Electronic excitations in B12As2 and their temperature dependence by vacuum ultraviolet ellipsometry.

The dielectric response function of epitaxial B(12)As(2) films on 4H-SiC was determined at room temperature and at 10 K in the spectral region of 3.6-9.8 eV, i.e., in the vacuum ultraviolet (VUV) spectral region, by synchrotron ellipsometry. The experimental dielectric function was simulated with the critical point parabolic band model. The parameters of the dispersive structures were derived by numerical fitting of the experimental data to the proposed model. New high energy optical transitions are resolved at 5.95, 7.8 and 8.82 eV and their lineshape and origin are discussed. The temperature dependence of the critical point energies and transition strengths was determined, and the excitonic effect is considered.

Semi-empirical AM1 calculation of the solvent effect on the fluorescence spectra of some dihydroquinolinones.

The COnductor-like Screening MOdel of solvent-solute interactions of Klamt and Schüürmann, COSMO, at the semiempirical AM1 level of MO calculations, augmented by limited singles and doubles configuration interaction, proves useful for the study of solvent induced shifts of fluorescence spectra. Optimization of geometry of ground S0 and excited S1 states for each solvent separately provides estimates of the changes of solvation energy accompanying the electron transition process and helps the understanding of the related solvent-solute reorganization and fluorescence mechanisms.

[Functional criteria for differentiating blast cells in acute leukemia]. / Funktsionalni kriterii za diferentsiatsiiata na blastnite kletki pri ostra levkoza.

Eighty nine patients were examined that had various clinical-morphological forms of acute leukosis, the phagocytic activity of leukosis cells being determined and the synthesis and secretion of lysozyme by them followed up, reflected in its serum level. Leukosis cells of monoblast type were established to have the ability to ingest staphylococci, candida and particles of latex, as well as to synthesize lysozyme, confirmed by the highly elevated enzyme quantity in the sera of the patients. Those functional manifestations are proposed to be used as additional criteria in the determination of cellular type of leukosis proliferation.