Radiation dose reconstruction for higher aquatic plants and fish in Glyboke Lake during the early phase of the Chernobyl accident.

This study deals with an assessment of radiation dose dynamics to fish and higher aquatic plants (helophytes) in Glyboke Lake (10-km exclusion zone) during the early phase of the Chernobyl accident. Models of radioactive contamination of water and sediment and models of radioactive contamination and radiation dose to fish and aquatic plants were developed. It was found that, in 1986, the total dose rate to fish reached 0.25 Gy d-1. Within 6 months after the accident, the dose rate due to 90Sr, 134Cs and 137Cs had increased. The absorbed dose to prey fish of Glyboke Lake for this period was estimated as being 27-81 Gy of which 4-40 Gy was formed by 131I exposure. The radiation dose rate due to 90Sr, 106Ru, 134+137Cs and 144Ce to aquatic plants reached its quasi-equilibrium values approximately 50 days after the accident and remained virtually unchanged until the end of the 1986 growing season. The highest levels of 89Sr, 91Y, 95Zr, 103Ru, 141Ce exposure were observed between 30 and 50 days with a decrease by 2-3 times at the end of the growing season. Radiation exposure of the short-lived 131I, 140Ba, 140La, 239Np reached its maximum within 5-15 days after the accident. The absorbed dose rate to aquatic plants reached 0.69 Gy d-1, while the contribution of cerium radionuclides to the total dose rate formed 50% in the initial period and reached 90% at the end of the growing season. The magnitude of the radiation dose rate to plant roots was 2.4 times higher than aboveground organs, and that of rhizomes was 1.6 times higher. During the growing season of 1986 the total dose of exposure of plants in Glyboke Lake was about 78 Gy. The results of this study emphasise the necessity to consider the history of exposure of past generation of living organisms as part of the assessment of current radiation effects.

The microbiome of oral cavity patients with periodontitis, adhesive and biofilm forming properties.

The work characterizes the intestinal microbiota of patients with ischemic stroke, including the spectrum, frequency and number of microorganisms, as well as the spectrum and amount of gas signaling molecules secreted by lactobacilli. It was found that in patients with ischemic stroke, the frequency of the main representatives of normal microflora, Bifidobacterium spp., Lactobacillus spp., Escherichia coli, decreased in 2-3 times, and the same time the prevalence of Clostridia spp., Bacillus spp., Peptostreptococcus spp., Klebsiella spp. increased in 2-3 times; yeast like fungi C. albicans was isolated in 25% of cases. Lactobacilli isolated from the intestinal microbiota of patients with ischemic stroke were represented by a wide variety of species: L. rhamnosus, L. fermentum, L. plantarum, L. brevis, L. pentosus, L. curvatus, L. salivarius. In most cases, they did not produce NO, they released CO 2 times less compared to healthy people. The most active NO producers - L. plantarum, CO - L. rhamnosus.

The microbiome of oral cavity patients with periodontitis, adhesive and biofilm forming properties.

The microbiome of oral cavity in healthy people and patients with periodontitis was analyzed to determine their adhesive properties and the ability to form biofilms. The study involved 2 groups: healthy, 18 people, and an experimental group, 20 patients with chronic generalized periodontitis moderate severity of the disease. The average age of the studied people was 35-45 years. Material - dental plaque, scraping from the mucous membrane of the back of the tongue, the contents of the periodontal groove and periodontal pocket, as well as oral fluid. The main method of diagnostic was bacteriological. The average adhesion index (AAI) was used to determine adhesion level of microorganisms to epithelial cells of oral cavity's mucous membrane. The microbiota's ability to form biofilm was tested on glass and plastic surface. The microbiota of oral cavity of patients with periodontitis was characterized by decrease in the frequency of bacteria of the genera: Streptococcus, Peptostreptococcus, Peptococcus, and an increase in Staphylococcus aureus, Veillonella spp., Bacillus spp. The microbiota of the oral cavity of patients with generalized periodontitis has a greater ability to adhere to the cells of the mucous membrane than in healthy people, while their ability to form biofilms and exhibit pathogenic properties is enhanced. The biofilm formation of microorganisms in healthy and sick people differs both on glass and on plastic surfaces.

Analysis of Methods for Evaluating the Functional State and Physical Fitness of Men and Women in The Second Period of Adulthood

Methods for evaluating the functional state of the body and physical fitness of men and women in the second period of adulthood have been analyzed in the article. The timely diagnosis of these indicators allows to optimally distribute exercises and adjust them to each trainee. Indicators of the functional state of the body and physical fitness should be analyzed in combination, as it allows to obtain more accurate results. Materials. Analysis of methods for evaluating the physical and functional state of the body is presented in the article. Methods. The following research methods have been used in the article: analysis and systematization of scientific and methodological literature, pedagogical experiment, testing, and statistical data processing. Results. The research has been conducted with the purpose of analyzing the existing methods for evaluating the physical and functional state of the body. The results of a comprehensive research of the indicators of the functional state and physical fitness are more accurate because the human factor is taken into account (the participants could not accurately meet the targets in the calculation). The results have led to a conclusion about the need to use a wide range of methods for diagnosing the functional state and physical fitness. Conclusion. Conditions for correct performance should be honored in functional tests and physical fitness tests, as this influences the reliability of the data. The results have led to a conclusion about the need to use a wide range of m

Impact of the motor activity of men and women in the second period of adulthood on physical fitness and functional indicators

The motor activity belongs to controllable factors that influence human health because it ensures disease prevention. Analysis of scientific publications has revealed that motor activity of adult people is insufficient; this leads to the development of hypodynamia and worsens health. The level and nature of motor activity should correspond to the peculiarities of the body (age, gender, functional state, physical fitness, etc.). This problem requires the study of the relationship between the motor activity of the adult men and women and their indicators of physical fitness and functional state of the body. The relationship between the motor activity and indicators dependent on it has been reviewed in the article. The impact of the motor activity on the functional state of the body and physical fitness has been determined. The results have led to a conclusion that the motor activity of adults should be analyzed along with the study of indicators of functional state and physical fitness.

Methane oxidation over mixed-conducting SrFe(Al)O3-delta-SrAl2O4 composite.

The steady-state CH4 conversion by oxygen permeating through mixed-conducting (SrFe)0.7(SrAl2)0.3Oz composite membranes, comprising strontium-deficient SrFe(Al)O3-delta perovskite and monoclinic SrAl2O4-based phases, occurs via different mechanisms in comparison to the dry methane interaction with the lattice oxygen. The catalytic behavior of powdered (SrFe)0.7(SrAl2)0.3Oz, studied by temperature-programmed reduction in dry CH4 at 523-1073 K, is governed by the level of oxygen nonstoichiometry in the crystal lattice of the perovskite component and is qualitatively similar to that of other perovskite-related ferrites, such as Sr0.7La0.3Fe0.8Al0.2O3-delta. While extensive oxygen release from the ferrite lattice at 700-900 K leads to predominant total oxidation of methane, significant selectivity to synthesis gas formation, with H2/CO ratios close to 2, is observed above 1000 K, when a critical value of oxygen deficiency is achieved. The steady-state oxidation over dense membranes at 1123-1223 K results, however, in prevailing total combustion, particularly due to excessive oxygen chemical potential at the membrane surface. In combination with surface-limited oxygen permeability, mass transport limitations in a porous layer at the membrane permeate side prevent reduction and enable stable operation of (SrFe)0.7(SrAl2)0.3Oz membranes under air/methane gradient. Taking into account the catalytic activity of SrFeO3-delta-based phases for the partial oxidation of methane to synthesis gas and the important role of mass transport-related effects, one promising approach for membrane development is the fabrication of thick layer of porous ferrite-based catalyst at the surface of dense (SrFe)0.7(SrAl2)0.3Oz composite.

Observation of neutronless fusion reactions in picosecond laser plasmas.

The yield of alpha particles in neutronless fusion reactions 11B +p in plasmas produced by picosecond laser pulses with the peak intensity of 2 x 10(18) W/cm2 has been observed. Experiments were carried out on the "Neodymium" laser facility at the pulse energy of 10-12 J and pulse duration of 1.5 ps. The composite targets 11B + (CH2)n were used. The yield of 10(3) alpha particles per pulse has been observed. The energy spectrum of alpha particles contains two maxima: at 3-4 MeV and at 6-10 MeV . The first of these peaks corresponds to the secondary alpha12 particles at the decay of the intermediate first excited state of 8Be, whereas the second peak demonstrates generation of alpha1 particles in the reaction 11B +p with the production of this excited state. Simultaneous measurements of neutrons result in zero yield, which proves the observation of neutronless fusion reactions in our experiments.

The effect of porphyrin supramolecular structure on singlet oxygen photogeneration.

This work is to show that activity of porphyrins in singlet oxygen generation (SOG) is determined not only by their molecular structure but also by supramolecular structure of porphyrin containing systems. This is demonstrated by results of studies of SOG in the gas phase by vacuum deposited tetraphenylporphyrin (TPP) layers under photoexcitation conditions. The structure of the layers was studied by atomic force microscopy (AFM), TEM in diffraction regime (TED) and by the flicker-noise spectroscopy (FNS) method. It was shown that substrates affect the deposited layers structure only at earlier stages of the layer formation. AFM and TED data, together with FNS quantitative parameters of TPP layers, show directly that the chemical activity of solid-phase systems can be determined not only by their chemical nature but also by their supramolecular structure.

Analysis of high- n dielectronic Rydberg satellites in the spectra of Na -like Zn XX and Mg -like Zn XIX.

We have observed spectra from highly charged zinc ions in a variety of laser-produced plasmas. Spectral features that are Na - and Mg -like satellites to high- n Rydberg transitions in the Ne -like Zn XXI spectrum are analyzed and modeled. Identifications and analysis are made by comparison with highly accurate atomic structure calculations and steady state collisional-radiative models. Each observed Zn XX and Zn XIX feature comprises up to approximately 2 dozen individual transitions, these transitions are excited principally by dielectronic recombination through autoionizing levels in Na - and Mg -like Zn19+ and Zn18+. We find these satellites to be ubiquitous in laser-produced plasmas formed by lasers with pulse lengths that span four orders of magnitude, from 1 ps to approximately 10 ns. The diagnostic potential of these Rydberg satellite lines is demonstrated.

Influence of optical thickness and hot electrons on Rydberg spectra of Ne-like and F-like copper ions.

Spectra in the 7.10 to 8.60 A range from highly charged copper ions are observed from three different laser-produced plasmas (LPPs). The LPPs are formed by a 15-ns Nd:glass laser pulse (type I: E(pulse)=1-8 J, lambda=1.064 microm), a 1-ps Nd:glass laser pulse (type II: E(pulse)=1 J, lambda=1.055 microm), and a 60-fs Ti:sapphire laser pulse (type III: E(pulse)=800 mJ, lambda=790 nm). The spectra of high-n (n

Mathematical analysis of subtypes of muscarinic receptors modulating heart and respiratory rhythms in rats.

Mathematical analysis of the data obtained in experiments on the whole organism revealed that blockade of M(2)-cholinergic receptors increased both heart and respiratory rates. Blockade of M(1)-cholinergic receptors alleviated tachycardia induced by M(2)-receptor blockade.

Production of intense low-energy positron beams with synchrotron radiation.

A low-energy positron beam is a unique probe of Fermi surfaces, defects, surfaces and interfaces. In high-energy electron and positron storage rings (E > 6 GeV) it is possible to generate intense synchrotron radiation with 1-3 MeV photons by installing a high-field superconducting wiggler. The strength of the wiggler should be ~8-12 T. High-energy photons are emitted from the wiggler and converted to low-energy positrons by using a suitable target-moderator system. For an 8 GeV electron storage ring at a beam current of 100 mA, final yields are estimated to be ~10(10)-10(12) (slow-e(+) s(-1)) with the size of positron source ~10(2)-10(3) cm(2). The possibility of increasing the brightness of the low-energy positron beam is discussed. Advantages of using synchrotron radiation for producing positrons are pointed out. The effect of a superconducting wiggler on the stored electron beam is also discussed.

Figure of merit of liquid-crystal materials for optically addressed spatial modulators.

A new figure of merit appropriate for optically addressed liquid-crystal spatial light modulators is derived. This figure of merit takes into account the change of phase retardation and switching time of a deformed liquid-crystal layer. The figure of merit is used in determining the optimal mix of polar and weak-polar components in the liquid-crystal layer.