9 research outputs found

    Inhibition of protein tyrosine phosphatase activity by diamide is reversed by epidermal growth factor in fibroblasts

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    AbstractDiamide (azodicarboxylic acid bis(dimethylamide)) inhibits protein tyrosine phosphatase activity in fibroblasts without altering protein tyrosine kinase activity associated with the epidermal growth factor receptor. The loss of protein tyrosine phosphatase activity caused by diamide is reversed by 2-mercaptoethanol or epidermal growth factor

    Integrated modifying zinc-containing additive for construction silicate compositions

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    Sodium silicate binders are a promising binder base for obtaining effective granular thermal insulation materials. Increasing water resistance, first of all, will expand the scope of their application in construction. At the same time, the features of the modification of sodium silicate binders by compounds of polyvalent metals have not been fully studied, the interaction with which leads to the formation of hardly soluble silicates. The purpose of this work was to develop a modifying complex based on a zinc-containing compound - zinc acetate to increase the water resistance and thermal characteristics of the porous granular material. The proposed modifying additive is a complex consisting of zinc acetate and an organic alcohol solvent. It is shown that the properties of porous granular material can be controlled by changing the composition of the zinc acetate solvent. Qualitative and quantitative dependences of the properties of porous granules (strength, water resistance, density, thermal conductivity) on the type of zinc-containing solution and its content in the compositions have been obtained. The concept of the mechanism of formation of sparingly soluble complexes during the modification of sodium silicate binders with zinc-containing aqueous-alcoholic solutions has been developed. X-ray phase analysis showed that the sodium silicate system modified with an aqueous alcohol solution of zinc acetate, in contrast to an aqueous solution of zinc acetate, is completely in an amorphous state. We believe that compounds of the Zn2SiO4H2O, ZnSiO3 type are in the amorphous state. The obtained research results made it possible to determine the rational composition of granular heat-insulating material with increased operational and functional characteristics (ρ = 200-280 kg / m3, λ = 0.052-0.063 W / (m °C), R = 1.3-1.8 MPa, Kr = 0.89-0.92, W = 16- 18 %)

    Structure formation and properties of thermochemically modified silicate-sodium compositions

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    Modern methods allow to improve the functional properties of silicate-sodium compositions. Increased water resistance primarily will allow their use in construction. The article presents the results of the study of modified silicate-sodium compositions by X-ray phase analysis, differential thermal analysis, thermo-gravimetric analysis. An organic zinc-containing compound, zinc acetate dihydrate, which is introduced into the binder in the form of a concentrated aqueous fluid, was used as a modifier. Using X-ray analysis, it was shown that in the hardening system “silicate-sodium binder an aqueous fluid of zinc acetate” in the temperature range 110-450°C various forms of hydroxides, silicates and zinc silicates are formed. In addition, at T = 450°C, only “traces” of ZnO were detected, and the crystalline phase of the hardly soluble zinc metasilicate ZnSiO3 prevailed. The results of the study of modified samples by thermal analysis indicate the processes of thermal decomposition of the modifying additive in the binder system and indicate the possible formation of a new crystalline phase (ZnSiO3) at a temperature of 440-450°C. It was revealed that temperature treatment of modified samples in the range of 440-450°C leads to a more significant increase in water resistance (by 25-28%) than during low-temperature curing (by 20-23%)

    Integrated modifying zinc-containing additive for construction silicate compositions

    No full text
    Sodium silicate binders are a promising binder base for obtaining effective granular thermal insulation materials. Increasing water resistance, first of all, will expand the scope of their application in construction. At the same time, the features of the modification of sodium silicate binders by compounds of polyvalent metals have not been fully studied, the interaction with which leads to the formation of hardly soluble silicates. The purpose of this work was to develop a modifying complex based on a zinc-containing compound - zinc acetate to increase the water resistance and thermal characteristics of the porous granular material. The proposed modifying additive is a complex consisting of zinc acetate and an organic alcohol solvent. It is shown that the properties of porous granular material can be controlled by changing the composition of the zinc acetate solvent. Qualitative and quantitative dependences of the properties of porous granules (strength, water resistance, density, thermal conductivity) on the type of zinc-containing solution and its content in the compositions have been obtained. The concept of the mechanism of formation of sparingly soluble complexes during the modification of sodium silicate binders with zinc-containing aqueous-alcoholic solutions has been developed. X-ray phase analysis showed that the sodium silicate system modified with an aqueous alcohol solution of zinc acetate, in contrast to an aqueous solution of zinc acetate, is completely in an amorphous state. We believe that compounds of the Zn2SiO4H2O, ZnSiO3 type are in the amorphous state. The obtained research results made it possible to determine the rational composition of granular heat-insulating material with increased operational and functional characteristics (ρ = 200-280 kg / m3, λ = 0.052-0.063 W / (m °C), R = 1.3-1.8 MPa, Kr = 0.89-0.92, W = 16- 18 %)

    Taxonomic assessment of Allium species from Kazakhstan based on ITS and matK markers

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    Abstract Background As part of nation-wide project to infer the genetic variation of the native flora in Kazakhstan, a study was attempted to assess phylogenetic relationships of endemic and rare Allium species. In total, 20 Allium species were collected in field trips in five different regions of Kazakhstan during 2015–2016. Most species (9) were collected in the southern part of the country along of Karatau mountains, followed by Altai mountains (5) in eastern Kazakhstan. The ITS and matK DNA regions were applied in order to assess the taxonomic relationships among species. The major goal of the study was to assess the taxonomic position of five endemic and rare species from Allium subgenus Reticulatobulbosa collected in Karatau mountains of Southern Kazakhstan. Results The 20 collected Allium species were assessed using morphological traits and a DNA barcoding approach. The morphological analyses of four different species in subgenus Reticulatobulbosa inferred similarities of A. inconspicuum and A. barszchewskii (both from section Companulata) that were separated from A. oreoscordum and A. oreoprasoides (section Nigrimontana) by several traits, including form of bulbs and leaves, presence of bracts, shape of perianth lobes and style. The Neighbor-Joining method was applied to generate ITS and matK phylogenetic trees for two groups of populations: 1) 20 Allium species collected within the project, and 2) 50 Allium worldwide species. Conclusions The analyses of nucleotide sequences of ITS and matK robustly confirmed the monophyletic origin of the Allium species. The variability in 20 local Allium species in ITS was 6.6 higher than in matK, therefore the topology of the ITS tree was better resolved. The taxonomy of Allium species largely coincided with a recent classification of this genus. Analyses of both ITS and matK suggest that A. oreoscordum is genetically close to A. oreoprasoides in section Nigrimontana of subgenus Reticulatobulbosa. This result was also confirmed using morphological description of individual plants of four species in subgenus Reticulatobulbosa. The study is another contribution to taxonomy clarification in Allium
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