Ventricular divergence correlates with epicardial wavebreaks and predicts ventricular arrhythmia in isolated rabbit hearts during therapeutic hypothermia

INTRODUCTION: High beat-to-beat morphological variation (divergence) on the ventricular electrogram during programmed ventricular stimulation (PVS) is associated with increased risk of ventricular fibrillation (VF), with unclear mechanisms. We hypothesized that ventricular divergence is associated with epicardial wavebreaks during PVS, and that it predicts VF occurrence. METHOD AND RESULTS: Langendorff-perfused rabbit hearts (n = 10) underwent 30-min therapeutic hypothermia (TH, 30°C), followed by a 20-min treatment with rotigaptide (300 nM), a gap junction modifier. VF inducibility was tested using burst ventricular pacing at the shortest pacing cycle length achieving 1:1 ventricular capture. Pseudo-ECG (p-ECG) and epicardial activation maps were simultaneously recorded for divergence and wavebreaks analysis, respectively. A total of 112 optical and p-ECG recordings (62 at TH, 50 at TH treated with rotigaptide) were analyzed. Adding rotigaptide reduced ventricular divergence, from 0.13±0.10 at TH to 0.09±0.07 (p = 0.018). Similarly, rotigaptide reduced the number of epicardial wavebreaks, from 0.59±0.73 at TH to 0.30±0.49 (p = 0.036). VF inducibility decreased, from 48±31% at TH to 22±32% after rotigaptide infusion (p = 0.032). Linear regression models showed that ventricular divergence correlated with epicardial wavebreaks during TH (p<0.001). CONCLUSION: Ventricular divergence correlated with, and might be predictive of epicardial wavebreaks during PVS at TH. Rotigaptide decreased both the ventricular divergence and epicardial wavebreaks, and reduced the probability of pacing-induced VF during TH

物理模型試驗應用於順向坡板岩變形特性之研究

本文主要探討臺灣板岩順向坡變形特性，藉由現場調查、地形分析與物理模型試驗說明板岩不同條件下之重力變形特性，並推估板岩變形過程與潛在崩壞機制。結果顯示，坡趾侵蝕透空與降雨入滲機制為板岩變形之關鍵，其將造成板岩材料強度弱化加速發生變形。此外，板岩變形初始發生於崖頂張力區，坡體將沿著高角度葉理滑移，並於侵蝕弱化帶附近形成剪切破壞或複合型破壞。而變形範圍內具有相當多葉理張開之現象，其將有助於地表水與地下水滲入，促使板岩變形區加速變形至崩壞。This paper focuses on characterizing the deformation of consequent slate slopes in Taiwan. Onsite surveys, terrain analysis, and a physical model test are used to describe the characteristics of gravity-driven deformation under various conditions and identify the process of slate deformation as well as potential failure mechanisms. Slate deformation is shown to begin in the tension zone at cliff tops, wherein the slope body slips along the highly inclined foliation, contributing to shear failure or composite failure near the eroded zone of weakness. The phenomenon of foliation opening is widespread within the area of deformation, enabling surface water and groundwater to seep in, thereby accelerating deformation and failure in the slate deformation zone

Does Long-Term Use of Silver Nanoparticles Have Persistent Inhibitory Effect on H. pylori Based on Mongolian Gerbil’s Model?

It is urgent to find alternative agents due to increasing failure rate of Helicobacter pylori (H. pylori) eradication. The study surveyed the long-term effect of silver nanoparticles (AgNP) on H. pylori based on Mongolian gerbil's model