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Adhesive strength formation is studied for the epoxy-anhydride matrix–fiber systems under different curing conditions. It is shown that strength formation occurs in several stages. The change in the degree of curing and the glass transition temperature during the curing process is also studied. [ABSTRACT FROM AUTHOR]

The physical-mechanical properties of epoxy matrices modified with polyethersulfone (PES) and unidirectional glass- and carbon-fiber-reinforced plastics (GFRP and CFRP) based on them were investigated. The fracture toughness of epoxy matrices modified with 20 wt% PES, increased by 4.3 times. The delamination energy of GFRP and CFRP with this content of PES in the matrix increases by 50 and 65%, respectively. A correlation between the fracture toughness of modified matrices and the delamination toughness of GFRP and CFRP was established, and the influence of structure of the matrices on the fracture toughness of the reinforced plastics was demonstrated. A significant increase in the fracture toughness of the matrices and reinforced plastics was also observed during the formation of extended phases enriched with PES. [ABSTRACT FROM AUTHOR]

To elucidate the colonization routes of the grey red-backed vole on Iturup Island based on the distribution and abundance of haplotypes of the mitochondrial cytochrome b gene fragment (662 bp), comparative analysis of the genetic variation of vole populations from different localities along the island perimeter and voles from Hokkaido, Kunashir, and Sakhalin islands, and as well as adjacent mainland areas, was carried out. All studied specimens of the grey red-backed voles from Iturup Island (68) were represented by a single haplotype that was the closest to the haplotypes of voles from Sakhalin Island. Only one specimen from Kunashir Island (the closest to Iturup), had the same haplotype. Three more specimens from this island were close to the haplotypes of voles from Sakhalin Island and fell into the same clade, while most of the haplotypes of Kunashir voles were close to the haplotypes of Hokkaido voles and together with them formed an independent clade, which was genetically very different from Sakhalin and Iturup voles. The obtained data on genetic variation of voles from Iturup Island strongly support recent introduction of the grey red-backed vole C. rufocanus to this island, most likely through the sea transport from Sakhalin. [ABSTRACT FROM AUTHOR]

An epoxy polysulfone binder modified with an active diluent, furfuryl glycidyl ether (FGE), is studied. The addition of FGE significantly improves the technological parameters of the high-viscosity binder. The processing temperature of modified binders varies in the range of 80 to 120°C depending on the FGE concentration. The phase decomposition of the binder during its preparation is not observed, but occurred during curing. The glass transition temperature of matrices based on the obtained binder remains at a high level: 100–107°С. The type of phase structure formed during the curing of the hybrid binder depends on the concentration of FGE and polysulfone PSK-1. [ABSTRACT FROM AUTHOR]

The application ability of oligomeric copolyimides (OCPI) as epoxy resin modifiers of fiber-reinforced composites was investigated. For this purpose, the properties of epoxy resin compositions based on an ED-20 epoxy resin and iso-MTHPA modified by oligomeric copolyimides with terminal anhydride groups were studied. It is shown that the incorporation of OCPI into the ED-20 epoxy resin does not reduce the manufacturability of the initial binder (the viscosity of all binders is almost similar in composite formation conditions), increases the "binder-fiber" interface strength (the growth in the adhesive strength reaches 40%) and can slightly improve or reduce the heat capacity (the alteration in the glass-temperature is ± 16-22°C). The magnitude of the effects obtained depends on the amount of injected oligoimide amount and its structure. An analysis of the results obtained allows us to suggest that the reactive oligomers can serve as modifiers of the epoxydiane resin in the production of fiber-reinforced structural plastics. [ABSTRACT FROM AUTHOR]

An epoxy resin modified with polysulfone (PSK-1) and furfuryl glycidyl ether (FGE) has been studied. It is shown that the addition of the active diluent FGE significantly reduces the viscosity of the epoxy–polysulfone blends. The obtained blends can be processed by traditional methods at low temperatures (from 40 to 80°C). The process of phase decomposition of a homogeneous initial blend occurs during the curing of the composition. Depending on the concentration of PSK-1 and FGE in ED-20, structures of the "matrix–dispersion" type can be formed during phase decomposition. [ABSTRACT FROM AUTHOR]

Geographic isolation is among the most important factors initiating speciation in mammals. The narrow-headed vole Lasiopodomys gregalis is a widely distributed species in steppe habitats of South Siberia that are highly fragmented by mountain ranges. There are three major mostly allopatric mitochondrial lineages of L. gregalis described throughout the distribution range that most plausibly split in the Middle Pleistocene. This study applies the analysis of five microsatellite loci and species distribution modelling to understand the patterns of isolation and migration between L. gregalis populations in South Siberia and in particular in Tuva basin where all three lineages occur simultaneously. Microsatellite analysis supported the population differentiation revealed previously, with three clusters corresponding to mitochondrial lineages and indicated that gene flow between them is strongly limited. There were only traces of hybridisation in the population near the contact zone of lineages B and C. SDM analysis predicted only a small number of potential contact zones between L. gregalis lineages and barriers corresponding to landscape heterogeneity. We presume that the forested mountain ranges act as the main insurmountable barriers to gene flow between major genetic lineages of L. gregalis. [ABSTRACT FROM AUTHOR]

Background: PROX1 is a specific target of the β-catenin/TCF pathway in the intestinal epithelium. It acts as a regulator of progression from a benign to a highly dysplastic phenotype in colorectal tumours. However, the clinical significance of PROX1 expression is not known.Methods: We studied the prognostic value of immunohistochemical expression of PROX1 in a series of 517 patients with colorectal cancer (CRC).Results: The majority of the tumour samples expressed PROX1 (91%, 471 out of 517). High PROX1 expression was associated with a poor grade of tumour differentiation (P<0.0001). In the subgroup of patients with colon cancer, high PROX1 expression was associated with unfavourable colorectal cancer-specific survival (CCSS) as compared with low PROX1 expression (CCSS 47% vs 62%; P=0.045; RR 1.47). The association between high PROX1 and poor outcome was further strengthened in female colon cancer patients (CCSS 38% vs 63%; P=0.007; RR 2.02). Nonetheless, in multivariate survival analysis PROX1 expression was not retained as an independent prognostic factor.Conclusion: High PROX1 expression is associated with a poor grade of tumour differentiation, and, in colon cancer patients, also with less favourable patient outcome. Our results strengthen the previous preclinical observations that PROX1 has a role in tumour progression in CRC. [ABSTRACT FROM AUTHOR]

Lymphatic vasculature has recently emerged as a prominent area in biomedical research because of its essential role in the maintenance of normal fluid homeostasis and the involvement in pathogenesis of several human diseases, such as solid tumor metastasis, inflammation and lymphedema. Identification of lymphatic endothelial specific markers and regulators, such as VEGFR-3, VEGF-C/D, PROX1, podoplanin, LYVE-1, ephrinB2 and FOXC2, and the development of mouse models have laid a foundation for our understanding of the major steps controlling growth and remodeling of lymphatic vessels. In this review we summarize recent advances in the field and discuss how this knowledge as well as use of model organisms, such as zebrafish and Xenopus, should allow further in depth analysis of the lymphatic vascular system. [ABSTRACT FROM AUTHOR]