Using method of DNA microelectrophoresis for the assessment of genotoxic effects of mutagens in cultured human hemopoietic cells

Formation of single- and double strand breaks in DNA which may be discovered by microelectrophoresis in agarose gel is one of the criterion of genetical lesions in cells as a result of apoptosis or of genotoxic agent action. Genotoxic action of nickel chloride at the level of DNA of the individual cells in the initial culture of human embryonic haemopoietic cells was studied. It has been shown that about 2% cells in the studied in vitro populations were in the apoptosis state. Nickel chloride induced increasing of the frequency of formation of electrophoretic tracks of "comet" type with destroyed DNA.     

Study of the dynamics of the electrode plasma in a high-current magnetically insulated transmission line

A series of experiments was carried out in the S-300 facility (3 MA, 0.15 Θ, 100 ns) to study the behavior of a section of a magnetically insulated transmission line (MITL) at current densities of up to 500 MA/cm² and linear current densities of up to 6 MA/cm (i.e., at parameters close to those expected in a fast Z-pinch fusion reactor projected in Sandia National Laboratories). The surface explosion of the ohmically heated MITL electrode is accompanied by the formation of a plasma layer on its surface. This can deteriorate of the transmission properties of the line because the vacuum gap is short-circuited by the plasma produced. The parameters of the electrode plasma and its effect on the MITL transmission properties were investigated experimentally. Possible consequences of the above effects are evaluated, and MHD simulations of the electrode explosion and the subsequent spread of the plasma layer are performed. It is shown that the time during which an MITL segment preserves its transmission properties conforms to the requirements of the conceptual fusion reactor.     

X-ray colonometry in the diagnosis of colonic dyskinesias and inflammatory diseases

Clinical and X-ray studies were made in 316 patients, which revealed intestinal dyskinesia, chronic colitis, and nonspecific ulcerative colitis in 105, 133, and 78 patients, respectively. Irrigoscopy (administration of a contrast enema, examination of the mucosal contour, and double contrasting) was performed in all the patients, by analyzing X-ray planimetric indices. X-ray colonoplanimetry makes it possible to objectify the interpretation of the X-ray pattern in chronic inflammatory diseases of the large bowel and colonic dyskinesia.     

Experiments with small-size dynamic loads in the S-300 high-power pulsed generator

Results are presented from experimental studies of promising output units for high-current pulsed generators within the framework of the program on inertial confinement fusion research with the use of fast Z-pinches. The experiments were carried out on the S-300 facility (4 MA, 70 ns, 0.15 Ω). Specifically, sharpening systems similar to plasma flow switches but operating in a nanosecond range were investigated. Switching rates to a load as high as 2.5 MA per 2.5 ns, stable switching of a 750-kA current to a low-size Z-pinch, and the radiative temperature of the load cavity wall of up to 50 eV were achieved.     

The dynamics of and radiation from a copper-wire corona in a megaampere Z-pinch

Evolution of the extreme ultraviolet (XUV) and soft X-ray (SXR) emission in the 50-to 2000-eV photon energy range from a plasma corona formed by loading a relatively thick Cu wire (with an initial diameter of 120 µm) was observed in a Z-pinch discharge with a maximum current of 2 MA and current rise time of 100 ns. A diagnostic complex consisting of a five-channel SXR polychromator, a four-frame X-ray pinhole camera, and a mica crystal spectrograph shows that double-humped emission pulses in the XUV and SXR spectral ranges are generated 70–130 ns after the onset of the discharge current. The total energy of the pulses is 5 kJ, and the maximum power is 60 GW. A part of the observed kiloelectronvolt X-ray emission from three to five spots with diameters of 1–2 mm consists of the Cu K-and L-shell lines.     

Formation of hot spots in the plasma of a Z-pinch produced from low-density deuterated polyethylene

Results are presented from experimental studies of the plasma formation dynamics in a Z-pinch produced from a cylindrical microporous agar-agar load. The experiments were performed on the S-300 facility at a current of 2 MA and current rise time of 100 ns. To enhance the energy concentration, a deuterated polyethylene neck with a mass density of 50–75 μg/cm³ and diameter of 1–2 mm was made in the central part of the load. The spatiotemporal characteristics of the Z-pinch were studied using an optical streak camera and fast frame photography in the optical and soft X-ray spectral ranges. X-ray emission was detected using semiconductor and vacuum diodes, and neutron emission was studied by means of the time-of-flight method. It is found that, in the course of continuous plasma production, hot spots with a diameter of 100 μm form in the pinch plasma. The hot spots emit short soft X-ray pulses with a duration of 2–4 ns, as well as neutron pulses with an average neutron energy of about 2.45 MeV. The maximum neutron yield was found to be 4.5 × 10⁹ neutrons per shot. The scenario of hot spot formation is adequately described by two-dimensional MHD simulations.     

Light Microscopic Autoradiography Followed by Electron Microscopy

We have developed a technique whereby sections processed for autoradiography to localize a labelled cell can then be re-sectioned for examination of the same cell under the electron microscope (Fig. 1). The benefits of this method are 1) positive ultrastructural identification of the tagged cell, as the cell is visible throughout the re-sectioning procedure, 2) no unnecessary sectioning, as each block is known to contain tagged cells, and 3) rapid tissue processing and examination.     

Oil content and lipid composition of safflower (Carthamus tinctorius) irrigated with saline water under greenhouse and field conditions

An intensive process of land deterioration of some regions in Uzbekistan including the Aral Sea basin has led to a significant increase in soil salinity levels and consequently to a considerable reduction of total fertile soil area, as these lands are of little use for plant growth. The area is estimated to be more than 1.4 million ha of seabed. As a result, there was an immediate need to cultivate new crops capable of stopping the movement of sands and the enlargement of saline soils. Safflower (Carthamus tinctorius) is considered to be a moderately salt‐tolerant crop and, as such, one of a few crops well suited to the cropping systems of salt‐affected soils. It is used in Uzbekistan as a reserve crop when the culture of the main crop fails. In spite of the great economic importance of this oil, there is almost no available information in the literature on the effect of salinity on oil quality and its chemical ingredients. The purpose of the present study was to determine, in greenhouse and field experiments, how irrigation with saline water would influence content of oil, lipids and other lipophylic components in safflower. We found that irrigation of safflower with moderate concentrations of saline water seems feasible, as far as oil and lipid composition is concerned. Consequently, safflower might be a potential crop for lands of little use for plant growth in Uzbekistan or other similar sites in the world.     

Label-free detection of mitochondrial distribution in cells by nonresonant Raman microspectroscopy

High spatial resolution Raman maps of fixed cells in an aqueous environment are reported. These maps were obtained by collecting individual Raman spectra via a Raman microspectrometer in a raster pattern on a 0.5-microm grid and assembling pseudocolor maps from the spectral hypercubes by multivariate methods. The Raman maps show the nucleus and the nucleoli of cells as well as subcellular organization in the cytoplasm. In particular, the distribution of mitochondria in the perinuclear region could be demonstrated by correlating distinct areas of the Raman maps with corresponding areas of fluorescence maps of the same cells after staining with mitochondria-specific labels. To the best of our knowledge, this is the first report of label-free detection of mitochondria inside a somatic mammalian cell using Raman microspectroscopy.