Investigation of the mechanism for rapid heating of nitrogen and air in gas discharges

A rapid heating of nitrogen-oxygen mixtures excited by gas discharges is investigated numerically with allowance for the following main processes: the reactions of predissociation of highly excited electronic states of oxygen molecules (which are populated via electron impact or via the quenching of the excited states of N₂ molecules), the reactions of quenching of the excited atoms O(¹ D) by nitrogen molecules, the VT relaxation reactions, etc. The calculated results adequately describe available experimental data on the dynamics of air heating in gas-discharge plasmas. It is shown that, over a broad range of values of the reduced electric field E/N, gas heating is maintained by a fixed fraction of the discharge power that is expended on the excitation of the electronic degrees of freedom of molecules (for discharges in air, η_E?28%). The lower the oxygen content of the mixture, the smaller the quantity η_E. The question of a rapid heating of nitrogen with a small admixture of oxygen is discussed.     

Effects of Myostatin and Growth Factors on Cultured Human Cells

A dedicated cell-based biological test system was used to study specific effects of myostatin and other human growth factors on the proliferation of cultured myoblasts and fibroblasts. Myostatin inhibited myoblast growth without affecting human fibroblasts. In this test system, human growth hormone and insulin-like growth factor I acted as antagonists of myostatin, which indicates that these agents have a potential for blocking its effects in vivo.     

Amyloidogenic domains, prions and structural inheritance: rudiments of early life or recent acquisition?

Amyloids are self-assembled fibre-like beta-rich protein aggregates. Amyloidogenic prion proteins propagate amyloid state in vivo and transmit it via infection or in cell divisions. While amyloid aggregation may occur in the absence of any other proteins, in vivo propagation of the amyloid state requires chaperone helpers. Yeast prion proteins contain prion domains which include distinct aggregation and propagation elements, responsible for these functions. Known aggregation and propagation elements are short in length and composed of relatively simple sequences, indicating possible ancient origin. Prion-like self-assembled structures could be involved in the initial steps of biological compartmentalization in early life.     

Systemic cytokine response in murine anthrax

Systemic pro-inflammatory cytokine release has been previously implicated as a major death-causing factor in anthrax, however, direct data have been absent. We determined the levels of IL-1 beta, IL-6 and TNF-alpha in serum of mice challenged with virulent (Ames) or attenuated (Sterne) strains of Bacillus anthracis. More than 10-fold increase in the IL-1beta levels was detected in Ames-challenged Balb/c mice, in contrast to more susceptible C57BL/6 mice, which showed no IL-1beta response. Balb/c mice have also responded with higher levels of IL-6. The A/J mice demonstrated IL-1beta and IL-6 systemic response to either Ames or Sterne strain of B. anthracis, whereas no increase in TNF-alpha was detected in any murine strain. We used RT-PCR for gene expression analyses in the liver which often is a major source of cytokines and one of the main targets in infectious diseases. A/J mice challenged with B. anthracis (Sterne) showed increased gene expression for Fas, FasL, Bax, IL-1 beta, TNF-alpha, TGF-beta, MIP-1alpha, KC and RANTES. These data favour the hypothesis that apoptotic cell death during anthrax infection causes chemokine-induced transmigration of inflammatory cells to vitally important organs such as liver. Administration of caspase inhibitors z-VAD-fmk and ac-YVAD-cmk improved survival in Sterne-challenged mice indicating a pathogenic role of apoptosis in anthrax.     

Photochemiluminescent detection of antiradical activity. V. Application in combination with the hydrogen peroxide-initiated chemiluminescence of blood plasma proteins to evaluate antioxidant homeostasis in humans

Disturbance of the steady state between pro- and antioxidants in tissues is an important aetiopathogenetic factor. Two method--(i) photosensitized chemiluminescence for detection of antiradical activity and (ii) hydrogen peroxide-initiated chemiluminescence of plasma proteins (CLP) and erythrocytes (CLE)--were tested in 136 healthy donors and 82 patients with untreated breast tumours for their applicability to detecting disturbances in antioxidant homeostasis in humans. The total antiradical capacity of water-soluble substances (ACW) and its urate-independent proportion (ACU) were lower (P <0.05) and CLP higher (P <0.001) in smokers in comparison to non-smokers. A significant negative correlation was found between the content of ascorbate in plasma and the intensity of CLP: r = -0.39, P <0.001. A significant reduction in ACU and increased values of CLP and CLE were seen according to the stage of disease in breast cancer patients. On the basis of these observations and model experiments we suggest that hydrogen peroxide-initiated chemiluminescence can serve as a parameter of oxidative modification of blood components and, in combination with the antioxidant parameters, can be used to describe the antioxidant homeostasis in humans and possibly to have value as a predictor of disease states.     

Analysis of kinetic parameters of gas phase bioreactors

The dependence of toluene elimination capacity on its load was obtained in five small-scale reactors filled with glass beads carrying biocatalyst cells. With increase in operation time the calculated maximal elimination capacity was shown to increase along with biomass density in the biocatalyst bed. Fivefold increase in trickling intensity did not affect the reactor performance. A simplified mathematical model for evaluation of minimal required biocatalyst bed volume at certain loading was developed based on experimental dependence of elimination capacity vs. loading.     

Secondary metabolites and lipids in Chara globularis Thuill

Sterols, volatiles and lipid fatty acids were analysed in the fresh-water alga Chara globularis. Five sterols, two of them new for the genus, were identified, together with 12 fatty acids from lipids. The volatiles appeared to form a complex mixture, containing mainly acids (part of them chlorinated), terpenoids, ketones, hydrocarbons, etc. No flavonoids have been found. Antibacterial activity of extracts has been tested, unpolar extracts showed moderate activity.     

Comparative Genome Analysis in Two Flax Species by C-Banding Patterns

C-banding patterns of the karyotypes of two closely related wild flax species, Linum austriacumL. (2n= 18) and Linum grandiflorumDesf. (2n= 16), were studied. The karyotypes of both species were similar in the chromosome morphology and size. In each species, metacentric and acrocentric chromosomes (1.7–4.3 m) and one satellite chromosome were observed. In the karyotypes of the species studied, all homologous chromosome pairs were identified, and quantitative idiograms were constructed. Eight chromosome pairs in the two species had similar C-banding patterns. A low level of intraspecific polymorphism in the intercalary and telomeric C-bands was shown in both species. The results indicate that the genomes of two flax species originated from one ancestral genome with the basic chromosome number of 8 or 9. Apparently, the duplication or loss of one chromosome with subsequent redistribution of the chromosome material in the ancestral form resulted in the divergence into two species,L. austriacumL. and L. grandiflorumDesf. A considerable similarity of chromosomes in these species provides evidence for their close phylogenetic relatedness, which makes it possible to place them in one section within the Linumgenus.     

Comparative study of the structure of some genetic probes used for typing Yersinia pestis strains

A nucleotide sequence common for genetic probes used for detection and investigation of Y. pestis strains MK, IS100, and HRSIII was identified on the basis of restriction, hybridization, and computer analysis. This region of chromosomal DNA is a part of low-molecular BX-probe (about 170 bp) we have developed. The results of genomic fingerprinting of Y. pestis strains by the BX-probe are promising as regards its future utilization for typing the strains isolated in various endemic areas.     

Physocalycoside,a new phenylethanoid glycoside from Phlomis physocalyx Hub.-Mor

A new phenylethanoid tetraglycoside, physocalycoside (2), was isolated from the aerial parts of Phlomis physocalyx. Its structure was identified as 3-hydroxy-4-methoxy-beta-phenylethoxy-O-[alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)]-4-O-feruloyl-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside, on the basis of spectroscopic evidence. In addition, one known iridoid glucoside, lamiide (1) and five known phenylethanoid glycosides, wiedemannioside C (3), verbascoside (= acteoside) (4), leucosceptoside A (5), martynoside (6), and forsythoside B (7) were also characterized. Compounds 2-7 demonstrated radical scavenging properties towards the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical.