Effect of acidic treatment of the chemical composition and bacterial oxidation of arsenic-bearing gold concentrate

Effect of acidic pretreatment of arsenic-bearing gold concentrate, a promising gold source, on its chemical composition and efficiency of its bacterial oxidation (BO) was studied. The titer of sulfobacilli during BO of the concentrate after high-temperature acidic treatment was 9.0 × 10⁷ cells/ml, the degree of arsenic sulfide oxidation being 71.1%, and in the control, 6.5 × 10⁷ cells/ml with the oxidation degree as low as 48.7%. Deeper oxidation of the main gold-containing mineral, arsenic sulfide, would allow more efficient gold recovery from the concentrate.     

The degree of infestation of ixodid ticks,collected from humans,with the tick-borne encephalitis virus in the territory of tomsk and its environs

Tick-borne encephalitis (TBE) virus was determined in ticks I. persulcatus and I. pavlovskyi, collected from humans attacked by ticks in city parks, forest-parks in city outskirts, and in suburban forests, by the enzymelinked immunosorbent assay method (ELISA). It was found that, in spite of I. pavlovskyi being the dominating species in Tomsk and its suburbs, the majority of ticks that attacked humans belonged to I. persulcatus. In ticks that possessed no sighs of the beginning of engorgement (hungry ticks), infestation with TBE virus was revealed by ELISA method less frequently. Percentage of I. persulcatus and I. pavlovskyi, infested with TBE virus, constituted 9.43 % and 3.7 %, respectively. In partly engorged ticks, it constituted 48.78 % and 35.0 %, respectively. In suburban forests, humans were also attacked by I. persulcatus more frequently. In this species, the fraction of infested specimens constituted 12.73 % and 41.54 % in partly engorged and hungry ticks, respectively. In I. pavlovskyi, this percentage constituted 6.06 % and 25 %, respectively. In other words, in all the groups examined, the fraction of infested ticks was noticeably lower in I. pavlovskyi; at the same time, the TBE virus is significantly more frequently revealed in partly engorged ticks.     

Microbial Biofilms in the Proshchal’naya Karst Cave (Far East,Russia)

Microbiology - Effect of abiotic (composition of drip and fracture water) and biotic factors (composition and activity of microbial complexes) on biofilm formation in the Proshchal’naya karst...     

Role of the microbial community in formation of speleothem (moonmilk) in the Snezhnaya carst cave (abkhazia)

The results of investigation of speleothem (moonmilk) from the Snezhnaya cave (West Caucasus, Abkhazia) are reported. The structure of microbial complexes from moonmilk was investigated by quantitative PCR; strains of culturable microorganisms were isolated and their preferred temperature and carbon sources were determined. Among eubacteria, ~34% belonged to the iron bacteria (Rhodoferax). Most bacterial strains were shown to be facultative psychrophiles with the maximum growth rate at 4°C. The microstructure and elemental composition of moonmilk were investigated using a scanning electron microscope (EVO-40HV, Carl Zeiss) and silicon drift X-ray detector X-MAX 80mm². The visually plastic and homogeneous mass of moonmilk was shown to be highly heterogeneous, containing various microstructures. The elemental composition of some nanostructures depended on the structure of bacterial biofilms. Some loci of the biofilm were found to contain up to 46% (wt/wt) of iron oxides. High calcium content, up to 61.5% (wt/wt), was found only in cubic crystalline structures which were not involved in microbiological processes.     

Downregulation of expression of mater genes <Emphasis Type="Italic">SOX9, FOXA2</Emphasis>, and <Emphasis Type="Italic">GATA4</Emphasis> in pancreatic cancer cells stimulated with TGFβ1 epithelial–mesenchymal transition

We show characteristic morphological changes corresponding to epithelial–mesenchymal transition (EMT) program fulfillment in PANC1 cell line stimulated with TGFβ1. Our results support downregulation of E-cadherin protein. We show 5- and 28-fold increase in SNAI1 and SNAI2 expression levels and 25- and 15-fold decrease in CDH1 and KRT8 expression levels, respectively, which confirms the EMT-program fulfillment. We demonstrate downregulation of expression of pancreatic master genes SOX9, FOXA2, and GATA4 (2-, 5-, and 4-fold, respectively) and absence of significant changes in HES1, NR5A2, and GATA6 expression levels in the cells stimulated with TGFβ1. Our results indicate the absence of induction of expression of PTF1A, PDX1, HNF1b, NEUROG3, RPBJL, NKX6.1, and ONECUT1 genes, which are inactive in PANC1 cell line after the EMT stimulated by TGFβ1.     

Microbiological factors of the formation of iron-containing minerals

In the present study, the process of biofilm formation in iron-containing aqueous medium in the presence of different organic compounds with different bioavailability (yeast extract, peptone, and humic substances) is considered. Investigations conducted using a scanning electronic microscope and X-ray diffraction analysis allow us to reveal the presence of biologically produced goethite (α-FeOOH) in the crystal structure. It was supposed that the supply of surface waters contaminated with organic compounds to ironcontaining underground waters could increase the risk of plugging aquifer pore space by biogenic iron-containing minerals.     

Polymorphism of Glutathione S-Transferase Genes M1 and T1 in Patients with Motor Neuron Disease from the Moscow Population

Comparison of the frequency distributions of alleles, genotypes, and genotype combinations of genes GSTM1and GSTT1 did not show statistically significant differences between patients with motor neuron disease (MND) and a random sample from the Moscow population. Apparently, these genes are not involved in MND pathogenesis in these patients.     

Bioindication of transboundary pollution of the Amur River with aromatic hydrocarbons after the technogenic accident in China

Applying bioindication methods for estimation of the ecological risk under pollution of aquatic ecosystems with hydrocarbons is discussed. The consequences of the transboundary pollution of the Amur River ecosystem with benzene derivatives released after the technogenic accident at a petroleum chemical plant in China are analyzed. Responses of microbial complexes involved in self-purification of water and accumulation of toxic substances in fish are considered.     

Brain-derived neurotrophic factor gene (BDNF) polymorphism among Moscow citizens

Recent studies showed that brain-derived neurotrophic factor (BDNF) can participate in pathogenesis of various CNS disorders, being connected with proliferation, differentiation, and survival of neurons. In present study, analysis of occurrence rate was performed for three single nucleotide polymorphisms (SNPs) located in BDNF gene (rs6267 (A/G) allele A—0.265; rs2049046 (A/T) allele A—0.407; rs11030107 (A/G) allele A—0.872) in randomized selection of Moscow citizens. Linkage disequilibrium of rs6165 and rs2049046 loci was shown. Differences in allele frequencies in studied selection and populations of other regions were discovered.