Robust surgery loading

We consider the robust surgery loading problem for a hospital’s operating theatre department, which concerns assigning surgeries and sufficient planned slack to operating room days. The objective is to maximize capacity utilization and minimize the risk of overtime, and thus cancelled patients. This research was performed in collaboration with the Erasmus MC, a large academic hospital in the Netherlands, which has also provided historical data for the experiments. We propose various constructive heuristics and local search methods that use statistical information on surgery durations to exploit the portfolio effect, and thereby to minimize the required slack. We demonstrate that our approach frees a lot of operating room capacity, which may be used to perform additional surgeries. Furthermore, we show that by combining advanced optimization techniques with extensive historical statistical records on surgery durations can significantly improve the operating room department utilization.     

a„Electrisches Fernsehen’' — vor fünfzig Jahren

Ohne ZusammenfassungDie alte Schreibweise ist in den Zitaten beibehalten.     

Anreicherung des Lapine-Virus durch Zerschäumung

Zusammenfassung Es gelingt, das Lapine-Virus vermittels der Schaumadsorption so zu potenzieren, daß die aus den Schäumen hergestellten Verdünnungen im Virulenztest eine Aktivitätssteigerung von 2 Zehnerpotenzen erkennen lassen. Diese Virulenzsteigerung wird auf die bei der Zerschäumung stattfindende Spreitung der Viruspartikel zurückgeführt.     

Kondensationen von Chlorkohlensäure-cholsäureäthylester mit Aminen und Phenolen

Ohne Zusammenfassung     

Simultaneous Quantification of Neomycin and Bacitracin by LC-ELSD

The first simultaneous quantification of neomycin and bacitracin using liquid chromatography evaporative light scattering detection as an alternative to MS detection and pre-/post-column derivatisation, respectively, was the aim of this study. The developed method was validated for two strength of neomycin and one strength of bacitracin in sterile pharmaceutical formulation and is a fast and efficient tool for content uniformity tests in quality control. With this method the separation of neomycin from sulfate and the base line separation of the four major components of bacitracin (bacitracin A, B1, B2 and B3) was achieved. These four components are responsible for 96% of the microbiological activity. A Phenomenex Synergi POLAR analytical column (250 mm × 4.6 mm, 4 μm I.D.) in combination with 0.5% perfluoropropionic acid and acetonitrile in gradient mode, the peaks of interest could be separated with high efficiency within 14 min. The calibration was performed using a second order regression with an R ² = 0.9999 for neomycin (B and C) sulfate and R ² = 0.9996 for bacitracin A, B1, B2 and B3. The results of the accuracy evaluation were 99.2 and 99.7%, respectively, for neomycin and 100.8% for bacitracin. Injection precision results are 0.4–1.5 RSD% recorded for six injections. The established method has a high potential for routine high-throughput analyses in the pharmaceutical industry.     

Eine Schnellmethode zur Bestimmung von Selen

Ohne Zusammenfassung