Experimental Research of the Diffraction and Vavilov-Cherenkov Radiation Generation in a Teflon Target

Geometry of Vavilov-Cherekov (VChR) radiation when an electron moves close to a dielectric target is in analogy to diffraction radiation (DR) geometry. In this case we may expect DR generation from the upstream face of the target besides that VChR. The joint observation of these booth types of radiation is very interesting from the pseudo-photon viewpoint, which is applicable for relativistic electrons. Unexpected results obtained in our experiment insist on reflection about nature both DR and VChR. The experiment was performed on the relativistic electron beam of the microtron of Tomsk Polytechnic University.Comment: This article will be published in Journal of Physic

GAMMA-RAY SPECTROMETRY OF HOT PLASMAS

Gamma-ray spectrometry provides diagnostics of fast ion behavior in plasmas of large tokamaks. Information acquiring with the gamma-ray diagnostics gives possibility to identify and distinguish simultaneously presence of fast alpha-particles and other ions He), to obtain its relative densities and also to perform tomographic radial profile reconstruction of the gammaemission sources

The effect of a single administration of streptozotocin on hippocampus metabolites in NODSCID mice

The significant increase in the number of people diagnosed with diabetes mellitus in recent years makes studies of this problem topical. The persistent hyperglycemia accompanying the development and course of type 1 diabetes mellitus (T1DM) can affect the func-tional and structural levels of the organization of the central nervous system. These changes may be medi­ated by metabolic aberrations. Magnetic resonance spectroscopy (MRS) is a common method of intravital detection of metabolic reactions. In this study, MRS of the hippocampus of NOD.CB17-Prkdcscid/NcrCrl mice (NODSCID) was performed 4 days after the administration of streptozotocin (STZ) to assess the effect of STZ itself, and 60 days after the administration of STZ to another group of animals to assess the effect of chronic hyperglycemia caused by the delayed ef­fect of STZ, involving the death of pancreatic β-cells. The simulation of T1DM by STZ administration is used worldwide. Nevertheless, the question remains whether there is a short-term effect of the introduc­tion of STZ at the level of hippocampal metabolites recorded by MRS. The comparison of experimental and control animal groups revealed no effect of STZ on metabolites in the hippocampus of NODSCID mice on day 4 after its administration. In contrast, another comparison of the experimental and control animals on day 60 after STZ administration showed elevated contents of alanine and taurine, and a reduced lactate content. Thus, the introduction of STZ itself does not affect the metabolism of the hippocampus, and MRS is a promising method for assessing the effect of T1DM on brain metabolism in animals

Radioluminescence properties of nanocomposite scintillators with BaF 2 fillers

In this paper, studies of the luminescence properties of nanocrystalline BaF 2 samples synthesized by laser ablation and pulse electron beam evaporation method are presented. The measurements of X-ray excited luminescence (XEL) showed the dependence between luminescence intensity and the shape of the spectrum on the morphology and particle size. Also, studies of X-ray excited luminescence, decay curves and optical transmittance for nanocomposite materials containing BaF 2 nanopowder are presented. Barium fluoride nanopowder, obtained by pulsed electron beam evaporation method is characterized by a lower intensity than the initial microcrystalline powder, but at the same time, XEL spectrum of the nanocomposite material with this nanocrystalline filler is more intense, then that for nanocomposite material with initial powder. © Published under licence by IOP Publishing Ltd

Study of the neuronal response to olfactory stimuli in control and LPS-stimulated mice by functional magnetic resonance imaging

Olfactory perception plays the key role in the inter­action of animals with biotic factors of the species-specific econiche. Identification of odorants informs nocturnal animals about social environment, presence of predators, or infected food. Olfactory efficiency depends on physiological conditions; in particular, odor sensitivity can be changed by infection. This work considers use of fMRI in the study of the influence of innate immunity activation on neuronal response during perception and differentiation of socially significant (2.5-dimethylpyrazine, 2-heptanon) and socially insignificant (1-hexanol and isoprene) olfactory stimuli by CD-1 mice. We stimulated innate immunity by intraperitoneal injection of bacterial lipopolysaccharide (LPS) at the dose 500 µg/kg three hours before tomography. Urethane anesthesia was used during MRI trail. Odor stimulation was done with a lab-made metering unit for supplying standard doses of volatile organic compounds. The supply of olfactory stimuli induced activation of neurons in the primary perceptual center and the centers of secondary processing of olfactory information. Olfactory stimulus type affected neuronal response rate in an olfactory bulb but did not affect response parameters in other brain regions studied. This increase in neuronal activity is likely to be of adaptive significance as a mechanism supporting olfactory sensitivity increase, which plays the key role in the identification of potential sources of infection

NMR metabolic profiling of the liver following administrationof alcohol andthemushroom Ganoderma lucidum in rats

We have evaluated the efficiency of a metabonomic approach to metabolic phenotyping and detection of early metabolic changes under a toxic influence. For this purpose, a metabolic profiling of rat liver was performed with 1H NMR spectroscopy. Rat tissues from animals in three groups were analyzed. Group C consisted of control animals; animals in group A received alcohol repeatedly (15 % ethanol); and animals in group A+ R received alcohol in combination with a hepatoprotective herbal medicine (Reishi, Ganoderma lucidum) repeatedly. Noteworthy, alcohol consumption did not cause pathological changes, but stimulated hepatocyte proliferation. Our data suggest that changes in metabolite concentrations in A represent a typical metabolic response to alcohol consumption, namely decrease in glycine, leucine, isoleucine, valine, choline and lactate content, and increase in TMAO content. Treatment with Reishi (A+ R) had positive effects, in that it restored the levels of glycine, valine and TMAO. Furthermore, increase in NAD, ATP, UTP, succinate, pyranose, and acetate concentrations was observed in A+ R. A correlation was found between the valine, isoleucine, lactate, cho­line, and pyranose content and the num­ber of binuclear hepatocytes. Binuclear hepatocytes indicate proliferative activity, and the concentration of the metabolites participating in the formation of new hepatic cells decreases. Thus, the study of liver tissues by 1H NMR spectroscopy allows for detection of early changes in metabolite concentra­tions following chronic consumption of alcohol at insignificant doses. Consequently, 1H NMR spectro­scopy can serve as a promising approach to detecting alcohol-related liver pathologies and assessing the efficiency of the therapy used