The Low-Temperature Sol-Gel Synthesis of Metal-Oxide Films on Polymer Substrates and the Determination of Their Optical and Dielectric Properties

Photoactive, optically transparent heterostructures from silver nanowires and titanium dioxide were obtained by the sol-gel method on the surface of a polyethylene terephthalate film. The characteristics of optical transmission on the wavelength and those of dielectric permittivity, conductivity and dissipation on frequency in the range of 25-1,000,000 Hz were investigated.

[SCREENING ASSESSMENT OF MATERIALS THROMBOGENICITY BY THE NUMBER OF PLATELETS ADHERED FROM THE FLOWING NATIVE BLOOD]

The materials used in the construction of implants contacting with blood should be resistant to thrombus formation. One of the stages of a thrombogenicity assessment of materials is to determine the number of platelets adhered to its surface during the exposure to flowing blood under ex viAvo conditions. The aim of this study was to develop a modified test for screening assessment of materials for their thrombogenicity in contact with native blood. For the purpose of the study, flow chambers of were developed, allowing to mountain simultaneously 16 material samples. The chamber was connected to the circulatory system of the experimental animal through arterial and venous ports in such a way that blood, passing through the chamber, returned to the animal. The exposure time was 1 min. After perfusion the samples were rinsed and stained. The number of platelets adhered per unit area was calculated automatically that allowed significant error diminution. A total of 9 experiments were carried out on pigs under ex vivo conditions. The method was validated using standard samples of pyrolytic carbon, VT-6 titanium, glass, and polytetrafluorethylene as reference materials. New materials for synthetic vascular prostheses have been investigated. The developed technique makes it possible to study the thrombogenicity of polymeric materials with sufficient reliability.

Dual-Mode Solution Plasma Processing for the Production of Chitosan/Ag Composites with the Antibacterial Effect

The development of novel biocompatible and biodegradable materials for medical applications has been drawing significant interest in the scientific community for years. Particularly, chitosan loaded with silver nanoparticles (Ag NPs) has a strong antimicrobial potential and could be applied, for example, as wound dressing material. In this work, chitosan/Ag NP composites were produced utilizing a single-step plasma-solution process, which is simple and environmentally friendly. An acetic solution of chitosan containing AgNO₃ was treated by the direct current (DC) atmospheric pressure glow discharge, with the liquid serving as either cathode or anode. The plasma-solution system with liquid anode is more useful for the production of Ag NPs. Nevertheless, the NP size is comparable for both cases. The plasma treatment with both polarities led to chitosan degradation. The cleavage of glucosidic chains mostly occurred in the system with the liquid cathode, whereas the side oxidation reactions took place when the solution served as the anode. The oxidation processes were possibly induced by the hydrogen peroxide H₂O₂ efficiently formed in the last case. The composite materials produced with both polarities of liquid electrode demonstrated the bactericidal action against Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus, and Gram-positive Bacillus subtilis.

Plasma-liquid synthesis of MoOx and WO3 as potential photocatalysts

Plasmas in contact with liquids represent a green chemistry method for the synthesis of metal oxides. In this work, underwater plasma was used for the synthesis of molybdenum and tungsten oxides. The obtained samples were analyzed by various techniques. Results showed that underwater plasma with Mo electrodes allows obtaining non-stoichiometric molybdenum oxide (MoOx). In the case of tungsten electrodes, monoclinic WO3 was formed. The synthesized oxides have a wide band gap (3.21 eV for MoOx and 3.27 eV for WO3). The photocatalytic and sorption activities of the synthesized oxides towards the decomposition of cationic and anionic dyes (Methylene Blue, Rhodamine B, and Reactive Red 6C) were studied. MoOx shows excellent photocatalytic performance under UV and visible light irradiation. The photocatalytic activity of WO3 under visible light is less than that under UV irradiation.

The version of microevolutionary relationships between the Siberian species Elymus margaritae, E. komarovii, and E. transbaicalensis (Poaceae) according to sequencing of the nuclear gene GBSS1 (waxy)

A comparative study was made of the sequence of the GBSS1 gene fragment in accessions of closely related species Elymus margaritae, E. komarovii, and E. transbaicalensis from Siberia. Nucleotide sequences of the gene were determined for St subgenomes in accessions of E. margaritae and E. komarovii from classical habitats. The StH-genomic constitution was confirmed, and microevolutionary relationships between species were evaluated by constructing the NJ dendrogram. It was shown that variants of the St subgenomes in accessions E. margaritae GUK-1009 and E. komarovii AUK-9803 belong to the North American ancestral line St2 of the genus Pseudoroegneria, in contrast to accessions E. margaritae AUK-0650 and E. komarovii GAR-0501. The latter belong to the Asian branch of St1, together with variants of subgenomes in the species E. gmelinii and E. pendulinus. That is, according to the differentiation levels of the St subgenome, accession E. margaritae GUK-1009 (holotype) is significantly distanted from the accession AUK-0650 (paratype), which in turn is close to accessions of E. komarovii and E. transbaicalensis from East Sayan. According to levels of differentiation of the H subgenome, the studied species did not show noticeable differences.

Assessment of the variability of Elymus caninus (Poaceae) and closely related taxa from Russia and Kazakhstan using ISSR markers

A comparative study of taxa that are morphologically close to Elymus caninus, occurring in the territory of Russia and Kazakhstan, was carried out based on the ISSR molecular fingerprints. Data showed that the studied taxa are groups of individuals phylogenetically closely related to E. caninus. The assumption is confirmed that E. viridiglumis, as an Elymus species, has a polyphyletic origin as a part of microevolutionary processes in populations E. caninus s. l., possibly involving E. mutabilis. For the Caucasian endemic E. prokudinii and Kazakhstan endemic E. goloskokovii, the origin as result of introgression or spontaneous mutagenesis, i.e. a manifestation of the natural intraspecific polymorphism of E. caninus, is also assumed.

Structural and Thermal Properties of Montmorillonite/Ionic Liquid Composites

Composites of montmorillonite K10 (MMT K10) and ionic liquid (IL) containing a 1-butyl-3-methyl-imidazolium cation ([BMIm]⁺) and various anions, such as bis (trifluoromethylsulfonyl) imide ([NTf₂]⁻), trifluoromethanesulfonate ([OTf]⁻), and dicyanamide ([DCA]⁻) have been obtained in this work. A number of methods, such as dynamic light scattering (DLS), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermal gravimetry (TG), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy, and nitrogen adsorption–desorption have been used to characterize clay, and to study the structure and thermal behaviour of the composites. It has been found that the MMT K10 powder has a narrow particle size distribution with a peak at 246 nm and a mesoporous structure (S_BET=195 m²/g). According to the FTIR spectra, MMT K10/IL interaction depends on the IL type. It has been identified that confined ionic liquid interacts with both clay and adsorbed water in accordance with the hydrophilicity and size of the anion, in the following order: [DCA]⁻ > [OTf]⁻ > [NTf₂]⁻. Characteristic temperatures of glass transition, crystallization, and melting have been determined for the ionic liquids under study and their MMT K10 composites. It has been revealed that when IL is adsorbed on the surface of clay, the phase transitions in IL change. The greatest changes are observed in the case of BMImNTf₂. By applying the method of thermogravimetric analysis, it is shown that composite formation is accompanied by a decrease in the IL thermal stability. Apparently, the highly developed surface of montmorillonite K10, obtained by acid treatment, plays a major role in the decrease in the IL’s thermal stability. The influence of the IL anion on the thermal and spectral characteristics of an MMT K10/IL composite was studied for the first time.

The MAR databases: development and implementation of databases specific for marine metagenomics

We introduce the marine databases; MarRef, MarDB and MarCat (https://mmp.sfb.uit.no/databases/), which are publicly available resources that promote marine research and innovation. These data resources, which have been implemented in the Marine Metagenomics Portal (MMP) (https://mmp.sfb.uit.no/), are collections of richly annotated and manually curated contextual (metadata) and sequence databases representing three tiers of accuracy. While MarRef is a database for completely sequenced marine prokaryotic genomes, which represent a marine prokaryote reference genome database, MarDB includes all incomplete sequenced prokaryotic genomes regardless level of completeness. The last database, MarCat, represents a gene (protein) catalog of uncultivable (and cultivable) marine genes and proteins derived from marine metagenomics samples. The first versions of MarRef and MarDB contain 612 and 3726 records, respectively. Each record is built up of 106 metadata fields including attributes for sampling, sequencing, assembly and annotation in addition to the organism and taxonomic information. Currently, MarCat contains 1227 records with 55 metadata fields. Ontologies and controlled vocabularies are used in the contextual databases to enhance consistency. The user-friendly web interface lets the visitors browse, filter and search in the contextual databases and perform BLAST searches against the corresponding sequence databases. All contextual and sequence databases are freely accessible and downloadable from https://s1.sfb.uit.no/public/mar/.

Genome composition and assessment of the divergence between Russian boreal species in the genus Elymus (Poaceae) detected on the basis of sequencing of the nuclear gene GBSSI

A comparative study of the sequence of GBSSI gene fragments in 10 species of the genus Elymus growing in the territory of Asian Russia was carried out. Data on the genomic composition and on the levels of interspecific divergence were obtained. This information is a necessary requirement for the construction of phylogenetically oriented taxonomic system of the genus Elymus within Russia.

Identification of artificial interspecific hybrids in the genus Elymus (Poaceae) by using ISSRmarkers

Reproductive relationships between species of the genus Elymus (Poaceae) from mixed populations of the Southern Urals were studied. The true hybrids were identified by using ISSR-markers in comparison with parental biotypes. The presence in the true hybrids of species-specific ISSR-bands from both parental forms is provided by high level of homozygosity of species in genus Elymus, as a result of predominant self-pollination.

Experimental study on the possibility of treatment of some hemorrhagic fevers

After intracerebral challenge with 100 PFU of Lassa virus (strain Josiah), all infected mice (CBA/calac) died (control group). Production of pro-inflammatory cytokines (IL-1beta, TNF-alpha) significantly increased in the blood of these mice during the infection. For neutralization of increasing concentrations of these cytokines recombinant IL-1RA was used intraperitonealy at a dose 100 microg kg(-1), everyday, within 5 days from the third day after the challenge. Injections of IL-1RA decreased the concentration of IL-1beta and TNF-alpha and resulted in survival of all infected mice (treatment group). Marburg fever (strain Popp) caused in guinea pigs by 5 LD(50) of virus lead to the significant increase of TNF-alpha in the animal's blood and caused a lethal outcome (control group). Treatment of infected guinea pigs by IL-1RA or anti-TNF serum decreased the concentration of TNF-alpha and resulted in survival of half of the animals (treatment group). For the treatment recombinant IL-1RA was used at a dose 100 microg kg(-1), intramuscularly, everyday, within 6 days from the third day after the challenge or anti-TNF serum, intramuscularly 0.5 ml (2000 U ml(-1); 1 U of the antiserum neutralises 0.03 ng of TNF-alpha), everyday, within 6 days from the third day after the challenge.

Genotyping of measles virus isolates from central Europe and Russia

Sequence analysis of 285 nucleotides located on the variable part of the N gene was undertaken on measles virus (MV) samples collected from acutely infected patients in Germany, the Czech Republic, Denmark, Poland, and Russia. Two distinct genotypes (C2 and D6) have circulated in Germany between 1993 and 1996. Isolates of genotype C2 were related to strains reported in Germany before 1993. This genotype was also found in the Czech Republic in 1992 and in Denmark in 1997. The occurrence of genotype D6 in Germany is described below for the first time. In 1998, this genotype was identified in Poland. Genotypes C2 and D6 were also reported in Spain and in the United Kingdom between 1992 and 1996. Therefore, it is concluded that these genotypes are widely distributed over Europe. The analysis of the isolates from Russia revealed that genotype A was present in 1988 in the European part of the country and in 1996 in Siberia. An isolate identified in 1997 in Siberia belonged to genotype D6, which had never been found previously in Russia. We also analysed MV obtained from a case of subacute sclerosing panencephalitis (SSPE) in 1995 in Turkey. A comparison of this sequence with published sequences implied that this SSPE case was associated with a new genetic lineage of MV.