53 research outputs found

    Mitochondrial respiration inhibition after exposure to UWB pulses as a possible mechanism of antitumor action

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    The respiration of isolated mice liver mitochondria after exposure to nanosecond UWB pulses (0.15 – 36 kV/cm, 0.6 – 1.0 GHz centre frequency, 3 – 20 ns pulse duration) has been investigated. The respiratory control (RC, the ratio of oxygen consumption) was estimated. The possibility of mitochondrial membrane electroporation was detected as the decrease in the electrical resistance, according to the β-dispersion of the electric current. The monotonous decrease of RC after 1000 UWB pulses from 0.15 kV/cm was observed, the ohmic resistance of mitochondria suspension was reduced. The obtained data indicate the inhibitory effect of UWB pulses on a state of irradiated mitochondria and its membrane

    Study of the switching characteristics of gas S-diodes

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    In the study, the switching properties of avalanche GaAs S-diodes are investigated. We studied diode assemblies of various configurations. It is shown that when using two or more diodes connected in series, the edge of the voltage pulse can be sharpened to about 1 ns

    Different sensitivity of normal and tumor cells to pulsed radiofrequency exposure

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    The effect of nanosecond radiofrequency pulses (nsRF) on tumor and normal cells has been studied. To determine the viability of cells, an MTT test was used, as well as a real time system for analyzing cell cultures-iCELLigence. It has been shown that ns RF pulses under certain combinations of operating conditions reduce cell proliferation of both tumor and normal cells. Double exposure to 1000 pulses leads to the most effective inhibition of tumor cell proliferation and was 40% after 5 days. Inhibition of the proliferative activity of normal cells was 10% and was maximum after 3 days, then cell growth resumed. The results obtained allow to consider ns RF pulses with different parameters as a promising effective factor for controlling cellular processes for biomedical purposes

    Bioregulation of amplitude-phase biological activity of Candida albicans by women reproductive tract microsymbionts

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    In this study, we propose a chronobiological method for examining inter-microbial interactions in bacterial and fungal associations in female reproductive tract. Fungal and bacterial species were isolated in 45 women of reproductive aged 19–35, with regular menstrual cycle, applying no hormonal contraceptives, without previous gynecological surgery, abortions, miscarriages with vaginal eubiosis and dysbiosis in history. Sexually transmitted diseases (HIV infection, syphilis, gonorrhea, trichomoniasis, chlamydiosis) were excluded in all subjects. Proliferation rate, morphogenesis and phospholipase activity were examined within the 48-hour period every 4 hours, in winter time, Moon phase IV. The data obtained were assessed by using Student’s t-test, Wilcoxon test, and least squares method. All subjects were divided into the groups: group 1 — women with vaginal eubiosis, group 2 — women with vaginal dysbiosis. It was shown that in all subjects experimental parameters of C. albicans cultures showed a diurnal dynamics characterized in healthy women by circadian rhythms with a single peak of activity. However, in women with vaginal dysbiosis C. albicans was characterized by significant ultradian (around 12 hours long) rhythms with two peaks of biological activity. Concurrence and consistency in manifested physiological functions related to clinical isolates was coupled to temporal pattern of distributed biological resources in fungi depending on course of infectious process. It was found that in vaginal eubiosis exometabolites released by dominant associated microbiota did not significantly change microbiota-related amplitude-phase parameters. The data obtained evidenced that temporal pattern of parameters related to C. albicans from healthy individuals was stable and independent on bacterial metabolites. In contrast, dominant microsymbiont in vaginal dysbiosis inhibited fungi-related rhythms, which might be important in establishing lactobacillus-associated biotope colonization resistance. Effects of metabolites released by the associated microbiota typical to dysbiosis was revealed by increased mesor, amplitude, preserved biorhythm spectral pattern in examined properties as well as amplitude-phase characteristics indicating at enhanced or sustained C. albicans adaptive potential. Therefore, the amplitude-phase parameter of C. albicans physiological activity served as a marker of opposite (enhanced/weakened) effect of microsymbiont survival described in “microbial dominant-associate” pairs

    DETERMINATION OF THE RATIONAL GEOMETRICAL PARAMETERS OF PLATE TYPE ELEMENTS OF MAGNETIC MATRIX OF THE POLYGRADIENT SEPARATOR

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    Introduction. Polygradient magnetic separation has wide application in industry and in biomedicine. Working process in polygradient separators takes place in a matrix, magnetic elements of which create magnetic forces sufficient to remove small ferro- and paramagnetic inclusions. Problem. The influence of mutual arrangement of elements on character of distribution of magnetic field is not taken into account during calculation of characteristics of magnetic field in magnetic matrixes. It makes comparative analysis of matrixes of different configurations quite difficult. Fulfillment of comparative analysis of strength characteristics of magnetic fields of multicomponent matrixes of polygradient separators of various configurations requires further researches. Goal. To determine the dependence of the strength characteristics of the polygradient electromagnetic separator on the geometrical parameters of the plate type elements of the multicomponent matrix. Methodology. The finite element method for calculation of power characteristics of separator magnetic field, method of comparative analysis and simple search method for determination of rational geometric parameters of the matrix have been used during the solution of the paper problem. Results. Estimation of entire spectrum of force field in plane of working zones of investigated structures in two-dimensional location for determination of rational variants of polygradient matrixes has been done. The main stages of computational experiment are given. Method of comparative analysis of power characteristics of investigated variants of matrix structures with corresponding characteristics of basic version of separator for determination of rational geometrical variants of polygradient matrixes has been applied. By results of calculations the rational geometric parameters of polygradient matrix has been chosen. The characteristics of power magnetic fields in working gaps of matrixes of polygradient separator have been studied. It made possible to determine the rational structural variants of matrix on basis of parameter of effective area of working zone. Practical value. The results of research can be used in practice of design of electromagnetic separators with polygradient matrixes

    Generation of electromagnetic fields of extremely high intensity by coherent summation of Cherenkov superradiance pulses

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    We demonstrate both theoretically and experimentally the possibility of correlating the phase of a Cherenkov superradiance (SR) pulse to the sharp edge of a current pulse, when spontaneous emission of the electron bunch edge serves as the seed for SR processes. By division of the driving voltage pulse across several parallel channels equipped with independent cathodes we can synchronize several SR sources to arrange a two-dimensional array. In the experiments carried out, coherent summation of radiation from four independent 8-mm wavelength band SR generators with peak power 600 MW results in the interference maximum of the directional diagram with an intensity that is equivalent to radiation from a single source with a power of 10 GW

    Coherent summation of emission from relativistic Cherenkov sources as a way of production of extremely high-intensity microwave pulses

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    For relativistic Cherenkov devices, we investigate the process of high-power microwave pulse generation with its phase correlating to the sharp edge of an e-beam current pulse. Our theoretical consideration is referred to quasi-stationary and superradiative (SR) generation regimes when spontaneous emission of the e-beam edge serves as the seed for the development of further coherent oscillations. Phase correlation of the excited microwave pulses with the characteristics of the current pulse front and/or an initial external electromagnetic pulse has been additionally confirmed by particle-in-cell simulations. Pulse-to-pulse stability of the radiation phase within several percents of the oscillation period makes it possible to arrange multichannel schemes producing mutually coherent microwave pulses. In the experiments that have been carried out, the cathodes of independent generators were powered by identical accelerating pulses from strictly synchronized voltage modulators, or by splitting the pulse from a single powerful modulator. For the 2-ns regime with the power of each Ka-band backward-wave oscillator about 100 MW, we demonstrate quadratic growth of the power density in the interference maximum of the directional diagram. In a short pulse SR regime, with the peak power of 600 MW in a single channel, for a four-channel 2-D array, we attained a 16-fold radiation intensity gain

    Iron-based ultrafine particles made in mode solutions and industrial waste waters

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    Iron and attendant impurities settled from industrial waste water by ferritizing and formation of nanoparticles in batch bacterials culture have been studies. Iron settlement by ferritizing forms magnetic sediment extractable by magnetic separation..

    LACTOFERIN IN THE PROBLEM OF ANTI-INFECTIOUS PROTECTION OF BABIES IN THEIR FIRST YEAR OF LIVING

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    The author  summarizes  the  results  of research  of the  antibacterial,  antiviral  and  antifungal  properties  of multifunctional  human protein  — lactoferrin,  in order  to determine  the prospects  for its use in the prevention  and  treatment  of infectious  diseases  of children in their first year of life. The mechanisms of anti-infectious effect of this protein with breastfed children have been described. Basic differences between human lactoferrin and cattle lactoferrin have been shown. Biotechnology of obtaining recombinant human lactoferrin from the milk of genetically engineered dairy animals (goat-producers) has been described. According to the studies, both by physical and chemical parameters and biological activity, human lactoferrin, obtained from milk-producing  goats, corresponds to its natural counterpart

    ВОЗМОЖНОСТИ ПРИМЕНЕНИЯ ЛАКТОФЕРРИНА У ДЕТЕЙ ПЕРВОГО ГОДА ЖИЗНИ

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    The author  summarizes  the  results  of research  of the  antibacterial,  antiviral  and  antifungal  properties  of multifunctional  human protein  — lactoferrin,  in order  to determine  the prospects  for its use in the prevention  and  treatment  of infectious  diseases  of children in their first year of life. The mechanisms of anti-infectious effect of this protein with breastfed children have been described. Basic differences between human lactoferrin and cattle lactoferrin have been shown. Biotechnology of obtaining recombinant human lactoferrin from the milk of genetically engineered dairy animals (goat-producers) has been described. According to the studies, both by physical and chemical parameters and biological activity, human lactoferrin, obtained from milk-producing  goats, corresponds to its natural counterpart.В статье обобщены результаты исследований, посвященных изучению антибактериальных, противовирусных и противогрибковых свойств многофункционального белка человека — лактоферрина, для определения перспектив его применения с целью профилактики и лечения инфекционной патологии у детей первого года жизни. Описаны механизмы противоинфекционного действия этого белка у детей, находящихся на грудном вскармливании. Показаны основные различия между лактоферрином человека и лактоферрином крупного рогатого скота. Описана биотехнология получения рекомбинантного лактоферрина человека из молока генно-инженерных молочных животных (коз-продуцентов). Согласно проведенным исследованиям, как по физико-химическим параметрам, так и по биологической активности лактоферрин  человека, выделенный из молока коз-продуцентов, соответствует его природному аналогу
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