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In this paper, on the basis of the classical quantum-mechanical approach, an explanation is considered of the physical mechanism of isotope fractionation associated with the predominance of a certain number of neutrons among nucleons and explaining the nonequilibrium accumulation of certain forms of stable isotopes of biogenic elements in heterogeneous systems. The reasons for the detected neutron effect can be: the interaction of the magnetic moments of atomic nuclei and valence electrons, leading to a change in the distance between them, including the effect of the changed distance between atoms on the energy of the covalent bond between the resonant pairs of atoms.

The sensitivity of DNA to electromagnetic radiation in different ranges differs depending on various factors. The aim of this study was to examine the molecular dynamics of DNA under the influence of external periodic influences with different frequencies. In the present paper, within the framework of a mechanical model without simplifications, we investigated the effect of various frequencies of external periodic action in the range from 1011 s−1 to 108 s−1 on the dynamics of a DNA molecule. It was shown that under the influence of an external periodic force, a DNA molecule can perform oscillatory movements with a specific frequency characteristic of this molecule, which differs from the frequency of the external influence ω. It was found that the frequency of such specific vibrations of a DNA molecule depends on the sequence of nucleotides. Using the developed mathematical model describing the rotational motion of the nitrogenous bases around the sugar–phosphate chain, it is possible to calculate the frequency and amplitude of the oscillations of an individual DNA area. Such calculations can find application in the field of molecular nanotechnology.

The deuterium content modification in an organism has a neuroprotective effect during the hypoxia model, affecting anxiety, memory and stress resistance. The aim of this work was to elucidate the possible mechanisms of the medium D/H composition modification on nerve cells. We studied the effect of an incubation medium with a 50 ppm deuterium content compared to a medium with 150 ppm on: (1) the activity of Wistar rats’ hippocampus CA1 field neurons, (2) the level of cultured cerebellar neuron death during glucose deprivation and temperature stress, (3) mitochondrial membrane potential (MMP) and the generation of reactive oxygen species in cultures of cerebellar neurons. The results of the analysis showed that the incubation of hippocampal sections in a medium with a 50 ppm deuterium reduced the amplitude of the pop-spike. The restoration of neuron activity was observed when sections were returned to the incubation medium with a 150 ppm deuterium content. An environment with a 50 ppm deuterium did not significantly affect the level of reactive oxygen species in neuron cultures, while MMP decreased by 16–20%. In experiments with glucose deprivation and temperature stress, the medium with 50 ppm increased the death of neurons. Thus, a short exposure of nerve cells in the medium with 50 ppm deuterium acts as an additional stressful factor, which is possibly associated with the violation of the cell energy balance. The decrease in the mitochondrial membrane potential, which is known to be associated with ATP synthesis, indicates that this effect may be associated with the cell energy imbalance. The decrease in the activity of the CA1 field hippocampal neurons may reflect reversible adaptive changes in the operation of fast-reacting ion channels.

In the present study, the effect of 2H/1H isotopic exchange in hydrogen bonds between nitrogenous base pairs on occurrence and open states zones dynamics is investigated. These processes are studied using mathematical modeling, taking into account the number of open states between base pairs. The calculations of the probability of occurrence of open states in different parts of the gene were done depending on the localization of the deuterium atom. The mathematical modeling study demonstrated significant inequality (dependent on single 2H/1H replacement in DNA) among three parts of the gene similar in length of the frequency of occurrence of the open states. In this paper, the new convenient approach of the analysis of the abnormal frequency of open states in different parts of the gene encoding interferon alpha 17 was presented, which took into account both rising and decreasing of them that allowed to make a prediction of the functional instability of the specific DNA regions. One advantage of the new algorithm is diminishing the number of both false positive and false negative results in data filtered by this approach compared to the pure fractile methods, such as deciles or quartiles.

The aim was to investigate prooxidant-antioxidant system in the blood and brain homogenates functional activity in rats with acute hypoxia model with different deuterium/protium (D/H) ratios in drinking diet. Studies have shown that consuming DDW (–665 ‰) within 8 weeks lead to deuterium concentration decrease in blood plasma at 317 ‰ and brain at 209 ‰ of rats, in comparison to control group, consuming natural water. DDW consumption before hypoxia modeling in rats improves antioxidant defense enzymes (catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase) activity in the blood, increasing its antioxidant potential by 20 %, while free radical oxidation intensity in plasma and biomolecules peroxide modification rate in erythrocytes. Also, in brain tissues consuming DDW, there were no abnormalities in catalase, superoxide dismutase activity, and it was noted increase (by 71 %) in reduced thiol-containing compounds concentration, which reduces nerve hypoxi? cell damage risk. Neuroprotective effect presence is confirmed by higher (by 32 %) antioxidant activity markers of lyophilized brain tissues, and by free radical oxidation lower intensity (by 13 %) and biomolecules oxidative modification rate (by 16 %) in these lyophilized tissues. Thus, the advisability of using DDW neuroprotective effects in cerebral circulation disturbance in experimental and clinical practice.

The paper presents the results of research and development of concentrated type p—i—n-diodes switches providing the switching time at the level of a few nanoseconds. To increase lock losses of (~40 dB) the authors use a cascade connection of diodes into waveguide and microstrip transmission line of q = p/2 electric length. Investigation results of creation of switching devices using longitudinally and transversely-distributed p—i—n-structures in the shortwave part of the millimeter wavelength range (f = 300 GHz) are presented. When developing switching devices intended to control the level of microwave power in the millimeter wavelength range, a number of special features arise limiting the achievement of optimal parameters. The dimensions of the metal ceramic packaged p—i—n-diodes and the mounting elements of semiconductor structures become comparable with the wavelength. As a result, package cannot be considered in the calculations and in the design as the capacity of the concentrated type. In our case the diode package is considered in the form of radial line which is able to transform the input impedance of the transmission line to the terminals of the diode structures, and realize high-impedance state (parallel resonance) in the device circuit in the mode of microwave power transmission. Engineering calculations for the given parameters of the silicon mesostructures showed the possibility of creating high-speed devices for switching microwave power with good characteristics. For diode assembling industrial clockwork ruby jewels with high quality of surface finish, strength and appropriate dimensions are applied as dielectric bushings. Suffice it to say that in the frequency range of 150 GHz, we used the bushings with dimensions of external diameter D = 0.4 mm and a height of h = 0.15 mm. The switches created provide transient units of nanoseconds, isolation more than 40 dB at relative frequency bandwidth of 30-40%. Evaluating progress in the development of millimeter wavelength devices, it should be noted that at frequencies greater than 200 GHz, the application of the concentrated type diodes is problematic. In this range it would seem to be promising to use bulk semiconductors. In this case surface-oriented p—i—n-structures can be applied as unified elements of the control devices in the shortwave part of the millimeter range, as well as in quasi-optical transmission lines.

Transmitting devices for small radars in the millimeter wavelength range with high resolution on range and noise immunity. The work presents the results of research and development of compact pulse oscillators with digital frequency switching from pulse to pulse. The oscillator consists of a frequency synthesizer and a synchronized amplifier on the IMPATT diode. Reference oscillator of synthesizer is synchronized by crystal oscillator with digital PLL system and contains a frequency multiplier and an amplifier operating in pulse mode. Small-sized frequency synthesizer of 8 mm wave lengths provides an output power of ~1.2 W per pulse with a frequency stability of no worse than 2•10–6. Radiation frequency is controlled by three-digit binary code in OOL levels. Synchronized amplifier made on IMPATT diodes provides microwave power up to 20 W in oscillator output with microwave pulse duration of 100—300 ns in an operating band. The oscillator can be used as a driving source for the synchronization of semiconductor and electro-vacuum devices of pulsed mode, and also as a transmitting device for small-sized radar of millimeter wave range.

The research concerning the effect of the remedies with the different antioxidant mechanisms on the indices of carbohydrate and lipid metabolism as well as the thiol link of the antioxidant system and the functional detoxication system in modeling conditions of the decompensated alloxan diabetes mellitus have been presented. The research was performed on 105 white nonlinear male-rats with initial body weight (b.w.) 200-230 g, divided into seven groups. Group 1 has consisted of the intact animals. Group 2 (the comparison group) has consisted of the animals suffering from the severe alloxan diabetes mellitus (intraperitoneal administration of alloxan monohydrate at 10 mg/100 g b.w. three times, with an interval of one day, against fasting) without correction. In groups 3-7 diabetes mellitus has also been modeled. The animals of group 3 were fed by the diet with the supplement containing the antioxidant complex with high content of carotenoid substances (1 mg lutein per day, orally for a month before simulations of diabetes mellitus and for a month after). The animals of group 4 have been given the sodium dichloroacetate (15 mg/100g bw) with drinking water for the month before and a month after the modeling of diabetes. The animals of group 5 have been injected with the reduced glutathione (15 mg/100 g of b.w.) daily one week prior to administration of alloxan and until the end of the experiment, the animals of group 6 have been injected with the quercithin (10 mg/100 g of b.w.) and the rats of group 7 have been given the water with the reduced content of deuterium (91 mg/l) instead of the usual drinking water. The development of experimental alloxan diabetes mellitus in rats has been accompanied by the increase in blood plasma of glucose concentration by 6.9-fold, cholesterol and lipoproteins of low density by 66 and 100% respectively. The compensatory activity increase of the antiradical protective enzymes (glutathione peroxidase and glutathione reductase) as well as the concentration decrease of reduced glutathione in erythrocytes by 11% have been revealed. According to the data concerning the level of the molecules with medium and low mass in blood plasma as well as in erythrocytes, the evident endogenous intoxication has taken place. The performed researches have proved the presence of the significant hypoglycemic effect of the usage of sodium dichloroacetate, of the water with the reduced content of deuterium and of quercithin - the glucose concentration in these groups was lower than in the comparison group by 36, 33 and 47% respectively. In the same groups as well as in the group of rats injected with glutathione the hypolipidemic effect of various manifestation degree has been detected, the most evident in animals from group 7 in which all the indices except triglycerides haven't differed from indices of the control group. The usage of various corrective methods has also assisted the adequate functioning of the antioxidant system that has been proved by the normalization of glutathione content except of groups 3 and 6 in which its concentration was lower than the control indices by 25 and 12% respectively. Endogenous intoxication has been significantly lower in groups 4, 5 and 7 in which the level of molecular of medium and low mass in blood plasma was normal and only in erythrocyte mass was increased by 49-74% than in the control group. Thus, the data obtained prove the usage availability of the antioxidant remedies in the complex therapy in patients suffering from the diabetes mellitus. The most interesting is the usage of antioxidants with the indirect mechanism of action, i.e. the water with the reduced content of deuterium and sodium dichloroacetate. Quercithin and the reduced glutathione deserve attention as well, and considering the hypoglycemic effect of the first one and the metabolic effects of glutathione aimed at the functioning maintenance of the non-specific organism resistance, the possibility of the combined usage of both antioxidants should be taken into account.