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The non-isothermal adsorption/desorption of gas in a cylindrical column filled with adsorbent particles has been considered theoretically. The model is based on Langmuir theory for equilibrium adsorption. Using the Heaviside operational method the analytical solutions for kinetics of changes of concentration of adsorbate in the inter- and intra-particle spaces were obtained. The numerical calculations of gas adsorption at different temperature of the gas flow ( T a  = 273–373 K) followed by desorption by the flow of inert gas through the column at T d  = 673 K were done. The results revealed the rather complex interrelations between spatial–temporal dependencies in distribution of concentrations of adsorbed gas inside adsorption column and temperatures of inlet gas. Graphical Abstract

Using the effective mass model for an electron and the dielectric continuum model, analytical solutions of the self-consistent Schrödinger-Poisson system of equations are obtained. Quantum mechanical theory of electronic stationary states, the oscillator strengths of quantum transitions and a method of potential profile calculation is developed for the experimentally constructed three-well resonance-tunneling structure — a separate cascade of quantum cascade detector. For the proposed method, a comparison with the results of other methods and with the results of the experiment was carried out. A good agreement between the calculated value of the detected energy and its experimental value has been obtained, the difference being no more than 2.5%.

Specific inhibitors of mitochondrial 2-oxoglutarate dehydrogenase (OGDH) are administered to animals to model the downregulation of the enzyme as observed in neurodegenerative diseases. Comparison of the effects of succinyl phosphonate (SP, 0.02 mmol/kg) and its uncharged precursor, triethyl succinyl phosphonate (TESP, 0.02 and 0.1 mmol/kg) reveals a biphasic response of the rat brain metabolism and physiology to increasing perturbation of OGDH function. At the low (TE)SP dose, glutamate, NAD+, and the activities of dehydrogenases of 2-oxoglutarate and malate increase, followed by their decreases at the high TESP dose. The complementary changes, i.e., an initial decrease followed by growth, are demonstrated by activities of pyruvate dehydrogenase and glutamine synthetase, and levels of oxidized glutathione and citrulline. While most of these indicators return to control levels at the high TESP dose, OGDH activity decreases and oxidized glutathione increases, compared to their control values. The first phase of metabolic perturbations does not cause significant physiological changes, but in the second phase, the ECG parameters and behavior reveal decreased adaptability and increased anxiety. Thus, lower levels of OGDH inhibition are compensated by the rearranged metabolic network, while the increased levels induce a metabolic switch to a lower redox state of the brain, associated with elevated stress of the animals.

The disturbed metabolism of vitamins B1 or B6, which are essential for neurotransmitters homeostasis, may cause seizures. Our study aims at revealing therapeutic potential of vitamins B1 and B6 by estimating the short- and long-term effects of their combined administration with the seizure inductor pentylenetetrazole (PTZ). The PTZ dose dependence of a seizure and its parameters according to modified Racine’s scale, along with delayed physiological and biochemical consequences the next day after the seizure are assessed regarding sexual dimorphism in epilepsy. PTZ sensitivity is stronger in the female than the male rats. The next day after a seizure, sex differences in behavior and brain biochemistry arise. The induced sex differences in anxiety and locomotor activity correspond to the disappearance of sex differences in the brain aspartate and alanine, with appearance of those in glutamate and glutamine. PTZ decreases the brain malate dehydrogenase activity and urea in the males and the phenylalanine in the females. The administration of vitamins B1 and B6 24 h before PTZ delays a seizure in female rats only. This desensitization is not observed at short intervals (0.5–2 h) between the administration of the vitamins and PTZ. With the increasing interval, the pyridoxal kinase (PLK) activity in the female brain decreases, suggesting that the PLK downregulation by vitamins contributes to the desensitization. The delayed effects of vitamins and/or PTZ are mostly sex-specific and interacting. Our findings on the sex differences in sensitivity to epileptogenic factors, action of vitamins B1/B6 and associated biochemical events have medical implications.

The use of biological plant protection products is promising for agriculture. In particular, chitosan-based biopesticides have become widespread for stimulating growth and protecting plants from a wide range of pathogens. Novochizol is a product obtained by intramolecular cross-linking of linear chitosan molecules and has a globular shape, which provides it with a number of advantages over chitosan. Novochizol has previously been shown to have a stimulating effect on the growth and development of common wheat (Triticum aestivum L.). However, the effect of this preparation on the protective mechanisms against rust diseases has not been studied before. Our studies have revealed the dose effect of the preparation on the development of stem rust of wheat. When treating plants with novochizol at a concentration of 0.125% four days before infection, the best results were obtained, namely: a stable reaction was observed and the number of pustules decreased. To identify critical points of the drug’s effect on the protective mechanism against stem rust, we used an adrenaline test, which allows for a quick assessment of the pro/antioxidant status of plant extracts. We also assessed the activity of the major antioxidant enzymes, peroxidase and catalase, using commercial kits and the Folin–Ciocalteu reaction to assess the concentration of phenolic compounds. As a result, two stages were identified in infected plants pretreated with novochizol: early (up to 10 h after inoculation), characterized by antioxidant activity, and late (10–244 h), with prooxidant activity. These stages correspond to two peaks of accumulation of reactive oxygen species (ROS) in response to pathogen infection. The first peak is associated with the accumulation of superoxide anion O2−, which is converted into oxygen and hydrogen peroxide under the action of the enzyme SOD (superoxide dismutase). The second peak is associated with the accumulation of H2O2. Hydrogen peroxide performs a protective function leading to the death of pathogen mycelial cells. In comparison with infected plants without novochizol treatment, we found a decrease in the activity of catalase (an enzyme that breaks down H2O2) at both stages, as well as peroxidase in the interval from 10 to 144 h after inoculation. Also, an increase in the concentration of phenolic compounds was found in the treated infected plants. We suggest that these changes under the influence of pretreatment with novochizol contribute to enhancements in plant defense functions against stem rust. Taking into account the physicochemical advantages of novochizol over chitosan, which provide a very low effective dose of the drug, the obtained results indicate its promise and safety as a biological plant protection product. This work is a preliminary stage for an extended analysis of the effect of novochizol on plant immunity using biochemical and molecular genetic approaches.

Purpose. Comparison of electrical circuits of experimental plants for obtaining micro- and nanosecond discharges in gas bubbles in water and comparing the experimental results obtained for disinfecting water using such discharges. Methodology. To obtain high-voltage pulses on the load in the form of a gas bubbles and a layer of water with a frequency of more than 2000 pulses per second, a method of generating micro- and nanosecond pulses using high-voltage pulse generators based on a pulse transformer (PT) according to Tesla, with a transistor opening switch IGBT in the low- voltage part of the circui. A current-limiting resistor with a resistance [R.sub.cl] = 24 k[OMEGA] is used to protect the transistor switch at microsecond discharges. At nanosecond discharges, a multi-gap spark gap is used to sharpen the front of high-voltage pulses. We used a capacitive voltage divider with a division factor of [K.sub.d] = 7653 to measure voltage pulses, a shunt with a resistance of [R.sub.s] = 2.5 [OMEGA] for measuring current pulses. RIGOL DS1102E digital oscilloscope with a 100 MHz bandwidth was used as a recording device. Results. The effect of micro- and nanosecond discharges in gas bubbles on microorganisms was experimentally investigated. It was possible to reduce the biochemical oxygen consumption of water during microsecond discharges, reduce the turbidity of water, and improve its organoleptic qualities. The energy released in a single pulse with microsecond discharges [W.sub.u] [approximately equals] 17 mJ, with nanosecond discharges [W.sub.u] [approximately equal to] 7.95 mJ. At nanosecond discharges, complete inactivation of E.coli bacteria was achieved. The disinfecting and purifying action of nanosecond pulses is better compared to microsecond pulses due to an increase in the amplitude of the pulsed voltage up to 30 kV, and a pulsed current of up to 35 A. Originality. The possibility of effective microbiological disinfection of water using nanosecond discharges in gas bubbles at low specific energy consumption has been experimentally shown. Practical value. The obtained experimental results on water disinfection using micro- and nanosecond discharges offer the prospect of industrial application of installations using such discharges for disinfecting and purification wastewater, swimming pools, and post-treatment of tap water. References 9, figures 3. Key words: high-voltage generator, micro- and nanosecond pulses, discharge in gas bubbles in water, disinfection and water purification by discharges, inactivation of microorganisms.

A promising direction for improving the balance of the diet of livestock and poultry by trace element composition is the enrichment with ultrafine particles of scarce trace elements. At the same time, it is important that they are evenly distributed throughout the volume of the feed mixture. The purpose of this study is to increase the uniformity of the distribution of ultrafine particles in feed mixture by developing special equipment and improving the technological process. The use of new technologies for preparing feed mixtures based on the control of process parameters makes it possible to obtain a product with specified functional parameters and preserved nutritional properties. Analysis of theoretical studies of the process of dosing and mixing ultrafine particles has shown that the best variant of their motion in the mixture flow is laminar motion. The designed processing line provides for the separate supply of premixed feed mixture and ultraparticles to the vibrating mixer. The efficiency of the mixing process in a vibrating mixer was assessed using three sections of a feed mixture with ultraparticles of iron, zinc, cobalt, and molybdenum powders. The optimal working parameters are achieved under the following conditions: the angular velocity of the vibrating mixer is 3–7 rad/s, the oscillation frequency is 9–37 Hz, the vibration mixing time is 113–333 s, and the time for opening the controlled dispenser (feeding ultrafine particles into the vibrating mixer) is 5–15 s. When using a controlled ultraparticle dispenser and a spherical impeller, the particles were distributed more evenly in the feed. The lowest effect on the value of this indicator in the three sections of the feed mixture has been recorded for zinc (up to 2.7%), followed by iron powders (up to 3.6%) and molybdenum powders (up to 9.5%). The developed equipment had the greatest effect on the uniformity of cobalt distribution (up to 20.5%). At the same time, the deviation from the norm (0.5 mg/kg) did not exceed 2%; i.e., the value of the qualitative indicator of uniformity of the distribution was 98%.

The study of physical processes associated with acoustic phonons in nitride-based nanosystems is of great importance for the effective operation of modern nanoscale devices. In this paper, a consistent theory of acoustic phonons arising in multilayer nitride-based semiconductor resonant tunneling structures, that can function as a separate cascade of a quantum cascade laser or detector is proposed. Using the physical and geometric parameters of a typical nanostructure, the spectrum of various types of acoustic phonons and the corresponding normalized components of the elastic displacement vector are calculated. It has been established that the spectrum of acoustic phonons of a multilayer nanostructure consists of two groups of the shear phonons dependencies and three groups of dependencies for a mixed spectrum of flexural and dilatational phonons. The dependencies of the acoustic phonons spectrum of the nanostructure and the components of the elastic displacement vector on its geometric parameters are studied. It has been established that for the components of the displacement vector u2 for shear phonons have a decrease in the absolute values of their maxima with increasing of energy level number. The components u1 and u3 of flexural and dilatational phonons behave respectively as symmetric and antisymmetric functions relatively the center of an separate selected layer of the nanostructure. The proposed theory can be further applied to study the interaction of electrons with acoustic phonons in multilayer resonant tunneling structures.

New high-performance analytical methods are developed for modeling the concentration fields of diffused gases in intra- and interparticle spaces in heterogeneous cylindrical n -component nanoporous media. The methods use the Heaviside operational method and Cauchy influence matrices for inhomogeneous adsorption boundary-value problems for systems of partial differential equations with feedbacks.

Unlike the OGDH-encoded 2-oxoglutarate dehydrogenase (OGDH), which is an essential enzyme present in all animal tissues, expression of the DHTKD1-encoded isoenzyme, 2-oxoadipate dehydrogenase (OADH), depends on a number of factors, and mutant DHTKD1 phenotypes are rarely manifested. Physiological significance of OADH is also obscured by the fact that both isoenzymes transform 2-oxoglutarate and 2-oxoadipate. By analogy with other members of the 2-oxo acid dehydrogenases family, OADH is assumed to be a component of the multienzyme complex that catalyzes oxidative decarboxylation of 2-oxoadipate. This study aims at molecular characterization of OADH from animal tissues. Phylogenetic analysis of 2-oxo acid dehydrogenases reveals OADH only in animals and Dictyostelium discoideum slime mold, within a common branch with bacterial OGDH. Examination of partially purified animal OADH by immunoblotting and mass spectrometry identifies two OADH isoforms with molecular weights of about 130 and 70 kDa. These isoforms are not observed upon the expression of human DHTKD1 protein in either bacterial or yeast system, where the synthesized OADH is of expected molecular weight (about 100 kDa). Thus, the OADH isoforms present in animal tissues, may result from the animal-specific regulation of the DHTKD1 expression and/or posttranslational modifications of the encoded protein. Mapping of the peptides identified in the OADH preparations, onto the protein structure suggests that the 70-kDa isoform is truncated at the N-terminus, but retains the active site. Since the N-terminal domain of OGDH is required for the formation of the multienzyme complex, it is possible that the 70-kDa isoform catalyzes non-oxidative transformation of dicarboxylic 2-oxo acids that does not require the multienzyme structure. In this case, the ratio of the OADH isoforms in animal tissues may correspond to the ratio between the oxidative and non-oxidative decarboxylation of 2-oxoadipate.