Quantum Chaos and Quantum Randomness - Paradigms of Entropy Production on the Smallest Scales

Quantum chaos is presented as a paradigm of information processing by dynamical systems at the bottom of the range of phase-space scales. Starting with a brief review of classical chaos as entropy flow from micro- to macro-scales, I argue that quantum chaos came as an indispensable rectification, removing inconsistencies related to entropy in classical chaos: Bottom-up information currents require an inexhaustible entropy production and a diverging information density in phase space, reminiscent of Gibbs' paradox in Statistical Mechanics. It is shown how a mere discretization of the state space of classical models already entails phenomena similar to hallmarks of quantum chaos, and how the unitary time evolution in a closed system directly implies the ''quantum death'' of classical chaos. As complementary evidence, I discuss quantum chaos under continuous measurement. Here, the two-way exchange of information with a macroscopic apparatus opens an inexhaustible source of entropy and lifts the limitations implied by unitary quantum dynamics in closed systems. The infiltration of fresh entropy restores permanent chaotic dynamics in observed quantum systems. Could other instances of stochasticity in quantum mechanics be interpreted in a similar guise? Where observed quantum systems generate randomness, that is, produce entropy without discernible source, could it have infiltrated from the macroscopic meter? This speculation is worked out for the case of spin measurement.Comment: 41 pages, 17 figure

Extracorporeal life support in patients with acute myocardial infarction complicated by cardiogenic shock - Design and rationale of the ECLS-SHOCK trial

Background In acute myocardial infarction complicated by cardiogenic shock the use of mechanical circulatory support devices remains controversial and data from randomized clinical trials are very limited. Extracorporeal life support (ECLS) venoarterial extracorporeal membrane oxygenation provides the strongest hemodynamic support in addition to oxygenation. However, despite increasing use it has not yet been properly investigated in randomized trials. Therefore, a prospective randomized adequately powered clinical trial is warranted. Study Design The ECLS-SHOCK trial is a 420-patient controlled, international, multicenter, randomized, open-label trial. It is designed to compare whether treatment with ECLS in addition to early revascularization with percutaneous coronary intervention or alternatively coronary artery bypass grafting and optimal medical treatment is beneficial in comparison to no-ECLS in patients with severe infarct-related cardiogenic shock. Patients will be randomized in a 1:1 fashion to one of the two treatment arms. The primary efficacy endpoint of ECLS-SHOCK is 30-day mortality. Secondary outcome measures such as hemodynamic, laboratory, and clinical parameters will serve as surrogate endpoints for prognosis. Furthermore, a longer follow-up at 6 and 12 months will be performed including quality of life assessment. Safety endpoints include peripheral ischemic vascular complications, bleeding and stroke. Conclusions The ECLS-SHOCK trial will address essential questions of efficacy and safety of ECLS in addition to early revascularization in acute myocardial infarction complicated by cardiogenic shock