Ascending Si diffusion into growing GaN nanowires from the SiC/Si substrate: up to the solubility limit and beyond.

We report a novel mechanism that allows the incorporation of Si into GaN nanowires up to and beyond the solubility limit. This mechanism is documented during the growth on vicinal (misoriented) SiC/Si hybrid substrates having the step bunches. Nanowires that are grown at these locations become heavily Si doped. Such high Si concentrations were verified by secondary-ion mass spectrometry. Photoluminescence data also point to very high carrier concentrations. Moreover, Raman spectroscopy together with quantum chemical modelling shows the build up of Si into Ga sites and indicates even the possibility of the formation of a Ga(Si)N solid solution. The microscopic mechanism responsible for heavy doping and even alloying is diffusion driven by the mechano-chemical effect, which allows for the extremely efficient injection of Si atoms into the nanowires from the step bunches at the vicinal SiC/Si substrates.

Micro-Raman Mapping of 3C-SiC Thin Films Grown by Solid-Gas Phase Epitaxy on Si (111).

A series of 3C-SiC films have been grown by a novel method of solid-gas phase epitaxy and studied by Raman scattering and scanning electron microscopy (SEM). It is shown that during the epitaxial growth in an atmosphere of CO, 3C-SiC films of high crystalline quality, with a thickness of 20 nm up to few hundreds nanometers can be formed on a (111) Si wafer, with a simultaneous growth of voids in the silicon substrate under the SiC film. The presence of these voids has been confirmed by SEM and micro-Raman line-mapping experiments. A significant enhancement of the Raman signal was observed in SiC films grown above the voids, and the mechanisms responsible for this enhancement are discussed.

[Monitoring of infectious diseases among wild boars].

Sixty-seven serum samples and 43 pathological material samples from wild boars, taken in 5 regions of Russia and in the Kharkov Region of the Ukraine in 2002 to 2005 were studied. Wild boars in some regions of Russia were shown to be carriers of Aujeszky's disease virus, porcine parvovirus, porcine circovirus type 2, lymphotropic herpesvirus-1, porcine cytomegalovirus, Mycoplasma hyopneumoniae and Pasteurella multocida. The classical swine fever (CSF) virus genome was detected by polymerase chain reaction in the samples from 10 wild boars from 2 Russian regions (the Tver and Moscow Regions). Sequencing of the E2 gene 5'-terminal region of detected CSF virus isolates showed that they were closely related to two field virus isolates early found in domestic pigs in the Moscow and Vladimir Regions, which suggests that there is an epizootic relation between the SCF outbreaks among wild boars and domestic pigs in these regions. Tests for porcine reproductive and respiratory syndrome, transmissible porcine gastroenteritis, porcine influenza, enteroviruses, and actinobacillus-induced pleuropneumonia were negative in all the regions under study.

[Immunological and biological characteristics of viral isolates of porcine reproductive and respiratory syndrome]. / Immunobiologicheskiie svoistva izoliatov virusa reproduktivnogo i respiratornogo sindroma svinei.

Described in the paper are study results of some immunobiological properties of 5 field isolates of the porcine reproductive and respiratory syndrome virus (PRRSV), obtained in Russia and Byelorussia in 1998-2001. According to the research work, the PRRSV isolates with different immunobiological properties have been circulating in the territories of Russia and Byelorussia. Three of the 4 examined virus isolates were found to be pathogenic and 1 avirulent to pigs.