Investigation of the angular distribution and energy spectrum of fast ions produced during irradiation of targets by short laser pulses in the SOKOL-P facility

Results are presented from experimental investigations of the angular distributions and energy spectra of fast ions produced in deuterium polyethylene targets under irradiation by picosecond laser pulses with intensities of up to 2 × 10¹⁸ W/cm² in the SOKOL-P facility. The parameters of ion fluxes were measured by time-of-flight spectrometers based on semiconductor detectors.     

The effect of hypoxia on the urokinase and adenylate cyclase systems in the culture of endothelial cells of the human umbilical vein

Hypoxia induces angiogenesis in ischemized tissues by means of pro-angiogenic factor expression. The key role in the growth processes and blood vessel functioning belongs to the matrix metalloproteinases, plasminogen, and its activator systems. Effect of hypoxia on expression of the urokinase activating agent plasminogen and its receptor in endothelium was studied in human umbilical vein endothelial cell model. Incubation of the endothelial cells under the conditions of hypoxia proved to reduce both urokinase formation in these cells and its secreting into the culture medium. The hypoxia-induced reduction of urokinase contents was accompanied by enhancement of expression of the urokinase receptor. The hypoxia also entailed reduction of the adenylate cyclase activity and cAMP contents in the endothelial cells. The data obtained suggest that reduction of the adenylate cyclase activity and cAMP contents under the conditions of hypoxia provide basis for suppression of the urokinase expression by the endothelial cells and, consequently, inhibition of blood vessel formation in the ischemized tissue.     

Fibulin-5 binds urokinase-type plasminogen activator and mediates urokinase-stimulated β1-integrin-dependent cell migration

uPA (urokinase-type plasminogen activator) stimulates cell migration through multiple pathways, including formation of plasmin and extracellular metalloproteinases, and binding to the uPAR (uPA receptor; also known as CD87), integrins and LRP1 (low-density lipoprotein receptor-related protein 1) which activate intracellular signalling pathways. In the present paper we report that uPA-mediated cell migration requires an interaction with fibulin-5. uPA stimulates migration of wild-type MEFs (mouse embryonic fibroblasts) (Fbln5+/+ MEFs), but has no effect on fibulin-5-deficient (Fbln5-/-) MEFs. Migration of MEFs in response to uPA requires an interaction of fibulin-5 with integrins, as MEFs expressing a mutant fibulin-5 incapable of binding integrins (Fbln(RGE/RGE) MEFs) do not migrate in response to uPA. Moreover, a blocking anti-(human β1-integrin) antibody inhibited the migration of PASMCs (pulmonary arterial smooth muscle cells) in response to uPA. Binding of uPA to fibulin-5 generates plasmin, which excises the integrin-binding N-terminal cbEGF (Ca2+-binding epidermal growth factor)-like domain, leading to loss of β1-integrin binding. We suggest that uPA promotes cell migration by binding to fibulin-5, initiating its cleavage by plasmin, which leads to its dissociation from β1-integrin and thereby unblocks the capacity of integrin to facilitate cell motility.     

Comparing Morphological and Molecular Estimates of Species Diversity in the Freshwater Genus Synura (Stramenopiles): A Model for Understanding Diversity of Eukaryotic Microorganisms

We performed a comparison of molecular and morphological diversity in a freshwater colonial genus Synura (Chrysophyceae, Stramenopiles), using the island of Newfoundland (Canada) as a case study. We examined the morphological species diversity in collections from 79 localities, and compared these findings to diversity based on molecular characters for 150 strains isolated from the same sites. Of 27 species or species-level lineages identified, only one third was recorded by both molecular and morphological techniques, showing both approaches are complementary in estimating species diversity within this genus. Eight taxa, each representing young evolutionary lineages, were recovered only by sequencing of isolated colonies, whereas ten species were recovered only microscopically. Our complex investigation, involving both morphological and molecular examinations, indicates that our knowledge of Synura diversity is still poor, limited only to a few well-studied areas. We revealed considerable cryptic diversity within the core S. petersenii and S. leptorrhabda lineages. We further resolved the phylogenetic position of two previously described taxa, S. kristiansenii and S. petersenii f. praefracta, propose species-level status for S. petersenii f. praefracta, and describe three new species, S. vinlandica, S. fluviatilis, and S. cornuta. Our findings add to the growing body of literature detailing distribution patterns observed in the genus, ranging from cosmopolitan species, to highly restricted taxa, to species such as S. hibernica found along coastal regions on multiple continents. Finally, our study illustrates the usefulness of combining detailed morphological information with gene sequence data to examine species diversity within chrysophyte algae.     

The investigation of the composition of liquid radioactive waste

In investigation the process of composition sediment of liquid unorganic radioactive waste, that are forming in cistern-selectors at PNPI RAS, it was discovered apart from great quantity of ions of different metals and radionuclides considerable maintenance of organic material (to 30% and more from volume of sediment) unknown origin. A supposition was made about its microbiological origin. Investigation shows, that the main microorganisms, setting this sediment, are the bacterious of Pseudomonas kind, capable of effectively bind in process of grow the radionuclide 90Sr, that confirms the potential posibility of using this microorganisms for bioremediation of liquid low radioactive wastes (LRW).     

Splign: algorithms for computing spliced alignments with identification of paralogs

Background  

The computation of accurate alignments of cDNA sequences against a genome is at the foundation of modern genome annotation pipelines. Several factors such as presence of paralogs, small exons, non-consensus splice signals, sequencing errors and polymorphic sites pose recognized difficulties to existing spliced alignment algorithms.     

Composite fluorine polymer-containing sorbents for isolation and purification of biopolymers

Composite fluoropolymer-containing sorbents based on porous silicas were synthesized for the isolation and purification of biopolymers under nondenaturing conditions. Examples of the application of these sorbents in the separation of various mixtures of peptides and proteins and purification of nucleic acids from various sources (plasmid DNA and DNA from nucleated human blood cells) using the cartridge, column, and batch (sorption in a stirred volume) methods are presented. It was shown that the sorbents can be used in laboratory practice because they are selective to nucleic acids (DNA and RNA) and proteins. These materials combine the mechanical properties of the inorganic matrix with the specific sorption properties of the polymer phase and exhibit enhanced stability to alkaline hydrolysis. Alternative methods of preparing sorbents containing polytetrafluoroethylene, polytrifluorostyrene, and polyfluorobutadiene are described. By the example of polyfluorobutadiene-containing sorbents, a completely new method for obtaining fluorinated polymer phases was developed: the polymer phase was preliminarily formed on the surface of porous disperse carriers and was fluorinated with xenon difluoride.