Investigation of supramolecular structure of the rare and rare-earth elements nanoparticles carrier when modified using microwave irradiation

In this paper, we present an IR and XRD study of the polypropylene fibrous nanoparticles carrier when its surface modified with rare and rare-earth elements nanoparticles using microwave irradiation, by the example of SnO2/TiO2 hetero-nanoparticles. The paper shows that the smectic mesomorph structure of the non-modified polypropylene fibrous carrier transforms into the monoclinic α-crystalline due to microwave irradiation. At the same time, the carrier material remains stereoregular and keeps its helical structure

Superficial acid-base properties of polymer fibres

Protolytic properties of fine fibre plastics based on polypropylene, polyethyleneterephthalate and polycarbonate were investigated. Acidic (carboxylic, hydroxyl) and basic Lewis sites (esters, carbonates, epoxies) were discovered on fibres surface using IR spectroscopy. The number of active groups of various nature and their pKa values were evaluated by potentiometric titration in aqueous and non-aqueous media. The tested fibres possess a low capacity for both acidic and basic sites on it. The results indicate that all the polymer fibre materials (PFM) due to the presence of carboxyl groups on the surfaces, enable modification of their surfaces with metal nanoparticles, thereby giving them unique properties, e.g., photocatalytic and bactericidal

Theory of selective excitation in Stimulated Raman Scattering

A semiclassical model is used to investigate the possibility of selectively exciting one of two closely spaced, uncoupled Raman transitions. The duration of the intense pump pulse that creates the Raman coherence is shorter than the vibrational period of a molecule (impulsive regime of interaction). Pulse shapes are found that provide either enhancement or suppression of particular vibrational excitations.Comment: RevTeX4,10 pages, 5 figures, submitted to Phys.Rev.

Hydrogen sensors based on In2O3 thin films with bimetallic Pt/Pd catalysts on the surface and tin and dysprosium impuri-ties in the bulk

This paper presents the results of studying the characteristics of hydrogen sensors based on thin In2O3 films modified with tin and dysprosium with dispersed double Pt/Pd catalysts deposited on the surface. To control the content of Sn and Dy in the films, an original technology was developed, and ceramic targets were fabricated from powders of the In–Dy–O, Dy–Sn–O, and In–Dy–Sn–O systems synthesized by the sol–gel method. Films of complex composition were obtained by RF magnetron sputtering of the corresponding targets. Structural features of the obtained thin films were studied by Raman spectroscopy. It is shown that various combinations of tin and dysprosium concentrations, as well as the presence of Pt/Pd catalysts on the surface, have a significant effect on the defectiveness of the films and the density of oxygen adsorption centers. As a result, the resistance of sensors in pure air (R0), the activation energies of the temperature dependences of R0, the bending of the energy bands at the grain boundaries of the semiconductor, and the responses to the action of hydrogen in the concentration range of 20–25,000 ppm change. A unique feature of Pt/Pd/ In2O3: Sn (0.5 at%), Dy (4.95 at%) films is their high sensitivity at 20–100 ppm and the absence of signal saturation in the region of high hydrogen concentrations of 5000–25,000 ppm, allowing them to be used to detect H2 in a wide range of concentrations

The study of the sorghum genetic diversity using the mul¬tiplex microsatellite analysis

This study is focused on evaluation of the genetic structure and diversity of the national sorghum collection. Analyzing the genetic diversity of crop species is of great importance for genetic resources management and food security of any country. Huge genetic diversity of sorghum provides a great opportunity to improve the agronomic characteristics of this crop. The efficiency of microsatellite  analysis has been demonstrated in many studies on the genetic diversity of different races and geographical groups of sorghum plants. Development of multiplex PCR analysis systems based on a set of polymorphic microsatellite loci will facilitate genetic tests on a large number of plant samples, thus making the research on sorghum diversity more efficient and comprehensive. A system of multiplex PCR analysis based on 12 polymorphic microsatellite loci was developed to perform single-stage high-throughput screening of cultivated and wild forms preserved in the sorghum germplasm collection. As a result of the microsatellite analysis of 200 sorghum plants, 229 alleles were detected. The studied loci showed high polymorphism. More than 17 alleles were identified in most loci, their polymorphic index content (PIC) ranging from 0.694 to 0.954. The value of the effective multiplex ratio (EMR) in the developed system was estimated at 0.833. The microsatellite analysis of sorghum accessions resulted in obtaining quantized gene expressions profiles, with a DNA profile for each accession, and revealed significant polymorphism among the plants of different sorghum varieties (races). The developed multiplex PCR system was shown to be efficient for evaluation of the genetic diversity and genetic relationships of sorghum plants from different races. The analysis of the obtained data using three bioinformatic techniques, NJ cluster analysis, PCoA, and the Bayesian model-based clustering, helped to classify the analyzed sorghum accessions into cluster groups according to their morphological and agronomic traits

Negative heterosis for meiotic recombination rate in spermatocytes of the domestic chicken Gallus gallus

Benefits and costs of meiotic recombination are a matter of discussion. Because recombination breaks allele combinations already tested by natural selection and generates new ones of unpredictable fitness, a high recombination rate is generally beneficial for the populations living in a fluctuating or a rapidly changing environment and costly in a stable environment. Besides genetic benefits and costs, there are cytological effects of recombination, both positive and negative. Recombination is necessary for chromosome synapsis and segregation. However, it involves a massive generation of double-strand DNA breaks, erroneous repair of which may lead to germ cell death or various mutations and chromosome rearrangements. Thus, the benefits of recombination (generation of new allele combinations) would prevail over its costs (occurrence of deleterious mutations) as long as the population remains sufficiently heterogeneous. Using immunolocalization of MLH1, a mismatch repair protein, at the synaptonemal complexes, we examined the number and distribution of recombination nodules in spermatocytes of two chicken breeds with high (Pervomai) and low (Russian Crested) recombination rates and their F1 hybrids and backcrosses. We detected negative heterosis for recombination rate in the F1 hybrids. Backcrosses to the Pervomai breed were rather homogenous and showed an intermediate recombination rate. The differences in overall recombination rate between the breeds, hybrids and backcrosses were mainly determined by the differences in the crossing over number in the seven largest macrochromosomes. The decrease in recombination rate in F1 is probably determined by difficulties in homology matching between the DNA sequences of genetically divergent breeds. The suppression of recombination in the hybrids may impede gene flow between parapatric populations and therefore accelerate their genetic divergence

Germline-restricted chromosome (GRC) is widespread among songbirds

An unusual supernumerary chromosome has been reported for two related avian species, the zebra and Bengalese finches. This large, germline-restricted chromosome (GRC) is eliminated from somatic cells and spermatids and transmitted via oocytes only. Its origin, distribution among avian lineages, and function were mostly unknown so far. Using immunolocalization of key meiotic proteins, we found that GRCs of varying size and genetic content are present in all 16 songbird species investigated and absent from germline genomes of all eight examined bird species from other avian orders. Results of fluorescent in situ hybridization of microdissected GRC probes and their sequencing indicate that GRCs show little homology between songbird species and contain a variety of repetitive elements and unique sequences with paralogs in the somatic genome. Our data suggest that the GRC evolved in the common ancestor of all songbirds and underwent significant changes in the extant descendant lineages

Аберрантный ангиогенез в ткани головного мозга при экспериментальной болезни Альцгеймера

The aim was to study the molecular mechanisms of the violation of the structural and functional integrity ofthe blood-brain barrier in chronic neurodegeneration of the Alzheimer’s type associated with the development of cerebral angiopathy.Materials and methods. The transgenic model of Alzheimer’s disease is the B6SLJ-Tg line mice (APPSwFlLon,PSEN1 * M146L * L286V) 6799Vas group which includes 9 months aged males. The control group included C57BL / 6 x SJL mice, males aged 9 months.Results. The total length of the vessels in the area of the dentate gyrus is 2.5 times greater in transgenic animal models of Alzheimer’s disease than in animals of the control group (p < 0.01). The average diameter of blood vessels in all areas of the hippocampus is smaller compared with the control (p < 0.05). Transgenic modeling of neurodegeneration in the CA2 zone of the hippocampus increases the relative area of tissue with increased permeability of blood-brain barrier (BBB) (17.80 [9.15; 36.75]) compared to control (1.38 [0.04; 7.60]) at p < 0.05. A similar difference (p < 0.05) is also observed in the hippocampal area CA1. A tendency (p > 0.05) to decrease the number of CD31+ endothelial cells in the dentate gyrus of the hippocampus (21.52 [17.56; 24.50]) in animals of the experimental group compared with the control group (23.08[21.18; 29.84]) was detected. A similar situation is observed in the CA2 and CA3 areas of the hippocampus.Conclusion. Neurodegenerative changes in the hippocampus of animals with a transgenic AD model are associated with impaired microcirculation in the brain tissue as a result of a reduction in the diameter and branching of blood vessels, and damage and increased permeability of BBB.Цель – изучение молекулярных механизмов нарушения структурно-функциональной целостности гематоэнцефалического барьера (ГЭБ) при хронической нейродегенерации  альцгеймеровского типа, ассоциированной с развитием церебральной ангипопатии. Материалы и методы. Опытная группа – генетическая модель болезни Альцгеймера (БА) – мыши линии B6SLJ -Tg(APPSwFlLon,PSEN1*M146L*L286V)6799Vas, самцы в возрасте 9 мес. Контрольная группа – мыши линии C57BL/6 x SJL, самцы в возрасте 9 мес.Результаты. У животных с генетической моделью БА в зубчатой извилине гиппокампа  общая длина сосудов в 2,5 раза больше, чем у контрольной группы (p < 0,01), при этом  средний диаметр сосудов во всех областях гиппокампа меньше по сравнению с контролем (p < 0,05). Выявлено, что при генетическом моделировании  нейродегенерации в СА2 зоне гиппокампа наблюдается увеличение относительной  площади ткани с повышенной проницаемостью ГЭБ (17,80 [9,15;36,75]) по сравнению с контролем (1,38 [0,04;7,60]) при p < 0,05. Подобное различие (p < 0,05) наблюдается и в зоне СА1 гиппокампа. У животных опытной группы выявлена тенденция (p > 0,05) к снижению количества CD31+ эндотелиальных клеток в зубчатой извилине гиппокампа (21,52 [17,56; 24,50]) по сравнению с контролем (23,08 [21,18; 29,84]). Аналогичная ситуация наблюдается в зонах СА2 и СА3 гиппокампа.Заключение. Нейродегенеративные изменения в гиппокампе животных с генетической  моделью БА ассоциированы с нарушением микроциркуляции в ткани головного мозга в  результате сокращения диаметра и разветвленности сосудов, повреждения и повышения проницаемости ГЭБ