77Se and 87Rb Solid state NMR study of the structure of Rb2[Pd(Se4)2].Se8.

The structure of Rb(2)[Pd(Se(4))(2)].Se(8) has been investigated using (87)Rb magic angle spinning and static NMR and (77)Se magic angle spinning NMR. The number and the integrated intensities of the (87)Rb and (77)Se resonances are in full agreement with the crystallographic structure of the compound. The (87)Rb and (77)Se nuclear spin interaction parameters have been used to characterize the main structural units of the compound: infinite [Rb(Se(8))](x)(x+) columns and polymeric [Pd(Se(4))(2)](x)(2x-) sheet anions.

Optical spectroscopy on Se clusters and chains confined in zeolites.

The incorporation of selenium into the supercages of zeolite Y leads to the formation of Se(8) rings and distorted Se chains in a ratio which is influenced by the nature of the zeolitic cations. Here we review Raman (including resonance Raman) and UV/vis absorption spectroscopy results on Se encapsulated into a number of cation-exchanged faujasite zeolites. Both rings and chains give rise to characteristic Raman bands. In particular, low-frequency Raman bands are attributed to localized vibrations in ordered segments of distorted chains. The UV/vis absorption spectra indicate an opening of the band gap of selenium upon confinement in these zeolites. This can be reversed through electronic interaction with zeolite cations.

Experimental infection of inbred mice with herpes simplex virus. II. Interferon production and activation of natural killer cells in the peritoneal exudate.

The peritoneal exudate cells (PEC) represent the first line of defence against the virus in the mouse model of intraperitoneal (i.p.) infection with herpes simplex virus (HSV). We have therefore studied interferon production and activation of natural killer (NK) cells in vitro in PEC of HSV-injected mice. Injection of HSV caused a marked increase in NK cell activity, as reported by others. PEC from HSV-injected mice also produced high titres of interferon. This observation may be important since induction of interferon appears to be the primary event whereas activation of NK cells - as generally accepted - represents a secondary effect of the interferon produced. The HSV-induced NK cells shared the properties of NK cells in that they were sensitive to a monoclonal anti-theta antibody and to a monoclonal anti-Qa 5 antibody. In contrast, the cells producing interferon were not sensitive to either antibody. Irradiation (200 R) of the mice 24 h before injection of the virus decreased interferon production by more than 90%. The identity of the interferon-producing cells is unknown, but they may represent B cells.