Properties of natural animal gamma-interferons and peculiarities of their action

Genetic haemochromatosis (GH) is the most common, autosomal recessive disorder in Northern Europe. The studies which led to the identification of the HFE gene are described. In the UK over 90% of patients with GH are homozygous for the C282Y mutation of this gene. This mutation is confined to populations of European origin. The significance of another mutation, H63D, in causing iron overload is less certain. Preliminary studies on the localization of the protein and the effects of the mutations are described. Genetic testing and the measurement of iron status now provide the means to allow for widespread testing for the prevention of iron overload and its consequences. However, questions remain about the clinical penetrance of GH.     

Nonmetallic Inclusions in 08Kh18N10T Steel as the Cause of Initiation of Defects in Heat-Exchange Tubes of Steam Generators of Nuclear Power Plants

Materials Science - We present the results of investigation of the microstructure of 08Kh18N10T steel in heat-exchange tubes after their long-term operation in steam generators of WWÉR-1000...     

Corrosion-mechanical resistance of pipe steel in hydrogen-sulfide containing media

We investigate the resistance to hydrogen-sulfide stress corrosion cracking and hydrogen-induced cracking of ASTM A333 steel intended for the oil and gas industry. On the basis of the results obtained for seven meltings of this steel supplied for the Tengiz gas-processing plant, we established that all meltings satisfy specifications of the NACE MR0175-96 standard in their chemical composition and strength characteristics (S < 0.005%. P < 0.025%, HRC < 22, etc.). For two of the seven investigated meltings, resistance to hydrogen-sulfide stress corrosion cracking is not high (threshold stresses < 0.8Σ^min _0.2) and one melting has a low resistance to hydrogen-induced cracking (coefficient of the length of regions of crack formation > 6% and coefficient of the width of regions of crack formation > 3%). Therefore, complete (100%) incoming control over the corrosion-mechanical resistance of all materials of equipment operating in hydrogen-sulfide-containing media must be carried out. Translated from Fizyko-Khimichna Mekhanika Materialiv. Vol. 36, No. 3, pp. 93–97, May-June. 2000.     

Confined Catalytic Janus Swimmers in a Crowded Channel: Geometry‐Driven Rectification Transients and Directional Locking

Self‐propelled Janus particles, acting as microscopic vehicles, have the potential to perform complex tasks on a microscopic scale, suitable, e.g., for environmental applications, on‐chip chemical information processing, or in vivo drug delivery. Development of these smart nanodevices requires a better understanding of how synthetic swimmers move in crowded and confined environments that mimic actual biosystems, e.g., network of blood vessels. Here, the dynamics of self‐propelled Janus particles interacting with catalytically passive silica beads in a narrow channel is studied both experimentally and through numerical simulations. Upon varying the area density of the silica beads and the width of the channel, active transport reveals a number of intriguing properties, which range from distinct bulk and boundary‐free diffusivity at low densities, to directional “locking” and channel “unclogging” at higher densities, whereby a Janus swimmer is capable of transporting large clusters of passive particles.     

Kinetics of hydrogen release on newly formed and hydrogenated metal surfaces

We study the regularities of cathodic processes accompanied by hydrogen depolarization as a function of the energy state of the metal surface, including its purity and degree of hydrogenation. It was established that hydrogen release on a newly formed metal surface (NFS) is activation-free and diffusion-controlled and its rate is determined by the exchange current. Hydrogenation of the surface increases the work function of escape of an electron, decreases the probability of escape of electrons from a metal into solution by changing the structure of the electric double layer, and, thus, slows down hydrogen release.Karpenko Physicomechanical Institute, Ukrainian Academy of Sciences, L'viv. Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 30, No. 1, pp. 53–60, January–February, 1994.     

Genetic algorithm based inversion of neural networks applied to optimised design of UWB planar antennas

An inversion of artificial neural networks using a genetic algorithm is presented for a novel concept of optimisation applied to UWB planar antennas of bow-tie type with respect to specified values of antenna performance in the frequency range 3.1-10.6 GHz. This efficient concept is shown to achieve significant reduction in computing time for optimisation. The multidimensional inversion is characterised by a simple composite fitness or target function that includes antenna parameters as a function of signal frequency or/and angle dependence. Good impedance matching and gain performance is achieved over the whole frequency range by adequately modifying the radiating contour profile of the conventional triangular bow-tie antenna.     

Degradation of the Tubing Metal in Hydrogen-Sulfide Environments

We analyze damages in tubing metal of domestic (D steel) and foreign (C-95 steel) production and also determine the coefficients of degradation of the metal after long-term exploitation. It is shown that the tubing metal of C-95 steel is subject to general corrosion, hydrogen-induced cracking, and hydrogen-sulfide stress corrosion cracking even under the conditions of inhibition. Tubing metal of D steel was not subject to hydrogen-sulfide stress corrosion cracking even after eleven years of exploitation. It is established that degradation of D steel is lower than that of C-95 steel.     

Resistance of 06KH20N8M3D2L ferritic-austenitic steel to hydrogen-sulfide corrosion cracking

Four experimental industrial melts of 06Kh20N8M3D2L cast ferritic-austenitic steel were obtained. Their susceptibility to hydrogen-sulfide stress-corrosion cracking is found and the influence of alloying components (Cr, Al, and Ti) on the resistance of this steel to hydrogen-sulfide stress-corrosion cracking is investigated. It is shown that the maximum resistance of cast steel to hydrogen-sulfide stress-corrosion cracking is attained as a result of its alloying with 20.5–20.7% of chromium, 0.015–0.042% of aluminum, and ≤0.06% of titanium. Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 44, No. 5, pp. 59–62, September–October, 2008.     

Distinctive features of damage to low-pressure deaerators of heat-electric power plants

We investigate causes of corrosion cracking of welded joints of low-pressure deaerators of heat-electric power plants and give recommendations for their repair with subsequent heat treatment of welds, which guarantees an increase in their corrosion crack resistance under operating conditions. Karpenko Physicomechanical Institute. Ukrainian Academy of Sciences. L'viv. Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 32, No. 5, pp. 101–103, September–October, 1996.     

Lectin of Bacillus subtilis sp. as overinducer of gamma-interferonogenesis

It has been demonstrated experimentally that lectin of Bacillus subtilis sp. in comparison with generally accepted Con A, PHA and lectin of "gold rain" grass--Laburnum anagyroides M e d i k in trials on white mice of CBA line gave in 4 hours of induction maximal titers of gamma-IFN in blood serum of animals--153.6 +/- 17.0 IU/ml. Practically identical titers had been obtained after induction by lectin "gold rain", some lower--after Con A and PHA. At swine gamma-IFN synthesis optimal density of cell suspension must contain 2.5 + 10(7) immunocytes in 1 ml, owing to which it is possible to obtain the titer equal 1 : 2150. Materials with using of bacterial lectins at various degree of purification had shown that maximal titers in blood serum of mongrel white mice were registered at administration to animals of non-purified lectin, 4 times lower--at using of half-purified and purified lectins. Data of these trials in vivo were confirmed by materials of gamma-IFN induction by immunocytes of swine, cattle and even man.