Effect of vein imaging device use on first-attempt peripheral intravenous catheter insertion success and catheter complications in children: A randomized controlled trial.

Discrete event simulation (DES) is a flexible and computationally efficient approach for modeling diverse processes; however, DES remains underutilized in health care and medical decision making due to a lack of reliable and reproducible implementations. We developed an open-source DES framework to simulate individual-level state-transition models (iSTMs) in continuous time accounting for treatment effects, time dependence on state residence, and age-dependent mortality. Our DES implementation employs a modular and easily adaptable structure, with each module corresponding to a unique transition between health states. To simulate the evolution of the process (i.e., individual state transitions), we adapted the next-reaction algorithm from the stochastic chemical reactions literature. Simulation-time dependence (age-dependent mortality) and state residence time dependence (transition from sick to sicker) are seamlessly incorporated into the DES framework via validated nonparametric and parametric sampling routines (e.g., inversion method) of event times. Treatment effects are integrated as scaling factors of the hazard functions (proportional hazards). We illustrate the framework's benefits by implementing the Sick-Sicker Model in R and conduct a cost-effectiveness analysis and probabilistic analysis. We also obtain epidemiological outcomes of interest from the DES output, such as disease prevalence, survival probabilities, and distributions of state-specific dwell times. Our DES framework offers a reliable and accessible alternative that enables the simulation of more realistic dynamics of state-transition processes at potentially lower implementation and computational costs than discrete-time iSTMs.HighlightsDiscrete event simulation (DES) is a flexible and efficient approach to simulate diverse processes in model-based decision analysis.The tutorial presents an open-source DES framework to simulate individual-level state-transition models (iSTMs) in continuous time.The modular structure of our DES framework accommodates treatment effects, time-dependent transitions, and age-dependent mortality using validated sampling methods.The coded example in R uses the Sick-Sicker Model to compute a cost-effectiveness analysis, epidemiological outcomes, probabilistic analysis, and value-of-information analysis.

Screw preload analysis of direct-to-abutment connections in completearch zirconia frameworks before and after thermomechanical aging.

Parallel solid-state nanopore measurements are expected to improve not only throughput but also molecular discrimination performance. Here, we report the development of a 16-channel solid-state nanopore array measurement system that enables parallel nanopore fabrication by dielectric breakdown and subsequent ionic current recording. The system supports two fabrication modes: pulsed-voltage-induced dielectric breakdown (MPVI) and controlled dielectric breakdown (CBD) under constant-voltage bias, allowing nanopore formation over a wide diameter range. To demonstrate the operation of the developed system, two experimental studies were conducted. In the first study, nanopores were fabricated in 5 nm-thick SiN membranes using MPVI, followed by detection of single-stranded DNA (ssDNA) translocation. Arrays of nanopores with diameters ranging from 1 to 2 nm were formed, and the pore-diameter dependence of dwell time and current blockade amplitude during ssDNA translocation could be evaluated at sub-nanometer resolution. In the second study, nanopores were fabricated in 14 nm-thick SiN membranes using CBD, and double-stranded DNA (dsDNA) translocation was detected. Analysis of current traces during CBD suggested that pore enlargement remained limited for a period after dielectric breakdown, followed by accelerated pore growth accompanied by a rapid increase in current. The resulting pore diameters were distributed within 8-10 nm for 13 of the 16 channels and within 8-9 nm for 12 channels, demonstrating tight size control across most channels. Using these fabricated nanopores, dsDNA translocation events were observed in all channels.

This study develops a reinforcement learning (RL)-based control framework with guaranteed predefined performance for nonlinear switched interconnected systems. This approach effectively addresses challenges arising from unmeasurable states and group average dwell time switching mechanisms, allowing both convergence time and accuracy to be preset via parameter configuration. First, the system equations are reconstructed to target nonlinear and interconnected terms, which are then approximated using neural networks (NNs). Additionally, an NNs-based switching state observer is designed to estimate the unmeasurable states. Second, within the backstepping synthesis framework, a distributed optimal controller is designed by integrating a performance transformation function into the cost function, with the resulting control law approximated via an identifier-actor-critic architecture. Furthermore, the group average dwell time-based stability analysis is generalized to address the optimal control challenges inherent in nonlinear switched interconnected systems. Compared with existing studies, this approach demonstrates enhanced extensibility and practicality for real-world applications. Finally, two simulation examples verify the effectiveness and superiority of the proposed method over state-of-the-art alternatives.

Objective.This study aimed to develop a dose prediction model for hybrid applicators in cervical cancer brachytherapy.Approach.A total of 216 previous treatment plans were collected and divided into three datasets: training (161 plans), testing (40 plans), and clinical evaluation (15 plans). The treatment plans included three hybrid applicator types: tandem and ovoids combined with interstitial needles, tandem and ring combined with interstitial needles, and tandem and cylinder combined with interstitial needles. The model was validated on the testing dataset using mean absolute error (MAE) for voxel-wise dose evaluation and on the clinical evaluation dataset using dice similarity coefficient (DSC) and dose statistic differences.Main results.The model achieved a voxel-wise MAE of 0.45 ± 0.27 Gy and showed no statistically significant differences (p> 0.05) in all key dose-volume histogram parameters when compared to clinical plans. The DSC values ranged from 0.74 to 0.77. Small dosimetric differences between the optimized and manually generated plans were observed for the high-risk clinical target volume (HR-CTV) D98%, HR-CTV D90%, and bladder D2cc.Significance.The developed dose prediction model demonstrates significant potential for application in hybrid applicator brachytherapy. This model can provide guidance for dose delivery during dwell time optimization. As a reference for optimization, it has the potential to streamline the planning process, reduce planning time, and improve consistency in adaptive workflows.

Beam teleportation for precision dose control in scanning transmission electron microscopy.

Incidence and risk factors of femoral venous catheter-related thrombosis in children: A retrospective cohort study.

How Do Spatial Architectural Features in a School Courtyard Influence Students' Dwell Time and Social Clustering Patterns?

Airborne pathogens and antimicrobial resistance (AMR) pose growing health risks in cities, where enclosed spaces, inadequate ventilation, and high population density enhance their persistence and dissemination. However, the microbial burden and risk associated with high-occupancy public spaces remain poorly quantified. Here, we compared bioaerosol characteristics across university cafeterias and a subway station, dry- and mixed-waste collection facilities (WCFs), and an urban air monitoring site by using culture-based, molecular, source-tracking, and risk-assessment approaches. The results showed that Crowded Public Spaces (CPSs) harbored culturable bacterial and AMR burdens comparable to those in WCFs, both far exceeding levels at the urban air monitoring site. Human-associated sources contributed to ∼50% of airborne bacteria, and multidrug-resistant isolates (∼60%), high-risk β-lactam ARGs, and clinically relevant pathogens were further enriched in CPSs. We further applied a population-weighted infection burden (PWIB) metric that integrates infection risk with pedestrian volume and dwell time. Although contamination levels in CPSs were similar to those in conventional microbial hotspots, CPSs contributed more to the city-scale infection burden once population exposure was taken into account. These findings reveal that urban airborne microbial risk is shaped not only by contamination intensity but also by human occupancy and exposure patterns. This study highlights the value of incorporating human activity into microbial risk assessment in high-density urban environments.

Peripherally inserted central catheter ports (PICC-ports) combine peripheral insertion with implantable reservoirs, offering reduced invasiveness compared to chest ports. Evidence from Latin America remains limited. To evaluate the safety, efficacy, and device survival of PICC-ports in oncology patients at a Colombian tertiary care center. Retrospective cohort study of 50 consecutive adult cancer patients receiving PICC-ports (January 2023-December 2024). All procedures were performed using ultrasound guidance and intracavitary electrocardiographic navigation under local anesthesia. Technical success: 100% (95% CI: 92.9%-100%). No early complications occurred. Late complications occurred in 4% of patients: one case of catheter-related thrombosis and one case of catheter dislodgement. Overall complication rate: 3.1 per 10,000 catheter-days (95% CI: 0.35-2.07). Median dwell time: 117 days. Catheter retention: 94.0% at 30 days, 89.2% at 90-180 days. PICC-port implementation achieved excellent safety outcomes comparable to international benchmarks, supporting its use as an alternative to chest ports in resource-constrained settings.

Transvenous lead extraction (TLE) requires high expertise in mechanical dilatation (MD), with double the risk of death and failure in low-volume centres. No automated tools support decision-making. We aimed to develop an ML-based model to predict the need for MD in patients undergoing TLE for infections. Five ML models (k-nearest neighbours, support vector machine, decision tree, random forest, and gradient boosting) were developed on a retrospective cohort of patients who underwent TLE at our centre. Each patient was described by 21 features (14 clinical, 7 device-related). Models were trained to distinguish MD from manual traction (MT). Five-fold nested cross-validation assessed performance and identified the best classifier. Feature importance analysis highlighted the most influential factors in model decisions. Data for model training were extracted from our 25-year TLE database (June 1998-March 2023), including 491 patients (77.8% male; age 69.7 ± 12.8 years) and 938 leads (ICD 21.2%; pacing 78.8%; indwelling time 61 ± 60 months). MT was used in 27.5% and MD in 72.5% of cases. In total, 393 patients were used for training and 98 for testing. According to nCV, the Gradient Boosting Machine performed best, with 89% accuracy (SD 2%), 95% sensitivity (SD 3%), 73% specificity (SD 8%), and 92% AUROC (SD 1%). The most relevant features were lead dwelling time, ejection fraction, creatinine, ICD presence, prior cardiac surgery, and permanent atrial fibrillation. ML tools showed reliable performance in predicting MD need in TLE procedures, supporting planning and referral to high-volume centres.

Single-shot ablation for AF: real-world procedural and one-year outcomes with the newly adopted PulseSelect PFA compared with cryoballoon from the 1STOP project

An ammonia-free solid-state nitridation strategy employing guanidinium carbonate (GdmC) as a carbon-nitrogen precursor is demonstrated using BaTaO2N as a model oxynitride perovskite. While BaTaO2N is a well-established compound, the present study focuses on the reaction chemistry enabled by GdmC under flowing N2. Systematic comparison with other nitrogen-containing reagents reveals that GdmC provides a unique balance between nitridation capability and reducing character, enabling phase-pure BaTaO2N formation within a short dwell time of 0.5 h. Thermal and structural analyses suggest the transient formation of carbon-nitrogen intermediates, including BaNCN species, which facilitate nitrogen incorporation into the perovskite lattice under ammonia-free conditions. Furthermore, partial La-substitution suppresses anion nonstoichiometry-related defects, leading to optical absorption characteristics comparable to those of ammonolyzed samples. These results highlight carbon-nitrogen solid-state chemistry as an effective approach for controlled nitrogen incorporation in complex oxynitride compounds.

Severe preterm intraventricular hemorrhage (IVH) with post-hemorrhagic ventricular dilatation (PHVD) may be difficult to manage when the clot burden is extensive and complete endoscopic evacuation is limited by clinical instability and rigid-scope constraints. We describe a staged clearance strategy in a preterm infant with bilateral grade IV IVH and progressive PHVD. Bilateral external ventricular drains (EVDs) were inserted for cerebrospinal fluid diversion. Low-dose intraventricular recombinant tissue plasminogen activator (0.1-0.3 mg per ventricle) was started 48 hours later and repeated every 48 hours for four sessions with a 2-hour dwell time under serial bedside cranial ultrasonographic surveillance. Sequential rigid neuroendoscopic lavage (NEL) was then performed, followed by 7 days of continuous ventricular irrigation using a bilateral inflow-outflow EVD configuration and a buffered glucose-containing artificial cerebrospinal fluid solution. No interval rebleeding, sustained intracranial hypertension, electrolyte instability, or culture-proven ventriculitis occurred during treatment. Ventricular size remained stable after drain removal, and no ventriculoperitoneal shunt had been required through the latest outpatient follow-up on postnatal day 157 (HD 151). This report presents a single-case conceptual proof-of-concept and technical feasibility experience for selected severe preterm IVH in a rigid-scope setting, rather than evidence of efficacy.

This paper addresses the global uniform asymptotic and global uniform exponential stabilisation problems for continuous-time switched nonlinear systems under hybrid or mixed state-dependent and time-dependent switching strategies with dwell-time ranges. Two types of hybrid switching methodologies, called hybrid switching in the mandatory or arbitrary sense, are considered, in which, to guarantee stability, access to the system state is mandatory or arbitrary, respectively. Hybrid switching in the arbitrary sense is a novel concept by which the stability of switched systems is guaranteed either using a state-dependent closed-loop switching strategy when the system state information is available, or by the time-dependent open-loop switching function when the state data is lost for any reason, such as sensor or communication failure. Moreover, the proposed stability conditions have several key features, such as applicability in both continuous and sampled-data control systems, providing dwell-time ranges, stabilisation of a wide range of switched systems independent of the stability property of each subsystem, and offering a flexible mode-dependent feature for the design parameters. Besides, multiple polynomial and discretised polynomial Lyapunov functions are utilised via Sum of Squares (SOS) programming to construct the required time-invariant and time-varying switched Lyapunov functions. Finally, the effectiveness of the proposed stabilisation methods is illustrated via a numerical example.

Continuous prostacyclin infusion is the standard of care for pulmonary arterial hypertension, requiring central venous access devices where dwell time is critical but associated with complications. Retrospective 10-year case series of 18 adult pulmonary arterial hypertension patients managed through central venous access devices by a specialized multidisciplinary team. Sixty-nine catheters were analyzed across 18 patients; median catheter survival estimated by the Kaplan-Meier method was 9.3 months (95% confidence interval (8.1-12)). Occlusion was the most frequent complication (1.20 per 1,000 catheter-days) and the leading removal reason across all device types. Catheter-related bloodstream infections occurred in four instances (0.22 per 1,000 catheter-days), with methicillin-susceptible Staphylococcus aureus as the only isolated pathogen. Catheter-related thrombosis was documented in two cases. Three catheters fractured, one of each device type. Evidence on central venous access device outcomes in pulmonary arterial hypertension remains scarce in middle-income countries. The median dwell time observed in this series was shorter than that reported in high-income country cohorts, while catheter-related bloodstream infection and thrombosis rates were numerically lower than those documented in comparable series. In this descriptive 10-year case series from a middle-income country, long-term central venous access devices for continuous epoprostenol infusion in pulmonary arterial hypertension were associated with a prolonged dwell time and low complication rates under a structured multidisciplinary follow-up model. Larger multicenter studies are needed to confirm generalizability and identify determinants of catheter longevity.

Self-expanding metal stents (SEMS) are a palliative treatment option for malignant esophageal strictures causing dysphagia. Retrosternal pain, reflux-related symptoms and migration remain relevant limitations. SEMS with an anti-reflux valve (SEMS-ART; Niti-S™ esophageal covered stent, anti-reflux type, TaeWoong Medical) may reduce these limitations but clinical data remain limited. This study evaluates safety, tolerability and clinical performance of SEMS-ART in malignant esophageal stricture and leakage. All patients treated with SEMS-ART for malignant esophageal stricture or leakage at the Medical University of Vienna, Department of General Surgery, between 01/2016 and 04/2021 were included into this retrospective analysis. Parameters regarding patients' safety, compliance and associated comorbidities like reflux and dysphagia were analyzed. Twenty patients were included. The cohort was predominantly male (90.0%) with a mean age of 65.3 years. Advanced esophageal cancer UICC stage III-IV was present in 75.0%. Technical success was achieved in all patients (100%). Adequate stent expansion was confirmed in all patients, while correct positioning and normal contrast passage were observed in 95%. Reflux, Dysphagia and Regurgitation resolved in all cases after SEMS insertion (p < 0.001). Dislocation occurred in 15.0% (n = 3) and primarily managed endoscopically. Mean SEMS dwell time was 88.3 days. 30-day SEMS-related safety was 95.0%, and no SEMS-related mortality occurred within the observational period. This small case series demonstrates high technical success of SEMS-ART, supporting feasibility and an acceptable safety profile on migration and symptom relief. These findings support the use of SEMS-ART in selected patients with malignant esophageal stricture and should be considered hypothesis-generating, supporting further prospective comparative studies.

Asymmetric VR collaborative games enhance social interaction and immersion, yet the combined impact of task complexity and collaboration frequency remains unclear. We designed and developed Escape: Asylum, an asymmetric VR puzzle game, and conducted a within-subjects study (N = 32) comparing two design modes: high complexity with high collaboration frequency and low complexity with low collaboration frequency. Behavioral performance and subjective experience data were collected. Results showed that participants in the HC-HC condition moved faster and spent a smaller proportion of time dwelling, but did not achieve better task performance. Participants in the LC-LC condition reported significantly higher enjoyment. Correlation analyses revealed that the proportion of dwell time was positively associated with enjoyment, IEQ and SUS, whereas movement speed and overall performance were negatively associated with these experiential measures. These findings suggest that in asymmetric VR puzzle games, behavioral efficiency does not equate to positive experience.

Arterial catheters are widely used in intensive care units for continuous hemodynamic monitoring and blood collection. Evidence-based practices for arterial catheter maintenance are not strictly followed by all medical staff in the pediatric intensive care unit. This study aimed to improve compliance with evidence-based practices for arterial catheter management in critically ill children in a Chinese pediatric intensive care unit. The JBI Evidence Implementation Framework was used to translate evidence into practice. The Integrated-Promoting Action on Research Implementation in Health Services (i-PARIHS) framework was used to identify barriers to compliance with best practices. An arterial catheter management strategy for critically ill children was developed based on the identified barriers, along with a simulation training module and a supply of 10-ml prefilled normal saline flush syringe. Field observations, a review of medical records, and interviews with medical staff and patients were used to assess baseline and follow-up audit compliance with best practices. Thirteen criteria were audited in the baseline and follow-up audits using 220 and 212 peripheral arterial catheters, respectively. In the follow-up audit, compliance with all criteria increased and the indwelling time of the peripheral arterial catheter was prolonged. The JBI Evidence Implementation Framework was used to improve compliance with the best practices. Future audits should be conducted to sustain the evidence-based behavior of all medical staff. http://links.lww.com/IJEBH/A642.