A microscopic theory is used to analyze optical gain in InGaN∕GaN quantum wells (QW). Experimental data are obtained from Hakki–Paoli measurements on edge-emitting lasers for different carrier densities. The simulations are based on the solution of the quantum kinetic Maxwell–Bloch equations, including many-body effects and a self-consistent treatment of piezoelectric fields. The results confirm the validity of a QW gain description for this material system with a substantial inhomogeneous broadening due to structural variation. They also give an estimate of the nonradiative recombination rate.

We report the first experiences with HELP apheresis as an emergency treatment for acute cardiovascular syndromes; two patients who were not eligible for lysis therapy and catheter intervention were treated with HELP apheresis instead. Both patients had a most severe, generalized atherosclerosis and reached the hospital too late for conventional measures. In both cases, the use of the apheresis dramatically improved the clinical situation to such an extent that the possibilities of this apheresis system urge further investigation.