106 research outputs found
Varietal reaction of potato plants grown on aeroponic installations
The article presents data on study of the productivity of potato early ripening varieties (Legenda, Russia; Red Scarlet, Netherlands) and middle-early varieties (Irbitskiy Russia; Gala, Germany) grown on aeroponic installations in artificial lighting conditions: three-tier adaptive installation (“Syntol” production) and single-tier installation produced by “Biological systems” plant. Potato plants were characterized by active growth and development. Their height ranged from 71.0 to 94.2 cm among the varieties, the number of leaves formed on one plant – from 23 to 31 pieces. The formation of mini-tubers was noted from the 46th day (Legenda variety) to the 53rd day (Irbitskiy variety). The first harvest was obtained at the 65th day in early varieties and at the 67th day for middle-early varieties beginning from planting of micro-plants on to the adaptation installation. The productivity of plants by varieties ranged from 123.0 g (Legenda) to 216.1 (Gala) g of mini-tubers per plant, output of mini tubers from 68.1 (Irbitskiy) to 105.2 (Legenda) pieces per plant, the mass of one mini-tuber ranged from 1.17(Legenda) to 2.73 g (Red Scarlet)
A gene expression system offering multiple levels of regulation: the Dual Drug Control (DDC) system
BACKGROUND: Whether for cell culture studies of protein function, construction of mouse models to enable in vivo analysis of disease epidemiology, or ultimately gene therapy of human diseases, a critical enabling step is the ability to achieve finely controlled regulation of gene expression. Previous efforts to achieve this goal have explored inducible drug regulation of gene expression, and construction of synthetic promoters based on two-hybrid paradigms, among others. RESULTS: In this report, we describe the combination of dimerizer-regulated two-hybrid and tetracycline regulatory elements in an ordered cascade, placing expression of endpoint reporters under the control of two distinct drugs. In this Dual Drug Control (DDC) system, a first plasmid expresses fusion proteins to DBD and AD, which interact only in the presence of a small molecule dimerizer; a second plasmid encodes a cassette transcriptionally responsive to the first DBD, directing expression of the Tet-OFF protein; and a third plasmid encodes a reporter gene transcriptionally responsive to binding by Tet-OFF. We evaluate the dynamic range and specificity of this system in comparison to other available systems. CONCLUSION: This study demonstrates the feasibility of combining two discrete drug-regulated expression systems in a temporally sequential cascade, without loss of dynamic range of signal induction. The efficient layering of control levels allowed by this combination of elements provides the potential for the generation of complex control circuitry that may advance ability to regulate gene expression in vivo
Approximation de la dépendance angulaire et énergétique de la section efficace de photoproduction des mésons sur les protons dans la gamme d'énergie voisine du seuil
Potentiometric sensors for the determination of cholinesterase inhibitors
Analytical characteristics of the determination of organophosphorus pesticides by means of cholinesterase potentiometric sensors with gelatin, paper, and cellulose nitrate membranes are examined with respect to the nature of membranes and determination conditions. A method is developed for the electrochemical activation of thione organophosphorus pesticides; this method consists in the electrochemical oxidation of the pesticides in the presence of sodium or potassium halides and provides an opportunity to significantly reduce the time for sample preparation and to simplify this procedure. © 1996 MAEe Cyrillic signK Hayκa/Interperiodica Publishing
Comparative assessment of electrochemical biosensors for determining inhibitors - Environmental pollutants
Electrochemical biosensors are developed on the basis of pH and carbon-paste electrodes with replaceable cholinesterase membranes supported on paper or polymeric membranes (Nylon, Hybond, Amersham and cellulose nitrate, Sartorius). Biosensors provide the rapid determination of Diazinon, Fozolone, Metaphos, and Koral with a detection limit of n × (10-8 to 10-9) M. The analytical characteristics of pesticide determination vary with the membrane material, which is due to the adsorption of the inhibitor on the membrane surface and depends on the hydrophobicity of the membrane material and the inhibitor. The modification of the biosensor sensitivity to pesticides on the addition of surfactants was studied, and the mechanism of biosensor response to inhibitors of various nature was investigated in both batch and flow-injection modes. © 1999 MAHK "Hayka/Interperiodica"
Electrochemical reduction of mucochloric acid and its 5-alkoxy derivatives
5-Alkoxy-3-chloro-2(5H)-furanones were synthesized by the electrochemical reduction of 5-alkoxy derivatives of mucochloric acid in acetonitrile on the lead electrode in the presence of acetic acid as a proton donor. A combined analysis of the experimental data and quantum chemical calculation of intermediates indicates the EE D C mechanism of reduction, including the tandem transfer of two electrons with chloride ion elimination at the stage of transfer of the second electron and protonation. © 2012 Springer Science+Business Media New York
INVESTIGATION OF LIPOPHILIC COMPOUNDS OF HERBS AND ROOTS OF CICHORIUM INTYBUS L
Cichorium intybus L., a perennial herbaceous plant of Asteraceae family, is widely distributed in the flora of Russia. Aboveground and underground parts of this plant are used in scientific and traditional medicine as hypoglycemic, antioxidant, hepatoprotective remedy. In this experiment lipophilic fractions of the herb and roots of chicory by method of gas chromatography with mass spectrometry detection was investigated. 4s a result of the research in the grass we revealed the presence of 14 compounds: derivatives of higher fatty alcohols, vital, isophytol, 3,7,11,15-tetrameth- yl-l,6,10,14-hexametre-3-ol, heneicosane, polien, first identifiedD-Iimonene. In the roots of chicory ordinary identified 12 substances - derivatives oflinoleic acid, first identified a-gorunen, (1-veteranen, a-amyrin and betulin
Sulfides, sulfones, and sulfoxides of the furan-2(5H)-one series. synthesis and structure
A number of 4- and 5-R-sulfanylfuran-2(5H)-one derivatives were synthesized, and their oxidation with various reagents was studied. The corresponding sulfones were obtained using hydrogen peroxide in acetic acid. 4-R-sulfanyl derivatives were selectively oxidized to sulfoxides with m-chloroperoxybenzoic acid. The molecular and crystal structures of some new sulfones and sulfoxides were determined by X-ray analysis. © 2014 Pleiades Publishing, Ltd
Topography of associations between cardiovascular risk factors and myelin loss in the ageing human brain.
Our knowledge of the mechanisms underlying the vulnerability of the brain's white matter microstructure to cardiovascular risk factors (CVRFs) is still limited. We used a quantitative magnetic resonance imaging (MRI) protocol in a single centre setting to investigate the cross-sectional association between CVRFs and brain tissue properties of white matter tracts in a large community-dwelling cohort (n = 1104, age range 46-87 years). Arterial hypertension was associated with lower myelin and axonal density MRI indices, paralleled by higher extracellular water content. Obesity showed similar associations, though with myelin difference only in male participants. Associations between CVRFs and white matter microstructure were observed predominantly in limbic and prefrontal tracts. Additional genetic, lifestyle and psychiatric factors did not modulate these results, but moderate-to-vigorous physical activity was linked to higher myelin content independently of CVRFs. Our findings complement previously described CVRF-related changes in brain water diffusion properties pointing towards myelin loss and neuroinflammation rather than neurodegeneration
Electrochemically driven molecular rotors based on ferrocene-1,1'-diyl-bisphosphinic acids
© 2015, Pleiades Publishing, Ltd. Based on ferrocene-1,1'-diyl-bisphosphinic acids Fc[P(R)(O)OH]2 (R = H, Me, Et, Ph) in methanol, two types of electrochemically driven molecular rotors are developed. Monoanions of acids are fixed in the cis-conformation due to the presence of an intramolecular hydrogen bond, whereas dianions are fixed in the trans-conformation due to electrostatic repulsion forces. Upon the transformation of monoanions to dianions, the controlled rotation of cyclopentadienyl rings from cis to trans-conformation occurs; the reverse switching leads to the reverse rotation. In one type of rotors, the rotation is controlled by the reversible variation of the solution pH and composition in the electrochemical oxidation-re-reduction cycle of N-phe-nyl-N'-isopropyl-1,4-phenylenediamine; in the other type, the rotation is determined by the one electron oxidation-re-reduction of the ferrocene nucleus in monoanions. The latter rotor type at room temperature can operate stably only for a short time (τ< 1 s) and at longer times is irreversibly destructed during the oxidation stage
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