[en] The shape of the cells and the released material (traces) from migrating adherent cells depends on the cell type, the surface coating of the culture plate, the extracellular matrix, and some other parameters. In our studies we investigated the effect of α-exposure (7-28 particle/cell/h) on cell cultures. C6 glioma cells and 3T3 cell-lines were grown on a 20 μm thick, chemically modified polypropylene foil and exposed to α-particles of an ²⁴¹Am (37 kBq) source through the foil. The average energy of the α particles was calculated by Monte-Carlo simulation of the whole collision cascade through the given pathway in air and in the foil. The α-dose was measured by CR-39 track detectors. Morphological changes of the cells were investigated by phase-contrast optical microscopy and by atomic force microscopy in low force contact mode. The static traces give information about the dynamics of cell migration and about the quality of the extracellular matrix

[en] A method has been worked out for the determination of the thermal neutron flux at 14 MeV neutron generators. A simple model forecasts the thermal flux at new fast neutron facilities. (orig.)

No abstract available

[en] The use of the Scanning Probe Microscope for analyzing latent tracks induced in CR-39 ions of carbon, oxygen and A ∼ 110 ions is described. (author)

[en] Langmuir-Blodgett (LB) multilayers of ferric arachidate on silicon wafers have been investigated by means of conversion electron Moessbauer spectroscopy (CEMS) and absorption Moessbauer spectroscopy (AMS) at different temperatures between 4.2 K and room temperature. At low temperatures we observe antiferromagnetic ordering in the two-dimensional model substance and determined the magnitude and the orientation of the internal magnetic field. We studied the phase transition and found with increasing temperature a slow decrease of the ordered phase, which has completely vanished at 130 K. In the present state it cannot be decided if we just observe superparamagnetic relaxation or if we observe additional effects arising from the low dimensionality of the system. Comparable measurements on small iron arachidate ''LB-particles'' have been performed but no significant difference between the films and the small particles can be observed. This has been expected because the two-dimensional structure is mainly preserved in the ''LB-particles''. (orig.)