We studied the behaviour in interphase and mitotic human cells of a 125 kDa (pI 6.5) antigen, associated with the nuclear matrix and detected in proliferating cells. Indirect immunofluorescence with a specific monoclonal antibody reveals that during interphase in WISH and Namalwa cells, as well as phytohaemagglutinin-stimulated lymphocytes, the antigen displays a speckled distribution in the nucleoplasm of all cells. At early prophase the fluorescence intensity of the coalesced speckles increases markedly. During metaphase and anaphase the antigen gives maximal fluorescence distributed diffusely in the nucleoplasm, while chromosomes remain negative. At anaphase and cytokinesis the antigen is still cytoplasmic, but fluorescence intensity decreases. Two-dimensional gel electrophoresis and immunoblotting reveal that the p125/6.5 antigen displays a net increase in isolated mitotic cells as compared to interphase cells. These results suggest that the p125/6.5 protein participates in late G2 phase and G2/M transition events preparing the cell for mitosis.

In this paper we present for the first time the results from the long-term testing of power p-n diodes, grown on 4H-SiC substrates by liquid phase epitaxy (LPE). A comparison with 4H-SiC p-n diodes, made on commercially available chemical vapor deposition (CVD) p + pn o n + epitaxial wafers within the same device processing, is given. The increase of the forward voltage drop, DV F , as a function of the time for LPE and CVD diodes was observed. The striking feature was that the forward degradation in LPE diodes is expressed in less extent than the CVD ones. The observed lower degradation of the LPE diodes is explained by the lower recombination centers density (<10 13 cm -3 ) in LPE layers and consequently of the lower defects propagation when the diodes are subjected to a current load. At the same time, an increase of the specific on-state resistance is observed, which is explained by the presence of thin transition layer.