Интенсификация возделывания картофеля

В статье описаны требования к качеству посадочного материала. Проведен анализ существующих технологий посадки картофеля. Предложена модернизированная конструкция посадочной машины и соответственно усовершенствованная технология посадки картофеля.The article describes the requirements for the quality of planting material. The analysis of existing potato planting technologies is carried out. A modernized planting machine design and, correspondingly, an improved technology for planting potatoes are proposed

Isolation of a HypC–HypD complex carrying diatomic CO and CN− ligands

The HypC and HypD maturases are required for the biosynthesis of the Fe(CN)2CO cofactor in the large subunit of [NiFe]-hydrogenases. Using infrared spectroscopy we demonstrate that an anaerobically purified, Strep-tagged HypCD complex from Escherichia coli exhibits absorption bands characteristic of diatomic CO and CN− ligands as well as CO2. Metal and sulphide analyses revealed that along with the [4Fe–4S]2+ cluster in HypD, the complex has two additional oxygen-labile Fe ions. We prove that HypD cysteine 41 is required for the coordination of all three ligands. These findings suggest that the HypCD complex carries minimally the Fe(CN)2CO cofactor

Potential energy surface of the 2A' Li2+Li doublet ground state

The lowest doublet electronic state for the lithium trimer (2A') is calculated for use in three-body scattering calculations using the valence electron FCI method with atomic cores represented using an effective core potential. It is shown that an accurate description of core-valence correlation is necessary for accurate calculations of molecular bond lengths, frequencies and dissociation energies. Interpolation between 2A' ab initio surface data points in a sparse grid is done using the global interpolant moving least squares method with a smooth radial data cutoff function included in the fitting weights and bivariate polynomials as a basis set. The Jahn-Teller splitting of the 2E' surface into the 2A1 and 2B2 states is investigated using a combination of both CASSCF and FCI levels of theory. Additionally, preliminary calculations of the 2A'' surface are also presented using second order spin restricted open-shell Moller-Plesset perturbation theory.Comment: 7 pages, 5 figure

Effect of metal ions on the physical properties of multilayers from hyaluronan and chitosan, and the adhesion, growth and adipogenic differentiation of multipotent mouse fibroblasts

[EN] Polyelectrolyte multilayers (PEMs) consisting of the polysaccharides hyaluronic acid (HA) as the polyanion and chitosan (Chi) as the polycation were prepared with layer-by-layer technique (LbL). The [Chi/HA](5) multilayers were exposed to solutions of metal ions (Ca2+, Co2+, Cu2+ and Fe3+). Binding of metal ions to [Chi/HA](5) multilayers by the formation of complexes with functional groups of polysaccharides modulates their physical properties and the bioactivity of PEMs with regard to the adhesion and function of multipotent murine C3H10T1/2 embryonic fibroblasts. Characterization of multilayer formation and surface properties using different analytical methods demonstrates changes in the wetting, surface potential and mechanical properties of multilayers depending on the concentration and type of metal ion. Most interestingly, it is observed that Fe3+ metal ions greatly promote adhesion and spreading of C3H10T1/2 cells on the low adhesive [Chi/HA](5) PEM system. The application of intermediate concentrations of Cu2+, Ca2+ and Co2+ as well as low concentrations of Fe3+ to PEMs also results in increased cell spreading. Moreover, it can be shown that complex formation of PEMs with Cu2+ and Fe3+ ions leads to increased metabolic activity in cells after 24 h and induces cell differentiation towards adipocytes in the absence of any additional adipogenic media supplements. Overall, complex formation of [Chi/HA](5) PEM with metal ions like Cu2+ and Fe3+ represents an interesting and cheap alternative to the use of growth factors for making cell-adhesive coatings and guiding stem cell differentiation on implants and scaffolds to regenerate connective-type of tissues.This work was part of the High-Performance Center Chemical and Biosystems Technology Halle/Leipzig, supported by the European Regional Development Fund (ERDF), and a grant to HK from the Martin Luther University Halle-Wittenberg for female PhD students. The work was further supported by the Fraunhofer Internal Programs under Grant No. Attract 069-608203 (CEHS). TG acknowledges the kind support by the Ministry of Science and Higher Education of the Russian Federation within the framework of state support for the creation and development of World-Class Research Centers ``Digital biodesign and personalized healthcare'' 075-15-2020926. GGF acknowledges funding by the State Research Agency. Ministry of Science and Innovation of Spain, grant PID2019106000RB-C21/AEI/10.13039/501100011033 project. We are grateful for the kind support by Christian Willems for the help in formatting and proof reading the manuscript.Kindi, H.; Menzel, M.; Heilmann, A.; Schmelzer, CEH.; Herzberg, M.; Fuhrmann, B.; Gallego-Ferrer, G.... (2021). Effect of metal ions on the physical properties of multilayers from hyaluronan and chitosan, and the adhesion, growth and adipogenic differentiation of multipotent mouse fibroblasts. Soft Matter. 17(36):8394-8410. https://doi.org/10.1039/d1sm00405k83948410173

Optical excitations in organic molecules, clusters and defects studied by first-principles Green's function methods

Spectroscopic and optical properties of nanosystems and point defects are discussed within the framework of Green's function methods. We use an approach based on evaluating the self-energy in the so-called GW approximation and solving the Bethe-Salpeter equation in the space of single-particle transitions. Plasmon-pole models or numerical energy integration, which have been used in most of the previous GW calculations, are not used. Fourier transforms of the dielectric function are also avoided. This approach is applied to benzene, naphthalene, passivated silicon clusters (containing more than one hundred atoms), and the F center in LiCl. In the latter, excitonic effects and the $1s \to 2p$ defect line are identified in the energy-resolved dielectric function. We also compare optical spectra obtained by solving the Bethe-Salpeter equation and by using time-dependent density functional theory in the local, adiabatic approximation. From this comparison, we conclude that both methods give similar predictions for optical excitations in benzene and naphthalene, but they differ in the spectra of small silicon clusters. As cluster size increases, both methods predict very low cross section for photoabsorption in the optical and near ultra-violet ranges. For the larger clusters, the computed cross section shows a slow increase as function of photon frequency. Ionization potentials and electron affinities of molecules and clusters are also calculated.Comment: 9 figures, 5 tables, to appear in Phys. Rev. B, 200

Lower Rydberg series of methane : A combined coupled cluster linear response and molecular quantum defect orbital calculation

Vertical excitation energies as well as related absolute photoabsorption oscillator strength data are very scarce in the literature for methane. In this study, we have characterized the three existing series of low-lying Rydberg states of CH4 by computing coupled cluster linear response (CCLR) vertical excitation energies together with oscillator strengths in the molecular-adapted quantum defect orbital formalism from a distorted Cs geometry selected on the basis of outer valence green function calculations. The present work provides a wide range of data of excitation energies and absolute oscillator strengths which correspond to the Rydberg series converging to the three lower ionization potential values of the distorted methane molecule, in energy regions for which experimentally measured data appear to be [email protected] [email protected] [email protected]

The [NiFe]-hydrogenase accessory chaperones HypC and HybG of Escherichia coli are iron- and carbon dioxide-binding proteins.

[NiFe]-hydrogenase accessory proteins HypC and HypD form a complex that binds a Fe–(CN)2CO moiety and CO2. In this study two HypC homologues from Escherichia coli were purified under strictly anaerobic conditions and both contained sub-stoichiometric amounts of iron (approx. 0.3 mol Fe/mol HypC). Infrared spectroscopic analysis identified a signature at 2337 cm−1 indicating bound CO2. Aerobically isolated HypC lacked both Fe and CO2. Exchange of either of the highly conserved amino acid residues Cys2 or His51 abolished both Fe- and CO2-binding. Our results suggest that HypC delivers CO2 bound directly to Fe for reduction to CO by HypD