Expression of Doublecortin,Glial Fibrillar Acidic Protein,and Vimentin in the Intact Subpallium and after Traumatic Injury to the Pallium in Juvenile Salmon,Oncorhynchus masou

Fetalization associated with a delay in development and the preservation of the features of the embryonic structure of the brain dominates the ontogeny of salmonids. The aim of the present study was to comparatively analyze the distribution of the glial-type aNSC markers such as vimentin and glial fibrillar acidic protein (GFAP) and the migratory neuronal precursors such as doublecortin in the telencephalon subpallium of juvenile masu salmon, Oncorhynchus masou, in normal conditions and at 1 week after an injury to the dorsal pallium. Immunohistochemical labeling of vimentin, GFAP, and doublecortin in the pallium of intact juvenile masu salmon revealed single cells with similar morphologies corresponding to a persistent pool of neuronal and/or glial progenitors. The study of the posttraumatic process showed the presence of intensely GFAP-labeled cells of the neuroepithelial type that form reactive neurogenic zones in all areas of the subpallial zone of juvenile masu salmon. A comparative analysis of the distribution of radial glia in the dorsal, ventral, and lateral zones of the subpallium showed a maximum concentration of cells in the dorsal part of subpallium (VD) and a minimum concentration in the lateral part of subpallium VL. An essential feature of posttraumatic immunolabeling in the masu salmon subpallium is the GFAP distribution patterns that are granular intracellular in the apical periventricular zone (PVZ) and fibrillar extracellular in the subventricular (SVZ) and parenchymal zones (PZ). In contrast to those in intact animals, most of the GFAP+ granules and constitutive neurogenic niches in injured fish were localized in the basal part of the PVZ. With the traumatic injury to the subpallium, the number of Vim+ cells in the lateral and ventral regions significantly increased. At 1 week post-injury, the total immunolabeling of vimentin cells in the PVZ was replaced by the granular pattern of Vim immunodistribution spreading from the PVZ to the SVZ and deeper parenchymal layers of the brain in all areas of the subpallium. A significant increase in the number of DC+ cells was observed also in all areas of the subpallium. The number of cells increased both in the PVZ and in the SVZ, as well as in the deeper PZ. Thus, at 1 week after the injury to the dorsal pallium, the number of DC, Vim, and GFAP expressing cells of the neuroepithelial type in the subpallium of juvenile masu salmon increased, and additionally GFAP+ radial glia appeared in VD, which was absent from intact animals.     

Microwave image reconstruction from 3-D fields coupled to 2-D parameter estimation

An efficient Gauss-Newton iterative imaging technique utilizing a three-dimensional (3-D) field solution coupled to a two-dimensional (2-D) parameter estimation scheme (3-D/2-D) is presented for microwave tomographic imaging in medical applications. While electromagnetic wave propagation is described fully by a 3-D vector field, a 3-D scalar model has been applied to improve the efficiency of the iterative reconstruction process with apparently limited reduction in accuracy. In addition, the image recovery has been restricted to 2-D but is generalizable to three dimensions. Image artifacts related primarily to 3-D effects are reduced when compared with results from an entirely two-dimensional inversion (2-D/2-D). Important advances in terms of improving algorithmic efficiency include use of a block solver for computing the field solutions and application of the dual mesh scheme and adjoint approach for Jacobian construction. Methods which enhance the image quality such as the log-magnitude/unwrapped phase minimization were also applied. Results obtained from synthetic measurement data show that the new 3-D/2-D algorithm consistently outperforms its 2-D/2-D counterpart in terms of reducing the effective imaging slice thickness in both permittivity and conductivity images over a range of inclusion sizes and background medium contrasts.     

Insights into Mechanisms of Damage Recognition and Catalysis by APE1-like Enzymes

Apurinic/apyrimidinic (AP) endonucleases are the key DNA repair enzymes in the base excision repair (BER) pathway, and are responsible for hydrolyzing phosphodiester bonds on the 5′ side of an AP site. The enzymes can recognize not only AP sites but also some types of damaged bases, such as 1,N⁶-ethenoadenosine, α-adenosine, and 5,6-dihydrouridine. Here, to elucidate the mechanism underlying such a broad substrate specificity as that of AP endonucleases, we performed a computational study of four homologous APE1-like endonucleases: insect (Drosophila melanogaster) Rrp1, amphibian (Xenopus laevis) APE1 (xAPE1), fish (Danio rerio) APE1 (zAPE1), and human APE1 (hAPE1). The contact between the amino acid residues of the active site of each homologous APE1-like enzyme and the set of damaged DNA substrates was analyzed. A comparison of molecular dynamic simulation data with the known catalytic efficiency of these enzymes allowed us to gain a deep insight into the differences in the efficiency of the cleavage of various damaged nucleotides. The obtained data support that the amino acid residues within the “damage recognition” loop containing residues Asn222–Ala230 significantly affect the catalytic-complex formation. Moreover, every damaged nucleotide has its unique position and a specific set of interactions with the amino acid residues of the active site.     

Joint redundancy and maintenance optimization for multistate series–parallel systems

This paper formulates the joint redundancy and replacement schedule optimization problem generalized to multistate system, where the system and its components have a range of performance levels. Multistate system reliability is defined as the ability to maintain a specified performance level. The system elements are chosen from a list of available products on the market and the number of such elements is determined for each system component. Each element is characterized by its capacity, reliability and cost. The reliability of a system element is characterized by its lifetime distribution with the hazard rate, which increases with time. It is specified as the expected number of failures during different time intervals. The optimal system structure and the number of element replacements during the study period are defined as those which provide the desired level of system reliability with minimal sum of costs of capital investments, maintenance and unsupplied demand caused by failures. A universal generating function technique is applied to evaluate the multistate system reliability. A genetic algorithm is used as an optimization technique. Examples of determination of the optimal system structure and replacement schedule are provided.     

Aromatic Polyimides as Efficient Materials for Organic Electroluminescent Devices

Derivatives of newly synthesized aromatic polyimides containing sulphur atoms in the backbone were studied as electron–hole-transporting and light-emitting materials for use in combination with tris(8-hydroxyquinoline)-aluminium in multilayer organic electroluminescent devices. Efficient bipolar charge transport has been revealed in the polymers. Bright electroluminescence (15000cdm^-2 at 14V) was observed in the visible range. The possible role of intermolecular donor–acceptor interactions in the mechanism of electroluminescence is discussed. © of SCI.     

Toward understanding the reaction between silicon carbide and iridium in a broad temperature range

The reaction between iridium and SiC in the 1000°C–1900°C temperature range was studied in details. The rate of this reaction was found to depend not only on temperature, but also on the grain sizes of the initial reagents, oxygen impurities in SiC, as well as the Ir: SiC ratio. The use of fine-grained initial reagents accelerates the reaction, whereas oxygen impurities in SiC powders slow it down. For the Ir: SiC ratio = 1:1, the IrSi silicide phase became dominant at 1400°C and remained the main phase at temperatures up to 1900°C. For the 3:1 ratio, Ir₂Si was the main phase at 1900°C. It was suggested that stabilization of this phase is due to the quenching effect. No Si-rich silicide phases were detected in the 1000°C–1900°C temperature range. The coefficients of thermal expansion of silicide phases were determined by high-temperature X-ray diffraction analysis.     

Pyrolysis of Complexes of Metallosulphophthalocyanines with Chitosan for Obtaining Graphite-Like Structures

Journal of Inorganic and Organometallic Polymers and Materials - The pyrolysis of chitosan and its polymeric complexes with metal phthalocyanines was studied by thermochemical and spectral methods....     

Carbon nanomaterials based on plant biopolymers as radionuclides sorbent

Abstract

The technogenic human activities associated with the operation of nuclear power facilities lead to the contamination of natural water bodies and soils with radioactive substances, including heavy radionuclides, such as uranium and thorium. Purification of natural water bodies is a pressing environmental issue. A study of the adsorption capacity for heavy U²³⁸ and Th²³² radionuclides by the samples of new carbon nanomaterials was conducted. Nanocarbon materials was synthesized based on vegetal polymers, such as technical lignin, starch and from lignocellulosic material—the bark. It was established that the investigated samples have different sorption indices in relation to radionuclides, which is determined by their chemical composition, as well as by the surface-capillary properties of carbonized materials. It is shown that the content of mobile and fixed forms of radionuclides on the investigated sorbents are significantly different. High sorption capacity of the carbonated lignin sample with respect to uranium are shown. A sample of nanocarbon materials synthesized based on the lignocellulosic complex of the bark exhibits high sorption properties in relation to thorium. The possibility of using the carbonic nanomaterial as the sorbents of radionuclides is shown.     

Thermoelectric properties of W1−xNbxSe2−ySy polycrystalline compounds

We investigate the thermoelectric properties of bulk polycrystalline samples of WSe₂-based compounds with partial substitutions in the cationic (W) and the anionic (Se) sublattices in the temperature range from 4.2 to 650 K. The substitution of W for Nb leads to a significant increase in the charge carrier concentration, however, deteriorates the charge carrier mobility. In contrast, the substitution of selenium for sulfur increases the charge carrier mobility, the thermal conductivity, and the Seebeck coefficient but conductivity changes non-monotonical. We show that the addition of sulfur in anionic sublattice affects the grain sizes in the polycrystalline material. Using substitutions in the anionic and cationic sublattices, we find the optimal ratio of the elements for better thermoelectric efficiency. The W_0.98Nb_0.02Se_1.7S_0.3 sample showed the best value of the figure of merit ZT = 0.26 (T = 650 K).