Remodeling of the composition of the membrane’s lipids of buckwheat plants (Fagopyrum esculentum Moench.) under conditions of phosphorous deficiency and seed bacterization with phosphate solubilizing microorganisms

This paper presents research results on the sensitivity of buckwheat (Fagopyrum esculentum Moench.) inoculated with phosphate solubilizing microorganisms (PSM) to phosphorus deficiency using the transformation of major photosynthetic tissues membrane lipids as the indicator. The analysis of glyco- and phospholipids performed has revealed the plants’ ability to react to a deficit in phosphorus with the selective accumulation of sulfoquinovosyldiacylglycerol (SQDG) and digalactosyldiacylglycerol (DGDG) along with a decrease in phosphatidylglycerol (PG). Pre-sowing seed bacterization with PSM has balanced out the negative impact of a phosphorus deficiency on plants by stabilizing the PG content and reducing the difference in the PG/SQDG ratio

LONG-TERM CHANGE OF RECLAIMED CHESTNUT SOLONETZIC SOILS AFTER SINGLE ROTOR INTERNAL PLOWING

Long-term change of the solonetzic salted chestnut soil complex of dry steppe after their agrotechnical improvement with a new facility of rotor plowing and mixing of illuvial and lower layers of soil is studied. Some technical parameters of the devices for soil-meliorative rotor-milling processing are discussed. More than 30 years after a single soil processing by plow PMS-70 at the depth of 40—45 cm, the soil consists of small uniformly sized aggregates. No morphological signs of the solonetzic paedogenesis restoration are revealed. The atmospheric precipitation moisture enters readily the soil, freely soluble salts sink at the depth sufficient for the elimination of their negative effect on the paedogenesis. The quantity of humus in the soil layer of 0—20 cm makes up 3,3 %, in the layer of 20—40 cm — 2,4 %. The quantity of absorbed Na+ in the layer of 20—30 cm is 10,6 % from the soil cation exchange capacity instead of 19,8 % of raw soil. The productivity increase of the agricultural crops makes up 25—60 and more percent to the yield level under the standard agriculture technology during the whole period of monitoring

LOW DRAUGHT SUBSOIL TILLAGE FACILITIES

The biogeosystem engineering is considered, and the verification of the biological, recreational, productive-economic resources of the soil-reclamation agrotechnics based on the rotary milling subsoiling is performed. The test data of the first-generation rotary milling subsoiling facility is provided. A fundamentally new engineering solution is developed. The structural synthesis of the new rotary milling subsoiling facility options in the second- and third-order approximations is performed. The draught minimization of the new facility under its operation is provided. The optimization criterion for the engineering solution synthesis results is developed; the facility parametric synthesis is performed; comparative energy characteristics of the new facility and prototype are given. The rotary milling chisel plough—gearbox transmits torque without passive draught to the tillage tool, and to the subsoiling one that operates full dip being horizontally located and moving progressively at the given depth of 20‒48 cm. The possibility of the reliable operation in the soil of the new engineering solution interconnect system is proved. The assignment and reliability indices of the subsoiling rotary milling facilities are given. Performance physics and physics of failures are considered; the new engineering solution reliability is proved. The fundamentally new principles of the innovation project development and the implementation of the land development plans in Russia are proposed

PLOUGHS FOR ROTOR INTERNAL TILLAGE OPERATIONS

The production method is worked out, and the technical solutions to the rotary internal soil mulching are proposed. On the basis of the long-term stationary studies, the synthesis problem on a new soil quality is solved. The goal of these investigations is the creation of the long-term optimal launch growing conditions. Technical parameters of the devices are described. The effect of their application on the soil and on the farming results is shown. The application prospects of the rotor subsurface tilling operations are indicated. It is noted that the considerable part of the drawbar and power balance of the rotary subsurface ploughs PMS-70, PMS-100, and others, is defined by the resistance to the tilling tool movement in the soil — to the bearing, ripper, gear plough tine

Structural and Electrochemical Characteristics of Platinum Nanoparticles Supported on Various Carbon Carriers

Graphene-like materials have attracted significant attention as alternative catalyst carriers due to the broad possibilities of changing their shape, composition, and properties. In this study we investigated the structural and electrochemical characteristics of platinum electrocatalysts supported on reduced graphene oxide (rGO), including those modified with amine functionalities, nitrogen heteroatoms (rGO-Am), and oxygen enriched (rGO-O). Synthesis of Pt nanoparticles (20 wt.%) on the graphene-like nanomaterials surface was carried out using a modified polyol procedure. The Pt20/rGO-Am showed a lower Pt nanoparticles size together with high Pt utilization and EASA values compared to rGO-supported catalysts and the Pt/C reference sample due to the uniform distribution of nucleation centers on the surface of graphene nanoparticles, and the greater ability of these centers to electrically bond with platinum

Calcium-regulated interactions of human α-lactalbumin with bee venom melittin

Affinity chromatography, fluorescence and circular dichroism spectroscopy methods have been used to study the interaction of melittin, a 26-residue peptide from bee venom, with Ca2+-binding α-lactalbumin from human milk. It has been revealed that melittin binds to the apo- and acidic states of α-lactalbumin while the presence of Ca2+ makes the interaction essentially weaker. The association constant for the complex of melittin with apo-α-lactalbumin determined from spectropolarimetric melittin-titration data is 2×107 M−1. The complexation of α-lactalbumin with melittin decreases its affinity to Ca2+ by three orders of magnitude. The interaction of apo-α-lactalbumin with melittin causes some changes in the environment of its aromatic amino acid residues and drastically alters the conformation of melittin, increasing its α-helical content but leaving its single tryptophan residue accessible to water. In the case of the acidic state of α-lactalbumin the interaction does not induce an increase in α-helical content of melittin

Ultraviolet Illumination-induced Reduction of α-lactalbumin Disulfide Bridges

Prolonged exposure of Ca2+-loaded or Ca2+-depleted human α-lactalbumin to ultraviolet light (270–290 nm, 1 mW/cm2, for 2 to 4 h) results in a 10-nm red shift of its tryptophan fluorescence spectrum. Gel chromatography of the UV-illuminated samples reveals two non-native protein forms: (1) a component with a red-shifted tryptophan fluorescence spectrum; and (2) a component with kynurenine-like fluorescent properties. The first component has from 0.6 to 0.9 free DTNB-reactive SH groups per protein molecule, which are absent in the native protein and is characterized by slightly lowered Ca2+-affinity (2 × 108 M−1 versus 8 × 108 M−1 for the native protein) and absence of observable thermal transition. The second component corresponds to the protein with photochemically modified tryptophan residues. It is assumed that the UV excitation of tryptophan residue(s) in α-lactalbumin is followed by a transfer of electrons to the SS bonds, resulting in their reduction. Mass spectrometry data obtained for trypsin-fragmented UV-illuminated α-lactalbumin with acrylodan-modified free thiol groups reveal the reduction of the 61–77 and 73–91 disulfide bridges. The effect observed has to be taken into account in any UV-region spectral studies of α-lactalbumin. Proteins 2003;51:498–503. © 2003 Wiley-Liss, Inc

Reduced Graphene Oxide-Supported Pt-Based Catalysts for PEM Fuel Cells with Enhanced Activity and Stability

Platinum (Pt)-based electrocatalysts supported by reduced graphene oxide (RGO) were synthesized using two different methods, namely: (i) a conventional two-step polyol process using RGO as the substrate, and (ii) a modified polyol process implicating the simultaneous reduction of a Pt nanoparticle precursor and graphene oxide (GO). The structure, morphology, and electrochemical performances of the obtained Pt/RGO catalysts were studied and compared with a reference Pt/carbon black Vulcan XC-72 (C) sample. It was shown that the Pt/RGO obtained by the optimized simultaneous reduction process had higher Pt utilization and electrochemically active surface area (EASA) values, and a better performance stability. The use of this catalyst at the cathode of a proton exchange membrane fuel cell (PEMFC) led to an increase in its maximum power density of up to 17%, and significantly enhanced its performance especially at high current densities. It is possible to conclude that the optimized synthesis procedure allows for a more uniform distribution of the Pt nanoparticles and ensures better binding of the particles to the surface of the support. The advantages of Pt/RGO synthesized in this way over conventional Pt/C are the high electrical conductivity and specific surface area provided by RGO, as well as a reduction in the percolation limit of the components of the electrocatalytic layer due to the high aspect ratio of RGO

Reduced Graphene Oxide and Its Modifications as Catalyst Supports and Catalyst Layer Modifiers for PEMFC

Reduced graphene oxide (RGO) and RGO modified by ozone (RGO-O) and fluorine (RGO-F) were synthesized. Pt nanoparticles were deposited on these materials and also on Vulcan XC-72 using the polyol method. The structural and electrochemical properties of the obtained catalysts were investigated in a model glass three-electrode electrochemical cell and in a laboratory PEM fuel cell. Among the RGO-based catalysts, the highest electrochemically active surface area (EASA) was obtained for the oxidized RGO supported catalyst. The EASA of the fluorine-modified RGO-supported catalyst was half as big. In the PEM fuel cell the performance of RGO-based catalysts did not exceed the activity of Vulcan XC-72-based catalysts. However, the addition of an RGO-O-based catalyst to Vulcan XC-72-based catalyst (in contrast to the RGO-F-based catalyst) allowed us to increase the catalyst layer activity and PEM fuel cell performance. Possible reasons for such an effect are discussed