We previously reported the feasibility and efficacy of a simulation-guided clinical catheter ablation of atrial fibrillation (AF) in an in-silico AF model. We developed a highly efficient realistic AF model reflecting the patient endocardial voltage and local conduction and tested its clinical feasibility. We acquired > 500 endocardial bipolar electrograms during right atrial pacing at the beginning of the AF ablation procedures. Based on the clinical bipolar electrograms, we generated simulated voltage maps by applying fibrosis and local activation maps adjusted for the fiber orientation. The software's accuracy (CUVIA2.5) was retrospectively tested in 17 patients and feasibility prospectively in 10 during clinical AF ablation. Results: We found excellent correlations between the clinical and simulated voltage maps (R = 0.933, p < 0.001) and clinical and virtual local conduction (R = 0.958, p < 0.001). The proportion of virtual local fibrosis was 15.4, 22.2, and 36.9% in the paroxysmal AF, persistent AF, and post-pulmonary vein isolation (PVI) states, respectively. The reconstructed virtual bipolar electrogram exhibited a relatively good similarities of morphology to the local clinical bipolar electrogram (R = 0.60 ± 0.08, p < 0.001). Feasibility testing revealed an in situ procedural computing time from the clinical data acquisition to wave-dynamics analyses of 48.2 ± 4.9 min. All virtual analyses were successfully achieved during clinical PVI procedures. We developed a highly efficient, realistic, in situ procedural simulation model reflective of individual anatomy, fiber orientation, fibrosis, and electrophysiology that can be applied during AF ablation. Catheter ablation (CA) is an effective approach for rhythm control management of atrial fibrillation (AF) 1,2. However, the recurrence rate after AF ablation procedures is still substantial 3. Although pulmonary vein isolation (PVI) is a well-established target of AF ablation, extra-pulmonary vein (PV) foci or drivers maintain AF in some patients, and extra-PV foci are more commonly found in AF patients with significant left atrial (LA) remodeling 4,5. The Substrate and Trigger Ablation for Reduction of Atrial Fibrillation trial part 2 (STAR AF2) demonstrated that an empirical extra-PV ablation did not improve the rhythm outcome compared with a circumferential PVI alone in patients with persistent AF (PeAF) 6. However, the one-year recurrence rate was higher than 40% regardless of any additional extra-PV ablation after the PVI, and the outcome of the invasive interventional catheter procedure was not adequate. Therefore, an innovative mapping technology to identify the core target of AF is needed in AF catheter ablation (AFCA). Simulation is a very useful computer-aided method for identifying appropriate intervention targets. We recently reported the feasibility of a simulation-guided PeAF ablation by applying a personalized heart computed tomography (CT) image-integrated AF simulation 7,8. To further this method, we developed a more realistic AF simulation r...

The purpose of this article is to empirically find the Environmental Kuznets Curve (EKC) relationship between income and carbon dioxide (CO2) emissions and to analyze the influence of population aging on such emissions. We utilize Korean regional panel data of 16 provinces during the period from 1998 to 2016. To account for the nonstationary time series in the panel, we employ a fully modified ordinary least squares (FMOLS) and estimate long-run elasticity. From the empirical results, we can find the nonlinear relationship between income and CO2 emissions. Additionally, we verify the fact that population aging reduces CO2 emissions. A 1% increase in the proportion of the elderly results in a 0.4% decrease in CO2 emissions. On the other hand, the younger population increases CO2 emissions. These results were in line with those of additional analysis on residential and transportation CO2 emissions, for the robustness check.

The highly selective detection of trace gases using transparent sensors at room temperature remains challenging. Herein, transparent nanopatterned chemiresistors composed of aligned 1D Au–SnO2 nanofibers, which can detect toxic NO2 gas at room temperature under visible light illumination is reported. Ten straight Au–SnO2 nanofibers are patterned on a glass substrate with transparent electrodes assisted by direct‐write, near‐field electrospinning, whose extremely low coverage of sensing materials (≈0.3%) lead to the high transparency (≈93%) of the sensor. The sensor exhibits a highly selective, sensitive, and reproducible response to sub‐ppm levels of NO2, and its detection limit is as low as 6 ppb. The unique room‐temperature NO2 sensing under visible light emanates from the localized surface plasmonic resonance effect of Au nanoparticles, thereby enabling the design of new transparent oxide‐based gas sensors without external heaters or light sources. The patterning of nanofibers with extremely low coverage provides a general strategy to design diverse compositions of gas sensors, which can facilitate the development of a wide range of new applications in transparent electronics and smart windows wirelessly connected to the Internet of Things.

Background The arrhythmogenic role of atrial complex morphology has not yet been clearly elucidated.We hypothesized that bumpy tissue geometry can induce action potential duration (APD) dispersion and wavebreak in atrial fibrillation (AF). Methods and ResultsWe simulated 2D-bumpy atrial model by varying the degree of bumpiness, and 3D-left atrial (LA) models integrated by LA computed tomographic (CT) images taken from 14 patients with persistent AF. We also analyzed wave-dynamic parameters with bipolar electrograms during AF and compared them with LA-CT geometry in 30 patients with persistent AF. In 2D-bumpy model, APD dispersion increased (p<0.001) and wavebreak occurred spontaneously when the surface bumpiness was higher, showing phase transition-like behavior (p<0.001). Bumpiness gradient 2D-model showed that spiral wave drifted in the direction of higher bumpiness, and phase singularity (PS) points were mostly located in areas with higher bumpiness. In 3D-LA model, PS density was higher in LA appendage (LAA) compared to other LA parts (p<0.05). In 30 persistent AF patients, the surface bumpiness of LAA was 5.8-times that of other LA parts (p<0.001), and exceeded critical bumpiness to induce wavebreak. Wave dynamics complexity parameters were consistently dominant in LAA (p<0.001). ConclusionThe bumpy tissue geometry promotes APD dispersion, wavebreak, and spiral wave drift in in silico human atrial tissue, and corresponds to clinical electro-anatomical maps.