Firebrand transport is a primary cause of fire spread in outdoor fires, but its prediction is challenging. This study develops a highly accurate and low-cost prediction model for firebrand transport using machine learning based on experimental data. Experimental dataset used is firebrand data from wood materials of single size and produced from a firebrand generator. First, five machine learning models were built and compared. The results showed that a Neural Network (NN) provided the best performance, accurately reproducing the landing distribution of firebrands. Next, SHAP analysis were used and it was found that physical indices, such as the Tachikawa number, were critical for accurate predictions. Based on this finding, a Physics-Constrained Neural Network (PCNN), which incorporates physical laws into the learning process, was developed. The PCNN model was tested against unseen data which is firebrand data generated from combustion experiments with roof assemblies. The PCNN, especially when constrained by the Tachikawa number, demonstrated more robust and accurate predictions on unseen, more complicated data compared to the standard NN. The ML technique developed in this study is able to predict firebrand transport with different shape. This work shows that machine learning, particularly PCNN, is a powerful tool for predicting complex firebrand transport, potentially contributing to future fire risk assessment. • NN proven to be superior for firebrand transport prediction to other four ML model • SHAP analysis identified Ta , Re , and velocity ratio as key physical features • PCNN showed improved generalization performance on unseen, complicated data • Ta as physical constraint was the most effective approach for improving PCNN

Arterial stiffness is a contributor to cardiovascular morbidity, but its role in elevated left ventricular (LV) filling pressure and heart failure with preserved ejection fraction (HFpEF) remains incompletely understood. This study aimed to evaluate the relationship between arterial stiffness and the ratio of early diastolic transmitral flow velocity (E) to early diastolic mitral annulus velocity (e'), as well as its association with LV diastolic dysfunction. This study cross-sectionally analyzed 335 patients with cardiovascular disease and an ejection fraction ≥50% who underwent the Cardio-Ankle Vascular Index (CAVI) measurement. Multivariable logistic regression was used to identify independent associated factors of elevated LV filling pressure, defined as E/e' >14. Smoothing spline analysis was used to assess the dose-response relationship between CAVI, age, and elevated E/e'. Mediation analysis was used to assess the direct and indirect effects of CAVI, age, and hypertension on elevated filling pressure. CAVI was independently associated with E/e' >14 (odds ratio (OR) 1.43; 95% confidence interval (CI): 1.17-1.74, p< 0.001) and diastolic dysfunction (OR 1.25; 95% CI 1.03-1.52, p = 0.024). CAVI enhanced risk stratification for elevated filling pressure (net reclassification index = 0.588, p < 0.001; integrated discrimination improvement = 0.035, p= 0.008). Smoothing spline analysis revealed a near-exponential increase in E/e' >14 risk above a CAVI threshold of 9.275. Mediated analysis indicated that CAVI accounted for 18.7% of the effect of age on elevated E/e' (p = 0.006). Arterial stiffness, as quantified by CAVI, independently increases the LV filling pressure and mediates age-related effects.

First, to evaluate whether the ratio of soluble fms-like tyrosine kinase-1 to placental growth factor (sFlt-1/PlGF) is associated with hemodynamic changes in ophthalmic artery (OA) Doppler in near-term pregnancy. Second, to assess the performance of OA Doppler to rule in and rule out angiogenic factor imbalance. This was a cross-sectional cohort study nested within the PE37 randomized controlled trial, involving nulliparous women recruited between January 2023 and January 2025 who underwent sFlt-1/PlGF ratio measurement between 35 + 0 and 36 + 6 weeks' gestation. We included a subsample of women who underwent OA Doppler evaluation, including measurement of OA peak systolic velocity (PSV) ratio and OA pulsatility index (PI), as well as assessment of mean arterial pressure (MAP) and mean uterine artery (UtA) PI. The operator was blinded to sFlt-1/PlGF ratio values. Trends in median values of OA and maternal-fetal Doppler parameters across sFlt-1/PlGF tertiles were analyzed using the Jonckheere-Terpstra test and quantile regression, adjusting for maternal body mass index, age and smoking status. The predictive performance of the OA-PSV ratio for sFlt-1/PlGF ratio ≥ 38 was evaluated using receiver-operating-characteristics-curve analysis. We included 203 women, of whom 62, 71 and 70 were in the lowest, middle and highest tertiles of the sFlt-1/PlGF ratio, respectively. With increasing sFlt-1/PlGF ratio tertile, there was a significant increase in the OA-PSV ratio (median, 0.45 (interquartile range (IQR), 0.39-0.53) vs 0.48 (IQR, 0.41-0.58) vs 0.59 (IQR, 0.50-0.66); adjusted P < 0.001), a significant decrease in OA-PI (median, 2.20 (IQR, 1.92-2.61) vs 2.13 (IQR, 1.86-2.37) vs 1.86 (IQR, 1.60-2.26); adjusted P = 0.031) and a significant increase in MAP (median, 87.0 (IQR, 82.7-92.0) mmHg vs 88.7 (IQR, 83.7-93.7) mmHgvs 94.7 (IQR, 89.3-100.0) mmHg; adjusted P < 0.001). In contrast, no significant trend was observed in mean UtA-PI across sFlt-1/PlGF ratio tertiles. Among those individuals with an OA-PSV ratio < 0.61, 90.5% truly had a sFlt-1/PlGF ratio < 38, at a 15% false-positive rate. This study provides new evidence of a significant association between the sFlt-1/PlGF ratio and OA Doppler parameters in near-term pregnancies, suggesting that OA Doppler indices, particularly the PSV ratio, reflect angiogenic imbalance. Given its non-invasive nature, accessibility and low cost, OA Doppler emerges as a promising surrogate tool for ruling out angiogenic imbalance. © 2026 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Lower-extremity peripheral artery disease often requires endovascular therapy. Target-lesion restenosis (TLRS) remains frequent, but current risk stratification is limited. We retrospectively analyzed 1,005 lesions from 917 patients undergoing endovascular therapy for lower-extremity atherosclerotic disease at a single center (2019-2024) with scheduled surveillance (approximately 6, 12, and 24 months) and administrative censoring at 36 months. The primary endpoint was time to first TLRS ≥ 50%, adjudicated by duplex ultrasound (peak systolic velocity ratio criteria) or CTA/DSA when available. Lesion‑level Fine-Gray competing‑risk models (death as a competing event) with patient‑level clustering were used. A prespecified Core model (clinical, anatomic, procedural/device covariates and C‑reactive protein) was compared with an Extended model additionally including the Atherogenic Index of Plasma (AIP) and log‑transformed Systemic Immune-Inflammation Index (SII). Models were internally validated by 1,000 bootstrap resamples and assessed at the 24‑month horizon using the C‑index, calibration, Brier score, integrated discrimination improvement (IDI), net reclassification improvement (NRI), and decision‑curve analysis. Among 917 patients (1,005 lesions), mean age was 75.2 ± 11.7 years and 68.6% were male. At 24 months, cumulative incidences were 31.4% for TLRS, 14.9% for clinically driven target‑lesion revascularization, and 12.3% for death. In multivariable analyses, GLASS stage III, lesion length ≥ 150mm, residual stenosis > 20%, chronic kidney disease, and Rutherford class 4-6 predicted higher TLRS risk, whereas good distal runoff was protective. In the Extended model, AIP and SII remained independent predictors and improved the optimism‑corrected 24‑month C‑index from 0.68 to 0.73 (Δ0.05, p = 0.002), reduced the Brier score (0.19 to 0.17), yielded positive IDI and NRI, and preserved good calibration. Exploratory analyses suggested lower TLRS risk with cilostazol and low‑dose rivaroxaban plus aspirin. AIP and SII improved lesion-level prediction of TLRS beyond conventional covariates. The Extended model may support risk-tiered surveillance after endovascular therapy; external validation is warranted.

To determine right ventricular dysfunction (RVD) prevalence in patients with heart failure and preserved ejection fraction (HFpEF); to systematically evaluate predictive values of echocardiographic parameters for RVD. A total of 163 patients diagnosed with HFpEF between January 2022 and January 2024 were retrospectively analyzed. All patients underwent assessment of right ventricular function. RVD was characterized by the presence of either a tricuspid annular plane systolic excursion (TAPSE) below 17mm or a right ventricular free wall strain (RV-FWS) absolute value under 20%. Baseline clinical characteristics and echocardiographic parameters were collected, including left atrial volume index (LAVI), mean ratio of early mitral inflow velocity to early diastolic mitral annular velocity (mean E/e'), systolic pulmonary artery pressure (sPAP), and right ventricular fractional area change (FAC). The prevalence of RVD among patients with HFpEF was 41.7% (68/163). The RVD group was characterized by substantially higher NT-proBNP levels. Echocardiographic measures including RV-FWS, sPAP, mean E/e', LAVI, TAPSE, and FAC independently predicted the occurrence of RVD. Among individual parameters, RV-FWS showed the best predictive performance. The combined predictive model incorporating the six aforementioned parameters exhibited excellent discriminatory ability. After internal validation using the bootstrap method, the corrected AUC was 0.989. RV-FWS and sPAP are the strongest independent echocardiographic predictors of RVD. An integrated assessment strategy combining multiparametric echocardiography with NT-proBNP measurement may substantially improve risk stratification of RVD in HFpEF.

This research examines the influence of abutments placement near the inner and outer walls, alongside the deployment of convergent-vertical and divergent-vertical bridge pier groups. Three positions 60, 90, and 120 degrees out of a 180-degree bend were selected and tested. Additionally, the impact of varying flow conditions in three states: clear water, incipient motion, and live bed, on bed changes and scour rate was examined. The findings revealed that, under incipient motion conditions, when piers were positioned at 60 degrees, the deepest scour of the main hole occurred near the piers; however, when placed at 120 degrees, this deepest scour shifted to the area around the outer abutment. The greatest scour depth under incipient motion conditions was observed in the convergent pier groups positioned at 90°, reaching about 1.3 times the flow depth. At this position, the maximum depth of the second scour hole and the sediment ridge height were higher compared to the 60° and 120° positions. When piers and abutments were positioned at 90°, the deepest scour of the second hole and the sediment deposit height increased as the ratio of average flow velocity to the critical velocity for bed particles rose from 0.87 to 0.98 and 1.03.

With the depletion of conventional oil and gas resources, global attention has shifted to deep unconventional reserves. Carbonate reservoirs account for a substantial portion of worldwide hydrocarbon reserves. However, their heterogeneous pore systems comprising pores, cracks, and vugs pose significant challenges for parameter prediction. Deep carbonate reservoirs exhibit complex pore structures, pronounced heterogeneity, and ambiguous seismic responses. To address these, we integrate the microscopic Gurevich squirt flow model with the mesoscopic Biot-Rayleigh theory, yielding a multi-scale elastic rock physics framework. This framework quantifies interrelations among microcracks, porosity, and P-wave dispersion. It also incorporates effects of fluid viscosity, temperature, and pressure on seismic wave attributes. Using the Voigt-Reuss-Hill average, differential effective medium theory, and Batzle-Wang equations, we construct a multi-scale elastic rock physics template for the Shunbei area, centered on P-to-S-wave velocity ratio and P-wave impedance. By combining this framework with seismic data, the template enables prediction of reservoir porosity and crack porosity. Results demonstrate that the template-based method effectively delineates high-quality reservoirs. Predictions align well with well-test data from three wells, validating the approach.

Drug Coated Balloon Angioplasty after Plain or Scoring Balloon for Vessel Preparation for Femoropopliteal Arterial Disease (DASBAD): A Randomised Controlled Trial.

Active flow control of high-lift multielement swept wings remains a critical yet underexplored field in aerodynamics. This study investigates the effects of the duty cycle (DC) and the jet-to-freestream velocity ratio (VR) on pulsed jet flow control (PJFC) actuators near the leading edge of a multielement swept wing with three major innovations. First, a threshold effect is identified at VR≈7.30. Below this threshold, a low DC actuation achieves comparable or superior maximum lift enhancement relative to a high DC operation. Second, mechanistic analysis reveals that at a high DC, the initial jet-induced vortex fails to merge with the dominant shear-layer vortex, leading to the emergence of an additional high-frequency shedding mode. In contrast, a low DC actuation increases the maximum lift coefficient by expanding the favorable suction pressure region, particularly at a lower VR. Third, PJFC delays the stall angle by approximately 4–6 degrees and achieves significant drag reduction at moderate angles of attack. These findings provide novel insights into the underlying mechanisms and enable a physics-informed selection of the VR and DC in effective active flow control on swept high-lift wings.

Inelastic responses are used in seismic design to estimate inelastic seismic demand from known elastic demand, yet current provisions remain limited, especially when damping and displacement ductility are considered. This study investigated the inelastic displacement ratio and inelastic velocity ratio for single degree of freedom (SDOF) systems subjected to near-fault ground motions, with particular focus on the effects of fling-step and forward-directivity motions. For numerical modeling and analysis, an extensive nonlinear response history analysis (NLRHA) was conducted on SDOF systems incorporating parametric variations in dynamic characteristics of structural systems such as elastic period, displacement ductility, and viscous damping under different ground motion conditions. From numerical modeling, empirical equations are proposed to express the inelastic displacement ratio ( I R D ) and inelastic velocity ratio ( I R V ) using elastic period, viscous damping ratio, displacement ductility, and the type of ground motion. In parallel, neural networks are trained on a dataset of 36,456 samples using additional variables, including the predominant period of the ground motion, moment magnitude, and closest rupture distance. Neural network models achieved R 2 = 0 . 944 (for I R D ) and R 2 = 0 . 916 (for I R V ) for unseen data, indicating the highest accuracy. Model explanations indicated that the predictions adhere to the domain knowledge. Comparative assessments reveal that while empirical equations capture general trends for design purposes, neural network models accurately predict even minor variations in inelastic responses. These data-driven methods provide a complementary approach in predicting the inelastic response compared to empirical equations. • Numerically simulated the inelastic responses of SDOF systems with damping under near-fault motions. • Influence of the ductility and viscous damping on inelastic responses was evaluated. • Empirical equations are proposed to estimate the inelastic displacement and velocity ratios. • Transformer-based models are developed to predict the inelastic responses.

Multi-directional elastic wave measurements during triaxial compression on Toyoura sand using planar piezoelectric transducers

Effect of vent spacing on flow structure and heat transfer of transversely superimposed jets in crossflow at low velocity ratio

This study aimed to assess whether a predictive model combining the Alberta Stroke Program Early CT Score (ASPECTS) and post-endovascular thrombectomy (EVT) transcranial Doppler (TCD) parameters could improve the prediction of early neurological deterioration (END) in patients with large artery occlusion (LAO) stroke after successful recanalization. In this prospective study, we enrolled 87 consecutive patients with anterior circulation LAO who achieved successful recanalization (modified Thrombolysis in Cerebral Infarction [mTICI] grade ≥2b), underwent post-EVT TCD monitoring within 48h, and had baseline ASPECTS assessment. Bilateral middle cerebral artery (MCA) flow velocities were measured, and key hemodynamic indices were subsequently calculated. The prespecified primary outcome was END within 72h; secondary outcomes included functional status at 90 days. Among the 87 successfully recanalized patients, END occurred in 21.8% (n = 19) within 72h after EVT. Compared with the non-END group, patients who developed END exhibited significantly higher ipsilateral MCA flow velocities, including peak systolic, end-diastolic, and mean flow velocities, as well as a significantly higher ipsilateral-to-contralateral mean flow velocity ratio. Multivariable analysis identified lower baseline ASPECTS (odds ratio [OR], 0.50, 95% confidence interval [CI], 0.31-0.80) and higher ipsilateral peak systolic velocity (iPSV) (OR, 2.15, 95% CI, 1.08-4.28) as independent predictors of END. Restricted cubic spline analysis suggested an approximately linear association between iPSV and END risk. A combined model incorporating iPSV and ASPECTS demonstrated superior discriminative performance in predicting END (area under the curve [AUC], 0.801; 95% CI, 0.700-0.902), outperforming either parameter alone. A model integrating post-EVT hemodynamic (iPSV) and baseline imaging (ASPECTS) data significantly improves the prediction of END after successful EVT. This multimodal approach, which showed superior discriminative ability (AUC = 0.801), may facilitate early risk stratification and support tailored clinical management. This prospective observational study was registered with the National Clinical Research Center of China on June 19, 2024 (Registration No. MR-36-24-042352). The study was registered during the enrollment period.

Persistent postinfectious olfactory dysfunction (PIOD) is a prevalent and often refractory condition, with low recovery rates following olfactory training (OT), primarily due to sustained localized inflammation and opacification within the olfactory cleft (OC). However, conventional radiological assessments of OC opacification overlook the vertical distribution of olfactory neuroepithelium, limiting prognostic accuracy. This study introduces a modified subregion computed tomography (CT) scoring system integrated with computational fluid dynamics (CFD) to evaluate OC opacification's role in baseline olfaction and OT efficacy. In this prospective study, 58 adults with persistent PIOD of more than 3 months' duration were enrolled and completed CT imaging, psychophysical olfactory testing (Sniffin' Sticks TDI score), and questionnaire assessments. Using a modified scoring system, the OC was segmented on coronal sections into upper (superior one-third) and lower (inferior two-thirds) portions, with three coronal sections assessed in both the anterior and posterior OC. Each section was scored dichotomously (0 for no opacification, 1 for opacification), and bilateral scores were recorded. Unsupervised K-means clustering identified phenotypes, random forest modeling predicted functional anosmia, and CFD analyzed airflow dynamics. Thirty-one patients completed 3-month OT with follow-up assessments. OC opacification was present in 69.0% of persistent PIOD patients, with opacification in the upper posterior OC notably serving as the primary determinant of baseline olfactory function. Random forest analysis further confirmed that upper OC opacification ranked as the top predictor for functional anosmia, with the combined model achieving an area under the curve of 0.920. Cluster analysis revealed three distinct phenotypes, among which the diffuse severe opacification cluster involving upper OC regions was associated with the poorest olfactory function. Although posterior OC opacification was positively correlated with increased airflow velocity ratios (r=0.570, p<0.01) and these ratios were negatively correlated with olfactory scores, OC airflow itself did not significantly mediate the relationship between structure and olfactory function. Only 25.8% of patients achieved clinically meaningful olfactory improvement. Significant improvements were observed in TDI (p=0.001), olfactory threshold (p=0.010), olfactory discrimination (p=0.028), and olfactory VAS scores (p<0.001) after OT. Baseline opacification in posterior-middle section of OC significantly predicted non-response. The modified subregion OC opacification scoring system provides a more refined assessment of site‑specific OC obstruction for patients with persistent PIOD, underscoring the critical role of OC opacification in mediating olfactory impairment and resistance to OT. For patients with persistent PIOD, this modified olfactory cleft opacification scoring system allows for olfactory assessment and prognosis by identifying specific opacification patterns associated with olfactory training outcomes.

This study employed a low-speed drop-hammer-impact test combined with the digital image correlation technique to investigate the dynamic failure performance of bamboo fiber/high-density polyethylene (BPE) composites and to explore the mechanism of fiber content's influence on it. Results indicated that with the increasing of BF content, the density, acoustic velocity, and Poisson's ratio of BPE gradually decreased, while the elastic modulus initially decreased and then increased. Although the introduction of Bamboo Fiber (BF) enhanced the rigidity of BPE, allowing the materials to withstand greater impact forces during initial fracture stages, it reduced the toughness of BPE. BPE with 80% BF content showed a higher crack propagation rate and a shorter fracture process compared to composites with lower BF content. However, according to the stress intensity factor (SIF) history, the introduction of BF could enhance the resistance of crack propagation, which depends on the dispersibility of BF and the interfacial bonding properties between BF and high-density polyethylene (HDPE). Overall, BF could increase the rigidity of BPE and restrict the crack propagation at the initial fracture stages. As an eco-friendly and sustainable material, the dynamic fracture toughness of BPE can contribute to the application and promotion of biomass fiber-filled composites.

To evaluate alterations in fetal cardiac function in pregnancies complicated by fetal growth restriction (FGR) by synthesizing evidence on myocardial performance index (MPI) and its constituent parameters for both the left and right ventricles. The secondary objective was to explore the influence of timing of FGR onset (early vs late) on these parameters. We conducted a systematic review and meta-analysis of observational studies by searching PubMed/MEDLINE, EMBASE, Scopus, Web of Science and the Cochrane Central Register of Controlled Trials (CENTRAL) databases from inception until August 2025. Eligible studies compared fetal MPI, isovolumetric contraction time (ICT), ejection time (ET), isovolumetric relaxation time (IRT) and/or peak early-to-late diastolic filling velocity ratio (E/A ratio) between FGR fetuses and healthy controls. Data reported in original publications as median with interquartile range, range or 95% CI were converted to mean ± SD. A random-effects model was used to calculate the pooled standardized mean difference (SMD) with 95% CI. Prespecified subgroup analyses were performed based on ventricular laterality, timing of FGR onset and data presentation type. The protocol was registered with PROSPERO (registration number: CRD420251075193). Fifteen studies, comprising 709 FGR fetuses and 867 controls, were included. Compared with controls, FGR fetuses exhibited significant left ventricular dysfunction, characterized by a higher left MPI (SMD, 0.85 (95% CI, 0.53-1.16)), prolonged left ICT (SMD, 0.53 (95% CI, 0.08-0.99)) and shorter left ET (SMD,-0.56 (95% CI, -0.84 to -0.29)). The most profound alteration was a prolongation of the left IRT in FGR cases (SMD, 2.48 (95% CI, 1.55-3.41)). Right ventricular assessment revealed a prolonged right IRT in FGR fetuses compared with controls (SMD, 1.90 (95% CI, 0.72-3.07)). Subgroup analysis showed that myocardial functional alterations affect both early- and late-onset FGR phenotypes, with early cases showing a non-significant trend toward more pronounced impairment. Sensitivity analysis including only studies that employed stricter diagnostic criteria for FGR confirmed these findings. Significant publication bias was detected for the analysis of left MPI and left IRT. FGR is associated with significant biventricular cardiac dysfunction, characterized primarily by impaired myocardial relaxation, as indicated by a markedly prolonged IRT. The IRT appears to be a more sensitive marker of cardiac compromise in FGR compared with the traditional E/A ratio. These findings support the use of MPI and its components as valuable adjunctive tools in the surveillance of FGR pregnancies. © 2026 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

A Duplex Ultrasound Observational Study Establishing the Impact of Position on Left Iliac Vein Compression.

Fish guidance structures (FGS) with adjacent bypasses can provide safe downstream passage at hydropower plants. To regulate bypass discharge, gates with partial openings are installed at bypass inlets. This study examines how flow constriction at such openings affects fish behaviour and bypass entrance efficiency (BEE). In a physical model, we quantified upstream velocities with acoustic Doppler velocimetry for gates configured with either a bottom (BO) or top opening (TO) under three approach-flow velocities U o . Ethohydraulic tests with brown trout (Salmo trutta) and common barbel (Barbus barbus) assessed their ability to locate and enter the bypass. Hydraulic measurements showed high bypass inflow velocities U by , in up to 2.0 m/s, velocity ratios U by , in / U o up to 6.7, and streamwise velocity gradients SVG x up to 21 s − 1 , exceeding common design recommendations. U by , in and SVG x , linked to opening location and geometry, emerged as key parameters associated with BEE and fish behaviour. Both species frequently avoided strong currents at the openings, with significantly lower and delayed passage through the TO. Brown trout tended to enter the BO more often and earlier than barbel, indicating species-specific preferences. Overall, BEE was low (BO: 27–59%; TO: 8–21%). Findings highlight that unfavourable hydraulics can impair FGS-bypass performance. Design recommendations are provided.

Left atrial diameter to left atrial appendage emptying velocity ratio predicts risk of recurrence of atrial fibrillation after all-zero fluoroscopy ablation.

The article considers a two-component, two-velocity medium containing interacting volumetric energy sources. The subject of the study is a system of two coupled wave equations with two different sound velocities. The system is regarded as a contrastive, if one of the velocities significantly exceeds the other. The exact solution has a two-kink structure and corresponds to source functions that exhibit trigonometric nonlinearity with respect to the unknown functions. A solution to the problem of the decay of a weak discontinuity is given, and an analysis of the dynamic properties of waves formed as a result of the interaction of the first and second components is performed. Conditions for the existence of subsonic and supersonic regimes of motion of the excitation area boundaries are indicated. Nonlinear properties of the source amplitudes are determined, caused by the dynamic properties of the boundaries and the ratio of the sound velocities in the first and second components. An example of an approximate solution of the contrast system is given for the nontrivial case when the product of the amplitudes of the source functions is equal to unity