Search Results (667)

Rising heat exposure increases the risk of heat-related illness during physical activity and outdoor work, suggesting a need for an accessible cooling strategy. The aim of this study was to examine the effects of a portable fan on physiological responses, perceived heat stress, and cognitive function during exercise in hot-humid conditions. Ten participants completed two trials, with a fan (WF) and without a fan (WOF), cycling at 50% of Heart rate reserve (HRR) in a controlled chamber (30 °C, 70% relative humidity). Skin temperature was continuously measured on the forehead, neck, chest, and thigh, and core temperature was measured via a tympanic probe, at a sampling rate of 1 Hz. Forehead and chest temperatures were lower in WF at 15 and 30 min (p < 0.05), while heart rate and tympanic temperature were unchanged. Breathing rate was lower in WF at 30 min (p < 0.05). Stroop test response times improved following exercise, with no difference between conditions. The use of a portable fan reduced upper-body skin temperature and perceived weakness but did not affect overall cognitive performance during short-term exposure. These findings suggest that localized cooling may help manage localized thermal discomfort during short-term exercise in hot-humid conditions. Full article

Background: The Heart Rate Recovery Index (HRRI), derived from post-exercise heart rate recovery (HRR), reflects autonomic function and cardiovascular performance. Whether HRRI reflects early myocardial dysfunction and left atrial remodelling in heart failure with preserved ejection fraction (HFpEF) has not been previously examined. The H₂FPEF score, which integrates clinical and echocardiographic parameters, is used to assess the likelihood of HFpEF. This study investigates the relationship between HRRI, H₂FPEF score, and echocardiographic markers of longitudinal systolic function, including mitral annular plane systolic excursion (MAPSE), as well as left atrial volume index (LAVI), in patients with preserved left ventricular ejection fraction. Methods: A prospective observational study included 241 patients referred for cardiac exercise testing at the Institute of Cardiovascular Diseases Timisoara and the Clinical County Hospital of Sibiu. HRRI was calculated as the ratio of heart rate acceleration time (AT) to deceleration time (DT) during exercise testing. A comprehensive echocardiographic assessment was performed on all patients. Statistical analysis involved univariate testing and multivariable logistic regression with stepwise selection. Results: HRRI was significantly lower in HFpEF patients compared with those without heart failure (1.97 ± 0.66 vs. 2.73 ± 1.08, p < 0.01). HRRI correlated significantly with exercise performance, age, H₂FPEF score, and echocardiographic markers of diastolic and longitudinal systolic dysfunction. ROC analysis identified an HRRI cut-off value of 2.25 for HFpEF detection (AUC = 0.748), while HRRI remained significantly associated with HFpEF after adjustment for the covariates included in the model. The combined HRRI–H₂FPEF score improved diagnostic discrimination compared with the H₂FPEF score alone (AUC 0.897 vs. 0.858), achieving an overall classification accuracy of 82.2%. Conclusions: In our study, HRRI is significantly reduced in HFpEF and distinguishes patients with and without heart failure. It shows associations with echocardiographic markers of diastolic and longitudinal systolic dysfunction, exercise capacity, and H₂FPEF score. Full article

Background: Wearable sensing technologies enable continuous monitoring of physiological states in athletes, yet age-related differences in autonomic and mechanical load among professional soccer players remain insufficiently characterized. This study investigated whether heart rate variability (HRV) indices and accelerometry-derived physical load differ between younger and older professional players during routine morning training sessions. Methods: Fourteen male professional soccer players were monitored using a wrist-worn biosensor. Participants were divided into two age groups: Group A (≤23 years, n = 7) and Group B (≥24 years, n = 7). The device was attached at 08:30 and recorded tri-axial acceleration and cardiac signals continuously until 11:30 (≈3 h). Extracted metrics included root mean square of successive differences (RMSSD), percentage of NN intervals differing by more than 50 ms (pNN50), heart rate recovery (HRR), maximum heart rate, and total beat count. Group differences and position-based differences were evaluated. Results: Accelerometry-based physical load showed no significant difference between age groups. In contrast, HRV indices demonstrated age-related divergence: RMSSD was significantly higher in Group A compared to Group B (p = 0.031), suggesting greater parasympathetic activity in younger players. Total beat count was significantly higher in Group B (p = 0.015). pNN50 showed no group difference (p = 0.918). Pre- and post-session HRR did not differ significantly between groups, whereas maximum heart rate was significantly higher in Group A (p = 0.0017). Position-based comparisons revealed no consistent differences across metrics. Conclusions: Although mechanical load was comparable between age groups, autonomic markers—particularly RMSSD—indicated higher parasympathetic modulation in younger professional players. These findings align with established sports physiology literature but provide preliminary evidence derived from real-world data collected in professional soccer athletes using a compact wrist-worn biosensor. The results support the utility of wearable HRV monitoring for age-related physiological profiling in elite sports environments. Full article

Background and Aim: Germline testing (GT) is increasingly relevant in pancreatic ductal adenocarcinoma (PDAC) because of therapeutic and familial implications. We evaluated real-world GT uptake, the diagnostic yield of pathogenic/likely pathogenic germline variants (P/LP), and their clinical implications. Methods: We retrospectively evaluated 674 consecutive patients with PDAC. GT was performed using targeted single-gene testing or multigene panels. Survival analyses among patients receiving platinum-based chemotherapy according to P/LP germline variant status in HRR-associated genes were exploratory. Results: Overall, 28.9% of patients underwent GT, increasing to 45.9% in 2021–2025 (p < 0.001). Results were available for 194 patients; 28 (14.4%) harbored P/LP variants, most commonly BRCA2 (4.6%) and ATM (3.1%). P/LP variants were identified in 6.8% of patients who did not meet classical referral criteria. Among the 28 carriers, 12 (42.9%) harbored BRCA1/2 or PALB2, variants with established therapeutic relevance, while eight (28.6%) carried ATM, FANCA, or FANCM, variants with potential therapeutic relevance. Of these 20 patients, 11 (55.0%) received matched therapy, and treatment was modified because of the germline result in six (30.0%). In exploratory analyses, among platinum-treated patients, carriers of P/LP germline variants in HRR-associated genes had longer PFS than non-carriers (23.9 vs. 4.8 months; log-rank p = 0.017), although only six HRR-associated variant carriers were included in this platinum-treated survival analysis. Conclusions: GT remained underused despite increasing implementation. Early systematic GT may identify clinically relevant variants missed by selective referral strategies and inform treatment, genetic counseling, and cascade testing. Survival findings require prospective validation. Full article

Inorganic pigments are widely used in elastomer technology primarily as coloring agents; however, the broader effects of these additives on the structure–property relationships of rubber composites remain insufficiently understood, particularly across different elastomer matrices. This study addresses this gap by systematically evaluating and comparing the effects of zirconium cerulean blue (Pigment Blue 71, PB71) and earth pigment iron ocher (IO) in natural rubber (NR), acrylonitrile–butadiene rubber (NBR), and styrene–butadiene rubber (SBR) composites. The influence of pigment loading (2–10 phr, parts per hundred parts of rubber) on rheometric behavior, crosslink density, mechanical performance, thermo-oxidative aging resistance, and combustion behavior was investigated to determine whether inorganic pigments provide benefits beyond coloration. The incorporation of pigments did not adversely affect vulcanization behavior, with the crosslink density of NR increasing from approximately 1.5 × 10⁻⁵ mol cm⁻³ for the unfilled vulcanizate to 1.5–2.3 × 10⁻⁵ mol cm⁻³ for pigment-containing composites, while SBR exhibited an increase from approximately 1.0 × 10⁻⁵ to 1.5–2.0 × 10⁻⁵ mol cm⁻³. Selected formulations also exhibited improved tensile strength and enhanced resistance to thermo-oxidative aging. Pyrolysis combustion flow calorimetry (PFCF) demonstrated that the incorporation of 10 phr IO reduced the peak heat release rate (pHRR) by approximately 11% (NR), 10% (NBR), and 3% (SBR), whereas 10 phr PB71 decreased this parameter by approximately 13%, 8%, and 38%, respectively. These findings demonstrate that inorganic pigments can serve as multifunctional colorants, simultaneously improving mechanical performance, thermo-oxidative stability, and fire resistance while maintaining effective coloration. Full article

Wind gusts are known to significantly influence wildfire behavior, yet their direct role in ignition dynamics remains underexplored in laboratory settings. This study investigates how controlled wind gusts affect ignition behavior, combustion transitions, and heat re-lease characteristics of wildland fuels using a bench-scale wind tunnel. Three fuel types, Excelsior, wild oat (Avena), and Wheatgrass were exposed to heated stainless-steel par-ticles under varying wind speeds (1.0 and 2.0 m/s) and gust frequencies (0.03, 0.05, and 0.07 Hz). Key ignition parameters, including ignition temperature, ignition delay, smol-dering-to-flaming (StF) transition, burnout time, and heat release rate (HRR), were measured and analyzed. The results show that increasing gust frequency consistently impacted ignition behavior which reduces ignition and transition times across all fuels while raising ignition temperatures and HRR. For instance, StF transition times in Avena dropped from 58 to 42 s and flaming ignition temperatures rose from ~415 °C to ~498 °C as gust frequency increased from 0.03 Hz to 0.07 Hz at 2.0 m/s wind speed. Also, for the same set of experiments, HRR rose from 1674 J/s to 2372 J/s with increasing gusts. These findings indicate that gusty winds enhance convective heat transfer and oxygen availability, accelerating fire initiation and intensifying combustion. The results offer valuable insights for improving predictive fire spread models, ignition risk assessments, and wildfire mitigation strategies under transient wind conditions. Full article

To address the discrepancy between the constant-power fire sources currently used in cable fire-related research and cable fire protection product testing and actual cable fires, this paper proposes a cable equivalent combustion simulation method based on electrical fault fires. The cable tunnel experiment platform was built and, based on energy equivalence, used an igniter to simulate a fault arc’s thermal effect and ignite the cable, obtaining the temperature rise characteristics at multiple points in the fire source area. Based on the experimental data, a simulation model for the mixed combustion of multiple cable materials was established and revised, and the heat release rate (HRR) under different fire scenarios was calculated. Then, an equivalent fire source device capable of simulating the aforementioned HRR curve was designed. The results indicate that under ignition conditions with an igniter power of 400 kW and duration of 90 s, the cable fire development exhibits nonlinear dynamic evolution, with a flame height of 0.63 m. The peak temperature rise rate and peak temperature at the measurement point reach 3.27 °C/s and 926 °C, respectively. When 39.4% of the insulation layer material of the cable participates in combustion, and the fuel molecular formula is C_2.28H_5.70O_1.42N_0.08Si_0.65, the relative error between simulated and experimental temperatures during stable combustion is 3.0%. Heat release rates for mild, moderate, and severe fires stabilize near 350 kW, 420 kW, and 530 kW under this calibrated cable model. The relative error between the temperature curve from the fire source device during the stable combustion stage and that from the actual combustion experiment is 3.4%, indicating favorable equivalence. Full article

Background/Objectives: Triple-negative breast cancer (TNBC) is enriched for germline pathogenic variants in BRCA1/2 and other DNA repair genes, but the additional value of extended germline profiling beyond BRCA1/2 remains insufficiently characterized in Russian patients. We aimed to characterize germline pathogenic/likely pathogenic variants (GPV/LPVs) and variants of uncertain significance (VUSes) in cancer predisposition and homologous recombination repair (HRR)-related genes in Russian TNBC patients and to assess the additional yield of extended germline profiling beyond BRCA1/2. Methods: We retrospectively analyzed germline DNA from 275 patients with histologically confirmed TNBC. Exome sequencing was performed for 204 patients and focused HRR-panel testing for 71 patients on the MGISEQ-G400 platform. Results: Overall, 114 patients (41.5%) harbored at least one germline GPV/LPV. BRCA1/2 GPV/LPVs were detected in 53 patients (19.3%), with BRCA1 predominating over BRCA2 (48 vs. 5 carriers) and the recurrent BRCA1 c.5329dup variant accounting for 23 cases. In the exome subset, 79 of 204 patients (38.7%) carried a GPV/LPV in Groups 1–3, including 48 (23.5%) with BC-related GPV/LPVs; non-BRCA Group 1 genes contributed seven additional carriers beyond BRCA1/2-only analysis. The expanded HRR set identified 52 GPV/LPV carriers (25.5%) versus 45 (22.1%) in the reference HRR panel, while the common HRR gene set identified 68 carriers (24.7%) in the full cohort. In addition, 183 unique VUSes were found in Groups 1–3 in the exome subset, affecting 128 patients (62.7%). Conclusions: Russian TNBC patients show a substantial germline GPV/LPV burden dominated by BRCA1/2 alterations and the recurrent BRCA1 c.5329dup founder variant. Extended germline profiling identified additional non-BRCA and HRR-related findings beyond BRCA1/2, but the incremental yield was moderate and accompanied by a considerable VUS burden. Broader germline testing may therefore support hereditary risk assessment and exploratory HRR-focused stratification, but non-BRCA HRR findings should not be considered sufficient for therapy selection without additional tumor-level or clinical evidence. Full article

Numerous previous investigations have exploited single-component aluminum hydroxide, silica, or phosphorus-containing organic agents to improve the fire resistance of epoxy resin. Existing literature confirms that ATH relies on endothermic dehydration and inorganic barrier layers to suppress combustion, while phosphorus organics exert radical quenching effects in the gas phase. However, separate use of these fillers generally requires high loading to achieve satisfactory flame retardancy, which inevitably weakens the mechanical properties of the epoxy matrix; few studies integrate N, P, and Si elements into ATH via chemical grafting to realize synergistic flame retardancy at low filler dosage, and the dual heat-transfer regulation effect of formed SiO₂-Al₂O₃ inorganic residues has rarely been systematically discussed in prior reports. This study presents an organic–inorganic hybrid flame retardant, SPDP-PTMS@ATH, synthesized by grafting N,P,Si-containing organic groups onto Al(OH)₃. The modified ATH retained its layered structure, as confirmed by FTIR, XPS, SEM, and XRD. At only 5 wt.% loading in epoxy, the additive significantly enhanced flame retardancy and smoke suppression: LOI increased to 33.5% (34% higher than pure EP), UL-94 reached V-0 rating, and peak HRR, THR, COPR, TSR, CO2PR, and SPR are reduced by 30.2%, 30.8%, 33.1%, 26.9%, 25.86%, and 15%, respectively. Char analysis revealed a denser, more graphitized structure with fewer defects. Moreover, tensile strength and elongation at break improved by 22.0% and 47.5%, respectively. This work demonstrates that low-loading SPDP-PTMS@ATH simultaneously boosts fire safety, smoke suppression, and mechanical performance, offering a cost-effective and sustainable route to high-performance epoxy composites. Full article

Poly(ADP-ribose) polymerase inhibitors (PARPis) have demonstrated remarkable efficacy in tumors carrying BRCA1/2 pathogenic variants (PVs) through the mechanism of synthetic lethality. PVs in other homologous recombination (HR) genes may also impair homologous recombination repair and confer sensitivity to PARPis; however, their predictive value remains uncertain and appears to vary according to the affected gene and tumor type. We review and critically discuss the current evidence regarding the predictive value of non-BRCA HR gene pathogenic variants as biomarkers of PARPi sensitivity across ovarian, breast, prostate, and pancreatic cancers. A narrative review was conducted between October 2023 and December 2025, first identifying pivotal clinical trials of PARP inhibitors across ovarian, breast, prostate, and pancreatic cancers, followed by a targeted search of PubMed, Embase, Web of Science, and Google Scholar for relevant preclinical and clinical studies. Seventeen clinical studies and multiple preclinical reports were analyzed regarding genomic frequency, HRD association, and treatment response. Preclinical studies consistently demonstrated increased PARPi sensitivity in models with alterations in several non-BRCA HR genes. Clinical evidence, however, was heterogeneous. PALB2 demonstrated the strongest and most consistent association with PARPi benefit across tumor types, while RAD51C and RAD51D also showed clinically meaningful activity, particularly in ovarian cancer. In contrast, evidence supporting PARPi sensitivity in tumors harboring ATM, CHEK2, CDK12, and several other HR gene alterations remained limited or inconsistent. Differences in gene function, biallelic inactivation, variant type, and current limitations of HRD companion diagnostic assays likely contribute to the observed variability in clinical response. Non-BRCA HR gene alterations represent promising predictive biomarkers for PARPi therapy but should not be considered a homogeneous group. Future biomarker-driven studies integrating comprehensive genomic profiling and functional assessment of homologous recombination deficiency are needed to refine patient selection and optimize the clinical application of PARPis beyond BRCA1/2-associated cancers. Full article

Triple-negative breast cancer (TNBC) lacking androgen receptor (AR) expression defines quadruple-negative breast cancer (QNBC), which is characterized by younger age at diagnosis, high Ki-67 index, and high genomic instability, however a comprehensive description of the genomic characteristics remains poorly defined. A total of 54 TNBC cases were categorized as TNBC with 100% AR expression (TNBC AR-100%) or QNBC, TNBC with 0% AR expression (TNBC AR-0%). Clinical, molecular, and genomic parameters, specifically pathogenic/likely pathogenic (P/LP) variants in homologous recombination repair (HRR) and cancer-related pathways were measured and analyzed. The QNBC cohort exhibited a high homologous recombination deficiency (HRD) score and a greater overall incidence of copy number variants (CNVs). QNBC harbored a higher mutation rate in TP53 and MYC signaling pathway than TNBC AR-100% tumors. P/LP variants corresponding to the HRR, PI3K/AKT, and RTK/RAS pathways were exclusively identified in QNBC. These results suggest that, at both molecular and genomic levels, the two groups are distinct, holding QNBC tumors more aggressive characteristics, genomic instability, and particular impairments in HRR and cancer-related pathways. In terms of actionability, these differences could potentially be leveraged through different combinations of therapies. Full article

Efficient fire safety engineering of insulated timber modular blocks requires an integrated assessment of material behavior, compartment fire dynamics, and structural response under thermal exposure. This study presents a performance-based framework that evaluates fire risk in modular timber systems combining combustible wood elements with polymer-based insulation. Key parameters—including ignition delay, heat release rate (HRR), charring rate, and encapsulation integrity—are modeled to quantify fire growth and structural degradation. A hybrid methodology integrating material characterization, compartment fire simulation, and mitigation analysis is applied to assess system performance under varying protection strategies. The results indicate that fire behavior is strongly governed by encapsulation reliability and cavity fire propagation pathways, with unprotected insulation leading to rapid HRR escalation and early flashover conditions. Conversely, the use of multi-layer fire-resistant linings and cavity barriers significantly delays ignition and preserves structural stability. Predictive modeling demonstrates that optimized configurations can achieve fire resistance levels comparable to conventional systems while maintaining modular efficiency. The findings highlight that efficient fire safety in insulated timber modular blocks depends on the coordinated design of materials, interfaces, and protective systems, supporting the adoption of performance-based fire engineering in modern modular construction. Full article

With increasing energy demand and environmental emission concerns, biodiesels have emerged as a promising alternative to traditional fossil diesel. This study investigates the effects of soybean (Glycine max) biodiesel–diesel blends containing 0–80% biodiesel on the performance, combustion, and emission characteristics of a diesel engine. The performance parameters evaluated include brake specific fuel consumption (BSFC), brake mean effective pressure (BMEP), brake power (BP), and brake thermal efficiency (BTE). Combustion characteristics are assessed through in-cylinder pressure, heat release rate (HRR), and cumulative heat release fractions (HRFs), while emission characteristics are analysed in terms of smoke opacity and nitrogen oxides (NOx) emissions. The primary objective of this study is to evaluate the impact of high-percentage biodiesel and fuel injection timing on overall engine characteristics. A one-dimensional (1D) model was developed using Diesel-RK (Version: 4.30.189) and GT-Suite software (Version: GT-ISE 2026). The models were calibrated and validated through model to model and further validated against experimental data. Using the simulation generated dataset, a machine learning-based surrogate prediction model was developed to rapidly estimate engine performance and emission characteristics directly from engine operating conditions and biodiesel blend ratios, eliminating the need for repeated Diesel-RK simulations. Multiple regression algorithms were evaluated, with the XGBoost tree ensemble model providing the highest prediction accuracy across the investigated performance parameters. Moreover, the Diesel-RK data were validated with experimental data. The results demonstrated model-to-model data and between model to experimental data, confirming the reliability of the developed models. The proposed Diesel-RK simulation and machine learning framework enables rapid and accurate prediction of engine performance and emissions, providing an efficient tool for evaluating biodiesel blends and supporting future engine design and optimisation. Full article

This study evaluated the reliability of five treadmill protocols that assess heart rate (HR) and blood lactate (Bla) responses in Thoroughbred horses to determine their effectiveness in serving as potential tools for monitoring fitness and the wellbeing of racehorses. Of the five exercise tests, four consisted of repeated interval gallops at constant speeds (8 m/s and 10 m/s) and grade (6°) and one test of a continuous gallop at constant speeds (8 m/s) and grade (6°). Eight hundred and twenty-three gallops in total were performed by 64 horses. The test–retest reliability and absolute agreement between treadmill tests were assessed using Intraclass correlation coefficient (ICC) with a two-way mixed-effect model. Statistical significance was set at p < 0.05. Overall, the mean of the mean HR for each of the five test gallops was 203 ± 11.3 bpm. The mean HR ICC of the five tests of 0.756 indicates good reliability of the tests, as HRs during each gallop were consistent between tests. Protocol comparison showed that all protocols have good reliability with gallops 1 and 5 scoring highest (0.79: 0.81) and gallop 4 lowest at 0.621. The recovery mean HR ICC for 30 s, 60 s, 90 s and 120 s recovery were 0.421, 0.504, 0.595 and 0.571 respectively. Overall, the data suggests that gallop HR is the more reliable variable with recovery HRR reliability improving to an acceptable level at 60 s and 90 s recovery. Together, the treadmill tests demonstrated acceptable reliability to measure both gallop HR and HHR responses, whereas BLa responses were less consistent. Full article

In this study, the effects of the type and content of phosphorus-based flame retardants, namely melamine polyphosphate (MPP) and aluminum diethylphosphinate (AlDPi), as well as their hybrid systems (MPP:AlDPi ratios of 1:1, 1:3, and 3:1), on the fire performance of acrylonitrile-butadiene-styrene (ABS) composites were investigated. The obtained results indicate that the synergistic action of MPP and AlDPi, including simultaneous inhibition of combustion in the gas phase and action in the condensed phase, leads to a significant improvement in the fire-retardant properties of ABS composites. For unmodified ABS, the peak Heat Release Rate (pHRR) and Total Heat Released (THR) values were 808.7 kW/m² and 86.5 MJ/m², respectively, while for the ABS/MPP_15/AlDPi_5, these values decreased to 292.9 kW/m² and 32.3 MJ/m². Simultaneously, the Effective Heat of Combustion (EHC) decreased from 22.3 to 15.5 MJ/kg, indicating inhibition of combustion processes in the gas phase. Fourier Transform Infrared Spectroscopy (FTIR) analysis of post-combustion residues (peaks 1280 and 1168 cm⁻¹) confirmed the contribution of additives to the formation of phosphorous derivatives in the condensed phase. The hybrid system ABS/MPP_15/AlDPi_5 exhibited the most favorable fire performance in cone calorimeter tests, characterized by reduced heat release and fire growth parameters. This was confirmed by the calculated fire performance indicators, including Fire Growth Rate Index (FIGRA), Maximum Average Rate of Heat Emission (MARHE), Fire Potential Index (FPI), and Flame Retardancy Index (FRI). Full article