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Abstract It would be clinically valuable if the efficacy of antiarrhythmic drugs could be simulated in advance. We developed a digital twin to predict amiodarone efficacy in high-risk atrial fibrillation (AF) patients post-ablation. Virtual left atrium models were created from computed tomography and electroanatomical maps to simulate AF and evaluate its response to varying amiodarone concentrations. As the amiodarone concentration increased in the virtual setting, action potential duration lengthened, peak upstroke velocities decreased, and virtual AF termination became more frequent. Patients were classified into effective (those with virtually terminated AF at therapeutic doses) and ineffective groups. The one-year clinical outcomes after AF ablation showed significantly better results in the effective group compared to the ineffective group, with AF recurrence rates of 20.8% vs. 45.1% (log-rank p = 0.031, adjusted hazard ratio, 0.37 [0.14-0.98]; p = 0.046). This study highlights the potential of a digital twin-guided approach in predicting amiodarone’s effectiveness and improving personalized AF management. Clinical Trial Registration Name: The Evaluation for Prognostic Factors After Catheter Ablation of Atrial Fibrillation: Cohort Study, Registration number: NCT02138695. The date of registration: 2014-05. URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02138695.

Abstract The application of artificial intelligence (AI) algorithms to 12-lead electrocardiogram (ECG) provides promising age prediction models. We explored whether the gap between the pre-procedural AI-ECG age and chronological age can predict atrial fibrillation (AF) recurrence after catheter ablation. We validated a pre-trained residual network-based model for age prediction on four multinational datasets. Then we estimated AI-ECG age using a pre-procedural sinus rhythm ECG among individuals on anti-arrhythmic drugs who underwent de-novo AF catheter ablation from two independent AF ablation cohorts. We categorized the AI-ECG age gap based on the mean absolute error of the AI-ECG age gap obtained from four model validation datasets; aged-ECG (≥10 years) and normal ECG age (

Abstract Background The impact of delaying atrial fibrillation catheter ablation (AFCA) for antiarrhythmic drug (AAD) management on the disease course remains unclear. This study investigated AFCA rhythm outcomes based on the diagnosis‐to‐ablation time (DAT) and AAD responsiveness in participants with persistent AF (PeAF). Methods We included data from 1038 AAD‐resistant PeAF participants, all of whom had a clear time point for AF diagnosis, especially PeAF at diagnosis time, and had undergone an AFCA for the first time. Participants who experienced recurrences of paroxysmal type on AAD therapy were analyzed as a cohort of AAD‐partial responders; those maintaining PeAF on AAD were AAD‐non‐responders. We determined the DAT cutoff for best discriminating long‐term rhythm outcomes using a maximum log‐likelihood estimation method based on the Cox proportional hazard regression model. Results Of the participants (79.8% male; median age 61), 806 (77.6%) were AAD‐non‐responders. AAD‐non‐responders had a higher body mass index and a larger left atrial diameter than AAD‐partial‐responders. They also had a higher incidence of AF recurrence after AFCA (adjusted hazard ratio 1.75, 95% confidence interval 1.33–2.30; log‐rank p

Abstract Background Hypertrophic cardiomyopathy (HCM) is frequently associated with atrial fibrillation (AF). We compared clinical, echocardiographic, and electrophysiological parameters between HCM subtypes and those without HCM at AF catheter ablation (AFCA) and analyzed post‐AFCA reverse remodeling and AF recurrence based on HCM presence and subtype. Methods Among 5161 consecutive patients who underwent de novo AFCA, we included HCM patients and control patients who were age‐, gender‐, and AF type‐matched. Between AF‐HCM patients and controls, we compared baseline values for left atrium (LA) wall thickness (LAWT), reverse remodeling at 1‐year follow‐up, and procedural outcomes over the course of follow‐up between two groups. Results A total of 122 AF‐HCM patients and 318 control patients were included. AF‐HCM patients had more frequent heart failure and higher LA diameter, E/Em, and LA pressure (all, p

Abstract The evidence about the associations of leukocyte telomere length (LTL) and intermediary cardiovascular phenotypes with adverse cardiovascular outcomes is inconclusive. This study assessed these relationships with cardiovascular imaging, electrocardiography, and the risks of sudden cardiac death (SCD), coronary events, and heart failure (HF) admission. We conducted a cross-sectional analysis of UK Biobank participants enrolled between 2006 and 2010. LTL was measured using quantitative polymerase chain reactions. Electronic health records were used to determine the incidence of SCD, coronary events, and HF admission. Cardiovascular measurements were made using cardiovascular magnetic resonance imaging and machine learning. The associations of LTL with SCD, coronary events, and HF admission and cardiac magnetic resonance imaging, electrocardiogram parameters of 33,043 and 19,554 participants were evaluated by multivariate regression. The median (interquartile range) follow-up period was 11.9 (11.2–12.6) years. Data was analyzed from January to May 2023. Among the 403,382 white participants without coronary artery disease or HF, 181,637 (45.0%) were male with a mean age of 57.1 years old. LTL was independently negatively associated with a risk of SCD (LTL third quartile vs first quartile: hazard ratio [HR]: 0.81, 95% confidence interval [CI]: 0.72–0.92), coronary events (LTL third quartile vs first quartile: HR: 0.88, 95% CI: 0.84–0.92), and HF admission (LTL fourth quartile vs first quartile: HR: 0.84, 95% CI: 0.74–0.95). LTL was also independently positively associated with cardiac remodeling, specifically left ventricular mass index, left-ventricular-end systolic and diastolic volumes, mean left ventricular myocardial wall thickness, left ventricular stroke volume, and with electrocardiogram changes along the negative degree of T-axis. Cross-sectional study results showed that LTL was positively associated with heart size and cardiac function in middle age, but electrocardiography results did not show these associations, which could explain the negative association between LTL and risk of SCD, coronary events, and HF admission in UK Biobank participants.

Abstract Background The reason for higher incidence of atrial fibrillation (AF) in Europe compared with East Asia is unclear. We aimed to investigate the association between modifiable lifestyle factors and lifetime risk of AF in Europe and East Asia, along with race/ethnic similarities and disparities. Methods 1:1 propensity score matched pairs of 242,763 East Asians and 242,763 White Europeans without AF were analyzed. Modifiable lifestyle factors considered were blood pressure, body mass index, cigarette smoking, diabetes, alcohol consumption, and physical activity, categorized as non-adverse or adverse levels. Lifetime risk of AF was estimated from the index age of 45 years to the attained age of 85 years, accounting for the competing risk of death. Results The overall lifetime risk of AF was higher in White Europeans than East Asians (20.9% vs 15.4%, p < 0.001). The lifetime risk of AF was similar between the two races in individuals with non-adverse lifestyle factor profiles (13.4% vs 12.9%, p = 0.575), whereas it was higher in White Europeans with adverse lifestyle factor profiles (22.1% vs 15.8%, p < 0.001). The difference in the lifetime risk of AF between the two races increased as the burden of adverse lifestyle factors worsened (1 adverse lifestyle factor; 4.3% to ≥ 3 adverse lifestyle factors; 11.2%). Compared with East Asians, the relative risk of AF in White Europeans was 23% and 62% higher for one (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.16–1.29) and ≥ 3 adverse lifestyle factors (HR 1.62, 95% CI 1.51–1.75), respectively. Conclusions The overall higher lifetime risk of AF in White Europeans compared with East Asians might be attributable to adverse lifestyle factors. Adherence to healthy lifestyle factors was associated with the lifetime risk of AF of about 1 in 8 regardless of race/ethnicity.

Abstract Ultrasonography (US)-guided fine-needle aspiration cytology (FNAC) is the primary modality for evaluating thyroid nodules. However, in cases of atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS), supplemental tests are necessary for a definitive diagnosis. Accordingly, we aimed to develop a non-invasive quantification software using the heterogeneity scores of thyroid nodules. This cross-sectional study retrospectively enrolled 188 patients who were categorized into four groups according to their diagnostic classification in the Bethesda system and surgical pathology [II-benign (B) (n = 24); III-B (n = 52); III-malignant (M) (n = 54); V/VI-M (n = 58)]. Heterogeneity scores were derived using an image pixel-based heterogeneity index, utilized as a coefficient of variation (CV) value, and analyzed across all US images. Differences in heterogeneity scores were compared using one-way analysis of variance with Tukey’s test. Diagnostic accuracy was determined by calculating the area under the receiver operating characteristic (AUROC) curve. The results of this study indicated significant differences in mean heterogeneity scores between benign and malignant thyroid nodules, except in the comparison between III-M and V/VI-M nodules. Among malignant nodules, the Bethesda classification was not observed to be associated with mean heterogeneity scores. Moreover, there was a positive correlation between heterogeneity scores and the combined diagnostic category, which was based on the Bethesda system and surgical cytology grades (R = 0.639, p

BackgroundThe role of anti-arrhythmic drugs (AADs) in recurrent atrial fibrillation (AF) after catheter ablation (CA) is not fully understood. The aim of this study was to explore the effects of AADs in patients who recurred after AFCA depending on extra-pulmonary vein triggers (ExPVTs) and post-ablation heart rate variability (HRV) parameters.MethodsWe analyzed 2,036 patients who underwent de-novo AFCA and 486 patients with post-AFCA recurrence who underwent rhythm control with AADs. We investigated the effects of ExPVTs and 3rd month HRV parameters on the post-AFCA recurrence and subsequent AAD responsiveness.ResultsA total of 486 out of 2,036 patients developed clinical recurrence of AF and subsequently underwent rhythm control with AADs. 486 out of 310 patients (63.8%) remained free of second recurrence at 1-year. Post-AFCA recurrence was significantly higher in patients with ExPVT [Log-rank p

PurposeAlthough left bundle branch area pacing (LBBAP) is an emerging conduction system pacing modality, it is unclear which parameters predict procedural success and how many implant attempts are acceptable. This study aimed to assess predictors of successful LBBAP, left bundle branch (LBB) capture, and factors associated with the number of LBBAP implant attempts.MethodsThis retrospective observational multicenter study was conducted in Korea. LBBAP was attempted in 119 patients; 89.3% of patients had bradyarrhythmia (atrioventricular block 82.4%), and 10.7% of patients had heart failure (cardiac resynchronization therapy) indication. Procedural success and electrophysiological and echocardiographic parameters were evaluated.ResultsThe acute success rate of lead implantation in LBBAP was 95.8% (114 of 119 patients) and that of LBB capture was 82.4% (98 of 119 patients). Fewer implant attempts were associated with LBBAP success (three or fewer vs. over three times, p = 0.014) and LBB capture (three or fewer vs. over three times, p = 0.010). In the multivariate linear regression, the patients with intraventricular conduction delay (IVCD) required a greater number of attempts than those without IVCD [estimates = 2.33 (0.35–4.31), p = 0.02], and the larger the right atrial (RA) size, the more the attempts required for LBBAP lead implantation [estimates = 2.08 (1.20–2.97), p

Background Increased left atrial pressure (LAP) contributes to dyspnea and heart failure with preserved ejection fraction in patients with atrial fibrillation (AF). The purpose of this study was to investigate the differences in baseline LAP and LAP response to rapid pacing between paroxysmal and persistent AF. Methods and Results This observational study prospectively enrolled 1369 participants who underwent AF catheter ablation, excluding those with reduced left ventricular ejection fraction. H2FPEF score was calculated by echocardiography and baseline characteristics. Patients underwent LAP measurements during AF, sinus rhythm, and heart rates of 90, 100, 110, and 120 beats per minute (bpm), induced by right atrial pacing and isoproterenol. The baseline LAP‐peak in the persistent AF group consistently exceeded that in the paroxysmal AF (PAF) group across each H2FPEF score subgroup (all P

Abstract Electrochemical nitrogen reduction reaction (NRR) is a sustainable alternative to the Haber‒Bosch process for ammonia (NH3) production. However, the significant uphill energy in the multistep NRR pathway is a bottleneck for favorable serial reactions. To overcome this challenge, we designed a vanadium oxide/nitride (V2O3/VN) hybrid electrocatalyst in which V2O3 and VN coexist coherently at the heterogeneous interface. Since single‐phase V2O3 and VN exhibit different surface catalytic kinetics for NRR, the V2O3/VN hybrid electrocatalyst can provide alternating reaction pathways, selecting a lower energy pathway for each material in the serial NRR pathway. As a result, the ammonia yield of the V2O3/VN hybrid electrocatalyst was 219.6 µg h−1 cm−2, and the Faradaic efficiency was 18.9%, which is much higher than that of single‐phase VN, V2O3, and VNxOy solid solution catalysts without heterointerfaces. Density functional theory calculations confirmed that the composition of these hybrid electrocatalysts allows NRR to proceed from a multistep reduction reaction to a low‐energy reaction pathway through the migration and adsorption of intermediate species. Therefore, the design of metal oxide/nitride hybrids with coherent heterointerfaces provides a novel strategy for synthesizing highly efficient electrochemical catalysts that induce steps favorable for the efficient low‐energy progression of NRR.

Background: The ideal long-term antithrombotic strategy for patients after successful catheter-based atrial fibrillation (AF) ablation is still uncertain. Presently, practices vary, and the advantages of oral anticoagulation (OAC) for the post-ablation population are not clearly established. To date, no randomized trials have addressed this therapeutic question. This study aimed to evaluate whether no OAC therapy is superior to apixaban in reducing the risk of stroke, systemic embolism, or major bleeding among patients without apparent recurrent atrial arrhythmias for at least 1 year after their AF ablation procedure. Methods: The ALONE-AF trial is a prospective, multicenter, open-label, randomized study with blinded outcome assessment. Patients with AF who have at least one non-gender stroke risk factor (as determined by the CHA2DS2-VASc score) and no documented recurrences of atrial arrhythmia for at least 12 months post-ablation will be randomly assigned to apixaban 5 mg b.i.d. or no OAC therapy. The primary endpoint is a composite outcome of stroke, systemic embolism, and major bleeding. Key secondary outcomes include clinically relevant non-major bleeding, all-cause mortality, myocardial infarction, transient ischemic attack, quality of life, and frailty analysis. Participants will be followed for a period of 2 years. The estimated total sample size is 840 subjects, with 420 subjects in each arm. Conclusion: The ALONE-AF trial aims to provide robust evidence for the optimal anticoagulation strategy for patients with stroke risk factors following successful AF ablation.

Objectives In the Fourth Industrial Revolution, there is a focus on managing diverse medical data to improve healthcare and prevent disease. The challenges include tracking detailed medical records across multiple institutions and the necessity of linking domestic public medical entities for efficient data sharing. This study explores MyHealthWay, a Korean healthcare platform designed to facilitate the integration and transfer of medical data from various sources, examining its development, importance, and legal implications. Methods To evaluate the management status and utilization of MyHealthWay, we analyzed data types, security, legal issues, domestic versus international issues, and infrastructure. Additionally, we discussed challenges such as resource and infrastructure constraints, regulatory hurdles, and future considerations for data management. Results The secure sharing of medical information via MyHealthWay can reduce the distance between patients and healthcare facilities, fostering personalized care and self-management of health. However, this approach faces legal challenges, particularly relating to data standardization and access to personal health information. Legal challenges in data standardization and access, particularly for secondary uses such as research, necessitate improved regulations. There is a crucial need for detailed governmental guidelines and clear data ownership standards at institutional levels. Conclusions This report highlights the role of Korea’s MyHealthWay, which was launched in 2023, in transforming healthcare through systematic data integration. Challenges include data privacy and legal complexities, and there is a need for data standardization and individual empowerment in health data management within a systematic medical big data framework.

Abstract Background and Objectives Although extra‐pulmonary vein (PV) triggers (ExPVTs) play a role in atrial fibrillation (AF) recurrence after catheter ablation (AFCA), the mechanism is unknown. We explored whether the locations of ExPVTs were associated with low‐voltage scar areas (LVAs). Methods Among 2255 consecutive patients who underwent a de novo AFCA, 1696 (male 72.1%, median 60 years old, paroxysmal 64.7%) were included who underwent isoproterenol provocation and voltage mapping of the left atrium (LA) during their procedures. We investigated the associations between ExPVTs and their mean LA voltage and colocalization of ExPVTs within LVAs (

Abstract Background High‐power short‐duration (HPSD) ablation creates wide, shallow lesions using radiofrequency (RF) heating. It is uncertain if adjusting RF energy based on atrial wall thickness provides extra benefits. We studied the safety and effectiveness of tailored HPSD energy based on left atrial (LA) wall thickness (LAWT) for circumferential pulmonary vein isolation (CPVI) in patients with paroxysmal atrial fibrillation (PAF). Methods We enrolled 212 patients (68.4% male, mean age: 59.5 ± 11.0 years) and randomly assigned them to two groups: LAWT‐guided CPVI (WT, n = 108) and conventional CPVI (control, n = 104). Both groups used an open irrigated‐tip deflectable catheter to apply 50 W for 10 s to the posterior LA, while controls used 60 W for 15 s on other LA regions. RF delivery time in WT was titrated (15 s at LAWT > 2.1 mm, 13 s at 1.4–2.1 mm, and 11 s at .999). The total procedure time, cardioversion rate, and post‐procedural AAD prescription rates did not significantly differ between the groups. Conclusions The LAWT‐guided energy titration strategy did not result in improved procedural safety and efficacy compared to the conventional 50–60 W‐HPSD CPVI in patients with PAF.

Abstract Although pulmonary vein isolation (PVI) gaps and extrapulmonary vein triggers contribute to recurrence after atrial fibrillation (AF) ablation, their precise mechanisms remain unproven. Our study assessed the impact of PVI gaps on rhythm outcomes using a human AF digital twin. We included 50 patients (76.0% with persistent AF) who underwent catheter ablation with a realistic AF digital twin by integrating computed tomography and electroanatomical mapping. We evaluated the final rhythm status, including AF and atrial tachycardia (AT), across 600 AF episodes, considering factors including PVI level, PVI gap number, and pacing locations. Our findings revealed that antral PVI had a significantly lower ratio of AF at the final rhythm (28% vs. 56%, p = 0.002) than ostial PVI. Increasing PVI gap numbers correlated with an increased ratio of AF at the final rhythm (p

Abstract Optical coherence tomography angiography (OCTA) provides unrivaled capability for depth-resolved visualization of retinal vasculature at the microcapillary level resolution. For OCTA image construction, repeated OCT scans from one location are required to identify blood vessels with active blood flow. The requirement for multi-scan-volumetric OCT can reduce OCTA imaging speed, which will induce eye movements and limit the image field-of-view. In principle, the blood flow should also affect the reflectance brightness profile along the vessel direction in a single-scan-volumetric OCT. Here we report a spatial vascular connectivity network (SVC-Net) for deep learning OCTA construction from single-scan-volumetric OCT. We quantitatively determine the optimal number of neighboring B-scans as image input, we compare the effects of neighboring B-scans to single B-scan input models, and we explore different loss functions for optimization of SVC-Net. This approach can improve the clinical implementation of OCTA by improving transverse image resolution or increasing the field-of-view.

BackgroundChronic rhinosinusitis (CRS) is an inflammatory disease affecting more than 10% of the global adult population. It is classified into Th1, Th2, and Th17 endotypes and eosinophilic and non-eosinophilic types. Th2-based inflammation and eosinophilic CRS (ECRS) are associated with tissue remodeling and fibrinolytic system impairment.ObjectiveTo elucidate the role of eosinophils in inducing fibrin deposition in CRS nasal polyp tissues and explore potential regulatory mechanisms.MethodsWe analyzed the expression of genes related to the serpin family and fibrinolytic system using Gene Expression Omnibus and Next-generation sequencing data. Differentially expression genes (DEGs) analysis was used to compare control and nasal polyp tissues, followed by KEGG and Gene ontology (GO) analysis. We measured the expression and correlation of plasminogen activator-1 (PAI-1), tissue plasminogen activator (t-PA), urokinase plasminogen activator (u-PA), and urokinase plasminogen activator surface receptor (u-PAR) in CRS tissues, and evaluated the effect of eosinophils on the fibrinolytic system using a cytokine array and co-culture.ResultsNasal polyp tissues showed upregulated PAI-1, u-PA, and u-PAR expression and downregulated t-PA expression. Fibrinolytic system-related genes positively correlated with Th2 cytokines, except for t-PA. Eosinophil-derived Chitinase-3-like protein 1 (CHI3L1) increased PAI-1 expression and decreased t-PA levels in fibroblasts and epithelial cells. The inhibition of CHI3L1 suppresses these alterations.ConclusionCHI3L1 contributes to fibrin deposition by impairing the fibrinolytic system during nasal polyp formation. The regulation of CHI3L1 expression may inhibit fibrin deposition and edema in ECRS, presenting a potential treatment for this condition.

Background A study was designed to investigate whether the coronary artery disease polygenic risk score (CAD‐PRS) may guide lipid‐lowering treatment initiation as well as deferral in primary prevention beyond established clinical risk scores. Methods and Results Participants were 311 799 individuals from the UK Biobank free of atherosclerotic cardiovascular disease, diabetes, chronic kidney disease, and lipid‐lowering treatment at baseline. Participants were categorized as statin indicated, statin indication unclear, or statin not indicated as defined by the European and US guidelines on statin use. For a median of 11.9 (11.2–12.6) years, 8196 major coronary events developed. CAD‐PRS added to European‐Systematic Coronary Risk Evaluation 2 (European‐SCORE2) and US‐Pooled Cohort Equation (US‐PCE) identified 18% and 12% of statin‐indication‐unclear individuals whose risk of major coronary events were the same as or higher than the average risk of statin‐indicated individuals and 16% and 12% of statin‐indicated individuals whose major coronary event risks were the same as or lower than the average risk of statin‐indication‐unclear individuals. For major coronary and atherosclerotic cardiovascular disease events, CAD‐PRS improved C‐statistics greater among statin‐indicated or statin‐indication‐unclear than statin‐not‐indicated individuals. For atherosclerotic cardiovascular disease events, CAD‐PRS added to the European evaluation and US equation resulted in a net reclassification improvement of 13.6% (95% CI, 11.8–15.5) and 14.7% (95% CI, 13.1–16.3) among statin‐indicated, 10.8% (95% CI, 9.6–12.0) and 15.3% (95% CI, 13.2–17.5) among statin‐indication‐unclear, and 0.9% (95% CI, 0.6–1.3) and 3.6% (95% CI, 3.0–4.2) among statin‐not‐indicated individuals. Conclusions CAD‐PRS may guide statin initiation as well as deferral among statin‐indication‐unclear or statin‐indicated individuals as defined by the European and US guidelines. CAD‐PRS had little clinical utility among statin‐not‐indicated individuals.

Abstract The structural performance of derailment containment provision (DCP) was investigated using a grid steel frame. The DCP which was installed within the gauge of a track was capable of resisting the impact loading in the case of derailed wheels. It was also possible to control the excessive lateral movement of the derailed train. In this study, the structural performance of DCP with a post-installed anchor to a railway concrete sleeper was evaluated. For this purpose, a total of nine specimens were manufactured and static tests were conducted to investigate the structural performance. Furthermore, the shear resistance of the connecting anchor was also evaluated using grid steel frame specimens. The initial test indicated that the developed DCP for railway using grid steel frames had sufficient load-carrying capacity and performance equivalent to about 150% of the design load. The developed DCP also demonstrated sufficient load-carrying capacity up to about 140% of the designed load in combination tests that simulated conceivable boundary conditions. As analytical results, the overall DCP behavior for the specimen railway that utilized grid steel frames was appropriately tracked, and detailed information was presented.

Abstract In this paper, a new approach is developed to numerically evaluate the structural performance of deteriorated prestressed concrete beams using the finite element analysis application RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology). A prestressing steel element was modified to represent the interaction between deteriorated concrete and prestressing steel. Considering the corrosion effects—as shown by the reduction of the prestressing steel section and loss of bond—a nonlinear material model was proposed for deteriorated prestressed concrete behavior. The modified damage index is intended to provide a numerical method for quantifying the structural performance of deteriorated prestressed concrete beams. The analytical procedure developed for the performance evaluation of deteriorated beams was validated by comparison with the credible test results, thereby enabling a more reliable and rational prestressed concrete beams design process.

This study investigates the influence of ferrite shape modifications on the performance and noise characteristics of an induction cooktop. The goal is to optimize the air gap dimensions between ferrites and cookware, enhancing efficiency while managing noise levels. Using finite element method (FEM) simulations, we analyze the spatial distribution of magnetic forces and their harmonics. Eight ferrite shape models were examined, focusing on both outer and inner air gaps. Model #8 (reduced outer air gap) and Model #9 (reduced inner air gap) were experimentally validated. Noise measurements indicated that Model #8 reduced 120 Hz harmonic noise components, while Model #9 increased them due to enhanced excitation forces. Current measurements confirmed that Model #9 achieved higher efficiency, with RMS current reduced to 94.54% of the base model. The study reveals a trade-off between performance and noise: inner air gap reduction significantly boosts efficiency but raises noise levels, whereas outer air gap reduction offers balanced improvements. These findings provide insights for optimizing induction cooktop designs, aiming for quieter operation without compromising efficiency.

BackgroundAlthough left ventricular (LV) diastolic dysfunction is more related to functional capacity after acute myocardial infarction (AMI), the determinants of LV diastolic functional change after reperfused AMI remain unknown. This study aimed to investigate the effects of microvascular obstruction (MVO) on mid-term changes in LV diastolic function after reperfused AMI.MethodsIn a cohort of 72 AMI patients who underwent successful revascularization, echocardiography and cardiovascular magnetic resonance imaging were repeated at 9-month intervals. The late gadolinium enhancement (LGE) amount, segmental extracellular volume fraction, global LV, and left atrial (LA) phasic functions, along with mitral inflow and tissue Doppler measurements, were repeated.ResultsAmong the included patients, 31 (43%) patients had MVO. During the 9-month interval, LV ejection fraction (EF) and LV global longitudinal strain (GLS) were significantly improved in accordance with a decrease in LGE amount (from 18.2 to 10.3 g, p

Background Although successful atrial fibrillation (AF) ablation can maintain sinus rhythm and reduce the left atrial (LA) dimension, blunted LA reverse remodeling can be observed in patients with atrial myopathy. We explored the potential mechanisms and long‐term outcomes in patients with blunted LA reverse remodeling after successful AF catheter ablation. Methods and Results We included 1685 patients who underwent baseline and 1‐year follow‐up echocardiograms, had a baseline LA dimension ≥40 mm, and did not have a recurrence of AF within a year. The patients were divided into tertile groups according to the delta value of the change in LA dimension on the preprocedure and 1‐year postprocedure echocardiography. After propensity score matching for age, sex, AF type, and LA dimension, 1272 patients were finally included in the analyses (424 in each group; the least/blunted, moderate, and the most reverse remodeling group). The patients in the T1 group (blunted LA reverse remodeling) were independently associated with higher left ventricular mass index (odds ratio [OR], 1.014 [95% CI, 1.005–1.022], P=0.001), change in ΔH2FPEF score (heavy, hypertensive, atrial fibrillation, pulmonary hypertension, elder, filling pressure) score (OR, 1.445 [95% CI, 1.121–1.861], P=0.004), ventricular epicardial adipose tissue volume (OR, 1.010 [95% CI, 1.003–1.017], P=0.003), thinner LA wall thickness (OR, 0.461 [95% CI, 0.271–0.785], P=0.004), lower LA voltage (OR, 0.670 [95% CI, 0.499–0.899], P=0.008), and showed higher long‐term AF recurrence (log‐rank P

Objectives The demand for polylactic acid (PLA) is increasing as an alternative to conventional petroleum-based plastics due to its eco-friendly characteristics. PLA can be processed through anaerobic digestion (AD) along with other organic wastes to promote efficient and controlled biodegradation. This study aimed to evaluate the feasibility of biogas production through AD of PLA and to enhance efficiency through the addition of conductive materials. Methods Two sets of biochemical methane potential (BMP) tests were conducted. The first BMP test involved substrate/inoculum ratios (SIRs) of 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6 (g COD PLA/g COD seed sludge). Conductive materials powdered activated carbon (PAC), carbon nanotube (CNT), and Magnetite were individually added to reactors at a concentration of 3 g/L in the second test. Results and Discussion The study revealed an increasing trend in methane production and methane yield with higher levels of PLA input. However, a decline in methane yield was observed when PLA was injected at levels surpassing 35g COD/L. This phenomenon can be attributed to a prolonged Lag phase, indicating a longer adaptation period for microorganisms, consequently resulting in a reduction of the conversion rate from 1g COD substrate to methane. The introduction of conductive material led to elevated cumulative methane production and methane yield in comparison to the control group. Notably, Magnetite exhibited the highest increase rate among the tested materials. Additionally, the addition of PAC demonstrated favorable results in terms of methane production rate at 99.4mL/L/Day and a Lag phase of 5.7 days. Conclusion Experiments were conducted to evaluate the effects of PLA biogas production and the injection of PAC, CNT, and Magnetite at various substrate/inoculum ratios. When PLA was used as a substrate for anaerobic digestion, its feasibility was confirmed. However, it exhibited lower efficiency compared to other substrates. Therefore, the addition of a conductive material was found to increase the biogas production efficiency.

Abstract Background It has become important to identify and manage risk factors for subclinical atrial fibrillation (AF) with an increase in its detection rate. Thus, this research aimed to investigate whether alcohol consumption contributes to the development of subclinical AF. Methods This prospective study enrolled 467 patients without AF from a multicenter pacemaker registry. The incidence of subclinical AF (episodes of atrial rate > 220 beats per minute without symptoms) was compared between alcohol-drinking and non-drinking groups. Results During followup (median 18 months), the incidence and risk of long-duration atrial high-rate episodes (AHRE) ≥ 24 h were increased in the alcohol group compared to the non-alcohol group [5.47 vs. 2.10 per 100 person-years, adjusted hazard ratio (HR), 2.83; 95% confidence interval (CI), 1.14–7.04; P = 0.03]. After propensity score matching, the incidence and risk of long-duration AHRE were higher in the alcohol group (6.97 vs. 1.27 per 100 person-years, adjusted HR, 7.84; 95% CI, 1.21–50.93; P = 0.03). The mean burden of long-duration subclinical AF was higher in the alcohol group than in the non-alcohol group (0.18 vs. 1.61% during follow-up, P = 0.08). Conclusion Alcohol consumption was associated with an increased risk of subclinical AF. Long-duration AHRE incidence and AHRE burden were higher in alcohol drinkers than in non-drinkers.

Abstract Aortic surgery is one of the most challenging types of surgeries, which is possibly related to cognitive sequelae. We aimed to investigate the changes in resting-state functional connectivity (rsFC) associated with intraoperative circulatory arrest (CA) in aortic surgery, exploring the relationship between the altered connectivity and postoperative cognitive functions. Thirty-eight patients participated in this study (14 with CA, 24 without). Functional magnetic resonance imaging was scanned on the fifth day after surgery or after the resolution of delirium if it was developed. We assessed the differences in the development of postoperative cognitive changes and rsFC between patients with and without CA. The occurrence of postoperative delirium and postoperative cognitive dysfunction was not significantly different between the patients with and without the application of CA. However, patients with CA showed increased in posterior cingulate cortex-based connectivity with the right superior temporal gyrus, right precuneus, and right hippocampus, and medial prefrontal cortex-based connectivity with the dorsolateral prefrontal cortex. The application of moderate hypothermic CA with unilateral antegrade cerebral perfusion is unlikely to affect aspects of postoperative cognitive changes, whereas it may lead to increased rsFC of the default mode network at a subclinical level following acute brain insults.

Background: Polypharmacy is commonly observed in atrial fibrillation (AF) and is associated with poorer clinical outcomes. Our study aimed to elucidate the polypharmacy prevalence, its associated risk factors, and its relationship with adverse clinical outcomes using a ‘real-world’ database. Methods: This study included 451,368 subjects without prior history of AF (median age, 54 [interquartile range, 48.0–63.0] years; 207,748 [46.0%] female) from the Korea National Health Insurance Service-Health Screening (NHIS-HealS) database between 2002 and 2013. All concomitant medications prescribed were collected, and the intake of five or more concomitant drugs was defined as polypharmacy. During the follow-up, all-cause death, major bleeding events, transient ischemic attack (TIA) or ischemic stroke, and admission due to worsened heart failure were recorded. Results: Based on up to 7.7 (6.8–8.3) years of follow-up and 768,306 person-years, there were 12,241 cases of new-onset AF identified. Among patients with new-onset AF (40.0% females, median age 63.0 [54.0–70.0] years), the polypharmacy prevalence was 30.9% (3784). For newly diagnosed AF, factors, such as advanced age (with each increase of 10 years, odds ratios (OR) 1.32, 95% confidence interval (CI) 1.26–1.40), hypertension (OR 4.00, 95% CI 3.62–4.43), diabetes mellitus (OR 3.25, 95% CI 2.86–3.70), chronic obstructive pulmonary disease (COPD) (OR 3.00, 95% CI 2.51–3.57), TIA/ischemic stroke (OR 2.36, 95% CI 2.03–2.73), dementia history (OR 2.30, 95% CI 1.06–4.98), end-stage renal disease (ESRD) or chronic kidney disease (CKD) (OR 1.97, 95% CI 1.38–2.82), and heart failure (OR 1.95, 95% CI 1.69–2.26), were found to be independently correlated with the incidence of polypharmacy. Polypharmacy significantly increased the incidence and risk of major bleeding (adjusted hazard ratio (aHR) 1.26, 95% CI 1.12–1.41). The study observed a statistically significant increase in the incidence of all-cause mortality, however, the risk for all-cause mortality elevated but did not show significance (aHR 1.11, 95% CI 0.99–1.24). The risk of stroke and admission for heart failure did not change with polypharmacy. Conclusions: In our investigation using data from a nationwide database, polypharmacy was widespread in new-onset AF population and was related to major bleeding events. However, polypharmacy does not serve as an independent risk factor for adverse outcomes, with exception of major bleeding event. For AF patients, ensuring tailored medication for comorbidities as well as reducing polypharmacy are essential considerations.

Abstract Lead‐acid batteries (LABs) are widely used as a power source in many applications due to their affordability, safety, and recyclability. However, as the demand for better electrochemical energy storage increases in various fields, there is a growing need for more advanced battery technologies. To meet this need, the application of LABs in hybrid electric vehicles and renewable energy storage has been explored, and the development of lead–carbon batteries (LCBs) has garnered significant attention as a promising solution. LCBs incorporate carbon materials in the negative electrode, successfully addressing the negative irreversible sulfation issue that plagues traditional LABs. Composite material additives and Pb–C composite electrodes have also gained popularity as effective ways to enhance negative electrode performance. This review article focuses on the role of carbon additives in the negative electrode of LCBs and discusses potential future additives that may be incorporated into the development of LCBs. Overall, this article provides insights into the potential of LCBs to offer more efficient and reliable energy storage.

Abstract Background The prognostic significance of resting heart rate and its therapeutic target in atrial fibrillation (AF) is uncertain. We sought to investigate the relationship between resting heart rate and cardiovascular outcomes in patients with non-paroxysmal AF (non-PAF). Methods In this propensity score-weighted, multi-center prospective cohort study, 3217 patients with non-PAF were analyzed. Patients were categorized according to the baseline resting heart rate and cardiovascular outcomes were accessed for a median follow-up of 30 months. The primary outcome was a composite of cardiovascular death, heart failure hospitalization, and myocardial infarction/critical limb ischemia. Results Freedom from primary outcome was longest among patients with resting heart rate 80–99 beats per minute (bpm) whereas shortest among those with ≤ 59 bpm (weighted log rank, p = 0.008). Compared with heart rate ≥ 100 bpm, resting heart rate 80–99 and 60–79 bpm was associated with reduced risk of primary outcome (weighted hazard ratio [WHR] 0.52, 95% confidence interval [CI] 0.32–0.84, p = 0.008 and WHR 0.58, 95% CI 0.37–0.92, p = 0.021 for heart rate 80–99 and 60–79 bpm, respectively). Using weighted restricted cubic spline curves, there was a U-shaped association between the resting heart rate and primary outcome with reduced risk of primary outcome in heart rate range of 68–99 bpm. This association was maintained regardless of atrioventricular node (AVN) blocker use or persistent/permanent AF (p for interaction 0.767 for AVN blocker use and 0.720 for AF type). Conclusion Resting heart rate was associated with cardiovascular outcomes in patients with non-PAF and those with resting heart rate between 68 and 99 bpm had lower risk of adverse cardiovascular events regardless of AVN blocker use or persistent/permanent AF.

Abstract Simple equations are expressed for tunnel conductivity, tunnel resistance and conductivity of a graphene-filled composite by the number of contacts and interphase part. More specially, the active filler amount is suggested by interphase depth, which changes the contact number. The conductivity of nanocomposite is presented by filler content, filler dimensions, tunneling length and interphase depth. The innovative model is surveyed by the experimented conductivity of real examples. Too, the impacts of numerous issues on the tunnel resistance, tunnel conductivity and conductivity of nanocomposite are discussed to validate the novel equations. The estimates agree with the experimented data and the impacts of several terms on the tunnel resistance, tunnel conductivity and conductivity of system are sensible. Thin and big nanosheets positively affect the nanocomposite’s conductivity, but thick nanosheets improve the tunnel conductivity. High conductivity is found at short tunnels, while the nanocomposite’s conductivity directly depends on the tunneling length. The dissimilar effects of these features on the tunneling properties and conductivity are described.

Abstract Alzheimer disease (AD) is the most prevalent cause of dementia in the elderly. Although impaired cognition and memory are the most prominent features of AD, abnormalities in visual functions often precede them, and are increasingly being used as diagnostic and prognostic markers for the disease. Retina contains the highest concentration of the essential fatty acid docosahexaenoic acid (DHA) in the body, and its deficiency is associated with several retinal diseases including diabetic retinopathy and age related macular degeneration. In this study, we tested the hypothesis that enriching retinal DHA through a novel dietary approach could ameliorate symptoms of retinopathy in 5XFAD mice, a widely employed model of AD. The results show that 5XFAD mice have significantly lower retinal DHA compared to their wild type littermates, and feeding the lysophosphatidylcholine (LPC) form of DHA and eicosapentaenoic acid (EPA) rapidly normalizes the DHA levels, and increases retinal EPA by several-fold. On the other hand, feeding similar amounts of DHA and EPA in the form of triacylglycerol had only modest effects on retinal DHA and EPA. Electroretinography measurements after 2 months of feeding the experimental diets showed a significant improvement in a-wave and b-wave functions by the LPC-diet, whereas the TAG-diet had only a modest benefit. Retinal amyloid β levels were decreased by about 50% by the LPC-DHA/EPA diet, and by about 17% with the TAG-DHA/EPA diet. These results show that enriching retinal DHA and EPA through dietary LPC could potentially improve visual abnormalities associated with AD.

Abstract Background Traditional right ventricular apical pacing can cause electrical–mechanical dyssynchrony. Therefore, physiological conduction system pacing was considered and became the reason for developing His bundle pacing (HBP). Recently, left bundle branch area pacing (LBBAP) has been implemented, which overcomes the shortcomings of HBP. Most initial large LBBAP studies reported that LBBAP was achieved through a lumenless pacing lead (LLL) with a fixed helix design; however, it is unavailable in Korea. LBBAP delivery sheaths using a conventional standard stylet-driven pacing lead (SDL) with an extendable helix design are currently available in Korea. In this review, we describe the methods and procedural skills required to perform the LBBAP using conventional SDL. Main body LBBAP has emerged as a new physiological CSP modality and has shown a stable and lower capture threshold and achieved a similarly paced QRS duration compared to HBP. It has also demonstrated stable early outcomes for feasibility and safety with a high success rate. Furthermore, the application of LBBAP has recently been extended to a resynchronization strategy. The LBBAP with SDL requires different handling and lead preparation owing to differences in lead and helix designs. Reported procedure-related acute complications of LBBAP include septal perforation during the procedure, pneumothorax, pocket infection, pocket hematoma, and lead dislodgements occurring during follow-up. Conclusion LBBAP with conventional SDL has similar implant success rates, procedural safety, and pacing characteristics as LBBAP with LLL. However, LBBAP with SDL requires different handling and lead preparation from that of LLL owing to the differences in the lead and helix designs.

We investigated the geochemistry of gas, pore fluid, and methane-derived authigenic carbonate (MDAC) from four sites in the southern Ulleung Basin, South Korea. In contrast to Sites 16GH-P1 and 16GH-P5, Sites 16GH-P3, and 16GH-P4 are characterized by acoustic chimney structures associated with gas flux. The composition of gas and isotopic signatures of methane (CH4) (C1/C2+ > 300, δ13CCH4 < -60‰, δDCH4 ≤ -190‰) indicate microbial source CH4 at all sites. The upward migration of CH4 can affect the chemical and isotopic properties of pore fluid and gas-related byproducts (e.g., gas hydrate (GH) and MDAC) within the shallow sediments including the current sulfate-methane transition (SMT) (< 5 meters below seafloor). Although no GH was found, elevated Cl- concentrations (maximum = 609 mM) with low δD and δ18O values in Site 16GH-P4 pore fluids delineate the influence of massive GH formation in deeper sediment. In contrast, relatively constant Cl-, δD, and δ18O values in fluids from Sites 16GH-P1, 16GH-P3, and 16GH-P5 indicate a predominant origin from seawater. Pore fluids also exhibit higher concentrations of H4SiO4, B, Mg2+, and K+, along with increasing alkalinity compared to seawater. These observations suggest that marine silicate weathering alters fluid chemistry within the sediment, affecting element and carbon cycles. High alkalinity (up to 60 mM) and Mg2+/Ca2+ ratios (> 6) alongside decreasing Ca2+ and Sr2+ concentrations imply carbonate precipitation. MDACs with diverse morphologies, mainly composed of aragonite and magnesian calcite, and characterized by low carbon isotopic values (δ13CMDAC < -31.3‰), were found at Sites 16GH-P3 and 16GH-P4. Interestingly, δ13CMDAC values at Site 16GH-P3 are clearly differentiated above and below the current SMT. High δ13CMDAC values above the SMT (> -34.3‰) suggest the combined influence of seawater and CH4 migrating upward on MDAC precipitation, whereas low δ13CMDAC values below it (< -41.6‰) indicate a predominant impact of CH4 on MDAC formation. Additionally, the vertical variation of δ18OMDAC values at Site 16GH-P4, compared to the theoretical values, reflects an association with GH dissociation and formation. Our findings improve the understanding of fluid, gas, and MDAC geochemistry in continental margin cold seeps, providing insights into global carbon and element cycles.

Abstract Hybridizing single‐walled carbon nanotubes (SWCNTs) with π‐conjugated organic small molecules (π‐OSMs) offers a promising approach for producing high‐performance thermoelectric (TE) materials through the facile optimization of the molecular geometry and energy levels of π‐OSMs. Designing a twisted molecular structure for the π‐OSM with the highest occupied molecular orbital energy level comparable to the valence band of SWCNTs enables effective energy filtering between the two materials. The SWCNTs/twisted π‐OSM hybrid exhibits a high Seebeck coefficient of 110.4 ± 2.6 µV K−1, leading to a significantly improved power factor of 2,136 µW m−1 K−2, which is 2.6 times higher than that of SWCNTs. Moreover, a maximum figure of merit over 0.13 at room temperature is achieved via the efficient TE transport of the SWCNTs/twisted π‐OSM hybrid. The study highlights the promising potential of optimizing molecular engineering of π‐OSMs for hybridization with SWCNTs to create next‐generation, efficient TE materials.

Abstract Obesity has been linked to atrial fibrillation (AF) burden and severity, and epidemiological studies suggest that AF is more prevalent in whites than Asian. We aimed to investigate whether obesity mediates associations with AF in Europe and Asia using patient-level data comparisons of two cohort studies. Using Korean National Health Insurance Service’s Health Screening (NHIS-HealS) and U.K. Biobank data, we included 401,206 Korean and 477,926 British aged 40–70 years without previous AF who received check-ups. The incidence and risk of AF were evaluated regarding different body mass index (BMI) values. The obese proportion (BMI ≥ 30.0 kg/m2, 2.8% vs. 24.3%, P

Abstract This paper presents a nonlinear analysis procedure for evaluating the seismic performance of reinforced concrete (RC) bridge columns with lap splices using a novel plastic hinge element considering shear deformation. To accurately assess the inelastic behavior of RC bridge columns, reliable three-dimensional (3D) constitutive models are required. However, developing a 3D nonlinear material model is difficult and computationally intensive. In this study, to address these issues, a new plastic hinge element considering shear deformation for RC bridge columns is developed. The new plastic hinge element is based on the Timoshenko beam theory and utilizes two-noded zero length element with six degrees of freedom. The finite element model was implemented in a computer program named Reinforced Concrete Analysis in Higher Evaluation System Technology (RCAHEST) developed by the authors. The developed plastic hinge element for seismic performance assessment of RC bridge columns with lap splices was validated through comparison of the numerical and experimental results.

In estuaries, freshwater discharge functions as a regulator of physicochemical and biological properties. We assessed the seasonal variability of the phytoplankton community in response to hydrological features and nutrient dynamics in two contrasting estuaries in the presence and absence of a dam on the western coast of Korea. Diversity and evenness were also evaluated through chemotaxonomic analysis. Seasonal and inter-estuarine comparisons revealed the overall predominance of diatoms in all seasons and the differentiated composition of small phytoplankton populations in each estuary, which was mainly characterized by significant contribution of cryptophytes in the continuously flushed estuary in contrast to the seasonal occurrence of pelagophytes and cyanobacteria in the intermittently perturbed estuary. Our one-way analysis of similarity and similarity percentage analysis showed obvious inter-estuarine discrepancy of the phytoplankton community in winter in relation to the high dissolved inorganic nitrogen concentration in the natural estuary, implying that the impact of freshwater inflow on the phenological response of phytoplankton can be maximized during active seawater intrusion in dry seasons in the prevalence of freshwater and seawater in the estuary. The contribution swing of diatoms and cryptophytes during the study period reflects the seasonal variability in nutrient dynamics, including absolute concentrations and stoichiometric ratios, which is especially associated with P-limitation on the western coast of Korea. The occurrence of cyanobacteria with a summer peak of phytoplankton biomass in the dammed estuary during the study period indicates the role of an estuarine dam as a conduit transporting phytoplankton and dissolved inorganic nutrients. These findings further suggest that the phytoplankton community structure, differentiated by the presence and absence of dams, influences bottom-up regulation and thus the food web structure in estuaries.

BackgroundThe comparative efficacy, saftey, and heart rate variability (HRV) parameters after pulmonary vein isolation using cryoballoon (Cryo-PVI), high-power short-duration (HPSD-PVI), and conventional radiofrequency ablation (conventional-PVI) for atrial fibrillation (AF) is unclear.Materials and methodsIn this propensity score-weighted, retrospective analysis of a single-center cohort, we analyzed 3,395 patients (26.2% female, 74.5% paroxysmal AF) who underwent AF catheter ablation without an empirical left atrial ablation. Procedural factors, recurrence rates, complication rates, and the post-procedural HRV parameters were compared across the Cryo-PVI (n = 625), HPSD-PVI (n = 748), and conventional-PVI (n = 2,022) groups.ResultsDespite the shortest procedural time in the Cryo-PVI group (74 min for Cryo-PVI vs. 104 min for HPSD-PVI vs. 153 min for conventional-PVI, p

Background Cerebral blood flow (CBF) is impaired in the early phase after return of spontaneous circulation. Sodium nitroprusside (SNP) administration via intracranial subdural catheters improves cerebral cortical microcirculation. We determined whether the SNP treatment improves CBF in the subcortical tissue and evaluated the effects of this treatment on cerebral lactate. Methods and Results Sixty minutes after return of spontaneous circulation following 14 minutes of untreated cardiac arrest, 14 minipigs randomly received 4 mg SNP or saline via intracranial subdural catheters. CBF was measured in regions of interest within the cerebrum and thalamus using dynamic susceptibility contrast‐magnetic resonance imaging. After return of spontaneous circulation, CBF was expressed as a percentage of the baseline value. In the saline group, the %CBF in the regions of interest within the cerebrum remained at approximately 50% until 3.5 hours after return of spontaneous circulation, whereas %CBF in the thalamic regions of interest recovered to approximately 73% at this time point. The percentages of the baseline values in the cortical gray matter and subcortical white matter were higher in the SNP group (group effect P=0.026 and 0.025, respectively) but not in the thalamus. The cerebral lactate/creatine ratio measured using magnetic resonance spectroscopy increased over time in the saline group but not in the SNP group (group–time interaction P=0.035). The thalamic lactate/creatine ratio was similar in the 2 groups. Conclusions SNP administered via intracranial subdural catheters improved CBF not only in the cortical gray matter but also in the subcortical white matter. The CBF improvement by SNP was accompanied by a decrease in cerebral lactate.

The composition of dissolved organic matter (DOM) in the coastal waters off Jeju Island, Korea, originates from a complex mixture of organic sources. This study examined the dynamics and sources of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in the coastal waters off Jeju Island. Seasonal variation in the DOC and DON concentrations was observed, with significantly higher levels during summer (DOC: 82 ± 15 µM and DON: 6.8 ± 2.0 µM) than during the other seasons. In 2017, the Kuroshio Intermediate Water had a greater impact on the coastal waters off Jeju Island during winter (79%) and spring (69%) than during the other seasons, while the Changjiang Diluted Water (CDW) (12%) and the Kuroshio Surface Water (47%) had a stronger impact during summer and the Yellow Sea Cold Water (10%) had a stronger impact during autumn. Although water mass analysis provides valuable insights, certain aspects of the DOM distribution in coastal seawater remain unexplained. During summer, while the mixing of the CDW influenced the concentrations of DOC and DON, a distinct pulse in these concentrations was observed within a specific salinity range, suggesting microbial activity as a source. The relationship between dissolved inorganic nitrogen (DIN) and salinity also exhibited the opposite trend to that between DON and salinity, indicating the conversion of DON into DIN through microbial activity. These findings suggest that microbial activity plays a key role in the observed DOM pulse, transforming particulate organic matter into DOM and then converting it into DIN during the long transportation from Changjiang River to Jeju Island. This organic matter cycle could thus serve as a source of DIN in oligotrophic regions. However, further research on the sources and distribution of organic matter using biogeochemical parameters is required to gain a better understanding of the intricate processes involved.

Backdoor attacks, which induce a trained model to behave as intended by an adversary for specific inputs, have recently emerged as a serious security threat in deep learning-based classification models. In particular, because a backdoor attack is executed solely by incorporating a small quantity of malicious data into a dataset, it poses a significant threat to authentication models, such as facial cognition systems. Depending on whether the label of the poisoned samples has been changed, backdoor attacks on deep learning-based face recognition methods are categorized into one of the two architectures: 1) corrupted label attack; and 2) clean label attack. Clean label attack methods have been actively studied because they can be performed without access to training datasets or training processes. However, the performance of previous clean label attack methods is limited in their application to deep learning-based face recognition methods because they only consider digital triggers with instance-specific characteristics. In this study, we propose a novel clean label backdoor attack, that solves the limitations of the scalability of previous clean label attack methods for deep learning-based face recognition models. To generate poisoned samples that are instance agnostic while including physical triggers, the proposed method applies three core techniques: 1) accessory injection; 2) optimization-based feature transfer; and 3) $N$ :1 mapping for generalization. From the experimental results under various conditions, we demonstrate that the proposed attack method is effective for deep learning-based face recognition models in terms of the attack success rate on unseen samples. We also show that the proposed method not only outperforms the recent clean label attack methods, but also maintains a comparable level of classification accuracy when applied to benign data.

Abstract Menopausal hormone therapy (MHT) in women can reduce troublesome menopause symptoms and prevent cognitive decline. This cross-sectional study investigated the MHT-related effect on brain morphology and its association with sex hormones in menopausal women by using an optimized diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL)-based voxel-based morphometry (VBM) method. Twenty-one menopausal women without MHT (noMHT) and 20 menopausal women with MHT were included in this study. Magnetic resonance imaging data were processed using SPM 12 with DARTEL-based VBM whole brain analysis approach. A 2-sample t-test and analysis of covariance (ANCOVA) adjusting for age and total intracranial volume were used to compare GM volume between noMHT and MHT women. The association between MHT (treatment period, hormones levels) and brain volume variations were analyzed by Spearman correlation. MHT women showed significantly larger volumes of the superior/middle/inferior frontal gyri, hypothalamus, inferior temporal gyrus, parahippocampal gyrus, hippocampus, cerebellar cortex, postcentral gyrus, precuneus, angular gyrus, supplementary motor area, superior occipital gyrus, and precentral gyrus compared to the noMHT women. The volumes of the angular gyrus and hypothalamus in MHT women positively correlated with treatment period. On the other hand, the hypothalamic volume negatively correlated with FSH and LH levels, and the volumes of the inferior frontal gyrus, and angular gyrus negatively correlated with progesterone levels, respectively. MHT-treated women showed larger GM volume than noMHT women. The anatomical structures that showed greater volume in association with MHT included the deep brain areas, frontal, temporal, parietal, and occipital gyri.

Abstract Hemodynamics in aortic dissection (AD) is closely associated with the risk of aortic aneurysm, rupture, and malperfusion. Altered blood flow in patients with AD can lead to severe complications such as visceral malperfusion. In this study, we aimed to investigate the effect of cannulation flow on hemodynamics in AD using a fluid–structure interaction simulation. We developed a specific-idealized AD model that included an intimal tear in the descending thoracic aorta, a re-entry tear in the left iliac artery, and nine branches. Two different cannulation methods were tested: (1) axillary cannulation (AC) only through the brachiocephalic trunk and (2) combined axillary and femoral cannulation (AFC) through the brachiocephalic trunk and the right common iliac artery. AC was found to result in the development of a pressure difference between the true lumen and false lumen, owing to the difference in the flow rate through each lumen. This pressure difference collapsed the true lumen, disturbing blood flow to the celiac and superior mesenteric arteries. However, in AFC, the pressure levels between the two lumens were similar, and no collapse occurred. Moreover, the visceral flow was higher than that in AC. Lastly, the stiffness of the intimal flap affected the true lumen's collapse.

Low back pain (LBP) is a common condition that affects people of all ages and income levels worldwide. The etiology of LBP may be mechanical, neuropathic, systemic, referred visceral, or secondary to other causes. Despite numerous studies, the diagnosis and management of LBP remain challenging due to the complex biomechanics of the spine and confounding factors, such as trivial degenerative imaging findings irrelevant to symptoms and psychological and emotional factors. However, it is imperative to identify the crucial signs (“red flags”) indicating a serious underlying condition. While many recent guidelines emphasize non-pharmacologic management approaches, such as education, reassurance, and physical and psychological care, as the first option, LBP patients in many countries, including South Korea, are prescribed medications. Multidisciplinary rehabilitation combined with prudent use of medications is required in patients unresponsive to first-line therapy. The development of practical guidelines apposite for South Korea is needed with multidisciplinary discussion.

Abstract A rational regulation of the solar water splitting reaction pathway by adjusting the surface composition and phase structure of catalysts is a substantial approach to ameliorate the sluggish reaction kinetics and improve the energy conversion efficiency. In this study, we demonstrate a nanocrystalline iron pyrophosphate (Fe4(P2O7)3, FePy)-regulated hybrid overlayer with amorphous iron phosphate (FePO4, FePi) on the surface of metal oxide nanostructure with boosted photoelectrochemical (PEC) water oxidation. By manipulating the facile electrochemical surface treatment followed by the phosphating process, nanocrystalline FePy is localized in the FePi amorphous overlayer to form a heterogeneous hybrid structure. The FePy-regulated hybrid overlayer (FePy@FePi) results in significantly enhanced PEC performance with long-term durability. Compared with the homogeneous FePi amorphous overlayer, FePy@FePi can improve the charge transfer efficiency more significantly, from 60% of FePi to 79% of FePy@FePi. Our density-functional theory calculations reveal that the coexistence of FePi and FePy phases on the surface of metal oxide results in much better oxygen evolution reaction kinetics, where the FePi was found to have a typical down-hill reaction for the conversion from OH* to O2, while FePy has a low free energy for the formation of OH*. Graphical abstract

Objectives: To compare unilateral versus bilateral antegrade cerebral perfusion (ACP) techniques on cerebral protection during acute type A aortic dissection repair. Methods: Using an institutional database, we retrospectively reviewed patients who underwent acute type A aortic dissection repair with selective ACP techniques from October 2008 to December 2019. Primary end point was the detection of neurologic dysfunctions. The secondary end point was mortality. For baseline adjustment, the propensity score matching method was used. Multivariable logistic regression analysis was performed to determine the predictor of neurologic events. Results: Among 522 patients (aged 62.0 ± 14.9 years; 45.7% women), unilateral and bilateral ACP techniques were used in 357 (64.7%) and 165 (35.3%) patients, respectively. Transient (19.6% vs 21.2%; P = .65) and permanent (7.0% vs 10.3%; P = .70) neurologic dysfunction rates were not significantly different in patients with unilateral versus bilateral ACP, respectively. Observed mortality rate was higher in the patients with bilateral ACP (hazard ratio, 2.05; 95% CI, 1.33-3.14; P = .001). Propensity-score matching yielded 94 pairs of patients. In matched analysis, bilateral ACP did not significantly lower the risks for transient (odds ratio, 0.87; 95% CI, 0.42-1.81; P = .71) and permanent (odds ratio, 1.42; 95% CI, 0.55-3.85; P = .47) neurologic dysfunction or death (hazard ratio, 1.65; 95% CI, 0.87-3.15; P = .13). In the multivariable analysis, the ACP technique was not significantly associated with perioperative neurologic deficit. Conclusions: Despite additional supply, the patients undergoing bilateral ACP during acute type A aortic dissection repair did not have superior outcomes in neurologic and death events compared with the patients undergoing unilateral ACP.

Abstract It has been becoming important to identify modifiable risk factors to prevent dementia. We investigated the association of individual and combined cardiovascular health (CVH) on dementia risk in older adults. From the National Health Insurance Service of Korea-Senior database, 191,013 participants aged ≥ 65 years without prior dementia or cerebrovascular diseases who had check-ups between 2004 and 2012 were assessed. Participants were stratified into three groups according to the number of optimal levels of CVH (low, 0–2; moderate, 3–4; and high CVH status, 5–6) and grouped by levels of individual CVH metrics, the number of optimal CVH metrics, and the CVH score. Over a median follow-up of 6.2 years, 34,872 participants were diagnosed with dementia. Compared with low CVH status, moderate and high CVH status were associated with a decreased risk of dementia (hazard ratio [95% confidence interval], 0.91 [0.89–0.92] for moderate; 0.78 [0.75–0.80] for high CVH status) including Alzheimer’s and vascular dementia. The risk of dementia decreased with an increase in the number of optimal CVH metrics (0.94 [0.93–0.94] per additional optimal metric) and with an increase in the CVH score (0.93 [0.93–0.94] per 1-point increase). After censoring for stroke, the association of CVH metrics with dementia risk was consistently observed. Among individual metrics, physical activity had the strongest association with the risk of dementia. In an older Asian population without prior dementia or cerebrovascular disease, a consistent relationship was observed between the improvement of a composite metric of CVH and the reduced risk of dementia.