Biomedical subjects

J Karger

Publications and source records attributed to J Karger.

4 recordsLinked to original sources

PubMed2000

Anisotropic diffusion in a nematic liquid crystal- An electric field PFG NMR approach

The access to self-diffusion coefficients in anisotropic systems such as thermotropic liquid crystals by means of PFG NMR is complicated by strong dipolar interactions. Additionally, problems arise due to the immediate orientation of low-molar-mass nematic liquid crystals in an external field. The director orientation can be changed by the application of an additional electric field. This can be exploited in order to reduce the dipolar interaction to such an extent that the NMR linewidths change from a solid-state to a liquid-like situation enabling PFG NMR experiments. Copyright 2000 Academic Press.

Journal Article↗

PubMed1997

Pulsed Field Gradient NMR Self-Diffusion Study in Distinct Phases of the Ternary System Water/n -Heptane/Igepal CA-520

We report on self-diffusion measurements of all the components in distinct phases of the ternary system water/n -heptane/Igepal CA-520 with pulsed field gradient NMR. The phases are also investigated with electron microscopy. The observed self-diffusion coefficients are discussed in comparison with the structural data obtained from the micrographs. They intimately reflect the effect of the phase state and phase boundaries on the molecular transport in this system.

Journal Article↗

PubMed1996

NMR Studies of Single-File Diffusion in Unidimensional Channel Zeolites

Single-file diffusion is the restricted propagation of particles that cannot pass each other. The occurrence of this phenomenon should be reflected by a change in the time dependence of the mean particle displacement in comparison with ordinary diffusion. Although this process is considered to be the rate-controlling mechanism in a large variety of processes, so far no direct evidence of this phenomenon has been provided. Diffusion measurements made with pulsed field gradient nuclear magnetic resonance (NMR) in unidimensional pore systems (zeolites AlPO4-5 and Theta-1) reflect the expected time dependence of single-file diffusion.

Journal Article↗

PubMed1989

[The cito-laboratory information system CILIS].

The cito-laboratory of a big hospital must be able to work a higher number of cito-analyzes economically and with a high degree of security and to send back the results as fast as possible to the demander. For that reason the simple employment of efficient analytical methods or tools is not sufficient. The cito-laboratory-information-system CILIS is able to support all the steps of work, which are necessary to workout cyto-results and to send them back to the demander. It is also able to relieve the nurses as well as the MTLA from writing and recording. CILIS is based on the computer A 5120. It is usable in other comparable institutions and with certain restrictions to further development or enlargement. In our hospital the system has been working since november 1986 during the regular shift and the shift from 2 pm till 10 pm and partly on working days from 10 pm to 7 am and respectively at the weekend. Since that time it has been approved excellently.

Germany, East↗