Electronic structure of ß-RbSm(MoO4)2 and chemical bonding in molybdates.

Microcrystals of orthorhombic rubidium samarium molybdate, ß-RbSm(MoO4)2, have been fabricated by solid state synthesis at T = 450 °C, 70 h, and at T = 600 °C, 150 h. The crystal structure has been refined by the Rietveld method in space group Pbcn with cell parameters a = 5.0984(2), b = 18.9742(6) and c = 8.0449(3) Å (R(B) = 1.72%). Thermal properties of ß-RbSm(MoO4)2 were traced by DSC over the temperature range of T = 20-965 °C, and the earlier reported ß â†” α phase transition at T ∼ 860-910 °C was not verified. The electronic structure of ß-RbSm(MoO4)2 was studied by employing theoretical calculations and X-ray photoelectron spectroscopy. It has been established that the O 2p-like states contribute mainly to the upper part of the valence band and occupy the valence band maximum, whereas the Mo 4d-like states contribute mainly to the lower part of the valence band. Chemical bonding effects have been analysed from the element core level binding energy data. In addition, it was found that the luminescence spectrum of ß-RbSm(MoO4)2 is rather peculiar among the Sm(3+) containing materials. The optical refractive index dispersion in ß-RbSm(MoO4)2 was also predicted by the first-principles calculations.

Defects in GaSe grown by Bridgman method.

Optical quality GaSe crystals have been grown by vertical Bridgman method. The structural properties and micromorphology of a cleaved GaSe(001) surface have been evaluated by RHEED, SEM and AFM. The cleaved GaSe(001) is atomically flat with as low roughness as ∼0.06 nm excepting local hillock type defects. The hillock-type formations are round-shaped with a bottom diameter of ∼200 nm and a height of ∼20-35 nm. The drastic depletion of the hillock material by gallium has been indicated by EDX measurements.

[Monitoring of enterovirus circulation in Irkutsk region].

AIM: Monitoring of circulation of enteroviruses (EVI) in Irkutsk Region and study of regional specter of circulating enteroviruses. MATERIALS AND METHODS: 1419 samples from patients with suspected EVI, contact in foci ofenterovirus infection, acute intestine infections and 964 samples of sewage water were studied in total. In 2011 isolation of viral agents from 97 samples positive on enterovirus by RT-PCR from patients with preliminary EVI diagnosis and 5 samples of sewage water of Irkutsk city was carried out. Transplantable line of human rhabdomyosarcoma RD cell culture was used for isolation of enteroviruses. Infection of cells and 2 serial passages of the studied material were carried out. The isolates were typed in neutralization reaction (NR) with a set of 32 diagnostic type-specific immune sera against viral poliomyelitis I-III; Coxsackie B1-6; Coxsackie A2, A4, A7, A9, A10; ECHO 68 - 71; ECHO 2, 4, 7, 8, 9, 12, 16, 20, 25, 26, 27, 29, 31, 33. RESULTS: In 2011 circulation of enterovirus serotypes that were previously absent on the territory of the region was established: ECHO 68, ECHO 70, ECHO 71. These strains were isolated from patients, circulation of ECHO 70 serotype was established also in samples of sewage water. The analysis of enterovirus landscape carried out showed the possibility of complication of epidemic situation on the territory of the region due to change of serovariants of causative agents of non-polioenterovirus infections and detection ofepidemically significant enteroviruses - ECHO 68, 70 and 71 serotypes. CONCLUSION: Determination of specter ofenterovirus serotypes, detection of serotypes that had not previously circulated in Irkutsk Region allows to prognose epidemic situation on morbidity of enterovirus infections and timely develop and make decisions for ensuring epidemiologic welfare of the population.

Molecular-beam epitaxy-grown Si whisker structures: morphological, optical and electrical properties.

Scanning electron microscopy, spectroscopic ellipsometry, and current-voltage and current-temperature measurements were employed to characterize nanowhisker structures grown by molecular-beam epitaxy on Si(111) substrates. Small clusters of gold deposited on the Si surface were used as the seeds for nanowhisker growth. The diameter of grown nanowhiskers and their length ranged from 70 to 200 nm and from 580 to 890 nm, respectively. The whiskers were found to inherit the (111) orientation of the Si substrate. By means of spectroscopic ellipsometry in the range 1.5-4.77 eV, lateral optical inhomogeneity of the nanowhisker layer was revealed, with optical properties of the layer substantially differing from those of single-crystal Si. Electrical measurements point to the presence of a Schottky barrier with height 0.70 eV in the structure and to the presence of electrically active centers non-uniformly distributed over the nanowhisker length.

[Pharmaceutical aspects of creating an effective drug form of carfecillin]. / Farmatsevticheskie aspekty sozdaniia éffektivnoi lekarstvennoi formy karfetsillina.

Physical and technological parameters of carfecillin powder and carfecillin with auxiliary substances in the form of the powder mixture and granulate were studied comparatively. Possible preparation of carfecillin capsules characterized by high levels of the antibiotic dissolution was shown.