Complete Minimal Kähler Surfaces in R6

We construct the first examples of minimal Kähler surfaces in R⁶ which are irreducible and neither holomorphic nor complex ruled.     

Application of the laser microprobe mass analyzer (LAMMA) to qualitative and quantitative single cell analysis

The laser microprobe mass analyzer (LAMMA ) is a new type of analytical instrument. It is a combination of a laser microscope with a time-of-flight (TOF ) mass spectrometer. By focusing an UV pulse laser beam onto the specimen positive and negative atomic and molecular ions are formed which are detected by the TOF mass analyzer. The detection limits reach 10^–20 g for some elements in an excited sample volume of 10^–13 cm³. With the aim of finding out whether the LAMMA instrument is capable of quantitative measurements on very small biological samples the ²³Na⁺ and ³⁹K⁺ contents of single mycobacterial cells (M. tuberculosis H 37 Ra) were measured and the results were compared with those obtained from “integral” methods (AAS, NAA , tracer). Furthermore, the influence of different temperatures applied during the washing procedure of the bacteria on the distribution of the Na⁺/K⁺ ratio within the cell population was investigated. First attempts to trace isonicotinic acid hydrazide (INH) in bacteria were made by comparison of the LAMMA spectra of INH treated and untreated cells.     

1H and 13C chemical shifts and coupling constants of lupane. Application of two-dimensional NMR techniques

2D NMR techniques (J-resolved ¹³C, ¹³C? ¹³C correlated, ¹H? ¹³C correlated) were used to gather more chemical shift and coupling information on the pentacyclic triterpene, lupane. They confirm and complete ¹³C assignments made earlier, and corroborate the constitution and major configurational details of lupane. Lupane is a parent compound and spectral reference in the study of sedimental demethylated triterpenes.     

Eine Erweiterung der Infinitesimalrechnung

Ohne Zusammenfassung     

Über das Löwnersche Ellipsoid und sein Analogon unter den einem Eikörper einbeschriebenen Ellipsoiden

Ohne ZusammenfassungDie Anregung zu meinem Teil an dieser Arbeit empfing ich im Rahmen eines Forschungsstipendiums. Ich möchte daher der Deutschen Forschungsgemeinschaft auch an dieser Stelle meinen Dank aussprechen. ludwig danzer.