Safety Metrics Research Articles

Outcomes following total ankle total talus replacement: A systematic review

BackgroundProsthetic substitution of the talus presents a significant challenge to the foot and ankle surgeon. The shear and compressive forces on the talus and its tenuous blood supply lead to high rates of avascular necrosis and eventual talar collapse. The purpose of this systematic review is to evaluate whether total ankle total talus replacement (TATTR) leads to improved clinical and radiographic outcomes with appropriate safety metrics in patients with a history of avascular necrosis or significant trauma. MethodsWe searched the concepts of talus, prosthesis, and arthroplasty in MEDLINE (PubMed), Embase (Elsevier), CINAHL Complete (EBSCOhost), and Scopus (Elsevier) from the database's inception through March 9, 2023. Inclusion Criteria were 1) previous trauma to the talus, 2) post-traumatic arthritis to the tibiotalar joint, 3) avascular necrosis of talus, 4) multiple failed prior interventions, 5) degenerative osteoarthritis to the tibiotalar joint, and 6) inflammatory arthropathy to tibiotalar joint. Patients less than 18 years of age and manuscripts in non-English languages were excluded. ResultsOf the 7625 references, 16 studies met the inclusion criteria, yielding data from 136 patients (139 ankles). The studies varied in design, with case reports and retrospective case series being predominant. The overall weighted average modified Coleman Methodology Score (mCMS) was 70.4 out of 100, indicating moderate flaws in study design that may be subject to various forms of bias and possible confounders. Demographics showed a diverse range of etiologies, with alumina ceramic being the primary prosthesis material. Functional scores demonstrated improvements in dorsiflexion and plantarflexion, although patient-reported outcome measures (PROs) were inconsistently reported. Complications included fractures, heterotopic ossification, prolonged wound healing, and infections. Revision details were sparsely reported. ConclusionTATTR is a promising treatment modality for improving short-term functional outcomes for patients with avascular necrosis or trauma-related issues. However, this systematic review underscores the need for standardized reporting, longer-term follow-ups, and further research to establish the procedure’s efficacy and safety, particularly in comparison to other treatment modalities. Level of EvidenceIII, Systematic Review of Level IV Studies

Efficacy and Safety of Kuoxin Formula in the Treatment of Dilated Cardiomyopathy-Related Heart Failure: Study Protocol of a Randomized, Double-Blind, Placebo-Controlled, Multi-Center Clinical Trial.

Dilated cardiomyopathy (DCM) is a severe heterogeneous cardiomyopathy characterized by cardiac enlargement and declining heart function, often leading to refractory heart failure and life-threatening outcomes, particularly prevalent in China. The challenge lies in the scarcity of targeted therapies with substantial efficacy for DCM. Additionally, traditional anti-heart failure drugs are constrained due to hypotension propensity or limited symptom improvement. Kuoxin Formula (KXF), internally endorsed at Longhua Hospital, demonstrates clear biological evidence for enhancing cardiac function and myocardial remodeling. Previous clinical studies suggest its potential to enhance patients' quality of life. This trial aims to further evaluate KXF's safety and efficacy in managing DCM-related heart failure. This prospective, randomized, double-blind, placebo-controlled, multicenter trial aims to recruit 230 DCM patients from five centers. Participants will be randomly assigned to either KXF or placebo for 12 weeks, with careful monitoring of key indicators and adverse events. The primary outcome measures the proportion of patients with NT-proBNP reduction exceeding 30%. Secondary outcomes include New York Heart Association functional classification, Traditional Chinese Medicine syndrome scores, 6-minute walk test, Lee's heart failure score, and Minnesota Heart Failure Quality of Life Scale score. Ventricular remodeling will be assessed using cardiac ultrasound and ELISA. Safety metrics and adverse events will be meticulously recorded. This study will be the first multicentered research conducted in China that utilizes a randomized, double-blind, placebo-controlled design to investigate the use of TCM in the treatment of DCM. It seeks to develop new theoretical frameworks and provide solid clinical data to support the integration of TCM and modern medicine in treating heart failure in DCM patients. China Clinical Trial Registry, ChiCTR2300068937. Registered on March 1, 2023. https://www.chictr.org.cn/bin/project/edit?pid=190926.

Combining echocardiography and fluoroscopy imaging in real time for left atrial appendage occlusion - single center experience from Poland.

Atrial fibrillation (AF) presents a growing health concern, often requiring stroke prevention measures, primarily through oral anticoagulation (OAC). Surgical interventions such as left atrial appendage occlusion (LAAO) offer alternatives when OAC is contraindicated. In recent years, percutaneous procedures have gained traction as minimally invasive options, demanding precise anatomical insights. Fusion imaging (FI), which combines transesophageal echocardiography (TEE) and fluoroscopy, has emerged as a potential game-changer in transcatheter interventions. This study introduces FI to LAAO procedures in Poland, assessing its role in guiding interventions, highlighting advantages, and exploring its potential to reshape cardiovascular interventions. We conducted a retrospective study involving LAAO procedures from March 2015 to December 2018, all utilizing FI. Patient indications, procedural specifics, and safety metrics were collected and analyzed. Follow-ups were conducted at 3 and 6 months. A cohort of 83 patients (mean age: 72.1 ±8.4 years) underwent successful LAAO procedures. FI provided precise device placement and anatomical assessment. Mean procedure time was 54.9 ±34.3 min, contrast medium usage averaged 33.7 ±22.7 ml, and creatinine levels remained stable. Patients were discharged in about 4.2 ±3.4 days. Adverse effects were rare, including minimal bleeding and cardiac tamponade. Follow-ups demonstrated favorable outcomes with low adverse event rates. This study marks the inaugural application of FI in Polish LAAO procedures. FI, offering enhanced visualization and reduced procedure times, holds promise in improving patient safety and treatment efficacy. We recommend its consideration as a standard visualization technique for LAAO procedures.

Rapid Electrochemical Diagnosis of Battery Health and Safety from Cells to Modules

Rapid electrochemical diagnosis of battery health and failure is critical for ensuring reliable battery performance and battery safety. Traditional battery health diagnostics such as capacity measurements and DC pulse tests are reliable and well-understood, however, these measurements of battery capacity and resistance do not capture all aspects of battery degradation. Other aspects of degradation, such as electrolyte decomposition, lithium-plating, and particle cracking are difficult to detect electrochemically but are crucial to measure to get a full picture of battery safety and flag out potential failures. In this work, lab- and field-aged commercial lithium-ion batteries and modules of various chemistries and formats are tested using a variety of traditional electrochemical characterization methods as well as using 2-minute pseudo-random DC pulse sequences at rest and during charge/discharge. The electrochemical measurements are compared to physical cell measurements, cell efficiency, drive cycle performance, physical and thermal heterogeneity, and qualitative safety metrics using statistical and machine-learning methods to discover if a comprehensive ‘battery health map’ can be accurately identified using only rapid DC measurements.

The impact of a blood-culture diagnostic stewardship intervention on utilization rates and antimicrobial stewardship.

Blood-culture overutilization is associated with increased cost and excessive antimicrobial use. We implemented an intervention in the adult intensive care unit (ICU), combining education based on the DISTRIBUTE algorithm and restriction to infectious diseases and ICU providers. Our intervention led to reduced blood-culture utilization without affecting safety metrics.

An adaptive hybrid deep learning-based reliability assessment framework for damping track system considering multi-random variables

Reliability assessment is essential in the design and management of rail transit system (RTS), with a heightened focus on damping tracks that feature low-stiffness structures and various uncertainties. However, existing research on RTS has notable gaps: one is the unexplored nonlinear track irregularities in surrogate model, while the other is the significant computational burden of current reliability analysis. Therefore, Firstly, based on a database acquired from simulations of rigid-flexible coupling dynamic models, a hybrid deep learning (DL) surrogate model is developed and trained. Notably, it accommodates both time-series and feature parameters data as inputs, and integrates a novel algorithm featuring slide window with variational decomposition mode-sample entropy, optimization algorithm and adaptive learning strategy (AS). Subsequently, an advanced reliability assessment framework is proposed, utilizing AS hybrid DL-based Probability Density Evolution Method (PDEM), which thoughtfully designed to analyze the two aforementioned categories of random variables and then applied to a train-steel spring floating slab track. Experimental studies show the proposed surrogate model effectively and robustly predicts four safety metrics, with each component's excellence confirmed. Furthermore, this framework shows higher accuracy than the Monte Carlo Method and enhances computational efficiency by 10 ∼ 30 times compared to traditional mechanism-based PDEM. Consequently, reliability assessments indicate values of 0.9312 and 0.9214 for wheel-load reduction rate and rail displacement, respectively, with other metrics showing zero safety hazards. Findings of this study have practical applicability in the field of RTS design and maintenance.

What do surrogate safety metrics measure? Understanding driving safety as a continuum

Road safety is an important public health issue; technology, policy, and educational interventions to prevent crashes are of significant interest to researchers and policymakers. In particular, there is significant ongoing research to proactively evaluate the safety of new technologies, including autonomous vehicles, before enough crashes occur to directly measure their impact.We analyze the distributional form of five diverse datasets that approximate motor vehicle safety incident severity, including one dataset of hard braking events that characterizes the severity of non-crash incidents. Our empirical analysis finds that all five datasets closely fit a lognormal distribution (Kolmogorov-Smirnov distance < 0.013; significance of loglikelihood ratio with other distributions < 0.000029).We demonstrate a linkage between two well-known but largely qualitative safety frameworks and the severity distributions observed in the data. We create a formal model of the Swiss Cheese Model (SCM) and show through analysis and simulations that this formalization leads to a lognormal distribution of the severity continuum of safety–critical incidents. This finding is not only consistent with the empirical data we examine, but represents a quantitative restatement of Heinrich’s Triangle, another heretofore largely qualitative framework that hypothesizes that safety events of increasing severity have decreasing frequency.Our results support the use of more frequent, low-severity events to rapidly assess safety in the absence of less frequent, high-severity events for any system consistent with our formalization of SCM. This includes any complex system designed for robustness to single-point failures, including autonomous vehicles.

Adjunctive rosiglitazone treatment for severe pediatric malaria: A randomized placebo-controlled trial in Mozambican children

ObjectivesWe tested the hypothesis that adjunctive rosiglitazone treatment would reduce levels of circulating angiopoietin-2 (Angpt-2) and improve outcomes of Mozambican children with severe malaria. MethodsA randomized, double-blind, placebo-controlled trial of rosiglitazone vs placebo as adjunctive treatment to artesunate in children with severe malaria was conducted. A 0.045 mg/kg/dose of rosiglitazone or matching placebo were administered, in addition to standard of malaria care, twice a day for 4 days. The primary endpoint was the rate of decline of Angpt-2 over 96 hours. Secondary outcomes included the longitudinal dynamics of angiopoietin-1 (Angpt-1) and the Angpt-2/Angpt-1 ratio over 96 hours, parasite clearance kinetics, clinical outcomes, and safety metrics. ResultsOverall, 180 children were enrolled; 91 were assigned to rosiglitazone and 89 to placebo. Children who received rosiglitazone had a steeper rate of decline of Angpt-2 over the first 96 hours of hospitalization compared to children who received placebo; however, the trend was not significant (P = 0.28). A similar non-significant trend was observed for Angpt-1 (P = 0.65) and the Angpt-2/Angpt-1 ratio (P = 0.34). All other secondary and safety outcomes were similar between groups (P >0.05). ConclusionAdjunctive rosiglitazone at this dosage was safe and well tolerated but did not significantly affect the longitudinal kinetics of circulating Angpt-2.

Interfacial polymerization using biobased solvents and their application as desalination and organic solvent nanofiltration membranes

Thin-film composite membranes are widely regarded as more sustainable technologies for desalination and organic solvent nanofiltration. However, the process of fabricating these membranes is not. This is because n-hexane, a toxic and hazardous solvent, or other fossil-derived oily solvents are used as the organic phase to fabricate polyamide selective layers of such membranes. Here we replaced fossil-derived solvents with benign, bio-renewable solvents that possess better environmental, health and safety metrics – cyclopentyl methyl ether (CPME) and 2-methyltetrahydrofuran (2-MeTHF). A fully aromatic polyamide thin film composite (TFC) membrane fabricated via CPME demonstrated a higher NaCl rejection (97.8%), while the same membrane fabricated using n-hexane only presented 92.4% rejection. Meanwhile a semi-aromatic polyamide TFC membrane fabricated with 2-MeTHF showed an ethanol permeance of 9.87 L m−2 h−1 bar−1 and 97.1% RB rejection, 3.7-fold higher than the TFC fabricated using n-hexane. This demonstrated the feasibility and advantages of replacing toxic and hazardous solvents that have long been the standard solvents used in membrane fabrication, with benign alternatives. This work could potentially improve the sustainability of membrane fabrication.

Process & occupational safety integrated inherently safer chemical plant design: Framework development and validation

Chemical plants encompass diverse chemical and non-chemical hazards that can potentially lead to accidents. Consequently, it is imperative to implement appropriate risk management strategies to effectively reduce these hazards. Inherent safety, with its emphasis on eliminating hazards at source, has resulted in notable success in generating safer process routes. Conventional inherent safety methodologies are limited to optimizing process designs by reducing chemical and process hazards; however, occupational safety hazards (e.g., burns, electrocutions, drowning, and vehicle incidents) associated with ancillary services and working environments are not commonly scrutinized in the inherent safety framework. To this end, this work developed a dedicated tool called Safety Metric for Plant Design (SMPD), integrating occupational safety and process safety aspects, to generate a holistic safer chemical plant via inherent safety oriented modifications. Firstly, the index framework was constructed based on the safety consideration of chemical and process, ancillary services, and working environments. Then, the index framework was integrated with the Fuzzy Risk Rating (FRR), Precedence Chart (PC), and Bayesian Network (BN) to develop SMPD, and the Systematic Risk Reduction Framework (SRRF) was proposed to implement the inherent safety oriented design. Lastly, the SMPD was demonstrated using the case study of a methanol plant. The results revealed that the overall safety level increased from 2.7 to 3.39 after SRRF-based design modifications, implying that the revised chemical plant design is inherently safer than the base design. The proposed SMPD addresses both process hazards and occupational hazards by inherently safer approaches. This work provides a new perspective for designers to shift from inherently safer process design to plant design, aiming to establish a safety design framework for chemical plants oriented towards inherent safety.

KB-Lanra 1001: A Phase 1b/2 Study of Safety, PK, PD, and Preliminary Efficacy of the Selective SYK Inhibitor Lanraplenib in Combination with the FLT3 Inhibitor Gilteritinib in FLT3-Mutated R/R AML

Background and Significance: FMS-like tyrosine kinase (FLT3)-mutation (FLT3 mut) in patients with newly diagnosed and relapsed/refractory (R/R) acute myeloid leukemia (AML) is associated with shorter overall survival (OS) and relapse-free survival. Gilteritinib is an approved therapy for R/R FLT3 mut AML, but reduction in FLT3 mut burden and sustained efficacy are rarely achieved, thus necessitating investigation of rational therapeutic combinations to improve outcomes. Spleen Tyrosine Kinase (SYK) is a non-receptor tyrosine kinase known to regulate intracellular signaling in response to extracellular stimuli via its immunoreceptor tyrosine-based activation motif (ITAM). SYK serves as a relay to an oncogenic transcriptional regulatory network (TRN) linked to HOXA9 and MEIS1-facilitated suppression of myeloid progenitor maturation and proliferation. SYK cooperates with internal tandem duplication (ITD)-mutated FLT3 to drive leukemogenesis. Lanraplenib (LANRA) is an oral, potent, selective, next-generation SYK inhibitor with a 24-hour half-life, and once-daily (QD) dosing. In preclinical studies, the combination of LANRA and the FLT3 inhibitor gilteritinib demonstrated strong antileukemic effects ex vivo, resulting in deeper responses, and extended overall survival in FLT3 ITD-driven AML patient-derived xenograft mouse models. LANRA in combination with gilteritinib is currently being evaluated in patients with R/R FLT3 mut AML in the KB-LANRA 1001 trial (NCT05028751). Study Design and Methods: KB-LANRA 1001 is a global, multicenter, open-label phase 1b/2 trial designed to determine the safety and maximally tolerated and/or recommended phase 2 dose (MTD/RP2D) of LANRA in combination with standard dose gilteritinib (120 mg QD) in patients with R/R FLT3 mut AML. Secondary endpoints include evaluating pharmacokinetics (PK), pharmacodynamics (PD), and response evaluation (complete response (CR), CR with partial hematologic recovery (CRh), duration of response (DoR), event-free survival (EFS) and OS of the combination. Key exploratory endpoints include reduction of FLT3 mutvariant allele frequency among patients who achieve CR/CRh, correlation with selected baseline biomarkers that may predict efficacy outcomes, and assessment of LANRA PD properties (including target engagement). Eligibility requirements include documented FLT3 mut (ITD, tyrosine kinase domain [TKD] or both), age ≥18, and receipt of at least 1 prior therapy. Oral LANRA + gilteritinib will be administered daily until progression/relapse, intolerance, or failure to achieve at least a partial response (PR) after 6 cycles. The phase 1b component will follow a 3+3 dose escalation design. A dose-escalation committee (DEC) will decide LANRA dose escalation based on prospectively defined definitions of dose-limiting toxicity and safety metrics. Enrollment of additional patients to dose cohort(s) previously cleared for safety and tolerability by the DEC will be allowed under specific conditions. The phase 2 component will further evaluate safety, PK, PD, and anti-leukemic activity of the combination at the LANRA RP2D

The use of mobile electronic prescribing to drive quality of oncology care delivery.

586 Background: This pilot technology enhancement project set out to improve the quality of care for oncology patients by developing a mobile application for writing prescriptions (non-chemotherapy) and narcotics. We describe usage of this new mobile application and associated timeliness of care delivery, provider workflow efficiencies and patient safety metrics. Methods: Agile methodology was used to develop the workflow and software for the mobile application. Internal Patient Safety Usability Testing (PSUT) was used to assess high-risk tasks amongst potential users (n = 7). High-risk tasks were defined as those which, based on human error, could lead to potential patient harm or unsafe conditions. High-risk tasks included the ability for users to understand/acknowledge allergy and drug interactions, edit a selection, select and send to the appropriate pharmacy, and locate the record of the completed prescription within the patient’s chart through the mobile application. A pilot study was also conducted among oncologists (n = 14). A quantitative metric was measured to understand the adoption and usability of the mobile application. Qualitative feedback was also obtained. Results: 1. PSUT identified a need for improvement with recognition of interaction severity and differentiating an allergy versus a drug interaction. A design modification was also made to introduce a three-second hold to acknowledge an allergy. This was done to encourage users to take appropriate time to visualize and comprehend allergy and interaction information before advancing the workflow. 2. During the pilot study, 400 mobile prescriptions were written. After-hours writing of prescriptions in the mobile application increased (11.8%) compared to the EMR (3.5%). The average amount of time from initiation of writing a prescription to completion was 62 seconds in the mobile application. There were no high-risk patient safety incidents observed during the pilot study. Qualitative data from participants included themes around convenience, feasibility, improved access to care, and safety. Conclusions: Usage of the pilot mobile application demonstrated a safe and efficient approach to increase the quality of care delivery for oncology patients. Usage also suggests an increase in patient access to care after hours.

A Diversity Analysis of Safety Metrics Comparing Vehicle Performance in the Lead-Vehicle Interaction Regime

A Diversity Analysis of Safety Metrics Comparing Vehicle Performance in the Lead-Vehicle Interaction Regime

Comparison of name brand and store brand eye care products: an evaluation of pricing, consumer safety metrics, allergenic contents, and marketing claims.

Comparison of name brand and store brand eye care products: an evaluation of pricing, consumer safety metrics, allergenic contents, and marketing claims.

Workflow Considerations for Biology-Guided Radiotherapy (BgRT) Implementation.

Biology-guided radiotherapy (BgRT) is a novel platform that combines real-time PET imaging with a 6MV Linac to target tumors. The performance and safety of BgRT was assessed in the BIOGUIDE-X clinical trial. This study aims to report on the BgRT workflow steps and assess the time required for each step of the BgRT process during this trial. A total of nine patients were enrolled in the second Cohort of the BIOGUIDE-X study which included patients treated with stereotactic body radiotherapy (SBRT) for lung tumors (5) and bone tumors (4). The pre-treatment BgRT workflow includes CT simulation, contouring, imaging-only (BgRT Modeling) PET acquisition, BgRT planning, patient specific QA and plan approval. The imaging-only PET acquisition on the X1 collects a representative PET volumetric 3D image and is an input to develop the BgRT treatment plan. The steps during the BgRT delivery session are kVCT localization, PET pre-scan, PET evaluation and BgRT delivery. The PET PreScan is a 1-pass short-duration PET acquisition that is used to confirm that the PET biodistribution on the day of treatment is consistent with that of the imaging-only PET. During BIOGUIDE-X, the BgRT delivery step was replaced by a 4-pass long-PET acquisition that was used to emulate the expected BgRT dose distribution without turning the beam on. To assess BgRT workflow, times from 18F-FDG injection to image-only PET acquisition, 18F-FDG injection to PET pre-scan, Pre-scan to PET evaluation, and PET evaluation to BgRT delivery (long PET acquisition) were recorded. Time between the 18F-FDG injection and the X1 imaging-only PET scan was 84 ± 19 minutes which includes time for 18F-FDG update. Average time to perform imaging-only PET scan was 26 ± 4 minutes. During the BgRT 'delivery' session, the mean time between the kVCT acquisition and PET pre-scan acquisition was 7 ± 3 minutes. The mean time to acquire a 1-pass PET pre-scan was 6 ± 1 then followed by 6 ± 1 minutes for the PET pre-scan dose calculation to estimate the BgRT doses that it would have delivered for this fraction. On average, the PET reconstruction, the PET signal localization verification and the evaluation of safety metrics took 11 ± 4 minutes. The mean time for BgRT 'delivery' was 27 ± 5 minutes based on the 4-pass long PET acquisition. Time from the start of the BgRT session to the end of the BgRT 'delivery' with this version of the investigative product release was 65 ± 9 minutes. The new processes introduced by the BgRT technology were evaluated and found clinically feasible. Improvements are being undertaken to shorten the time required for each step and to increase patient comfort ahead of BgRT clinical implementation.

Towards establishing uniform metrics for evaluating the safety of lithium metal batteries

Lithium metal batteries (LMBs) with ultra-high theoretical energy densities are regarded as excellent candidates for the next energy storage devices. Unfortunately, there are many factors can cause the temperature of LMBs to exceed a safe range and trigger thermal runaway. Countless effort has been invested in designing safe components of batteries to realize the application of LMBs. However, most studies only focus on one single aspect since there is no uniform metrics for evaluating the safety of LMBs. Herein, this review comprehensively summarizes all the trigger factors of thermal runaway and proposes the complete safety metrics of LMBs. A comprehensive overview of the development of safe LMBs is provided to discuss the gap between studies and practical applications. Finally, the future directions of academic research are proposed according to the challenges existing in current studies.

Patient-Reported Cognitive Outcomes and Survival after Stereotactic Radiosurgery for 15 or More Brain Metastases

Overall survival (OS) in metastatic cancer patients has been improving with continued advancements, necessitating greater attention to treatment related toxicities. Patients with ≥ 15 brain metastases (BM) continue to be treated with whole brain radiation therapy (WBRT), despite poor neurocognitive outcomes. We analyzed our institutional experience of treating these patients with stereotactic radiosurgery (SRS), with the aim of evaluating safety, cognitive outcomes, and survival metrics. Patients who received SRS for ≥ 15 BMs in 1-5 fractions from 2014-2022 using the previously described single isocenter multi-target technique were included. Cognitive outcomes were objectively evaluated using serial Patient-Reported Outcome Measurement Information System (PROMIS) scores. Kaplan-Meier method was used for survival analysis and log-rank test was used for intergroup comparisons. A total of 118 patients underwent 124 courses of LINAC-based SRS. The mean and median number of lesions treated per patient was 24.8 and 20, respectively (range 15 - 94). Most common primary histologies were lung (47.6%), melanoma (21.0%), and breast (14.5%). The median SRS dose was 24 Gy (range 18 - 30 Gy) with 87.9% receiving 3 fraction SRS. At the time of SRS, 19.4% patients had received prior WBRT and 24.2% had received at least one prior SRS course. The rate of any grade radiation necrosis (RN) and ≥ grade 3 RN were 15.3% and 3.2% respectively. New onset seizures were seen in 2.4%, alopecia in 2.4%, and subjective cognitive decline in 4% of patients. Median follow-up by reverse Kaplan-Meier method was 17.8 months (m). Cognitive data was available for 38 patients. Mean PROMIS scores at baseline, 3m, 6m and 9m after SRS were 32.0, 31.6, 30.4 and 28.7 out of 40, respectively. When longitudinal trends were available, 25 of 31 patients had a stable or improved PROMIS score. The 12m local control was 97.6%. Cumulative incidence of distant intracranial failure was 79.2%. One year freedom from neurological death, leptomeningeal disease, and salvage WBRT were 85.6%, 87.6% and 71.7% respectively. Median OS from brain metastases diagnosis was 11.3m (95% CI 7.2m - 15.3m) overall, while it was 9.2m (6.5 - 11.8m) after excluding patients who had prior WBRT or SRS (n = 79). One-year survival was 40% from diagnosis and 38.7% from SRS. On Cox regression analysis, prior WBRT (p = 0.002), higher KPS (p = 0.050), systemic therapy after SRS (p<0.001), and controlled extracranial disease (p = 0.007) predicted for improved OS. We present here the largest study evaluating SRS for patients with ≥ 15 BMs. We found that SRS was safe, had favorable cognitive outcomes, and comparable survival outcomes to contemporary studies evaluating WBRT in this patient population. Treatment-naïve patients had a median survival of > 6 months, long enough to benefit from cognitive sparing with SRS. Our study supports further randomized studies comparing SRS and memory avoidance WBRT approaches for patients with ≥ 15 BMs.

Effects of radiation heat loss on planar and spherical hydrofluorocarbon/air flames

Hydrofluorocarbons (HFC), which are mildly flammable and pose potential fire risks, have received greater attention as a viable low global warming potential alternative to traditional refrigerant and fire-suppressant compounds. Therefore, there is a demand to accurately quantify their flammability and reactivity to establish proper safety metrics. This study investigates the effects of radiation heat loss on slowly-propagating HFC/air laminar flames. Planar 1-D simulations of R-32/air and R-1234yf/air flames show significant reductions in laminar flame speed due to radiative heat losses from the flame zone. Simulations of spherically expanding flames (SEF) revealed that the radiation-induced flow needs to be considered when interpreting data from experiments. To this end, a Spherical-flame RADiation-Induced Flow (SRADIF) model was developed to estimate the burned gas inward flow velocities in constant-pressure SEFs, utilizing the optically thin limit assumption to model radiation heat loss. The model was validated against results from detailed numerical simulations of SEFs, from which radiation-induced inward flow was derived using a new formulation considering both the radiation heat loss and convective flow effects. Results show that SRADIF accurately predicts the inward flow velocity for R-32/air mixtures over a range of conditions and performs significantly better compared to existing analytical models. However, the model was unable to accurately predict flow velocities for R-1234yf/air flames and the reason for this is discussed. (224 words)

AI in Surgical Curriculum Design and Unintended Outcomes for Technical Competencies in Simulation Training

To better elucidate the role of artificial intelligence (AI) in surgical skills training requires investigations in the potential existence of a hidden curriculum. To assess the pedagogical value of AI-selected technical competencies and their extended effects in surgical simulation training. This cohort study was a follow-up of a randomized clinical trial conducted at the Neurosurgical Simulation and Artificial Intelligence Learning Centre at the Montreal Neurological Institute, McGill University, Montreal, Canada. Surgical performance metrics of medical students exposed to an AI-enhanced training curriculum were compared with a control group of participants who received no feedback and with expert benchmarks. Cross-sectional data were collected from January to April 2021 from medical students and from March 2015 to May 2016 from experts. This follow-up secondary analysis was conducted from June to September 2022. Participants included medical students (undergraduate year 0-2) in the intervention cohorts and neurosurgeons to establish expertise benchmarks. Performance assessment and personalized feedback by an intelligent tutor on 4 AI-selected learning objectives during simulation training. Outcomes of interest were unintended performance outcomes, measured by significant within-participant difference from baseline in 270 performance metrics in the intervention cohort that was not observed in the control cohort. A total of 46 medical students (median [range] age, 22 [18-27] years; 27 [59%] women) and 14 surgeons (median [range] age, 45 [35-59] years; 14 [100%] men) were included in this study, and no participant was lost to follow-up. Feedback on 4 AI-selected technical competencies was associated with additional performance change in 32 metrics over the entire procedure and 20 metrics during tumor removal that was not observed in the control group. Participants exposed to the AI-enhanced curriculum demonstrated significant improvement in safety metrics, such as reducing the rate of healthy tissue removal (mean difference, -7.05 × 10-5 [95% CI, -1.09 × 10-4 to -3.14 × 10-5] mm3 per 20 ms; P < .001) and maintaining a focused bimanual control of the operative field (mean difference in maximum instrument divergence, -4.99 [95% CI, -8.48 to -1.49] mm, P = .006) compared with the control group. However, negative unintended effects were also observed. These included a significantly lower velocity and acceleration in the dominant hand (velocity: mean difference, -0.13 [95% CI, -0.17 to -0.09] mm per 20 ms; P < .001; acceleration: mean difference, -2.25 × 10-2 [95% CI, -3.20 × 10-2 to -1.31 × 10-2] mm per 20 ms2; P < .001) and a significant reduction in the rate of tumor removal (mean difference, -4.85 × 10-5 [95% CI, -7.22 × 10-5 to -2.48 × 10-5] mm3 per 20 ms; P < .001) compared with control. These unintended outcomes diverged students' movement and efficiency performance metrics away from the expertise benchmarks. In this cohort study of medical students, an AI-enhanced curriculum for bimanual surgical skills resulted in unintended changes that improved performance in safety but negatively affected some efficiency metrics. Incorporating AI in course design requires ongoing assessment to maintain transparency and foster evidence-based learning objectives.

Potential field-based modeling and stability analysis of heterogeneous traffic flow

Car-following behavior is influenced by multiple factors. Utilizing the potential field theory, previously determined as a comprehensive representation of these influencing factors, this study introduces a unified potential field-based car-following model tailored for mixed traffic flow. Considering the diverse information receptivity of various vehicle types, the model is shaped to encapsulate both Human Driven Vehicles and Connected and Automated Vehicles. Using the characteristic equation-based method, the stability conditions of the model are delineated. Subsequently, a detailed examination of mixed traffic flow stability was conducted across varying Connected and Automated Vehicles penetration rates. Leveraging a dataset of 300 real-world trajectories, the results were benchmarked against classical models such as the Intelligent Driver Model. Notably, our proposed model exhibited an 18.67 % improvement in safety metrics and a 1.36 % improvement in fuel economy over the Intelligent Driver Model when representing Connected and Automated Vehicles. The stability of the mixed traffic flow was found to correlate strongly with vehicular time delay and acceleration parameter weights. Furthermore, augmenting the Connected and Automated Vehicles penetration rate surfaced as a promising strategy to bolster traffic flow stability. Collectively, these findings furnish substantial enhancements to the existing body of knowledge on mixed traffic flow stability, offering pragmatic insights for future research and real-world applications, including traffic management, urban planning, and the development of Intelligent Transport Systems.