Reactive molecular dynamics simulations of lithium-ion battery electrolyte degradation.

The development of reliable computational methods for novel battery materials has become essential due to the recently intensified research efforts on more sustainable energy storage materials. Here, we use a recently developed framework allowing to consistently incorporate quantum-mechanical activation barriers to classical molecular dynamics simulations to study the reductive solvent decomposition and formation of the solid electrolyte interphase for a graphite/carbonate electrolyte interface. We focus on deriving condensed-phase effective rates based on the elementary gas-phase reduction and decomposition energy barriers. After a short initial transient limited by the elementary barriers, we observe that the effective rate shows a transition to a kinetically slow regime influenced by the changing coordination environment and the ionic fluxes between the bulk electrolyte and the interface. We also discuss the impact of the decomposition on the ionic mobility. Thus, our work shows how elementary first-principles properties can be mechanistically leveraged to provide fundamental insights into electrochemical stability of battery electrolytes.

Intracoronary shunt in off-pump coronary artery bypass graft.

This study was performed to compare the early postoperative results of off Pump Coronary Artery Bypass Graft (OPCABG) with or without using Intra Coronary Shunt (ICS). We randomized 208 patients scheduled for OPCABG into shunt group (group 1, n = 104) and no-shunt group (group 2, n = 104). The two groups were well matched according to the age, gender, angina class, New York Heart Association (NYHA) functional class, or operative priority and disease severity. Peri- and post-operative changes in electrocardiography, wall motion abnormality in echocardiography, rate of myocardial infarction, mortality, morbidity, cardiac enzymes and ICU stay were recorded. There was no significant difference between two groups in changes of electrocardiography, myocardial infarction, left ventricular ejection fraction (LVEF), in hospital mortality and ICU stay but Creatine Kinase Myocardial Band (CK-MB) enzyme was higher in no shunt group, while troponin-I was increased in shunt group. Preoperative LVEF was higher in no-shunt group, but postoperative LVEF was higher in shunt group (p > 0.05). Also, the change of LVEF before and after operation in each group was not significant. Using intracoronary shunt in off pump coronary artery bypass graft leads to less change in cardiac enzymes but had no effect on perioperative and postoperative myocardial infarction, LVEF, mortality and morbidity.