to effective mental health services worsens this issue, particularly within schools, which are critical settings for early intervention. The study aims to develop and implement a school-based support team improvement intervention to enhance the mental health of adolescent learners in secondary schools. This study will employ a sequential explanatory mixed-methods approach design. The research will be conducted at selected secondary schools, and the participants for the study will be adolescents aged 13–19 and members of the school-based support team (SBST). Questionnaires will be administered to learners to determine the prevalence of common mental health challenges among adolescents and to determine the factors associated with mental health challenges among adolescents. A scoping review will also be conducted to examine existing interventions aimed at supporting learners with mental health challenges. Following the quantitative phase, interviews will be conducted with SBST members to explore the challenges and successes in supporting learners with mental health problems. The second phase will involve the development and implementation of the SBST quality-improvement intervention to support adolescents experiencing mental health challenges in secondary schools. The researcher will use Statistical Package for the Social Sciences (SPSS, 30.0.0) for quantitative data analysis and statistical interpretation. In addition, ANOVA will be employed to compare, identify, and understand specific factors that significantly impact adolescents’ mental health. The qualitative data will be analysed using Colaizzi’s seven-step framework and will be facilitated with NVIVO 15.

Generative AI tools receptivity promotes designer self perceived creativity through dual cognitive paths moderated by technophobia

Photo-Stitching of Nitroalkanes via Cross-Denitrative Olefination

Clustering recovered 18650 lithium-ion cells to improve homogeneity in second-life battery pack construction

Second-life use of lithium-ion batteries depends on assembling packs from recovered cells that behave as consistently as possible; however, recovered cells are often heterogeneous because of mixed models and different aging histories. This study aimed to improve pack-level homogeneity by clustering recovered cylindrical 18650 cells using laboratory-measured electrical variables and validating the approach through the construction and testing of a second-life pack. Cells were extracted from discarded laptop batteries, screened using safety and basic performance criteria, and characterized under a standardized charge–discharge protocol. For each retained cell, discharged capacity and internal resistance were measured, and health indicators were computed from nominal specifications and experimental results. Correlation analysis was used to identify the most informative variables associated with health status and to avoid redundant predictors prior to clustering. Clustering performance was evaluated across different numbers of groups using a cohesion–separation index, and two iterative selection algorithms were applied to select non-overlapping, highly homogeneous subsets of cells for series–parallel pack assembly. Using the same pack topology, the refined algorithm produced a second-life pack with higher usable capacity (8.98 Ah versus 8.72 Ah), lower equivalent internal resistance (76.38 mΩ versus 78.90 mΩ), and higher estimated maximum power (716.97 W versus 694.08 W) compared with the baseline algorithm. Overall, the results show that clustering guided by discharged capacity and internal resistance, combined with iterative refinement, enables the construction of more homogeneous and electrically consistent second-life packs from heterogeneous recovered cells.

misoTar: a novel approach for predicting miRNA and isomiR targets

Analysis of vapor cloud explosion behavior in LPG spherical tanks using multi-energy modeling and machine-learning-based factor assessment

Vapor cloud explosions (VCEs) associated with liquefied petroleum gas (LPG) storage systems represent a significant hazard in refinery operations. Accurate estimation of explosion distance is essential for safety setback design and quantitative risk assessment. This study developed an integrated framework that combines physics-based and data-driven techniques to study VCE behavior resulting from LPG releases from a 20,000-barrel pressurized spherical tank under realistic refinery conditions. A total of 336 leakage scenarios were simulated using DNV PHAST 2022 and the Multi-Energy method. Seven influencing parameters were considered, including leak diameter, LPG composition (propane–butane ratio), leak location, atmospheric category, seasonal period, day/night conditions, and three overpressure thresholds (0.02, 0.14, and 0.21 bar). The results revealed a wide dispersion in explosion distance across scenarios, with maximum distances exceeding 2,100 m for catastrophic full-bore ruptures. Feature-importance analysis using a Random Forest regression model showed that leak diameter was the dominant controlling parameter, accounting for approximately 74% of the predictive importance, while LPG composition contributed an additional 24–25%. Operational and atmospheric parameters had comparatively minor effects. The three investigated overpressure thresholds produced nearly identical explosion distances across the evaluated scenarios, indicating that within the low-pressure range, explosion extent is primarily governed by the released fuel mass and flammable cloud geometry rather than the threshold value. A classical power-law correlation was used to describe the geometric scaling between leak diameter and explosion distance; however, its predictive capability was limited (RMSE ≈ 337 m) due to its single-variable formulation. In contrast, the Random Forest model captured multi-factor interactions within the PHAST-generated dataset with very high predictive accuracy (R² ≈ 0.9997, RMSE ≈ 9 m). This hybrid framework provides a transparent approach for analyzing LPG vapor cloud explosions and offers practical insights for safety-distance determination, refinery layout optimization, and risk-based inspection planning.

Broadband achromatic metalens for the short-wave infrared

Abstract The 1.8-2.3  $$\upmu$$ m band lies within the short-wavelength infrared (SWIR) region and serves as a key operational window for a wide range of applications, including quantum sensing, molecular spectroscopy, and free-space quantum and classical optical communication. Despite its significance, optical devices operating in this band still face two major challenges: chromatic aberration across the wide spectral range and the difficulty of integration due to bulky optical elements. Metalenses are composed of subwavelength nanostructures that locally control the phase and group delay of light, enabling precise wavefront shaping and broadband dispersion compensation. These capabilities make them highly promising for use in infrared optical systems, particularly in applications such as focusing and imaging for compact integrated devices. In this study, we propose a metalens design based on a CaF $$_2$$ substrate, where each nanocell consists of a single-bar silicon structure. These nanocells are periodically arranged with a 900 nm period, enabling precise control of dispersion and phase. By systematically fine-tuning the bar length and width, the design enables simultaneous dispersion compensation and phase modulation, achieving stable focusing performance over a broad spectral range. Finite-Difference Time-Domain (FDTD) simulations demonstrate effective suppression of chromatic aberration across 1800–2300 nm, with simulated focal-length variation within 6% of the target value. We further analyze the polarization distribution across the focal spot and find a weak wavelength dependence of the degree of polarization (DoP), which we attribute to the spatially varying polarization state in the high-NA focal region together with the wavelength-dependent anisotropic response of the nanostructures. Meanwhile, this design offers a compact, broadband, and high-performance approach for beam collimation and wavefront shaping in the SWIR band, showing promising potential for applications in quantum communication and sensing systems.

Pharmacist-led educational intervention to improve knowledge, medication adherence, and asthma control among asthma patients at Ayder Comprehensive Specialized Hospital: A protocol for randomized controlled trial

Objective To evaluate the effect of a pharmacist‑led educational intervention on medication knowledge, adherence, and asthma control among adult asthma patients at Ayder Comprehensive Specialized Hospital, Ethiopia. Methods A single‑blind, parallel‑group randomized controlled trial will be conducted. All eligible adult asthma patients on active follow‑up at the chest clinic of Ayder Comprehensive Specialized Hospital will be included. Participants will be randomly assigned via a computer‑generated sequence to an intervention group (structured pharmacist‑led education using teach‑back, illustrated pamphlets, a follow‑up phone call and SMS) or a control group (routine care). Outcome assessors will be blinded to group allocation. Outcomes will be measured at baseline and after three months, including medication adherence (GMAS), asthma control (ACT), medication knowledge, correct inhaler technique, and domain‑specific adherence barriers. Data will be analyzed using intention‑to‑treat with multivariable binary logistic regression, chi‑square tests, independent T-test, McNemar test, Mann‑Whitney U test, and Fisher’s exact test where appropriate. Subgroup analyses will be performed to explore whether the intervention effect differs across patient characteristics. A p‑value < 0.05 will be considered statistically significant, with 95% confidence intervals reported. Trial registry Pan African Clinical Trials Registry (PACTR202508565637179).

Intelligent identification of dolphin whistle in acoustic signals via deep learning

Waist circumference versus BMI: A cross-sectional study comparing Cardiometabolic Risk association in the Nepalese Population

Background Obesity is a major cardiometabolic risk factor. Although body mass index (BMI) and waist circumference (WC) are established predictors of cardiometabolic risk, their predictive value may vary across ethnic groups. South Asians, including Nepalese individuals, exhibit a distinctive “thin-fat” phenotype characterized by increased central adiposity and higher body fat despite relatively normal BMI levels. Therefore, internationally validated anthropometric cutoffs may not accurately reflect cardiometabolic risk in the Nepalese population. Whether WC better predicts cardiometabolic risk than BMI in Nepalese individuals remains unclear. We conducted a comparative analysis of WC and BMI to evaluate their predictive ability for clinically relevant cardiometabolic outcomes. Methods In this cross-sectional study of 678 adults, BMI and waist circumference (WC) were evaluated as anthropometric indicators of cardiometabolic risk in the Nepalese population. Their associations were examined across six clinically relevant outcomes: hypertension, diabetes mellitus, thyroid disease, fatty liver disease (FLD), non-alcoholic fatty liver disease (NAFLD), and dyslipidemia. Comparative performance of BMI and WC was assessed using correlation analysis with biochemical markers, multivariable logistic regression adjusting for key covariates, and receiver operating characteristic (ROC) curve analysis to evaluate their relative predictive and discriminatory ability in this setting. Results BMI and waist circumference (WC) were strongly correlated (ρ = 0.75) but demonstrated distinct patterns in cardiometabolic associations. WC showed stronger correlation with triglycerides (ρ = 0.35 vs 0.24 for BMI) and was the only measure significantly associated with hypertension. Both BMI and WC were significantly associated with fatty liver disease (FLD), non-alcoholic fatty liver disease (NAFLD), and dyslipidemia; however, BMI generally showed higher odds ratios per unit increase compared to WC. Predictive performance was comparable between BMI and WC, with similar AUC values in the fair-to-acceptable range (0.6–0.7) across most outcomes. Notably, discrimination improved substantially (>0.8) when BMI and WC were combined with age and sex, yielding good predictive accuracy. Conclusion BMI and WC provide complementary information for cardiometabolic risk in the Nepalese population. Combined assessment with age and sex improves risk stratification, indicating that integrating both measures with calibrated thresholds enhances clinical prediction compared with using either alone.

Distinct site-specific bacterial microbiota within and between skin physiologic types in healthy Koreans: a pilot study

Factors associated with procedural difficulty and major adverse events during transcatheter closure of the patent ductus arteriosus

Transcatheter closure of the patent ductus arteriosus (PDA) is widely accepted as an alternative to surgical ligation. However, major complications are uncommon. Therefore, procedural difficulty, including device repositioning or change, may provide additional insight into technical challenges encountered during PDA closure. We aimed to identify the clinical and anatomical risk factors associated with procedural difficulty or major adverse events during transcatheter PDA closure and to document the prevalence and types of complications encountered in a single tertiary center. This retrospective cohort study included 341 patients who underwent a transcatheter PDA closure between 2010 and 2023. A composite primary outcome, defined as procedural difficulty or major adverse events, included device malposition requiring reposition or change, unsuccessful device deployment, device embolization, hemodynamic instability requiring intervention, or unplanned surgical conversion. Demographic, anatomical, and hemodynamic variables were analyzed. Univariate and multivariate logistic regression analyses were performed to identify independent predictors. Procedural difficulty or major adverse events occurred in 49 patients (14.3%). There was no procedure-related mortality. Device embolization occurred in three patients (0.8%), all requiring surgical ligation. Multivariate analysis revealed that a minimum PDA diameter >5 mm (odds ratio [OR] = 2.75, P  = 0.013), PDA length >8 mm (OR = 2.81, P  = 0.009), and non-type A (non-conical) duct morphology (OR = 2.88, P  = 0.025) were independently associated with the composite outcome. In conclusion, larger PDA diameter, longer ductal length, and non-conical morphology were significantly associated with increased procedural difficulty or major adverse events during transcatheter PDA closure. These findings highlight the importance of detailed anatomical assessment in patients undergoing transcatheter PDA closure.

AGFR-Net: anatomy-guided feature refinement for robust multi-label thoracic disease classification from chest X-rays

Real-world implementation and cost impact analysis of Oncotype DX testing in early-stage breast cancer

Background The decision on appropriate adjuvant treatment for patients with hormone receptor-positive (HR+) and human epidermal growth factor receptor 2 -negative (HER2-) early breast cancer (eBC) is sometimes challenging. Genomic assays have improved individualized treatment decisions by providing information on the genomic risk of tumors. The Oncotype DX assay (ODX) is both prognostic and predictive of chemotherapy benefit. This study aimed to evaluate the implementation process of the ODX into clinical practice, the impact of ODX on adjuvant chemotherapy treatment decisions and conduct a cost impact analysis. Patients and methods A retrospective study at Tampere University Hospital included 129 patients with HR + , HER2- eBC tested with ODX between September 2021 and September 2023. Treatment decisions as well as adjuvant chemotherapy (CT) costs, associated health provider costs, and societal costs were projected. Results ODX testing significantly altered CT recommendations by reducing unnecessary CT for 73% of the study patients. With ODX testing, the cost impact analysis revealed partial cost savings for the health care provider due to reduced CT administration. From a societal perspective, the use of ODX resulted in substantial savings largely attributed to the maintenance of work productivity among working-aged and employed patients. Conclusion This study highlights the importance of streamlined testing processes and the need for clinician training in interpreting test results in a real-world setting. In addition, the findings underscore the role of ODX in enhancing personalized treatment in HR + , HER2- eBC while reducing overtreatment. The cost analysis indicates substantial cost savings with ODX testing.

Investigation into ultrasonic wave propagation and defect detection in wind turbine main shaft based on COMSOL

The endurance effort on a mechanical treadmill does not activate the complement system among trained young women

The complement system (CS) plays a crucial role not only in pathogen-related immune responses but also in immunomodulatory effects associated with increased levels of damage-associated molecular patterns and tissue regeneration. The involvement of CS in response to physical exertion remains unclear. In the present study, the impact of an endurance effort on a mechanical treadmill on CS activation was investigated in healthy young premenopausal women. Twenty-eight well-trained women aged 21–26 years, playing handball or soccer, respectively, performed a progressive test on a mechanical treadmill until exhaustion. The CS component (C1q, C2, C3, C3b/iC3b, C4, C4b, C5, C5a, Factors I, H, B, adipsin, and mannose-binding lectin) concentration in blood was analyzed before, after the test, and 24 hours after the physical test using Luminex xMAP (Multi Analyte Profiling) technology. Progressive effort did not significantly affect the analyzed CS compounds. The lack of CS activation observed in the studied groups of young women suggests that the endurance effort on a mechanical treadmill did not activate an innate immunity. From this perspective, it does not appear to be an inflammatory factor. Considering the small number of participants, this hypothesis needs further exploration.

Effect of hydrophobic and hydrophilic groups on physicochemical properties of nonionic gemini surfactants for oilfield application

The oral and lower airway microbiota and coronary heart disease in COPD patients and controls

Background Chronic obstructive pulmonary disease (COPD) and coronary heart disease (CHD) are major causes of morbidity and mortality, with shared risk factors and often co-occurring. This study investigated the association between both the oral and lower airway microbiome and CHD in healthy controls and COPD patients. Methods 228 participants from the MicroCOPD study (101 controls and 127 COPD patients) underwent coronary CT angiography to assess calcium score (CaSc) and coronary stenosis. Oral wash (OW) and bronchoalveolar lavage (BAL) samples were collected. Microbial DNA was analyzed using 16S rRNA gene sequencing with the Illumina MiSeq platform. Microbiome composition and diversity were analysed using established pipelines in Quantitative Insights into Microbial Ecology 2 (QIIME 2) and R. Results Alpha diversity (Shannon index) differed significantly between COPD patients and controls in OW (p < 0.01), but not BAL. No statistically significant alpha (Shannon or Faith’s PD) diversity differences were found between CHD and non-CHD groups. Beta diversity analysis (Bray-Curtis dissimilarity) revealed no significant differences in microbial composition between CHD and non-CHD groups, both for COPD patients and controls (p > 0.05). Firmicutes dominated across all subgroups, followed by Bacteroidetes and Actinobacteria . Several taxa were found to be differentially abundant between CHD and non-CHD groups but comprised less than 1% of all taxa. Conclusion The microbiome differed between COPD patients and controls, but we could not find evidence that either the oral or lower airway microbiome differed between those with and without coronary heart disease.