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Atrial fibrillation (AF) is the most common sustained tachyarrhythmia and its increasing prevalence has resulted in a growing healthcare burden. A recent landmark randomized trial, the EAST-AFNET 4 (Early Treatment of Atrial Fibrillation for Stroke Prevention Trial), highlighted the importance of early rhythm control in AF, which was previously underemphasized. Rhythm control therapy includes antiarrhythmic drugs, direct-current cardioversion, and catheter ablation. Currently, catheter ablation is indicated for patients with AF who are either refractory or intolerant to antiarrhythmic drugs or who exhibit decreased left ventricular systolic function. Catheter ablation can be categorized according to the energy source used, including radiofrequency ablation (RFA), cryoablation, laser ablation, and the recently emerging pulsed field ablation (PFA). Catheter ablation techniques can also be divided into the point-by-point ablation method, which ablates the pulmonary vein (PV) antrum one point at a time, and the single-shot technique, which uses a spherical catheter to ablate the PV antrum in a single application. PFA is known to be applicable to both point-by-point and single-shot techniques and is expected to be promising owing to its tissue specificity, resulting in less collateral damage than catheter ablation involving thermal energy, such as RFA and cryoablation. In this review, we aimed to outline catheter ablation for rhythm control in AF by reviewing previous studies.

Abstract Background There is limited research on the intra‐individual efficacy of ventricular pacing minimization algorithms developed by Biotronik—the Ventricular Pace Suppression algorithm (VpS) and the Intrinsic Rhythm Support plus algorithm (IRSplus) (BIOTRONIK SE & Co. KG, Berlin, Germany). We performed a randomized pilot trial that evaluated the efficacy of two algorithms in patients with symptomatic sinus node dysfunction (SND) who received a dual‐chamber pacemaker. Methods The trial was conducted in 11 tertiary hospitals in South Korea. The patients were randomized to either the VpS or IRSplus algorithm group after a 3‐month period of fixed atrioventricular (AV) delay. The primary outcome was the ventricular pacing percentage (Vp%) at each follow‐up visit. The secondary outcomes were the occurrence of heart failure (HF) and atrial fibrillation (AF) during the study period. Results Data from 131 patients were analyzed. Initially, their average Vp% over 3 months with a fixed AV interval was 14.1 ± 19.4%. Patients were randomly assigned to VpS and IRSplus groups, with 66 and 65 in each. Algorithms reduced average Vp% to 4.0 ± 11.3% at 9 months and 6.7 ± 14.9% at 15 months. These algorithms were more effective for patients with paced AV delay (PAVD) ≤300 ms compared to those with PAVD >300 ms. Both algorithms were equally effective in reducing Vp%. Clinical AF or HF hospitalization was not observed during the study period. Conclusion The VpS and IRSplus algorithms are effective and safe in minimizing unnecessary ventricular pacing in patients with SND.

BackgroundData on the clinical impact of beta-blockers (BBs) in patients with myocardial infarction (MI) who had non-reduced left ventricular ejection fraction (LVEF) after percutaneous coronary intervention are limited.MethodsFrom 2016 to 2020, we evaluated a cohort of 12,101 myocardial infarction patients with a non-reduced LVEF (≥40%) from the Korean Acute Myocardial Infarction Registry V. Patients were divided into two groups based on their BB (carvedilol, bisoprolol, or nebivolol) treatment at discharge: with beta-blocker treatment (BB, n = 9,468) and without beta-blocker treatment (non-BB, n = 2,633). The primary endpoint after discharge was the occurrence of patient-oriented composite endpoints (POCEs), including all-cause mortality, any MI, or any revascularization at 1-year follow-up.ResultsThe median follow-up period was 353 days (interquartile range, 198–378 days). At 1-year follow-up, no significant differences were observed in the primary endpoint between the BB group and the non-BB group. Before propensity score (PS) matching, the POCE incidence was 3.1% in the BB group vs. 3.4% in the non-BB group [hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.68–1.09, p = 0.225]. After PS matching, the POCE incidence remained similar between the two groups (3.7% vs. 3.4%, HR 1.01, 95% CI 0.76–1.35, p = 0.931). Individual outcomes, including all-cause mortality, myocardial infarction, and revascularization, also showed no significant differences between the two groups. Independent predictors of 1-year POCEs after discharge were age, chronic kidney disease, reduced LVEF, and multivessel disease.ConclusionBB treatment in patients with acute MI and non-reduced LVEF was not associated with a significant reduction in cardiovascular outcomes at 1-year follow-up.

This study explored the correlation between microstructure and mechanical properties in additively manufactured Inconel 718 superalloys with low and high electron beam (EB) currents. The relative densities of the as-built Inconel 718 superalloys with low EB currents ranged from 99.45 to 99.79 %, while the alloys with high EB currents demonstrated relatively high relative densities ranging from 99.82 to 99.96 %. The microstructures of the alloys with low EB currents had columnar grain microstructures with a strong texture parallel to the built direction (BD). The high-angle grain boundary density of the alloys with low EB currents was lower than with high EB currents. In addition, the alloys contained fine γ″ precipitates with an average size of 32 nm. Although the fracture-initiating sites for the alloys consisted of defects, such as micro-cracks and gas-entrapped pores, the alloys with low EB currents demonstrated excellent tensile strength and good uniform elongation due to the single-crystal-like microstructures and fine γ″ precipitates. The γ″ precipitates easily grew in deep and narrow melt pools due to sufficient thermal transfer with increasing penetration depth. However, the growth of γ″ precipitates was limited in the shallow and wide melt pools, and the shallow and wide melt pools resulted in single-crystal-like microstructures and strong textures parallel to the BD. Therefore, the morphology of the melt pool, determined by the EB current, played an important role in the single-crystalline microstructure and growth of the γ” precipitates.

We aimed to fabricate reliable memory devices using HfO2, which is gaining attention as a charge-trapping layer material for next-generation NAND flash memory. To this end, a new atomic layer deposition process using sequential remote plasma (RP) and direct plasma (DP) was designed to create charge-trapping memory devices. Subsequently, the operational characteristics of the devices were analyzed based on the thickness ratio of thin films deposited using the sequential RP and DP processes. As the thickness of the initially RP-deposited thin film increased, the memory window and retention also increased, while the interface defect density and leakage current decreased. When the thickness of the RP-deposited thin film was 7 nm, a maximum memory window of 10.1 V was achieved at an operating voltage of ±10 V, and the interface trap density (Dit) reached a minimum value of 1.0 × 1012 eV−1cm−2. Once the RP-deposited thin film reaches a certain thickness, the ion bombardment effect from DP on the substrate is expected to decrease, improving the Si/SiO2/HfO2 interface and thereby enhancing device endurance and reliability. This study confirmed that the proposed sequential RP and DP deposition processes could resolve issues related to unstable interface layers, improve device performance, and enhance process throughput.

For the precise operation of Unmanned Aerial Vehicles (UAV), Real-Time Kinematic (RTK) techniques of Global Navigation Satellite System (GNSS) have been used as a positioning source. In a typical drone platform with a low-cost multi-frequency receiver, there are several dual-frequency measurements and a small set of single-frequency measurements at one time. In this paper, considering the measurement characteristics, we introduce a novel method that aims to detect a cycle slip of a small set of single-frequency measurements using dual-frequency measurements of other satellites. The performance of the proposed single-frequency cycle slip detection methods is compared with a conventional Doppler-based approach using flight test data of a drone platform.

Background/Aims The clinical benefit of strict blood glucose-lowering therapy for patients with coronary artery disease (CAD) is still debated. We aimed to evaluate the long-term outcomes of patients with diabetes who underwent percutaneous coronary intervention (PCI), according to the mean hemoglobin A1c (HbA1c) level after PCI. Methods We evaluated 675 diabetes patients with CAD treated with PCI. We categorized the study population into three groups based on the mean observed HbA1c levels during the follow-up duration, as follows: aggressive control (AC) group (HbA1c level < 6.5%, n = 148), moderate control (MC) group (HbA1c level ≥ 6.5% and < 7.0%, n = 138), and uncontrolled (UC) group (HbA1c level ≥ 7.0%, n = 389). The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCEs), defined as cardiac death, myocardial infarction, repeat target vessel revascularization, and stroke. Results The mean HbA1c level of the AC group was significantly lower than that of the MC and UC groups (6.04% ± 0.36% vs. 6.74% ± 0.14% vs. 8.39% ± 1.20%, p < 0.001). The incidence of MACCEs was significantly lower in the AC group than in the MC and UC groups (16.0% vs. 24.3% vs. 26.3%, p = 0.010), mostly driven by the incidence of stroke (4.4% vs. 14.0% vs. 11.4%, p = 0.013). Multivariate Cox regression analysis showed that only the AC group was associated with a reduced rate of MACCEs (hazard ratio, 0.499; 95% confidence interval, 0.316 to 0.786; p = 0.004) compared with the UC group. Conclusions Our study showed that intensive glycemic control (HbA1c level < 6.5%) is associated with improved clinical outcomes after PCI in patients with diabetes.

This study aimed to determine the impact of dysglycemia on myocardial injury and cardiac dysfunction in acute myocardial infarctions (AMIs). From 2005 to 2016, a total of 1,593 patients with AMIs who underwent percutaneous coronary intervention were enrolled. The patients were classified into five groups according to the admission glucose level: ≤80, 81 to 140, 141 to 200, 201 to 260, and ≥261 mg/dL. The clinical and echocardiographic parameters and 30-day mortality were analyzed. The peak troponin I and white blood cell levels had a positive linear relationship to the admission glucose level. The left ventricular ejection fraction had an inverted U-shape trend, and the E/E' ratio was U-shaped based on euglycemia. The 30-day mortality also increased as the admission glucose increased, and the cut-off value for predicting the mortality was 202.5 mg/dL. Dysglycemia, especially hyperglycemia, appears to be associated with myocardial injury and could be another adjunctive parameter for predicting mortality in patients with AMIs.

Purulent pericarditis is defined as a localized pericardial infection with gross pus formation in the pericardial space. Although purulent pericarditis is now rare in the antibiotic era, it may be life-threatening. We describe a rare case of purulent pericarditis that originated from a subdiaphragmatic suppurative focus in an immunocompromised host.

BackgroundHemorheologic indices are known to be related to vascular complications in variable clinical settings. However, little is known about the associations between hemorheologic parameters and acute myocardial infarction (AMI) in type 2 diabetes mellitus (T2DM). The purpose of this study was to demonstrate the changes of hemorheologic environment inside of blood using hemorheologic parameters, especially the elongation index (EI) and critical shear stress (CSS) in diabetics with versus without AMI.MethodsA total of 195 patients with T2DM were enrolled. Patients were divided into the study group with AMI (AMI+, n=77) and control group (AMI−, n=118) who had no history of coronary artery disease. Hemorheologic parameters such as EI and CSS were measured and compared between the two groups.ResultsThe EI was lower (30.44%±1.77% in AMI+ and 31.47%±1.48% in AMI−, P

A 73-year-old woman was referred to the pulmonology department for abnormal findings on chest computed tomography. She had undergone a laparoscopic staging operation including a hysterectomy, bilateral salpingo-oophorectomy, bilateral pelvic node and para-aortic node dissection, and concurrent chemo-radiation therapy for endometrial serous carcinoma stage IIIc cancer 15 months earlier. A follow-up chest computed tomography after the chemotherapy showed that the right lower lobe bronchus was obstructed, and it was necessary to differentiate a primary lung malignancy from a metastasis and secretion. A positron emission tomography revealed an intense hypermetabolic nodule in the right lower lobe bronchus and diffuse hypometabolism of the right lower lobe lung. Bronchoscopy revealed a tumor mass obstructing the right lower lobe bronchus, and an endobronchial biopsy confirmed a metastatic serous carcinoma from the endometrium. We described an endobronchial metastasis from an endometrial carcinoma with various diagnostic images and histology. To the best of our knowledge, this is the first report of an endobronchial metastasis from an endometrial carcinoma in Korea.

Coronary artery aneurysm is a rare congenital or vascular inflammation-based anomaly for which the clinical course and optimal timing of treatment remain unclear. Here, we report a case of sudden death caused by a giant coronary artery aneurysm of the left anterior descending artery that presented with chest pain. This case suggests that urgent interventional or surgical repair is needed when a large coronary aneurysm presents with acute ischemic symptoms.

Recently, sinkholes have significantly increased in urban areas as a result of subsurface cavities and ground softening. In this study, a small-loop electromagnetic survey was conducted in a testbed where anomaly zones comprised of cavities, areas of ground softening, and underground facilities were simulated in the ground under road pavement using the CMD Mini Explorer. The equipment was only able to measure the electrical resistivity (ER) at three depths. As, occasionally, the equipment was unable to detect the anomaly zones using the ER measured at those three depths, survey measurements were taken at three heights to collect the ER at seven depths using the superposition method. The result shows that the anomaly zones can be detected qualitatively by visually observing the contour map of the ER. In addition, another method for detecting anomaly zones in the ground statistically using a box plot and the relative standard deviation was employed in this study. Consequently, the position and depth of the cavities, areas of ground softening, and underground facilities in the testbed can also be determined quantitatively.

Wogonin is a natural plant-derived flavonoid isolated from the roots of Scutellaria baicalensis. Varicella-zoster virus (VZV) is an α-herpesvirus, which causes chickenpox and shingles. Antiviral activities of natural plant-derived compounds against VZV have not been fully described. Here, we identify the significant inhibitory activity of wogonin against VZV replication. Transcription levels of the VZV genes such as open reading frame 4, 14, and 63 and infectious progeny virus were reduced with wogonin treatment in VZV-infected primary human fibroblast cells. Consistent to our polymerase chain reaction (PCR) array data, our qRT-PCR and ELISA data suggest wogonin treatment induced type I interferon (IFN)-mediated signaling pathways and activated toll-like receptor (TLR) 9 expression. Interestingly, wogonin specifically suppressed AMP-activated protein kinase (AMPK) activity and a pharmacological inhibition of AMPK by compound C resulted in the significant reduction of viral titers. Altogether, the data here indicate that wogonin has promising and potent anti-VZV activities.

Three strains of the green microalga Botryococcus braunii (JJS, KCM, and KJD) were isolated from different water bodies in Korea and grown as batch cultures in the laboratory. The effects of different growth media and temperatures on the growth rate were investigated, as well as the effect of temperature on the total lipid content and lipid profile. All three strains had the highest growth rates in BG-11 medium and at 25°C. Maximal lipid production (g L-1) was at 30°C in the JJS strain and at 25°C in the KCM and KJD strains. However, all the three strains produced the greatest percent dry weight of total lipids at 15°C and had the lowest percent dry weight of total lipids at 25°C. In general, oleic acid, linolenic acid, and behenic acid were the most common fatty acids in all three strains. However, the three strains varied considerably in their fatty acid profiles at different culture temperatures.

Abstract Neurovascular coupling is a precise mechanism that induces increased blood flow to activated brain regions, thereby providing oxygen and glucose. In this study, we hypothesized that N-methyl-D-aspartate (NMDA) receptor signaling, the most well characterized neurotransmitter signaling system which regulates delivery of essential molecules through the blood–brain barrier (BBB). Upon application of NMDA in both in vitro and in vivo models, increased delivery of bioactive molecules that was mediated through modulation of molecules involved in molecular delivery, including clathrin and caveolin were observed. Also, NMDA activation induced structural changes in the BBB and increased transcellular permeability that showed regional heterogeneity in its responses. Moreover, NMDA receptor activation increased endosomal trafficking and facilitated inactivation of lysosomal pathways and consequently increased molecular delivery mediated by activation of calmodulin-dependent protein kinase II (CaMKII) and RhoA/protein kinase C (PKC). Subsequent in vivo experiments using mice specifically lacking NMDA receptor subunit 1 in endothelial cells showed decreased neuronal density in the brain cortex, suggesting that a deficiency in NMDA receptor signaling in brain endothelial cells induces neuronal losses. Together, these results highlight the importance of NMDA-receptor-mediated signaling in the regulation of BBB permeability that surprisingly also affected CD31 staining.

This article, titled "Wide Complex Tachycardia: Mind Your Medicine!" discusses the case of a 59-year-old male who presented to the emergency room with palpitations. The patient had a history of persistent atrial fibrillation and was taking multiple medications, including flecainide. The electrocardiogram (ECG) showed a wide complex tachycardia with right bundle branch block pattern and right axis deviation. Further analysis of the ECG revealed atypical atrioventricular Wenckebach block. The patient underwent successful radiofrequency ablation of an atrial focus. The article also discusses the use-dependent properties and potential toxicity of flecainide. [Extracted from the article]

This document is a case study published in the journal Circulation. It presents the case of a 50-year-old woman who was referred to the emergency department after experiencing a wide complex tachycardia. The patient had elevated levels of troponin I and N-terminal pro-brain natriuretic peptide, and further evaluation revealed a diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC). The article discusses the ECG findings and diagnostic criteria for ARVC, as well as the treatment and genetic factors associated with the condition. [Extracted from the article]

5'-Adenosine monophosphate (AMP)-activated protein kinase (AMPK), a cellular energy sensor, is an essential enzyme that helps cells maintain stable energy levels during metabolic stress. The hypothalamus is pivotal in regulating energy balance within the body. Certain neurons in the hypothalamus are sensitive to fluctuations in food availability and energy stores, triggering adaptive responses to preserve systemic energy equilibrium. AMPK, expressed in these hypothalamic neurons, is instrumental in these regulatory processes. Hypothalamic AMPK activity is modulated by key metabolic hormones. Anorexigenic hormones, including leptin, insulin, and glucagon-like peptide 1, suppress hypothalamic AMPK activity, whereas the hunger hormone ghrelin activates it. These hormonal influences on hypothalamic AMPK activity are central to their roles in controlling food consumption and energy expenditure. Additionally, hypothalamic AMPK activity responds to variations in glucose concentrations. It becomes active during hypoglycemia but is deactivated when glucose is introduced directly into the hypothalamus. These shifts in AMPK activity within hypothalamic neurons are critical for maintaining glucose balance. Considering the vital function of hypothalamic AMPK in the regulation of overall energy and glucose balance, developing chemical agents that target the hypothalamus to modulate AMPK activity presents a promising therapeutic approach for metabolic conditions such as obesity and type 2 diabetes mellitus. [ABSTRACT FROM AUTHOR]