Resonant Excitation of the Ferroelectric Soft Mode by a Narrow-Band THz Pulse.

This study investigates the impact of narrow-band terahertz pulses on the ferroelectric order parameter in BaSrTiO films on various substrates. THz radiation in the range of 1-2 THz with the pulse width of about 0.15 THz was separated from a broadband pulse with the interference technique.

Synthesis, Structure, Spectral-Luminescent Properties, and Biological Activity of Chlorine-Substituted -[2-(Phenyliminomethyl)phenyl]-4-methylbenzenesulfamide and Their Zinc(II) Complexes.

New azomethine compounds of 2-(-tosylamino)benzaldehyde or 5-chloro-2-(-tosylamino)benzaldehyde and the corresponding chlorine-substituted anilines, zinc(II) complexes based on them have been synthesized. The structures of azomethines and their complexes were determined by elemental analysis, IR, H NMR, X-ray spectroscopy, and X-ray diffraction. It is found that all ZnL complexes have a tetrahedral structure according to XAFS and X-ray diffraction data.

Assessing the toxicity and accumulation of bulk- and nano-CuO in Hordeum sativum L.

The effects of bulk- and nano-CuO were monitored on barley (Hordeum sativum L.) in hydroponic conditions. The anatomical and cyto-/morphometric parameters of plants, exposed to both types of CuO in different doses (300 and 2000 mg/L) were recorded.

The influence of application of biochar and metal-tolerant bacteria in polluted soil on morpho-physiological and anatomical parameters of spring barley.

The paper presents the results of the model experiment on spring barley (Hordeum vulgare L.) grown in polluted soil. The influence of separate and combined application of wood biochar and heavy metal-tolerant bacteria on morpho-physiological, anatomical and ultrastructural parameters of H.

Tetrahedral nickel(ii) and cobalt(ii) bis-o-iminobenzosemiquinonates.

The new bis-o-iminobenzosemiquinonate nickel and cobalt complexes (imSQt-Bu)2M (M = Ni (1), Co (2)), where imSQ is a radical anion of 4,6-di-tert-butyl-N-(tert-butyl)-o-iminobenzoquinone, were synthesized and characterized in detail. The molecular structures of 1 and 2 have been established by single-crystal X-ray analysis. The metal atoms in 1 and 2 have a distorted tetrahedral environment, and the dihedral angles between the planes of two radical imSQ ligands are approximately 80° in both complexes.

Common and rare iron, sulfur, and zinc minerals in technogenically contaminated hydromorphic soil from Southern Russia.

Soils formed after the desiccation of Lake Atamanskoe, which has served as a reservoir for liquid industrial waste from the city of Kamensk-Shakhtinsky during a long time, were studied. These soils differ from zonal soils by a strong contamination with zinc and sulfur. Preliminary studies showed that Fe compounds fix a significant part of zinc.

Anatomical and ultrastructural responses of Hordeum sativum to the soil spiked by copper.

Effects of Cu toxicity from contaminated soil were analysed in spring barley (Hordeum sativum distichum), a widely cultivated species in South Russia. In this study, H. sativum was planted outdoors in one of the most fertile soils-Haplic Chernozem spiked with high concentration of Cu and examined between the boot and head emergence phase of growth.

Transient Second Harmonic Generation Induced by Single Cycle THz pulses in BaSrTiO/MgO.

The ability to switch ferroics (magnets, ferroelectrics, multiferroics) between two stable bit states is the main principle of modern data storage technology. Due to many new ideas, originating from fundamental research during the last 50 years, this technology has developed in a breath-taking fashion. Ever increasing demands for faster and more energy efficient data storage strongly motivate fundamental studies of dynamics in ferroics triggered by ultrashort stimuli.

Variation of the photoluminescence spectrum of InAs/GaAs heterostructures grown by ion-beam deposition.

This work reports on an experimental investigation of the influence of vertical stacking of quantum dots, the thickness of GaAs potential barriers, and their isovalent doping with bismuth on the photoluminescence properties of InAs/GaAs heterostructures. The experimental samples were grown by ion-beam deposition. We showed that using three vertically stacked layers of InAs quantum dots separated by thin GaAs barrier layers was accompanied by a red-shift of the photoluminescence peak of InAs/GaAs heterostructures.

Toxicity of copper oxide nanoparticles on spring barley (Hordeum sativum distichum).

The rapid growth of copper oxide nanoparticles (CuO NPs) production and its abundant uses in many industries, and increasing release into an environment from both intentional and unintentional sources, create risks to spring barley (Hordeum sativum distichum), one of the most important staple food crop. Thereby, the aim of this study was to investigate the phytotoxicity of CuO NPs on H. sativum growth in hydroponic system.

[Features of redox processes in the amniotic fluid at placental insufficiency].

Activity of prooxidant enzymes (NADPH-oxidase and xanthine oxidase), antioxidant enzymes (superoxide dismutase (SOD) and catalase), enzymes of the glutathione-dependent systems, as well as antioxidant vitamins (retinol and a-tocopherol), lipid peroxidation products (LPP) (conjugated dienes and Schiff bases), and peroxide chemiluminescence were studied in the amniotic fluid at different periods of physiological pregnancy and placental insufficiency (PI). It was found that at PI the activity of NADPH-oxidase, xanthine oxidase increased and the activity of SOD, catalase, glutathione peroxidase, glutathione reductase, glutathione transferase and the content of fat-soluble vitamins decreased. The direct and inverse correlation between the studied pro- and antioxidant parameters and the content of LPP products, was found ro be different in the II and III trimesters of gestation.

THz Electric Field-Induced Second Harmonic Generation in Inorganic Ferroelectric.

Second Harmonic Generation induced by the electric field of a strong nearly single-cycle terahertz pulse with the peak amplitude of 300 kV/cm is studied in a classical inorganic ferroelectric thin film of (BaSr)TiO. The dependences of the SHG intensity on the polarization of the incoming light is revealed and interpreted in terms of electric polarization induced in the plane of the film. As the THz pulse pumps the medium in the range of phononic excitations, the induced polarization is explained as a dynamical change of the ferrolectric order parameter.

Obtaining and doping of InAs-QD/GaAs(001) nanostructures by ion beam sputtering.

The features of InAs quantum dots obtained on GaAs(001) single-crystal substrates by ion-beam sputtering were investigated. It has been shown that in the range of ion energies of 150 to 200 eV at a temperature of 500 °C and a beam current of 120 µA InAs quantum dots with average dimensions below 15 nm and a surface density of 10 cm are formed. The technique of controlled doping of InAs/GaAs nanostructures using a SnTe solid-state source was proposed.

Tunable pyroelectric properties of barium strontium titanate thin films.

We studied the influence of the induced strain and applied electric field on the ground state of ferroelectric BaSrTiO thin films, deposited on the cubic (0 0 1) substrate. The dependence of the pyroelectric coefficient on the applied field is calculated for the different values of the induced strain. We found that tuning of the misfit strain in the film under the dielectric bolometer mode by the proper selection of substrate makes it possible to create the structures with very large values of the pyroelectric coefficient.

Protein Profile and Morphological Alterations in Penumbra after Focal Photothrombotic Infarction in the Rat Cerebral Cortex.

After ischemic stroke, cell damage propagates from infarct core to surrounding tissues (penumbra). To reveal proteins involved in neurodegeneration and neuroprotection in penumbra, we studied protein expression changes in 2-mm ring around the core of photothrombotic infarct induced in the rat brain cortex by local laser irradiation after administration of Bengal Rose. The ultrastructural study showed edema and degeneration of neurons, glia, and capillaries.

2-Hetaryl-1,3-tropolones based on five-membered nitrogen heterocycles: synthesis, structure and properties.

A series of derivatives of 2-hetaryl-1,3-tropolone (β-tropolone) was prepared by the acid-catalyzed reaction of 2-methylbenzoxazoles, 2-methylbenzothiazoles and 2,3,3-trimethylindoline with 3,4,5,6-tetrachloro-1,2-benzoquinone. The molecular structures of the three representative compounds were determined by X-ray crystallography. In crystal and (as shown by the DFT PBE0/6-311+G** calculations) in solution, 2-hetaryl-4,5,6,7-tetrachloro- and 2-hetaryl-5,6,7-trichloro-1,3-tropolones exist in the NH-tautomeric form with a strong resonance-assisted intramolecular N-H···O hydrogen bond.

Indirect Magnetic Exchange between o-Iminosemiquinonate Ligands Controlled by Apical Substituent in Pentacoordinated Gallium(III) Complexes.

A number of pentacoordinated gallium complexes iSQ2GaR (1-7) (R = Et (1), Me (2), N3 (3), Cl (4), Br (5), I (6), NCS (7)) where iSQ is a radical anion of 4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-iminobenzoquinone were synthesized, and crystalline samples of 1-7 were characterized using magnetic susceptibility measurements. The character of magnetic exchange interaction between spins of o-iminosemiquinonate radicals was found to be strongly influenced by the nature of the apical substituent. The antiferromagnetic coupling is predominant when the apical position is occupied by halogens or other tested inorganic anions, and the value of exchange interaction parameter varies from -99 to -176 K for R = I and NCS, respectively.

A quantum chemical study of bis-(iminoquinonephenolate) Zn(II) complexes.

A computational DFT B3LYP*/6-311++G(d,p) study performed on bis-(iminoquinonephenolate) Zn(II) complex [Zn(II)(C(12)H(8)NO(2))(2)] has revealed a previously unexplored mechanism for valence tautomerism inherent in transition metal complexes with redox active (noninnocent) ligands. The occurrence of energy-close isomeric forms of the complex and their low energy barrier interconversion is caused not by the intramolecular electron transfer (IET) between the metal and ligand frontier orbitals, but the intersystem conversion within a redox active ligand without involvement of a metal center. This mechanism gives a new insight into the origin of the previously experimentally studied isomeric forms of bis-(iminoquinonephenolate) Zn(II) complexes that must be assigned to [Zn(II)((1)L(-1))(2)] (8) and [Zn(II)((1)L(-1))((3)L(-1))] (9) structures.