2,785 research outputs found

    Experiment K-6-12. Morphometric studies of atrial or granules and hepatocytes. Part 1: Morphometric study of the liver; Part 2: The atrial granular accumulations

    Get PDF
    The livers of flight, F, rats from the Cosmos 1887 mission were markedly paler and heavier than those of the synchronous, S, and vivarium, V, controls. In the F group, microscopic study revealed extensive hepatocytic intracytoplasmic vacuolization which was moderate in the S and minimal in the V groups. The vacuoles were not sudanophilic and therefore were regarded as glycogenic in origin. To obtain objective data concerning the extent of the vacuolization, livers were examined by computer assisted morphometry. Measurements of profile area and perimeter of the hepatocyte nuclei and vacuoles were evaluated according to stereological principles. Results indicated that the volume density of the nuclei was less in the F group than in the S(p equal less than 0.0002) and V(p equal less than 0.001) groups. Mean volume of individual nuclei did not differ. Volume density of the vacuoles was greater in the F than in the V group (p equal less than 0.02) while their mean diameter was less (p equal less than 0.05). To ascertain the relationship between increase in liver weight of the flight animals and the results of this study, an assumption was made that the specific gravity of the vacuolar contents was similar to the other extranuclear components of the hepatocyte. On that basis, calculations showed that the elevated vacuolar volume density in the flight group did not cause the increased liver weight in those animals, but that the non-nuclear, non-vacuolar parenchymal compartment did contribute significantly. Factors that may have played a causal role in liver weight and vacuolar compartment increases are discussed

    Methodological foundations of teaching "histology" subject in foreign medical students

    Get PDF
    МЕДИЦИНСКИЕ УЧЕБНЫЕ ЗАВЕДЕНИЯОБРАЗОВАНИЕ МЕДИЦИНСКОЕСТУДЕНТЫ МЕДИЦИНСКИХ УЧЕБНЫХ ЗАВЕДЕНИЙИНОСТРАННЫЕ СТУДЕНТЫГИСТОЛОГИЯ /ОБУЧГИСТОЛОГИЯ (ДИСЦИПЛИНА)МЕТОДИКА ПРЕПОДАВАНИ

    Mathematical modeling of three-layer beam hydroelastic oscillations

    Get PDF
    The problem of hydroelastic oscillations of three-layer beam interacting with viscous liquid layer is set up and analytically solved. The problem presents the equation system of a three-layer beam and Navier-Stokes equations. The following boundary conditions are chosen: the no-slip conditions, the conditions for pressure at the edges, the simply supported edges conditions. The problem is solved for the steady-state harmonic regime. The frequency dependent distribution functions of the beam deflection are constructed. The given function allows investigating the resonance hydroelastic oscillations of a three-layer beam, as well as its deflected mode

    Effect of ultrasonic treatment on the dissolution of milk solids during the reconstitution of skim milk powder

    Get PDF
    ArticleThe producing reconstituted milk products that retain the same sensory properties as those of raw milk products is of high interest to the food industry In the technology of producing reconstituted milk processing products, the most significant factor that determines the component transition degree and the usefulness of the product being produced is the recombination process. It determines the possibility of bringing the organoleptic characteristics of reconstituted milk to the properties of the genuine one. One promising method to improve the process of milk powder recombination is ultrasonic exposure. The aim of the present study is to improve the process of milk powder recombination using ultrasonic exposure. The results of the conducted studies show that the ultrasonic treatment eliminates the agglomerates of dried milk particles in water and provides more accessible interaction between the particles and water, and as a result, improves the recombination process. The application of ultrasonic treatment during the reconstitution of the skim milk powder improved the dissolution of milk solids, as evidenced by around a 75% reduction in the amount of centrifuged insoluble sediment. The mass fractions of protein and lactose have increased by 4.8 and 6.5%, respectively

    Optical spectra, crystal-field parameters, and magnetic susceptibility of the new multiferroic NdFe3(BO3)4

    Full text link
    We report high-resolution optical absorption spectra for NdFe3(BO3)4 trigonal single crystal which is known to exhibit a giant magnetoelectric effect below the temperature of magnetic ordering TN = 33 K. The analysis of the temperature-dependent polarized spectra reveals the energies and, in some cases, symmetries and exchange splittings of Nd3+ 84 Kramers doublets. We perform crystal-field calculations starting from the exchange-charge model, obtain a set of six real crystal-field parameters, and calculate wave functions and magnetic g-factors. In particular, the values g(perpendicular) = 2.385, g(parallel) = 1.376 were found for the Nd3+ ground-state doublet. We obtain Bloc=7.88 T and |JFN|= 0.48 K for the values of the local effective magnetic field at liquid helium temperatures at the Nd3+ site and the Nd - Fe exchange integral, respectively, using the experimentally measured Nd3+ ground-state splitting of 8.8 cm-1. To check reliability of our set of crystal field parameters we model the magnetic susceptibility data from literature. A dimer containing two nearest-neighbor iron ions in the spiral chain is considered to partly account for quasi-one-dimensional properties of iron borates, and then the mean-field approximation is used. The results of calculations with the exchange parameters for Fe3+ ions Jnn = -6.25 K (intra-chain interactions) and Jnnn = -1.92 K (inter-chain interactions) obtained from fitting agree well with the experimental data.Comment: 13 pages, 8 figures, 2 table

    The application of micro-wave treatment to reduce barley contamination

    Get PDF
    ArticleThe goal of this work is to study the applicability of ultra high frequency electromagnetic field treatment for decontaminating barley grain used in brewing while preserving its technological properties. The germination rates and/or yield of the treated sample seed were compared with those of the untreated seed germinated under normal conditions. To determine optimal treatment conditions, a two-factor analysis was carried out, taking the mycological state of the grain into account. The heating rate and the duration of electromagnetic exposure were chosen as variables; these values varied from 0.4 to 0.8 °C s-1 and from 30 to 90 s, respectively. It was found that germination of the treated barley seed was increased about 10.1–15.7% compared with that of the untreated seed. The microbial load decreased up to 80%. A heating rate of 0.4 °C s-1 and treatment exposure time of 30 s showed the strongest effect of decontamination while preserving the viability of the barley grain

    Experiment K-6-16. Morphological examination of rat testes. The effect of Cosmos 1887 flight on spermatogonial population and testosterone level in rat testes

    Get PDF
    Testes from rats flown on Cosmos 1887 for twelve and a half days were compared to basal control, synchronous control and vivarium maintained rats. When the mean weights of flight testes, normalized for weight/100 gms, were compared to the vivarium controls they were 6.7 percent lighter. Although the flight testes were lighter than the synchronous, the difference is not significant. Counts of spermatogonial cells from 5 animals in each group revealed a 4 percent decrease in flight compared to vivarium controls. In both cases the t-Test significance was less than 0.02. The serum testosterone levels of all animals (flight, synchronous and vivarium) were significantly below the basal controls

    Inversionless light amplification and optical switching controlled by state-dependent alignment of molecules

    Full text link
    We propose a method to achieve amplification without population inversion by anisotropic molecules whose orientation by an external electric field is state-dependent. It is based on decoupling of the lower-state molecules from the resonant light while the excited ones remain emitting. The suitable class of molecules is discussed, the equation for the gain factor is derived, and the magnitude of the inversionless amplification is estimated for the typical experimental conditions. Such switching of the sample from absorbing to amplifying via transparent state is shown to be possible both with the aid of dc and ac control electric fields.Comment: AMS-LaTeX v1.2, 4 pages with 4 figure
    corecore