[Effects of overlapping induction on the utilization of complex operating structures: estimation using the practical application of a simulation model]. / Effekte von überlappenden Einleitungen auf die Auslastung einer komplexen OP-Struktur : Einschätzung mithilfe der praktischen Anwendung eines Simulationsmodells.

Reduction of costs or increase in efficiency may lead to optimization of cost-effectiveness in operating rooms. Overlapping induction by additional anesthesia teams reduces the changeover time between surgical interventions and, therefore, increases utilization effectiveness of surgical theatres. From an economic point of view overlapping induction should be performed where the highest increase in efficacy and revenues is possible. This article presents a software tool to vary the number of anesthesia teams in different single or clustered operating rooms. Using the example of a university hospital it could be demonstrated that the simulated addition of one anesthesia team to different clusters of operations rooms resulted in an increase of 15-40 % of operations and an increase up to 81 % of utilization effectiveness. Therefore, the presented simulation tool may help to estimate the maximum effect of staff allocation in surgical theatres.

Characterisation of antibiotic moenomycin A interaction with phospholipid model membranes.

Using a combination of physico-chemical techniques (MAS NMR, DSC, freeze-fracture electron microscopy, molecular modelling) the antibiotic moenomycin A was found to be anchored by its hydrophobic chain into multilamellar POPC membranes. The lamellar phase structure of the modified membrane is retained, while moenomycin A in water at different concentrations does not form any other but isotropic phase structures. The mobility of POPC molecule segments is reduced with increasing moenomycin A concentrations. Freeze-fracture electron microscopy images show ripple like structures for low moenomycin A concentrations, which are rare for high concentrations. A sugar-group network of the antibiotic seems to cover the whole membrane surface for molar ratios moenomycin A/POPC of 1:2, which is supported by 13C-MAS (Magic Angle Spinning) 31P-NMR, and molecular modelling.

Ligand binding and conformational motions in myoglobin.

Myoglobin, a small globular haem protein that binds gaseous ligands such as O2, CO and NO reversibly at the haem iron, serves as a model for studying structural and dynamic aspects of protein reactions. Time-resolved spectroscopic measurements after photodissociation of the ligand revealed a complex ligand-binding reaction with multiple kinetic intermediates, resulting from protein relaxation and movements of the ligand within the protein. To observe the structural changes induced by ligand dissociation, we have carried out X-ray crystallographic investigations of carbon monoxy-myoglobin (MbCO mutant L29W) crystals illuminated below and above 180 K, complemented by time-resolved infrared spectroscopy of CO rebinding. Here we show that below 180 K photodissociated ligands migrate to specific sites within an internal cavity--the distal haem pocket--of an essentially immobilized, frozen protein, from where they subsequently rebind by thermally activated barrier crossing. Upon photodissociation above 180 K, ligands escape from the distal pocket, aided by protein fluctuations that transiently open exit channels. We recover most of the ligands in a cavity on the opposite side of the haem group.