Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 159
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Small ; 20(5): e2305997, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37726226

RESUMEN

Functionality in molecular electronics relies on inclusion of molecular orbital energy level within a transmission window. This can be achieved by designing the active molecule with accessible energy levels or by widening the window. While many studies have adopted the first approach, the latter is challenging because defects in the active molecular component cause low breakdown voltages. Here, it is shown that control over the packing structure of monolayer via supramolecular mixing transforms an inert molecule into a highly tunable rectifier. Binary mixed monolayer composed of alkanethiolates with and without carboxylic acid head group as a proof of concept is formed via a surface-exchange reaction. The monolayer withstands high voltages up to |4.5 V| and shows a dynamic rectification-external bias relationship in magnitude and polarity. Sub-highest occupied molecular orbital (HOMO) levels activated by the widened transmission window account for these observations. This work demonstrates that simple supramolecular mixing can imbue new electrical properties in electro-inactive organic molecules.

2.
Nano Lett ; 23(20): 9626-9633, 2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37819875

RESUMEN

Recently, neuromorphic computing has been proposed to overcome the drawbacks of the current von Neumann computing architecture. Especially, spiking neural network (SNN) has received significant attention due to its ability to mimic the spike-driven behavior of biological neurons and synapses, potentially leading to low-power consumption and other advantages. In this work, we designed the indium-gallium-zinc oxide (IGZO) channel charge-trap flash (CTF) synaptic device based on a HfO2/Al2O3/Si3N4/Al2O3 layer. Our IGZO-based CTF device exhibits synaptic functions with 128 levels of synaptic weight states and spike-timing-dependent plasticity. The SNN-restricted Boltzmann machine was used to simulate the fabricated CTF device to evaluate the efficiency for the SNN system, achieving the high pattern-recognition accuracy of 83.9%. We believe that our results show the suitability of the fabricated IGZO CTF device as a synaptic device for neuromorphic computing.

3.
Small ; 19(7): e2206311, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36461737

RESUMEN

Poor stability of CsPbBr3 perovskite nanocrystals (NCs) to moisture/heat/light has significantly limited their application as a green phosphor, despite their outstanding luminescent properties. Here, a remarkably stable CsPbBr3 NCs-silica composite phosphor functionalized with surface phenyl molecules (CsPbBr3 -SiO2 Ph ) is synthesized by controlling low-temperature hydrolysis and condensation reaction of perhydropolysilazane in the presence of CsPbBr3 NCs followed by phenyl-functionalization. Through the process, CsPbBr3 NCs are confined in a compact silica matrix, which is impermeable to H2 O. The synthesis strategy is extended to a classical red quantum dot, CdZnSeS@ZnS NCs, to fabricate a white light emitting diode (WLED) consisting of CsPbBr3 -SiO2 Ph and CdZnSeS@ZnS-SiO2 Ph phosphor and silicone resin packaged on a commercial blue InGaN chip with luminous efficacy (LE) of 9.36 lm W-1 . The WLED undergoes enhancements in both green and red photoluminescence over time to achieve a highly efficient performance of 38.80 lm W-1 . More importantly, the WLED exhibits unprecedented operational stability of LE/LE0  = 94% after 101 h-operation at 20 mA (2.56 V). The ultra-high operational stability and efficient performance are mainly attributed to thermal curing and aging through which grain growth occurs as well as deactivation of defect states by permeated atmospheric O2 .

4.
J Cardiovasc Electrophysiol ; 34(1): 189-196, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36349711

RESUMEN

INTRODUCTION: This study aimed to elucidate the relationship between premature ventricular complexes (PVCs) and right ventricular (RV) dysfunction, and the effects of radiofrequency catheter ablation (RFCA) on RV function. METHODS: A total of 110 patients (age, 50.8 ± 14.4 years; 30 men) without structural heart disease who had undergone RFCA for RV outflow tract (RVOT) PVCs were retrospectively included. RV function was assessed using fractional area change (FAC) and global longitudinal strain (GLS) before and after RFCA. Clinical data were compared between the RV dysfunction (n = 63) and preserved RV function (n = 47) groups. The relationship between PVC burden and RV function was analyzed. Change in RV function before and after RFCA was compared between patients with successful and failed RFCA. RESULTS: PVC burden was significantly higher in the RV dysfunction group than in the preserved RV function group (p < .001). FAC and GLS were significantly worse in proportion to PVC burden (p < .001 and p < .001, respectively). The risk factor associated with RV dysfunction was PVC burden [odds ratio (95% confidence interval), 1.092 (1.052-1.134); p < .001]. Improvement in FAC (13.0 ± 8.7% and -2.5 ± 5.6%, respectively; p < .001) and GLS (-6.8 ± 5.7% and 2.1 ± 4.2%, respectively; p < .001) was significant in the patients with successful RFCA, compared to the patients in whom RFCA failed. CONCLUSIONS: Frequent RVOT PVCs are associated with RV dysfunction. RV dysfunction is reversible by successful RFCA.


Asunto(s)
Ablación por Catéter , Disfunción Ventricular Derecha , Complejos Prematuros Ventriculares , Masculino , Humanos , Adulto , Persona de Mediana Edad , Anciano , Estudios Retrospectivos , Función Ventricular Derecha , Resultado del Tratamiento , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/cirugía , Complejos Prematuros Ventriculares/diagnóstico , Complejos Prematuros Ventriculares/cirugía , Complejos Prematuros Ventriculares/complicaciones , Ablación por Catéter/efectos adversos , Disfunción Ventricular Derecha/diagnóstico por imagen , Disfunción Ventricular Derecha/etiología , Disfunción Ventricular Derecha/cirugía
5.
Nano Lett ; 22(14): 5742-5750, 2022 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-35666985

RESUMEN

This paper reports an approach to repurpose low-cost, bulk multilayer MoS2 for development of ultraefficient hydrogen evolution reaction (HER) catalysts over large areas (>cm2). We create working electrodes for use in HER by dry transfer of MoS2 nano- and microflakes to gold thin films deposited on prestrained thermoplastic substrates. By relieving the prestrain at a macroscopic scale, a tunable level of tensile strain is developed in the MoS2 and consequently results in a local phase transition as a result of spontaneously formed surface wrinkles. Using electrochemical impedance spectroscopy, we verified that electrochemical activation of the strained MoS2 lowered the charge transfer resistance within the materials system, achieving HER activity comparable to platinum (Pt). Raman and X-ray photoelectron spectroscopy show that desulfurization in the multilayer MoS2 was promoted by the phase transition; the combined effect of desulfurization and the lower charge resistance induced superior HER performance.

6.
Community Ment Health J ; 59(5): 942-953, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36547814

RESUMEN

In order to formulate and implement a community-based suicide prevention program, as well as evaluate the effectiveness of these programs, it is necessary to understand the epidemiological characteristics of self-harm. Clinical data were collected from the National Emergency Department Information System (NEDIS) data panel in Korea for patients seen after self-harm episodes. Socioeconomic factors were collected from Statistics Korea. Variables representing SP provisions (SPPs) were collected from the Korea Foundation for Suicide Prevention. Increasing the number of mental health providers resulted in lower annual emergency department visit rate after self-harm (VRSH) in the entire population, as well as in both the young and elderly populations. An increase in the mental health budget led to a significant reduction in VRSHs. However, the number of suicide prevention centers did not have any significant association with the VRSH. This study also provides substantial evidence that community-based SPPs are effective in preventing self-harm.


Asunto(s)
Conducta Autodestructiva , Suicidio , Humanos , Anciano , Prevención del Suicidio , Suicidio/psicología , Conducta Autodestructiva/epidemiología , Conducta Autodestructiva/prevención & control , Sistema de Registros , Servicio de Urgencia en Hospital , República de Corea/epidemiología
7.
Small ; 18(14): e2107060, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35187805

RESUMEN

With narrow and dense nanoarchitectures increasingly adopted to improve optical functionality, achieving the complete wetting of photonic devices is required when aiming at underwater molecule detection over the water-repellent optical materials. Despite continuous advances in photonic applications, real-time monitoring of nanoscale wetting transitions across nanostructures with 10-nm gaps, the distance at which photonic performance is maximized, remains a chronic hurdle when attempting to quantify the water influx and molecules therein. For this reason, the present study develops a photonic switch that transforms the wetting transition into perceivable color changes using a liquid-permeable Fabry-Perot resonator. Electro-capillary-induced Cassie-to-Wenzel transitions produce an optical memory effect in the photonic switch, as confirmed by surface-energy analysis, simulations, and an experimental demonstration. The results show that controlling the wetting behavior using the proposed photonic switch is a promising strategy for the integration of aqueous media with photonic hotspots in plasmonic nanostructures such as biochemical sensors.


Asunto(s)
Nanoestructuras , Agua , Acción Capilar , Nanoestructuras/química , Fotones , Agua/química , Humectabilidad
8.
Rev Cardiovasc Med ; 23(1): 10, 2022 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-35092202

RESUMEN

BACKGROUND: Patients with ischemic stroke are vulnerable to heart failure with preserved ejection fraction (HFpEF) because these conditions share common risk factors. Although evaluation of the ascending aorta, aortic arch, and proximal descending thoracic aorta is an essential step to determine the source of the causative embolism, the relationship between the degree of aortic atheroma and left ventricular (LV) diastolic function has not been extensively investigated. METHODS: We analyzed the transesophageal and transthoracic echocardiography in ischemic stroke patients. Patients with previous coronary artery disease, valvular heart disease of more than moderate degree, and an LV ejection fraction of less than 50% were excluded. The relationships between the grade of the aortic atheroma, aortic stiffness indexes, and diastolic functional indexes were evaluated. RESULTS: In 295 patients, the atheroma grade was significantly correlated with aortic stiffness index, ratio of mitral annular and inflow velocities (E/e'), left atrial volume index, and LV diastolic elastance. With further adjustment for age, hypertension, diabetes, estimated glomerular filtration rate, left atrial volume index, and LV mass index, the significance of the atheroma grade was attenuated. In the subgroup analysis, the atheroma grade was significantly and independently related to E/e' in women (ß = 0.181, p = 0.032), but not in men. However, atheroma grade was not associated with poor clinical outcomes in either sex. CONCLUSIONS: Aortic atheroma grade was significantly and independently related to LV diastolic function, especially in women. This suggests that aortic atheroma is an index of arterial stiffness and a potential risk factor for HFpEF through ventricular-vascular interactions, especially in women.


Asunto(s)
Insuficiencia Cardíaca , Accidente Cerebrovascular Isquémico , Placa Aterosclerótica , Disfunción Ventricular Izquierda , Aorta/diagnóstico por imagen , Femenino , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/diagnóstico por imagen , Humanos , Masculino , Placa Aterosclerótica/complicaciones , Pronóstico , Volumen Sistólico , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/etiología , Función Ventricular Izquierda
9.
BMC Cardiovasc Disord ; 22(1): 507, 2022 11 26.
Artículo en Inglés | MEDLINE | ID: mdl-36435744

RESUMEN

BACKGROUND: To investigate the differential contribution of the left atrial (LA) function and left ventricular (LV) fibrosis to pulmonary arterial systolic pressure (PASP) in hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM) and reperfused acute myocardial infarction (AMI). METHODS: Data of 370 patients with HCM (n = 133), DCM (n = 114) and reperfused AMI (n = 123) who underwent both echocardiography and cardiovascular magnetic resonance (CMR) were comprehensively reviewed. Phasic LA volumes, LA-global longitudinal strain (GLS), LA stiffness index, defined as E/e'/LA-GLS and extracellular volume fraction (ECV) of LV were measured using CMR. RESULTS: E/e' was correlated with PASP in all groups; however, the predicted value was significantly attenuated after adjusting for LA volume and LA strain in HCM and DCM, but remained significant in AMI. The LA stiffness index was related to PASP in HCM (p = 0.01) and DCM (p = 0.03) independent of LA volume index and E/e', but not in AMI. In DCM, ECV was significantly related to PASP (p < 0.001) independent of LA volume index and E/e'. When subdivided according to the linear regression between PASP and E/e', patients in the discrepantly high PASP group had lower total emptying fraction and reservoir fraction of left atrium in HCM and DCM but not in AMI. CONCLUSIONS: The LA function in HCM and DCM and LV fibrosis in DCM correlated with PASP independent of E/e' and LA size, contrary to that in AMI. These results suggest the presence of LA dysfunction in non-ischemic cardiomyopathies and usefulness of ECV measurement in DCM for the comprehensive evaluation of LV diastolic function.


Asunto(s)
Cardiomiopatía Dilatada , Cardiomiopatía Hipertrófica , Infarto del Miocardio , Humanos , Presión Arterial , Función del Atrio Izquierdo , Cardiomiopatía Dilatada/diagnóstico por imagen , Fibrosis , Infarto del Miocardio/diagnóstico por imagen
10.
J Interv Cardiol ; 2021: 8846656, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33536856

RESUMEN

BACKGROUND: The age of candidates for device closure of atrial septal defect (ASD) has been increasing. Thus, concerns exist about dyspnea aggravation or atrial fibrillation development after device closure due to augmentation of left ventricular (LV) and left atrial (LA) preload. This study aimed to examine patterns and determinants of serial pulmonary arterial pressure and left ventricular filling pressure changes after device closure of ASD. METHODS: Among the 86 consecutive patients who underwent percutaneous device closure of ASD, those with end-stage renal disease or those without pre- or postprocedural Doppler data were excluded. The clinical, transesophageal, and transthoracic echocardiographic findings of 78 patients were collected at baseline, one-day postprocedure, and one-year follow-up. RESULTS: The mean age of study patients was 49.8 ± 15.0 years, and the average maximal defect diameter and device size were 20.2 ± 6.0 mm and 23.8 ± 6.4 mm. Four patients (5.6%) underwent new-onset atrial fibrillation, and five patients (6.4%) took diuretics within one-year after closure. Some patients (n = 21; 27%) exhibited paradoxically increased tricuspid regurgitant velocity (TRV) one-day postprocedure; they also were older with lower e', glomerular filtration rate, and LV ejection fraction and a higher LA volume index. However, even in these patients, TRV deceased below baseline levels one-year later. Both E/e' and LA volume index significantly increased immediately after device closure, but all decreased one-year later. Larger defect size and higher TRV were significantly correlated with immediate E/e' elevation. CONCLUSION: In older, renal, diastolic, and systolic dysfunctional patients with larger LA and scheduled for larger device implantation, peri-interventional preload reduction therapy would be beneficial.


Asunto(s)
Fibrilación Atrial , Cateterismo Cardíaco , Defectos del Tabique Interatrial/cirugía , Complicaciones Posoperatorias , Dispositivo Oclusor Septal , Disfunción Ventricular Izquierda/epidemiología , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/epidemiología , Fibrilación Atrial/etiología , Cateterismo Cardíaco/efectos adversos , Cateterismo Cardíaco/instrumentación , Cateterismo Cardíaco/métodos , Femenino , Defectos del Tabique Interatrial/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/epidemiología , Presión Esfenoidal Pulmonar , Insuficiencia Renal/epidemiología , Ajuste de Riesgo , Factores de Riesgo , Resultado del Tratamiento
11.
BMC Cardiovasc Disord ; 21(1): 17, 2021 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-33407155

RESUMEN

BACKGROUND: Short QT syndrome is a rare, inherited channelopathy associated with sudden cardiac arrest (SCA) but the characteristics and prognosis of short QT interval (SQTI) in Korean patients remain unclear. This study aimed to determine the clinical characteristics and outcomes of SQTI in a Korean population. METHODS: Consecutive patients with SQTI from January 1999 to March 2019 in three university hospitals in South Korea were recruited. SQTI was defined as a Bazett's formula-corrected QT interval (QTc) ≤ 340 ms in serial electrocardiograms. Age- and sex-matched patients with a normal QTc and without overt cardiovascular disease were included in a 1:4 ratio. Clinical and ECG features and outcomes were compared between patients with and without SQTI. RESULTS: 34 patients with SQTI [age, 23.5 (21-30.5) years; 31 male] were followed up for 4.8 (2.0-7.8) years. Early repolarization, tall T wave, and U wave were significantly more frequent in patients with SQTI than in those without SQTI. QT dispersion [44.0 (28.0-73.0) vs. 20.0 (12.0-35.0) ms, P < 0.001] was significantly wider and heart rate [52.0 (47.0-58.0) vs. 70.0 (62.3-84.0)/min, P < 0.001] was significantly slower in patients with SQTI than in those without. Atrial fibrillation (AF, 11.8% vs. 2.2%, P = 0.030) and ventricular arrhythmia (VA)/SCA (8.7% vs. 0%, P = 0.007) were significantly more frequent in patients with SQTI than in those without. SQTI was significantly associated with AF [odds ratio, 5.911; 95% confidence interval, 1.257-27.808; P = 0.025] and VA/SCA. CONCLUSIONS: In this subset of Korean population, SQTI was associated with AF and VA/SCA.


Asunto(s)
Arritmias Cardíacas/fisiopatología , Fibrilación Atrial/fisiopatología , Sistema de Conducción Cardíaco/anomalías , Sistema de Conducción Cardíaco/fisiopatología , Cardiopatías Congénitas/fisiopatología , Frecuencia Cardíaca , Potenciales de Acción , Adulto , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/mortalidad , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/mortalidad , Muerte Súbita Cardíaca/epidemiología , Electrocardiografía , Femenino , Cardiopatías Congénitas/diagnóstico , Cardiopatías Congénitas/mortalidad , Humanos , Masculino , Prevalencia , Pronóstico , República de Corea , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Adulto Joven
12.
BMC Cardiovasc Disord ; 21(1): 346, 2021 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-34281506

RESUMEN

BACKGROUND: The relationship between the characteristics of cardiac implantable electronic device (CIED) leads and subclinical cardiac perforations remains unclear. This study aimed to evaluate the incidence of subclinical cardiac perforation among various CIED leads using cardiac computed tomography (CT). METHODS: A total of 271 consecutive patients with 463 CIED leads, who underwent cardiac CT after CIED implantation, were included in this retrospective observational study. Cardiac CT images were reviewed by one radiologist and two cardiologists. Subclinical perforation was defined as traversal of the lead tip past the outer myocardial layer without symptoms and signs related to cardiac perforation. We compared the subclinical cardiac perforation rates of the available lead types. RESULTS: A total of 219, 49, and 3 patients had pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy, respectively. The total subclinical cardiac perforation rate was 5.6%. Subclinical cardiac perforation by screw-in ventricular leads was significantly more frequent than that caused by tined ventricular leads (13.3% vs 3.3%, respectively, p = 0.002). There were no significant differences in the incidence of cardiac perforation between atrial and ventricular leads, screw-in and tined atrial leads, pacing and defibrillator ventricular leads, nor between magnetic resonance (MR)-conditional and MR-unsafe screw-in ventricular leads. Screw-in ventricular leads were significantly associated with subclinical cardiac perforation [odds ratio, 4.554; 95% confidence interval, 1.587-13.065, p = 0.005]. There was no case subclinical cardiac perforation by septal ventricular leads. CONCLUSIONS: Subclinical cardiac perforation by screw-in ventricular leads is not rare. Septal pacing may be helpful in avoiding cardiac perforation.


Asunto(s)
Desfibriladores Implantables/efectos adversos , Lesiones Cardíacas/diagnóstico por imagen , Tomografía Computarizada Multidetector , Marcapaso Artificial/efectos adversos , Anciano , Dispositivos de Terapia de Resincronización Cardíaca/efectos adversos , Femenino , Lesiones Cardíacas/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos
13.
BMC Cardiovasc Disord ; 21(1): 546, 2021 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-34789163

RESUMEN

BACKGROUND: An association has been identified between mitral valve prolapse (MVP) and sudden cardiac arrest (SCA), and ventricular arrhythmias (VA). This study aimed to elucidate predictive factors for SCA or VA in MVP patients. METHODS: MVP patients who underwent cardiac magnetic resonance (CMR) were retrospectively included. Patients with other structural heart disease or causes of aborted SCA were excluded. Clinical characteristics (sex, age, body mass index, histories of diabetes, hypertension, and dyslipidemia) and electrocardiographic (PR interval, QRS duration, corrected QT interval, inverted T wave in the inferior leads, bundle branch block, and atrial fibrillation), echocardiographic [mitral regurgitation grade, prolapsing mitral leaflet, and right ventricular systolic pressure (RVSP)], and CMR [left atrial volume index, both ventricular ejection fractions, both ventricular end-diastolic and systolic volume indexes, prolapse distance, mitral annular disjunction, systolic curling motion, presence of late gadolinium enhancement (LGE), LGE volume and proportion] parameters were analyzed. RESULTS: Of the 85 patients [age, 54.0 (41.0-65.0) years; 46 men], seven experienced SCA or VA. Younger age and wide QRS complex were observed more often in the SCA/VA group than in the no-SCA/VA group. The SCA/VA group exhibited lower RVSP, more systolic curling motion and LGE, greater LGE volume, and higher LGE proportion. The presence of LGE [hazard ratio (HR), 19.8; 95% confidence interval (CI) 2.65-148.15; P = 0.004], LGE volume (HR 1.08; 95% CI 1.02-1.14; P = 0.006) and LGE proportion (HR 1.32; 95% CI 1.08-1.60; P = 0.006) were independently associated with higher risk of SCA or VA in MVP patients together with systolic curling motion in each model. CONCLUSIONS: The presence of systolic curling motion, high LGE volume and proportion, and the presence of LGE on CMR were independent predictive factors for SCA or VA in MVP patients.


Asunto(s)
Muerte Súbita Cardíaca/etiología , Imagen por Resonancia Magnética , Prolapso de la Válvula Mitral/diagnóstico por imagen , Fibrilación Ventricular/etiología , Ecocardiografía , Electrocardiografía , Gadolinio , Humanos , Prolapso de la Válvula Mitral/complicaciones , Prolapso de la Válvula Mitral/fisiopatología , Valor Predictivo de las Pruebas , Estudios Retrospectivos
14.
Cardiovasc Ultrasound ; 19(1): 4, 2021 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-33407484

RESUMEN

BACKGROUND: Left atrial (LA) enlargement and dysfunction are related to clinical course in patients with hypertrophic cardiomyopathy (HCM). We aimed to investigate genetic contribution to LA structural and functional remodeling. METHODS: Two hundred twelve patients were consecutively enrolled, and echocardiography and extensive genetic analysis were performed. Cardiac magnetic resonance (CMR) was performed in 135 patients. Echocardiography was also performed in controls (n = 30). RESULTS: Patients with HCM had lower late-diastolic mitral annular velocity (a') and higher LA volume index (LAVI) than controls. Patients with pathogenic or likely pathogenic sarcomere gene mutations (PSM, n = 67, 32%) had higher LAVI and lower CMR-derived LA total emptying fraction (37.0 ± 18.5 vs. 44.2 ± 12.4%, p = 0.025). In patients without AF (n = 187), the PSM had lower a' (6.9 ± 2.0 vs. 7.8 ± 1.9 cm/s, p = 0.004) than others. The PSM had higher prevalence and amount of late gadolinium enhancement (LGE) in the left ventricle (LV). In multivariate analysis, PSM was significantly related to lower a' independent of E/e', LV mass index, and LAVI. However, the relation significantly attenuated after adjustment for the extent of LGE in the LV, suggesting common myopathy in the LV and LA. In addition, PSM was significantly related to lower LA total emptying fraction independent of age, E/e', s', LV ejection fraction, LV myocardial global longitudinal strain and %LGE mass. CONCLUSIONS: PSM was related to LA dysfunction independent of LV filling pressure and LAVI, suggesting its contribution to atrial myopathy in HCM.


Asunto(s)
Función del Atrio Izquierdo/fisiología , Cardiomiopatía Hipertrófica/genética , ADN/genética , Atrios Cardíacos/fisiopatología , Mutación , Sarcómeros/genética , Cardiomiopatía Hipertrófica/diagnóstico , Cardiomiopatía Hipertrófica/fisiopatología , Análisis Mutacional de ADN , Ecocardiografía , Femenino , Atrios Cardíacos/diagnóstico por imagen , Humanos , Imagen por Resonancia Cinemagnética , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
15.
Br J Neurosurg ; 35(6): 757-765, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32865435

RESUMEN

OBJECTIVE: Adjacent segment degeneration (ASD) is a well-known problem of posterior lumbar interbody fusion (PLIF). A device for interspinous assisted motion (DIAM) has been recently applied at the adjacent segment to pedicle screw instrumentation to create a dynamic transition zone. The aim of this study was to determine whether DIAM implantation at the adjacent segment could reduce the occurrence of radiologic and symptomatic ASD. METHODS: This retrospective study reviewed 51 patients who underwent PLIF with or without DIAM between 2005 and 2016. They were followed up for more than 24 months. The mean follow-up was over 5 years. Fourteen patients underwent PLIF with DIAM implantation at the cephalad level (Group A) and 37 patients received PLIF only (Group B). In radiologic ASD, several parameters were measured using pre- and post-operative radiographs and magnetic resonance image for lumbar degenerative disease and paraspinal muscle. Visual analogue scale (VAS) and Roland-Morris Disability Questionnaire (RMDQ) scores of back and leg were used to investigate symptomatic ASD. RESULTS: In postoperative radiographic changes, disc height narrowing and progression of spondylolisthesis at adjacent segment were significantly less in group A than those in group B (0.58 mm versus 1.17 mm, p = 0.038 and 0.30 mm versus 1.69 mm, p = 0.041, respectively). In clinical assessments, back VAS and RMDQ scores improved significantly more in group A (-4.07 versus -2.54, p = 0.029 and -7.57 versus -5.43, p = 0.016, respectively). CONCLUSION: DIAM implantation with single-level PLIF could prevent disc height narrowing and progression of spondylolisthesis at adjacent segment. Clinically, DIAM implantation reduced back pain and disability. Therefore, DIAM implantation could help slow the progression of both radiologic and symptomatic ASD.


Asunto(s)
Degeneración del Disco Intervertebral , Fusión Vertebral , Estudios de Seguimiento , Humanos , Degeneración del Disco Intervertebral/diagnóstico por imagen , Degeneración del Disco Intervertebral/cirugía , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Estudios Retrospectivos , Fusión Vertebral/efectos adversos , Resultado del Tratamiento
16.
J Physiol ; 598(17): 3597-3612, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32495943

RESUMEN

KEY POINTS: The interatrial conduction, including Bachmann's bundle, the posterior septal conduction, the anterior septal conduction, and the cavo-tricuspid isthmus, contributes to the maintenance mechanisms of atrial fibrillation in a 3D biatrial model. The interatrial conduction ablation including a cavo-tricuspid isthmus ablation significantly affects the wave dynamics of atrial fibrillation (AF) and facilitates the AF termination or atrial tachycardia conversion of the AF after the circumferential pulmonary vein isolation. Additional cavo-tricuspid isthmus ablation after the circumferential pulmonary vein isolation improves long-term rhythm outcome after clinical AF catheter ablation. ABSTRACT: Although it is known that atrial fibrillation (AF) is mainly a left atrial (LA) disease, the role of the right atrium (RA) and interatrial conduction (IAC), including the cavo-tricuspid isthmus (CTI), has not been clearly defined. We tested AF wave dynamics with or without IAC in computational modelling and the rhythm outcome of AF catheter ablation (AFCA) including CTI ablation in clinical cohort data. We evaluated the dominant frequency (DF) in 3D biatrial AF simulations integrated with 3D-computed tomograms obtained from 10 patients. The IAC was implemented at Bachmann's bundle, posterior septum and the CTI. After virtual circumferential PV isolation (CPVI), we disconnected IACs one by one, and observed the wave dynamics. We compared the long-term rhythm outcome after CPVI alone and additional CTI ablation in 846 patients with AFCA. LA-DF was higher than RA-DF in AF (P < 0.001). After CPVI, the DF decreased significantly by additional IAC ablation (P = 0.003), especially in the LA (P = 0.016). The amount of DF reduction (P = 0.020) and rates of AF termination (P < 0.001) or AT conversion (P = 0.021) were significantly higher after IAC ablations including CTI than those without. In clinical AFCA, the AF recurrence rate was significantly lower in patients with additional CTI ablation than CPVI alone during 25 ± 20 months' follow-up (hazard ratio 0.60 [0.46-0.79], P < 0.001, Log rank P < 0.001). IAC contributes to the maintenance mechanism of AF, and IAC including CTI ablation affects AF wave dynamics, facilitating AF termination in 3D biatrial modelling. Additional CTI ablation after CPVI improves the long-term rhythm outcome in clinical AFCA, potentially in a paroxysmal type with accompanying atrial flutter, or atrial dimension close to normal.


Asunto(s)
Fibrilación Atrial , Ablación por Catéter , Venas Pulmonares , Fibrilación Atrial/cirugía , Atrios Cardíacos/diagnóstico por imagen , Atrios Cardíacos/cirugía , Frecuencia Cardíaca , Humanos , Resultado del Tratamiento
17.
J Am Chem Soc ; 2020 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-33201702

RESUMEN

Various metal oxide clusters upward of 8 atoms (Cu, Cd, Co, Fe, Ga, Mn, Mo, Ni, Sn, W, Zn, In, and Al) were incorporated into the pores of the metal-organic framework (MOF) NU-1000 via atomic layer deposition (ALD) and tested via high-throughput screening for catalytic isomerization and selective hydrogenation of propyne. Cu and Co were found to be the most active for propyne hydrogenation to propylene, and synergistic bimetallic combinations of Co and Zn, along with standalone Zn and Cd, were established as the most active for conversion to the isomerized product, propadiene. The combination of Co and Zn in NU-1000 diminished the propensity for full hydrogenation to propane as well as coking compared to its individual components. This study highlights the potential for high-throughput screening to survey monometallic and bimetallic cluster combinations that best affect the efficient transformation of small molecules, while discerning mechanistic differences in isomerization and hydrogenation by different metals.

18.
J Am Chem Soc ; 142(1): 242-250, 2020 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-31851505

RESUMEN

The postmodification of metal organic frameworks (MOFs) affords exceedingly high surface area materials with precisely installed chemical features, which provide new opportunities for detailed structure-function correlation in the field of catalysis. Here, we significantly expand upon the number of vapor-phase postmodification processes reported to date through screening a library of atomic layer deposition (ALD) precursors, which span metals across the periodic table and which include ligands from four distinct precursor classes. With a large library of precursors and synthesis conditions, we discern trends in the compatibility of precursor classes for well-behaved ALD in MOFs (AIM) and identify challenges and solutions to more precise postsynthetic modification.


Asunto(s)
Gases/química , Estructuras Metalorgánicas/química , Catálisis , Relación Estructura-Actividad
19.
J Cardiovasc Electrophysiol ; 31(2): 457-464, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31919909

RESUMEN

INSTRUCTION: Longer atrial fibrillation (AF) durations have higher recurrence rates after rhythm control. However, there is limited data on the effect of the AF duration on recurrence after atrial fibrillation catheter ablation (AFCA). In the present study, we investigated the rhythm outcome of AFCA according to the AF duration based on the first electrocardiogram (ECG) diagnosis. METHODS AND RESULTS: We included 1005 patients with AF (75% male, 59 ± 11 years old) who underwent AFCA and whose first ECG diagnosis time point was evident. The clinical characteristics and rhythm outcomes were compared based on the AF duration (≤3 years, n = 537; >3 years, n = 468) and AF burden (paroxysmal atrial fibrillation [PAF], n = 387; persistent atrial fibrillation [PeAF], n = 618). Longer AF durations were associated with older age (P = .020), larger left atrial size (P = .009) and a higher number of patients with hypertension (P < .001) or PeAF (P < .001). During 24 ± 22 months of follow-up, the postablation clinical recurrence rate was higher in patients with a longer AF duration (logrank P = .002). The AF recurrence rate was significantly higher in PeAF patients with an AF duration >3 years (logrank P = 0.009), but not in subjects with PAF (logrank P = .939). In a multivariate Cox regression analysis, a longer AF duration was significantly associated with a higher clinical recurrence rate after AFCA in PeAF patients (adjusted hazard ratio, 1.06; range, 1.03-0.10; P = 0.001), but not PAF. CONCLUSION: Although longer AF duration was associated with higher clinical recurrence rates after AFCA, the rate was significant in patients with PeAF lasting >3 years, but not in PAF patients.


Asunto(s)
Fibrilación Atrial/cirugía , Ablación por Catéter/efectos adversos , Venas Pulmonares/cirugía , Potenciales de Acción , Anciano , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/fisiopatología , Bases de Datos Factuales , Electrocardiografía , Técnicas Electrofisiológicas Cardíacas , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Venas Pulmonares/fisiopatología , Recurrencia , Sistema de Registros , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
20.
Circ J ; 85(1): 59-68, 2020 12 25.
Artículo en Inglés | MEDLINE | ID: mdl-33281141

RESUMEN

BACKGROUND: Coronary interventions using drug-eluting stents (DESs) of left main coronary artery (LMCA) lesions have shown favorable clinical outcomes. However, duration of dual antiplatelet therapy (DAPT) after LMCA interventions has not yet been investigated.Methods and Results:From a multicenter Korean Multicenter Angioplasty Team (KOMATE) registry, 1,004 patients who received DES implantations for LMCA lesions and did not experience major adverse cardiovascular events (including major bleeding) for 1 year after coronary intervention were analyzed. Patients were divided into 2 groups; DAPT ≤12 (n=503) and >12 months (n=501). The primary endpoint was number of net clinical adverse events (NACEs), composite of cardiac deaths, myocardial infarctions, stent thrombosis and major bleeding events. During a 4.5-year follow-up period after LMCA interventions, the DAPT >12 months group showed a lower NACE rate than the DAPT ≤12 months group (adjusted-HR 0.53 [0.29-0.99], P=0.045). For patients who maintained DAPT >12 months, rate of cardiac deaths, myocardial infarctions, and stent thrombosis events were lower than in patients who had DAPT ≤12 months (adjusted-HR 0.35 [0.17-0.73], P=0.005) without increased major bleeding (P=0.402). CONCLUSIONS: For patients who can continue DAPT without major bleeding events, prolonged DAPT (>12 months) after LMCA stenting demonstrated better long-term efficacy outcomes than DAPT ≤12 months with comparable safety.


Asunto(s)
Enfermedad de la Arteria Coronaria , Intervención Coronaria Percutánea , Inhibidores de Agregación Plaquetaria , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Quimioterapia Combinada , Hemorragia/inducido químicamente , Hemorragia/epidemiología , Humanos , Infarto del Miocardio/epidemiología , Inhibidores de Agregación Plaquetaria/uso terapéutico , República de Corea , Stents , Trombosis/epidemiología , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA