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Abstract: The diversity of alien plant species in the Russian part of the Arctic (RA) is analyzed by generalizing different publications. Alien plant species are found in all regions of the RA, but their share in regional floras is relatively small compared with more southern biomes and is unevenly distributed, from 1–2% in the north of Yakutia and in the continental part of Chukotka to 22–27% on the Kola Peninsula and in the Bolshezemelskaya tundra. The low species diversity of alien species in the RA is explained by two groups of factors. The first one includes social and economic indicators: relatively late and still focal economic development of the region and generally low human migration activity here. The second one combines natural factors, among which the climate is of paramount importance. It has been shown that plurizonal species with the northern border of their ranges in the boreal zone are mainly introduced into the RA, but the direct donor regions are often not known when alien species are introduced. These species are clearly better adapted to a wide range of conditions, allowing them to survive in the harsh Arctic climate. By the way of invasion into the RA, unintentionally introduced species prevail, and transport, migration activity, Arctic tourism, and introduction with contaminated materials are the main pathways. The distribution of alien species is local, and it is mostly associated with settlements and industrial centers.

The results of recent studies on invasions of alien species in the Holarctic are given in a review format. Most of these studies were presented at the Fifth International Symposium “Invasions of Alien Species in the Holarctic,” which was held in Russia in 2017. For this review, we used recent publications in the Russian Journal of Biological Invasionsand other journals. The main trends in studies of invasions of alien species in the Holarctic are highlighted.

Human activities, including biological invasions, cause large-scale changes in the distribution of organisms, one of the consequences of which is biotic homogenization, revealed to various degrees for different biotic groups. Russian researchers use the term “unification of biota” to explain the increase in taxonomic similarity between regions as a result of invasions, but there are no quantitative estimates of this phenomenon. The change in the similarity or difference between regional floras taking into account the alien species naturalized in them is estimated for the regions of the middle part of European Russia by comparing the Jaccard similarity coefficients. Inclusion of the naturalized plant species in the floras increases their distinctions owing to differentiated naturalization depending on natural conditions. However, the presence of different structural groups has different effects on the similarity/differences between the floras. The annual/biennial species have a greater homogenizing effect unlike the herbaceous perennials and tree species, as well as the species biogeographically associated with the analyzed floras, unlike the species alien to European Russia (with their natural distribution ranges beyond the territory of European Russia). The analysis does disagrees with the opinion of Russian authors on unambiguous “unification of biota” as a result of alien species introduction and confirms the view of some researchers that biotic homogenization is not an inevitable fact in biological invasions.

Establishment of “blacklists” is one of the attempts to focus on the issue of biological invasions of alien species that pose the most significant threat to regional biodiversity of a certain region. Blacklists contain biological and environmental characteristics and information on invasive species distribution. In Russia, regional blacklists of invasive species are often based on expert opinions or various criteria. For the standardization of alien species information, we propose (1) to use a quantitative assessment of the participation of invasive species in regional floras and plant communities, which makes it possible to evaluate objectively the invasive status of a species and the degree of its impact; (2) to include all invasive species of the region in the regional “Black Books”; and (3) to present potentially invasive species as separate lists. We offer 65 invasive alien plant species for inclusion in the regional Black Book of Voronezh oblast: 9 species are transformers, 20 are actively inhabiting and naturalizing in disturbed seminatural and natural habitats, and 32 are spreading in disturbed habitats. The status of four species is still not defined. Twenty-two species are potentially invasive, because they do not have large spread in the area, but showed themselves as invasive in adjacent regions (in deciduous forests and forest-steppe zones).

Morphological, structural and chemical evolution in Ti/B/H2 system is studied in detail as a function of mechanical treatment. Ti/B powder continuously changes both in composition and morphology during ball-milling in H2 flow: The powder composition varies from Ti/B to TiH2-x/B causing a change in mechanical properties. The role of boron additive also changes from preventing the Ti nanoparticles from sticking together in the early stages to a matrix material participating in Ti - B interface reactions in the intermediate and final stages of the process. Boron atoms participating in the formation of nanoscopic holes give rise to new H states in the hydride by changing the local atomic state of Ti atoms. The dynamics of the formation of these sites and the redistribution of hydrogen between different types of occupation sites in dependence of phase composition and milling time of the powders are also studied.

We report on the assembly and characterisation of a high potential, stable, mediator‐less and cofactor free biocathode based on a fungal laccase (Lc), adsorbed on highly dispersed carbonaceous materials. First, the stability and activity of Trametes hirsutaLc immobilised on different carbon particles were studied and compared to the solubilised enzyme. Based on the experimental results and a literature analysis, the carbonaceous material BM‐4 was chosen to design efficient and stable biocatalysts for the production of a ‘floating' air diffusion Lc‐based biocathode. Voltammetric characteristics and operational stability of the biocathode were investigated. The current density of oxygen reduction at the motionless biocathode in a quiet, air saturated citrate buffer (100 mM, pH 4.5, 23 °C) reached values as high as 0.3 mA cm–2already at 0.7 V versusNHE. The operational stability of the biocathode depended on the current density of the device. For example, at low current density (20 μA cm–2), the biocathode lost only 5× of its initial power after 1 month of continuous operation. However, when the device was polarised at 150 mV it lost more than 32× of its initial power in just 10 min. We also found that co‐immobilisation of Lc and peroxidase on highly dispersed carbon materials could protect the biocatalyst from rapid inactivation by hydrogen peroxide produced during electrocatalytic reactions at high‐current densities.

The effect of h-BN additive on hydrogen sorption by Ti under mechanical treatment in H2/He flow and on the thermal stability of Ti-hydride produced during milling were studied using kinetic, structural, microscopic, and spectroscopic techniques and theoretical first-principles calculations. The results obtained were compared with the corresponding properties of pure Ti and Ti with graphite additive. Like graphite, hexagonal BN was found to be an effective additive to improve the hydrogen sorption capacity of Ti. New types of occupation sites available for hydrogen, very similar to those detected for Ti/C, were observed. These sites are characterized by a low H2desorption temperature:  630−670 K instead of ∼1000 K.

Abstract: The screening of potential redox mediators for laccase was performed using homogeneous enzyme preparations from Coriolus hirsutus and Coriolus zonatus. It was discovered that derivatives of 1-phenyl-3-methyl-pyrazolones were efficient substrates for the laccases. The characterization of two representatives of the 1-phenyl-pyrazolone class, sodium 1-phenyl-3-methyl-4-methylamino-pyrazolone-5-N(4)-methanesulfonate and 1-(3′-sulfophenyl)-3-methylpyrazolone-5, in the reaction catalyzed by laccase was carried out using spectral, electrochemical, and enzyme kinetics methods. The kinetic parameters for the oxidation of the newly discovered substrates were comparable with those for 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonate) (ABTS) oxidation by laccase. Electrochemical experiments demonstrated that oxidation of these compounds yielded two high-potential intermediates capable of oxidizing veratryl alcohol, which was used as a lignin model substrate, to the corresponding aldehyde and acid. 1-(3′-Sulfophenyl)-3-methylpyrazolone-5 was about 30–40% as effective in degrading veratryl alcohol compared to ABTS as judged from high-performance liquid chromatography kinetic studies. 1-Phenyl-3-methyl-pyrazolones may be of commerical interest for oxidoreductase-catalyzed biodegradation of organic compounds.

The formation of chemically induced dynamic nuclear polarization (¹H-CIDNP) and its time evolution in course of the photochemical reactions of 2,2‘-dipyridyl in its triplet state with the tryptophan−tyrosine dipeptide and with a 1:1 mixture of N-acetyl tryptophan and N-acetyl tyrosine is studied in acid (pH 3.0), neutral (pH 7.4), and basic (pH 11.4) solution. Time resolution on the microsecond scale allows us to establish the full reaction scheme and to determine all relevant transient intermediates. The stationary value of spin polarization is found to depend strongly on secondary reaction steps and does only in part reflect the primary process of triplet quenching. Degenerate electron exchange, spin relaxation in paramagnetic intermediates, and radical pair reactions in the bulk are identified from the polarization kinetics. In particular, the increase of tyrosine quenching efficiency and the influence of intramolecular electron transfer from the tyrosine moiety to the transient tryptophan radical are revealed when the amino acids are linked in the dipeptide in comparison with the case that they are separated in the 1:1 mixture. The strong effect of linkage on the amplitude and the kinetics of spin polarization is discussed with regard to application of this method to studying structure and folding kinetics of proteins.

The population dynamics of the gypsy moth and the genomic DNA of the nuclear polyhedrosis virus (NPV) pathogenic for this insect were simultaneously studied using nucleic acid molecular hybridization (NAMH). It was demonstrated that population outbreaks of the gypsy moth were accompanied by an increase in its sensitivity to NPV and in the genetic polymorphism of NPV strains circulating in the insect populations. The hybridization activity of the virus strains isolated at the phase of gypsy moth population growth was significantly higher (p< 0.001) than the activity of the strains isolated at the phase of population decrease.

A combination of time-resolved electron paramagnetic resonance (TREPR) and laser flash photolysis (LFP) studies of flexible acyl-containing biradicals over a wide temperature range is reported. In contrast to previous reports, it is shown that the main channel of intersystem crossing in these biradicals is the electron spin relaxation of the acyl moiety rather than spin−orbit interaction in the biradical. This relaxation determines the decay rate of the electron spin polarization at low temperatures and the biradical lifetime at high temperatures. The relaxation mechanism is attributed to the spin-rotation interaction, associated with the rotation of the carbonyl group about the neighboring C−C bond axis. From a model simulation of the time profile of the spin-polarized TREPR signal based on the numerical solution of the stochastic Liouville equation of the spin density matrix in frame of realistic model of biradical, the Arrhenius parameters for correlation times of spin rotation interaction and activation energies for molecular and spin dynamics were determined in two solvents, 2-propanol and hexane.

The effect of mechanical activation on the structural and chemical transformations in the zirconium−carbon−hydrogen system was studied using X-ray powder diffraction, transmission electron microscopy and kinetic techniques. A zirconium−graphite mixture was subjected to high-energy impact milling in a permanent hydrogen flow. A two-stage process was observed:  first, the formation of tetragonal ε-ZrH1.8-2 accompanied by carbon amorphization, and second the decomposition of ε-ZrH1.8-2 synthesized at the first stage to cubic δ-ZrH1.6 + γ-ZrH + α-Zr. In the first stage, the size of the hydride particles decreased drastically to only a few nanometers dispersed in larger particles of amorphous carbon, while in the second stage the newly formed Zr particles compacted again to gain the size of microns, while the carbon partially crystallized. While the first stage is governed by the fast reaction kinetics of hydrogen with zirconium, the second stage is governed by the greater affinity of zirconium to carbon as compared to hydrogen.

Time-resolved chemically induced dynamic nuclear polarization (CIDNP) and laser flash photolysis (LFP) techniques have been used to study the kinetics and mechanism of the photochemical reaction between 2,2‘-dipyridyl (DP) and the dipeptide l-tryptophan-l-tyrosine (TrpH-TyrOH) in acidic aqueous solution (pH = 3.8). Analysis of the geminate CIDNP pattern reveals that the quenching of the protonated triplet dipyridyl ^TDPH⁺ results in the formation of both tryptophan and tyrosine radicals from the dipeptide with comparative efficiency. The total quenching rate constant of triplet dipyridyl by TrpH-TyrOH was found to be (2.5 ± 0.3) × 10⁹ M^-1 s^-1. The radical transformation TrpH^+•→TyrO^• via intramolecular electron transfer (IET) leads to an increasing tyrosyl radical concentration, growth of the tyrosine CIDNP signals, fast decay of the CIDNP signal of TrpH, and inversion of the CIDNP sign from emission to enhanced absorption for DP. The nuclear spin−lattice relaxation times of the radicals formed in the reactions and the rate constant for IET (5 × 10⁵s^-1) were determined by quantitative analysis of the CIDNP kinetics at different dipeptide concentrations in D2O. A significant isotope effect (kH/kD = 1.5) was found for the IET rate constant by LFP measurements. In the presence of efficient IET, degenerate electron exchange between the TrpH^•+ radical of the dipeptide and the diamagnetic molecule makes a negligible contribution to the decay of tryptophan CIDNP signal.

Iridium oxide films with different values of crystallinity degree K are synthesized. Properties of the films and their morphological features are examined. The charging of the films in a 1 M H2SO4solution is studied voltammetrically. The most amorphous films (K = 0.08–0.26) acquire the largest overall charge q(in a fixed potential range) relative to films with higher crystallinity degrees; however, the qvs. K dependence is not additive, and the charge remains virtually invariant beginning with K ≥ 0.26. The contribution of slow charging processes, which is quite perceptible in the amorphous films, is absent in samples with higher crystallinity degrees, which have faster charge kinetics. The fast charging processes, which are not limited by diffusion, occur in boundary regions of IrO2crystallites (and/or the “oxide” part of a crystalline hydrated iridium oxide) and the amorphous phase. The transport of charge-compensating ions in the boundary regions occurs without considerable complications, as in the loose network of amorphous phase IrO2· xH2O. The assumption about the formation of a “metallic” highly-conducting IrO2cluster at K ≥ 0.26 is substantiated. The cluster rules out large resistances in the course of charge transport, which is a possible reason for the slow charging of amorphous films with K < 0.26.

The knowledge of virus reproduction is necessary to design new safe drugs for inhibition of infections. Ultra-violet irradiation of virus proteins with labeled virus genome fragments permits to identify specific nucleic acid binding proteins. Affinity modification of enzymes with nucleotide derivatives could help to determine NTP-binding proteins and those involved in viral genome replication. Photoreactive analogues of nucleic acids are among the tools used to detect elongation subunits of replicative complexes. Affinity modification approach has already resulted in successful treatment of virus diseases.

Temperature-programmed reduction by hydrogen, temperature-programmed desorption of O2, local X-ray spectral analysis, and scanning electron microscopy are used to study redox processes occurring on the Ni–Cr2O3/MgO and Ni/MgO catalysts for carbon dioxide reforming of methane. The reduction of Ni/MgO leads to the formation of nickel clusters distributed over the surface of MgO. During the reduction of NiO–Cr2O3/MgO, chromates are transformed into chromites, and then nickel is formed by the reduction of spinel NiCr2O4. Reoxidation leads to the oxidized structures NiO, NiCr2O4, and NiCrO4.

Expression of hepato-specific genes in slow- and fast-growing hepatocellular murine carcinomas was studied. A fast-growing dedifferentiated transplantable hepatocarcinoma variant (fgHCC) arose from the highly differentiated slow-growing hepatocarcinoma (sgHCC). In contrast to the parental hepatocarcinoma, expression of the hepatocyte nuclear factor 4 (HNF4), one of the key regulators of hepatocyte differentiation, and several HNF-4-responsive genes, transferrin, transthyretin, hepatocyte nuclear factor 1 (HNF1), and serum albumin, was downregulated in fgHCC. The expression of exogenous HNF4 in the fgHCC cell culture partially restored the expression of hepato-specific genes and led to the formation of epithelial islets in the culture. The described system may serve as an appropriate model for further analysis of mechanisms underlying hepatocarcinogenesis and liver tumor progression.

The reaction mechanism and details of the formation of CIDNP (chemically induced dynamic nuclear polarization) in the photoreactions of 2,2‘-dipyridyl (DP) and N-acetyl histidine (HisH) in aqueous solution have been studied using laser flash photolysis and time-resolved CIDNP techniques. The triplet state ^TDP reacts with protonated HisH2⁺ via hydrogen atom transfer with a rate constant kH = 1.2 × 10⁸ M^-1 s^-1, and with deprotonated His^- via electron transfer with ke = 7.5 × 10⁹ M^-1 s^-1. No reaction occurs when the histidine imidazole ring is in its neutral state HisH, or when the dipyridyl triplet is protonated, ^TDPH⁺. The nuclear spin−lattice relaxation times in the radicals formed in these reactions have been determined from the CIDNP kinetics:  T1 = 44 ± 9 μs for all DP protons, T1 = 196 ± 25 μs for the β-CH2 protons of HisH, and T1 = 16 ± 5 μs for the H-2 and H-4 protons of HisH. Under strongly basic conditions the CIDNP is greatly affected by degenerate electron exchange between the neutral His· radical and His^- anion, with rate constant kex = 1.5 × 10⁸ M^-1 s^-1.

The mechanism of the reactions between photoexcited 2,2‘-dipyridyl and N-acetyl tryptophan has been studied by laser flash photolysis and time-resolved CIDNP (Chemically Induced Dynamic Nuclear Polarization). The transient absorption spectra obtained at different delays after the laser pulse are attributed to the triplet state of dipyridyl and to dipyridyl and tryptophan radicals. Depending on the pH of the solution, all three intermediates can be present in either protonated or deprotonated forms. It is shown that irrespective of pH the primary photochemical step is electron transfer from the tryptophan to triplet dipyridyl followed by protonation/deprotonation of the radicals so formed. The rate constant of the reaction of triplet dipyridyl with tryptophan is close to the diffusion-controlled limit and decreases slightly with increasing pH. The kinetics and the stationary value of the CIDNP are determined by the rates of radical termination, nuclear paramagnetic relaxation, and degenerate electron exchange. The last reaction is important for the protonated tryptophan radical and determines the CIDNP kinetics of tryptophan in acidic conditions. The nuclear relaxation times estimated from the CIDNP kinetics are 44 ± 9 μs for all protons in the dipyridyl radical, 91 ± 20 μs for the β-CH2, 44 ± 9 μs for H2,6, and 63 ± 12 μs for H4 aromatic protons in the tryptophan radical.

¹H and ¹³C chemically induced dynamic nuclear polarization (CIDNP) and time-resolved stimulated nuclear polarization (SNP) have been applied to the investigation of spin and molecular dynamics in biradicals, generated in the photolysis of 2,2,12,12-tetramethylcyclododecanone, at low magnetic field in the temperature range from 200 to 360 K. This reaction involves two consecutive biradical stages, the primary acyl−alkyl and the secondary bis-alkyl biradical, with different reaction products. Characteristic differences in the CIDNP field dependencies and SNP decay times for nuclei of different reaction products are seen at high temperatures. Upon cooling, the emission maximum position shifts to low field and the width of the ¹H CIDNP field dependencies of the acyl−alkyl biradical products decreases. Below 243 K these effects reverse direction, furthermore, a significant slowing down of the SNP decay is observed. Calculations of the ¹H and ¹³C CIDNP field dependencies and the SNP kinetics for the primary biradical have been performed based on the numerical solution of the stochastic Liouville equation for the biradical spin density matrix. They use a model of restricted diffusion for the description of the molecular dynamics and take into account the distance dependence of the exchange interaction. Good quantitative agreement between the calculations and experimental data is found for the whole temperature range when using the appropriate dependence of some of the parameters on temperature. In particular, it was necessary for the quantitative simulation in the low temperature range to introduce a temperature dependence of the biradical reactivity. The model calculations qualitatively confirm that the low-temperature broadening of the CIDNP field dependencies, and the increase of the SNP decay time are caused by the slowing down of the molecular mobility and the decreasing of reactivity. For the products of the secondary biradical, a qualitative interpretation is given showing that in comparison with the products of the primary biradical spin−orbit interaction is of less importance for the biradical spin dynamics, that the influence of the molecular mobility under the temperature variation is more pronounced, that the lifetime is longer, and that the nuclear polarization is more efficiently formed.

1.Acrolein and methacrolein coordinately bond through the aldehyde group oxygen during adsorption on the surface of cobalt molybdate catalysts modified by Co, V, and Mo ions.2.The C=C bond of the aldehyde does not participate in the formation of surface compounds with cobalt molybdate.3.Acrylates and methacrylates are formed in the interaction of acrylic and methacrylic acids with the catalyst surface.4.Modification of cobalt molybdate with Co, V, and Mo ions changes the strength of surface bonding and affects the catalytic reaction involved in the formation of CO and CO2.

Abstract: The level of specific binding and affinity of 17β-estradiol for receptors in the cytosol fraction of uteruses of CBA and C57Bl/6 mice exposed to 1,2-dimethylhydrazine for a long time was studied. Estrogen receptors were studied by separating free and receptor-bound hormone with dextran-coated carbon. The theoretical number of sites of ligand binding with receptor protein and the level of free binding sites were shown to be higher in CBA mice sensitive to carcinogenesis induction in comparison with C57Bl/6 mice resistant to the carcinogen effect in both the experimental and control groups over the course of the experiment. The ligand affinity for receptor protein was more or less the same in all the groups.

Low- and high-field ¹H chemically induced dynamic nuclear polarizations (CIDNP) have been applied to investigate geminate reactions of consecutive biradicals generated during the photolysis of 2,12-dihydroxy-2,12-dimethylcyclododecanone. The detailed mechanism of the reaction is established. It is shown that the fast chemical transformation (decarbonylation) of the primary acyl-ketyl biradical manifests itself in CIDNP effects in low and high magnetic fields:  the difference in the CIDNP field dependencies for the products of the primary and secondary biradicals is observed, and the net and multiplet effects for the products of the secondary bis-ketyl biradical develop in different time scales. The first observation of the CIDNP “memory effect” in biradical reactions is reported. Model calculations of the CIDNP kinetics based on the numerical solution of the stochastic Liouville equation for the Fourier transform of the biradical spin density matrix have been performed, and a good agreement between the theoretical calculations and experimental data has been found.

1.The surface of a SnO2-Sb2O4 catalyst is uniformly homogeneous with respect to the heats of adsorption of isobutylene. The heats vary from 50 to 20 kcal/mole as the degree of coverage is increased to 18% of a monolayer.2.Isobutylene is adsorbed on SnO2-Sb2O4 in two forms: reversible (desorbed in the range 79–100° with Edes=21 kcal/mole) and irreversible.3.Irreversibly chemisorbed isobutylene exists on the surface primarily in the form of thep-methallyl complex.

Several time-resolved spectroscopic techniques (¹H CIDNP, time-resolved EPR, and nanosecond laser flash photolysis) have been used to investigate geminate reactions of consecutive biradicals generated from photolysis of 2-hydroxy-2,12-dimethylcyclododecanone (1). It is shown that the primary photochemical process is Norrish type I cleavage, yielding an acyl−ketyl biradical, which is transformed to an alkyl−ketyl biradical via decarbonylation. The rate constant for decarbonylation, estimated by theoretical modeling of the TR-CIDNP kinetics, is (4.2 ± 1.0) × 10⁵ s^-1. The calculations are based on the numerical solution of the stochastic Liouville equation for the Fourier transform of the biradical spin density matrix. The lifetime of the acyl−ketyl biradical (τ = 67 ± 8 ns) has been measured using laser flash photolysis. The distribution of reaction products in the photolysis of 1, including recombination to the starting ketone, was determined from the CIDNP amplitude and kinetics. The reaction products include unstable compounds containing enol functional groups, which are transformed to the keto form during the dark reaction of tautomerization.

Laser flash photolysis (LFP), low-field chemically induced dynamic nuclear polarization (CIDNP), and time-resolved electron paramagnetic resonance (TREPR) techniques have been used for the comparative study of magnetic field and spin effects in acyl−ketyl and bis(ketyl)biradicals formed during the photolysis of 2-hydroxy-2,12-dimethylcyclododecanone (1-OH) and 2,12-dihydroxy-2,12-dimethylcyclododecanone (2-OH), respectively. The short biradical lifetime, the small magnetic field effect (MFE) on a biradical lifetime, and the low intensity of spin-correlated radical pair (SCRP) polarization observed during the photolysis of 1-OH indicate that the main channel of intersystem crossing in acyl−ketyl biradical is spin−orbit coupling (SOC). For bis(ketyl) biradicals observed during the photolysis of 2-OH, SOC is of minor importance, and both MFE and SCRP polarization are much larger. It is shown that the presence of significant SOC in biradicals can result in an increase of the CIDNP intensity at low magnetic fields. Calculations of biradical evolution, based on the numerical solution of the stochastic Liouville equation (SLE), were carried out by taking into account (1) the molecular dynamics of the polymethylene chain linking the radical centers, (2) the distance-dependent exchange interaction, (3) the chemical reactions of the biradical, (4) the spin relaxation processes, and (5) state-to-state transitions caused by hyperfine interaction and SOC. A common set of parameters was found which allows quantitative description of the field dependence of the biradical lifetime, the CIDNP field dependence, and the TREPR spectra and kinetics.

CIDNP effects arising in the geminate evolution of consecutive biradicals formed during the photolysis of 2,2,12,12-tetramethylcyclododecanone were investigated by the low- and high-field¹H and¹³C CIDNP and time-resolved¹H CIDNP methods. The¹H field dependence of nuclear polarization induced in the recombination and disproportionation products of the consecutive biradicals as well as the¹³C CIDNP spectra at low and high magnetic fields was analyzed. It was confirmed that two types of biradicals (acyl−alkyl and bisalkyl) of different chain lengths contribute to the spin polarization. Model calculations of the geminate recombination kinetics were based on the numerical solution of the stochastic Liouville equation for the Fourier transform of the biradical spin density matrix. A detailed kinetic analysis of the CIDNP effects allowed us to reveal all chemical transformations of the alkyl−acyl and bisalkyl biradicals and to estimate the probability of the “hidden” recombination of the biradicals to the starting ketone, as well as to determine the product distribution.

Films of general composition CoxNi1-xOy with x = 0, 11.1, 22.2, 33.3, 44.4, 55.6, 66.7, 77.8, 88.9, and 100 mol %, prepared by thermal decomposition of 2-propanol solutions of Ni and Co nitrates on Ni supports, have been characterized by X-ray diffraction (XRD), infrared spectroscopy (IRS), and X-ray photoelectron spectroscopy (XPS). These techniques have provided the surface chemical composition, the crystalline structure, and the oxidation state of Co and Ni in the bulk as well as on the surface. The results have revealed, in addition to previous work where NiO and NixCo2-xO4 solid solutions were found to be the predominant crystalline phases, that Ni and Co hydroxides interact in the surface layer of nanosized crystallites of the oxide phase. The interaction in the hydroxylated surface has a redox character and results in two oxidation states (+2 and +3) for both Ni and Co ions. This work has shown that Co hydroxide fragments are localized in the periphery of Ni hydroxide domains. The redox interaction between the hydroxides prevents Ni ions from being oxidized to higher valency states in anodic electrocatalytic processes, which results in improved anodic corrosion stability of Ni + Co mixed oxides.

We studied the effect of endogenous immunoregulatory myelopeptide-2 on the development of spontaneous and urethane-induced lung adenomas. Long-term treatment with myelopeptide-2 (25 injections) in parallel with urethane poisoning decreased animal mortality caused by this carcinogen. Short-term treatment with myelopeptide-2 decreased the number of spontaneous and urethane-induced lung tumors in mice. Myelopeptide-2 delayed the appearance of urethane-induced tumors irrespective of the number of injections.

Nanostructured systems, including the products of copper ions recovery - nanoparticles of copper, copper(I) oxide or complex copper particles and copper oxides, have been obtained. Copper ions were reduced by tert-butylamine borane in aqueous solutions of poly(N-vinylpyrrolidone) at room temperature under air. Different synthesis conditions allowed controlling both the size of the resulting particles and the final product of the synthesis. The composition, morphology and size characteristics of nanocomposites were studied by methods of electron microscopy and XRD. The efficiency of the Cu/CeO2 catalytic system in the purification of hydrogen from CO was shown.

A new method of estimating the protective properties of oxide films on pearlitic steels consists in potentiometrically titrating and determining the relative quantity of potassium molybdate required to a specimen (with or without an oxide coating) to reach a potential of –200 mV against the reference silver-chloride electrode in a 0.1 N solution of sodium sulfate.

Abstract: Mating of males infected with tick-borne encephalitis virus (strain Sofyin) with intact females results in a marked decrease in the weight of embryos and an almost threefodl increase in embryonal mortality. Viral RNA was identified by the polymerase chain reaction in embryonal tissues of 2 out of 11 litters. In one case the infection of the progeny was confirmed by biological test.

A very simple mathematical model of blood coagulation is considered, consisting of a set of three partial differential equations that treat blood as an active (excitable) medium. Many well-known phenomena (running pulses, trigger waves, and dissipative structures) can be observed in such a medium. Recent analytic and numerical results obtained by the authors using this model are presented. The following aspects of the formation of dynamic and static structures in this medium are discussed: (1) three scenarios of the formation of spatially localized standing structures (peaks) observed in the model, (2) complex dynamical modes induced by unstable trigger waves, some of the modes leading to unattenuated activity (dynamical chaos) in the entire space, and (3) a new type of excitation propagation in active media — stable multihumped peaks due to trigger wave bifurcation — predicted by the model.