310 research outputs found
Lateral-angular and temporal characteristics of EAS optical radiation
Characteristics of the direct and scattered components of electron-photon shower optical radiation for distances R 500 m from the shower core to a detector, allowing for the Cerenkov and fluorescent mechanism of photon generation are presented. The results of calculations are employed to clarify the techniques for determination of the shower parameters detected by both installations registering fluorescent light and those recording Cerenkov light
Analytical-numerical methods of calculations of energy and three-dimensional particle distributions in electromagnetic cascades
Analytical and numerical methods of calculation of the energy and three dimensional EPS characteristics are reported. The angular and lateral functions of electrons in EPS have been obtained by the Landau and small angle approximations A and B and compared with earlier data. A numerical method of solution of cascade equations for the EPS distribution function moments has been constructed. Considering the equilibrium rms angle as an example, errors appearing when approximating the elementary process cross sections by their asymptotic expressions are analyzed
Analysis of molecular mechanisms of the development of experimental diabetes in Wistar rats under conditions of intermittent hypoxia
There is strong evidence that hypoxic training, within the context of diabetes, constitutes a specialized form of exercise performed under conditions of intermittent hypoxia. This approach holds promise for effectively managing and enhancing diabetes outcomes, as it has the potential to influence metabolism and physiological processes within the body significantly. The key elements of hypoxic training in diabetes encompass activities geared toward activating metabolic pathways, enhancing mitochondrial function, and regulating blood glucose levels. Such interventions can potentially lead to improvements in insulin resistance, a reduction in glycemia, and an overall enhancement of cardiorespiratory function. Hypoxic training achieves these benefits by heightening insulin sensitivity and reducing blood glucose levels, which can be particularly advantageous for individuals with diabetes.
The aim of the work is to determine changes in the expression of genes associated with the course of diabetes under conditions of exposure to intermittent hypoxia in pancreatic tissue samples of Wistar rats.
Materials and methods. Analysis of gene expression was used by the polymerase chain reaction method with reverse transcription in real-time using the RT2 Profiler™ PCR Array Rat Diabetes kit (QIAGEN, Germany), where the pancreas of experimental animals was studied.
Results. According to the results of the PCR study of animals with experimental diabetes and the influence of hypoxic training on its course, the activity of the studied genes can be divided as follows: genes with low expression compared to the control group of animals, where ∆∆Cт <30 (Ace; Cd28; Ctla4; Dusp4 ; Enpp1; Foxp3; G6pc; Gcgr; Glp1r; Gpd1; Gsk3b; Hmox1; Ide; Ikbkb; Il10; Il6; Ins1; Nfkb1; Nkx2-1; Parp1; Pdx1; Pik3cd; Pik3r1; Ppargc1a; Ptpn1; Rab4a; Retn; Slc14a2 ; Snap25; Sod2; Stx4; Stxbp1; Stxbp2; Tnf; Tnfrsf1a; Tnfrsf1b; Ucp2; Vamp2; Vegfa); genes in which no significant changes were detected in the samples in relation to the control group (Acly; Adra1a; Adrb3; Agt; Akt2; Aqp2; Ccl5; Ccr2; Ceacam1; Cebpa; Dpp4; Fbp1; Foxc2; Foxg1; Gcg; Gck; Hnf1b; Hnf4a ; Icam1; Ifng; Igfbp5; Il12b; Il4r; Inppl1; Irs1; Irs2; Mapk14; Mapk8; Neurod1; Nos3; Nrf1; Nsf; Ppara; Pparg; Pygl; Sell; Serpine1; Slc2a4; Snap23; Srebf1; Stxbp4; Tgfb1; Trib3 ; Vamp3; Vapa); there are no genes with high expression compared to the control group.
Conclusions. The Nkx2-1 genes, Pik3r1, and Slc14a2 in rats subjected to experimental diabetes displayed notably reduced protein expression activity. Hypoxic training demonstrated an impact on mitigating the expression of the Nkx2-1 protein, which suggests that it might affect the mitochondrial muscle respiratory chain, modulate insulin signaling, and potentially rectify molecular deficiencies associated with diabetic nephropathy. Expression of Dpp4 genes, Gck, Ifng, Mapk8, Nsf and Sell in rats with experimental diabetes and the effect of hypoxic training on it were reduced to the level of control (intact) rats. As a result of the normalization of Dpp4 gene expression, Gck, Ifng, Mapk8, Nsf and Sell may be the influence of the effects of hypoxic training on molecular mechanisms of regulation of hormones and signals related to metabolism and the endocrine system, effects on the immune system and inflammatory processes, as well as insulin resistance
Alignment in Gamma-Hadron Families of Cosmic Rays
Alignment of main fluxes of energy in a target plane is found in families of
cosmic ray particles detected in deep lead X-ray chambers. The fraction of
events with alignment is unexpectedly large for families with high energy and
large number of hadrons. This can be considered as evidence for the existence
of coplanar scattering of secondary particles in interaction of particles with
superhigh energy, eV. Data analysis suggests that production of
most aligned groups occurs low above the chamber and is characterized by a
coplanar scattering and quasiscaling spectrum of secondaries in the
fragmentation region. The most elaborated hypothesis for explanation of
alignment is related to the quark-gluon string rupture. However, the problem of
theoretical interpretation of our results still remains open.Comment: 15 pages, 2 tables, 6 figures (not included), Stanford University
preprint SU-ITP-94-2
Results of investigation of muon fluxes of superhigh energy cosmic rays with X-ray emulsion chambers
The overall data from the investigation of the cosmic ray muon flux in the range of zenith angles (0-90) deg within the energy range (3.5 to 5.0) TeV is presented. The exposure of large X-ray emulsion chambers underground was 1200 tons. year. The data were processe using the method which was applied in the experiment Pamir and differred from the earlier applied one. The obtained value of a slope power index of the differential energy spectrum of the global muon flux is =3.7 that corresponds to the slope of the pion generation differential spectrum, gamma sub PI = 2.75 + or - .04. The analysis of the muon zenith-angular distribution showed that the contribution of rapid generation muons in the total muon flux agree the best with the value .2% and less with .7% at a 90% reliability level
Quantitative characteristics of the neurotensin content in the hypothalamic arcuate nucleus in arterial hypertension of different etiologies
The aim of this work is to determine the features of the neurotensin content in the hypothalamic ARC in Wistar rat and SHR strains in arterial hypertension of different etiology: endocrine-salt and essential.
Materials and methods. The study was performed on 24 adult male rats at the age of 13–14 months, weight of 250–270 g, which were divided into three experimental groups of 8 animals each. The 1st group (control) – Wistar rats with normal BP indices (Psys / Pdias = 110/75 ± 5 mm Hg), the 2nd – Wistar rats with endocrine-salt model of hypertension (Psys/Pdias = 145/110 ± 10 mm Hg); the 3rd – SHR with spontaneous arterial hypertension (Psys/Pdias = 150/110 ± 10 mm Hg). An immunohistochemical method was used to study the content of neurotensin in the arcuate nucleus, analyzed by digital processing with Image J and EXCEL-7.0.
Results. Persistent increase in BP is accompanied by an increase in the content and concentration of neurotensin in the hypothalamic ARC, does not depend on the etiology of hypertension and has a compensatory character. In SHR with essential hypertension there is a higher expression of neurotensin in the hypothalamic ARC in comparison with the endocrine-salt model of hypertension, but the number of neurons involved in the synthesis and accumulation of the neurohormone is significantly lower, which characterizes the morphological features of cellular populations in the hypothalamus of the animals of this strain and can play a role in the development and progression of hypertension
Shape of primary proton spectrum in multi-TeV region from data on vertical muon flux
It is shown, that primary proton spectrum, reconstructed from sea-level and
underground data on muon spectrum with the use of QGSJET 01, QGSJET II, NEXUS
3.97 and SIBYLL 2.1 interaction models, demonstrates not only model-dependent
intensity, but also model-dependent form. For correct reproduction of muon
spectrum shape primary proton flux should have non-constant power index for all
considered models, except SIBYLL 2.1, with break at energies around 10-15 TeV
and value of exponent before break close to that obtained in ATIC-2 experiment.
To validate presence of this break understanding of inclusive spectra behavior
in fragmentation region in p-air collisions should be improved, but we show,
that it is impossible to do on the basis of the existing experimental data on
primary nuclei, atmospheric muon and hadron fluxes.Comment: Submitted to Phys. Rev.
Experimental study of the pattern of genes activated by multi-day intermittent hypoxia in the rat pancreas
Intermittent hypoxia affects a variety of pathological conditions in the body and is used in medicine to reproduce the sanogenic therapeutic effect. Intermittent hypoxia is used for clinical indications to improve lung function; increase the body’s adaptive capacity; in obstructive sleep apnoea syndrome; in anaemia, diabetes mellitus. In cancer radiotherapy, intermittent hypoxic training helps to increase the sensitivity of the tumour to treatment. Intermittent hypoxia is useful in rehabilitation medicine to improve the physical recovery of patients after surgery or injury to improve the body’s functional capabilities. However, to date, the activity of regulatory genes, that activate the molecular mechanisms of the above-mentioned sanogenic effects of intermittent hypoxia has not been sufficiently studied.
The aim of the study: to determine the expression of hypoxia-related genes in pancreas of Wistar rats under intermittent hypoxia.
Materials and methods. The CFX-96 Touch™ real-time reverse transcription polymerase chain reaction (PCR) (Bio-Rad, USA) and the RT2 Profiler™ PCR Array Rat Hypoxia Signalling Pathway kit (QIAGEN, Germany) were used to analyse gene expression in experimental animals, where 84 genes involved in the hypoxia signalling pathway identified in the pancreas were studied.
Results. According to the results of PCR analysis of pancreatic samples from intact animals and animals exposed to hypoxic training, the activity of the gene panel can be distributed as follows: genes with high expression compared to the intact group of animals, genes with low expression compared to the intact group of animals and genes in which no significant changes were detected in the samples compared to the intact group of animals. We have found, that the genes Cops5, F10, Jmjd6, Lgals3, Rbpjl, Vegfa have high expression activity compared to the intact group of animals.
Conclusions. The increase in the expression of Cops5 by 10.29 times, Lgals3 by 2.94 times and Rbpjl by 5.73 times as a result of intermittent hypoxia can be regarded as an activating factor for the increase in the proliferation of endocrine and exocrine pancreatic cells and the growth of their antiapoptotic potential. The 3.20-fold increase in Jmjd6 gene expression under intermittent hypoxia can be interpreted as a regulatory effect through protein dehydroxylation and promotion of antiapoptotic protein activity in endocrine and exocrine pancreatic cells. The 5.99-fold increased level of Vegfa expression may promote angiogenesis in the pancreas under intermittent hypoxia
Temperature Dependence of Extended and Fractional SU(3) Monopole Currents
We examine in pure SU(3) the dependence of extended monopole current k and
cross-species extended monopole current k^{cross} on temperature t, monopole
size L, and fractional monopole charge 1/q. We find that features of both k and
k^{cross} are sensitive to t for a range of L and q. In particular, the
spatial-temporal asymmetry ratios of both k and k^{cross} are sensitive over a
range of L and q to the SU(3) deconfinement transition. The motivation for
studying cross, extended, and fractional monopoles in SU(3) is given.Comment: 15 pages (archiving final publication version; very minor revisions
Structure of Abrikosov Vortices in SU(2) Lattice Gauge Theory
We calculate the electric flux and magnetic monopole current distribution in
the presence of a static quark-antiquark pair for SU(2) lattice gauge theory in
the maximal Abelian gauge. The current distribution confines the flux in a dual
Abrikosov vortex whose core size is comparable to the flux penetration depth.
The observed structure is described by a dual Ginzburg-Landau model.Comment: 15 pages, latex file, three figure postscript files appended, Report
No. LSUHEP No. 138-199
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