Ekkehard Hoffmann

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A theoretical investigation is presented which allows the calculation of states of maximal reaction rates for single enzymes and for unbranched enzymatic chains. As an extension to previous papers (Heinrich & Holzhütter, 1985, Biomed. biochim. Acta 44, 959-969; Heinrich et al., 1987, Bull. math. Biol. 49, 539-595) a detailed enzymatic mechanism was taken(More)
We use a correlation function analysis of the field quadratures to characterize both the blackbody radiation emitted by a 50 Ω load resistor and the quantum properties of two types of beam splitters in the microwave regime. To this end, we first study vacuum fluctuations as a function of frequency in a Planck spectroscopy experiment and then measure the(More)
Path entanglement constitutes an essential resource in quantum information and communication protocols. Here, we demonstrate frequency-degenerate entanglement between continuous-variable quantum microwaves propagating along two spatially separated paths. We combine a squeezed and a vacuum state using a microwave beam splitter. Via correlation measurements,(More)
Quantum state reconstruction of weak propagating microwaves to date requires the use of linear amplifiers. We introduce a theory which, even in the presence of significant amplifier noise, allows one to use these devices for measuring all quadrature moments of propagating quantum microwaves based on cross correlations from a dual-path amplification setup.(More)
Die Untersuchung HÖRSTAT im Nordwesten Deutschlands ergab, dass rund 16 % der Erwachsenen nach dem Kriterium der Weltgesundheitsorganisation (WHO) schwerhörig sind. Die Belastbarkeit landesweiter Hochrechnungen aus regional durchgeführten epidemiologischen Untersuchungen kann indes infrage gestellt werden. Die Studie „Wie hört Deutschland?“ wurde unabhängig(More)
Optimal values of the rate constants of a reversible enzymatic reaction are calculated by maximizing the enzymatic activity. The results depend on the substrate and product concentrations. Expressions for optimal maximal activities are derived and conclusions are drawn for the optimal ratios of substrate concentrations and Michaelis-constants.
In order to understand the repeated occurrences of auditory impairments caused by toy pistols, an analysis of the circumstances involved was performed at Justus-Liebig University of Giessen. The acoustic impact of toy pistols on the ear was determined with a special measuring system for impulse noise. Results were compared with the acoustic impacts of the(More)
The HÖRSTAT study conducted in Northwest Germany found hearing impairment in approximately 16% of adults when applying the World Health Organization (WHO) criterion. However, the robustness of extrapolations to a national level might be questioned, as the epidemiological data were collected on a regional level. Independently from HÖRSTAT, the “Hearing in(More)