Endoscopy in the Paul trap: The influence of the micromotion

We show that three real-valued parameters govern the quantum motion of an ion stored in the Paul trap. These parameters are two angles of rotation in phase space and a squeezing parameter. The time dependence of these parameters simplifies considerably using Floquet solutions. This allows us to use the method of quantum state endoscopy to measure a pure state of the vibratory motion of an ion taking into account the full time dependence of the trapping potential. Received: 19 June 1996     

Zur Konstitution der bimolekularen Fettsäurecyanide

Ohne Zusammenfassung     

Sensing of oxygen in microtiter plates: a novel tool for screening drugs against pathogenic yeasts

Most antibiotics were discovered via their inhibition of growth of target organisms. However, yeasts in particular have the capability to adapt metabolic pathways to the availability of nutrients e.g. yeasts can easily switch between respiratory and fermentative pathways in response to oxygen concentration, or can even use both simultaneously. Thus, we cultivated S. cerevisiae BY4741 and C. albicans 1386 in microtiter plates with integrated oxygen sensors to characterize the availability of oxygen for the organisms and to detect influences of fungicides on the oxygen consumption rates. The relevance of the respiratory pathway was indicated by the almost total consumption of oxygen during the first 1–3 h of the cultivation in the microtiter plates, when an increase in turbidity could hardly be seen. Moreover, the sensitivity of S. cerevisiae to inhibitors of the respiratory chain, such as myxothiazol, could be detected via a reduced oxygen consumption rate, whereas no inhibition of growth was observed. Thus, not only was the sensitivity of the test organism for the test compound detectable, but the affected pathway was also highlighted. Other compounds, such as pyrrolnitrin and ambruticin VS-3, inhibited growth of C. albicans 1386 and of S. cerevisiae (only pyrrolnitrin), which was additionally observed as reduced oxygen consumption rates. Thus, the determination of oxygen in microtiter plates via fluorescent dyes is a versatile supplement to standard growth inhibition tests.