Hyposensitizing effect of high altitude and immunogenetic law

The studies were carried out in 24 sexually mature male guinea pigs. They were used as model of immediate-type allergic reaction (active cutaneous anaphylaxis). The animals were divided in 2 groups: control and experimental. The control group was housed in the mountain valley during the study, and the experimental group stayed for 45 days in high mountains (Anzob, 3375 m above sea level). On the day +30, all animals were sensitized with horse serum. On the 12th day of sensitization, blood was taken for analysis, and on the 15th day, an allergic reaction was provoked. We have revealed that, under high-altitude conditions, the severity of reaction was 1.5 times lower than in controls. Moreover, the animals kept in highlands exhibited lower contents of T and B lymphocytes, and IgE antibodies than in the control group. On the contrary, the numbers of phagocytically active neutrophils, as well as total effect of phagocytosis, proved to be higher in this group. This shift may be facilitated by hypoxia, since aerobic processes are known to prevail in the energy metabolism of lymphocytes, and anaerobic processes dominate in neutrophils. The allergic conditions are developed in three stages. Immunological stage is the first and main one, and allergic restructuring of the body immunity largely depends on it. What is the matter of reconstruction under the high-altitude conditions? We suggest, that, along with Haeckel–M ller biogenetic rule, there is also an immunogenetic law: “The activation sequence of events in the body’s defense system is a reproduction of phylogenesis, i.e., switching of subsequent link in defense system follows the evolutionary principles of complication and improvement. Namely, with respect to failing of previous link to completely eliminate the antigen in defense system”. One may conventionally consider that the first protective barrier against antigens is the most evolutionarily ancient structure, i.e., skin and mucous membrane; the second represents factors of nonspecific defense (phagocytosis, lysozyme, interferon, etc.); the third barrier is presented by cellular immunity (T effector cells, etc.), with humoral immunity serving as the fourth barrier. The fifth protective barrier provides evolutionarily late defense, i.e. allergic reaction, which is triggered by Ig E antibodies. On the mentioned basis, one may state that the decreased allergic reaction (the 5th barrier) in the animals from the experimental group was caused by adaptive changes in protective mechanisms of body. One may suggest that, under the high-altitude conditions an increase was observed in functional activity of phagocytes (2nd barrier), along with a decrease in activity of lymphocytes, i.e., cell populations responsible for the evolutionary later protective barriers

Electron transport and optical properties of shallow GaAs/InGaAs/GaAs quantum wells with a thin central AlAs barrier

Shallow GaAs/InGaAs/GaAs quantum well structures with and without a three monolayer thick AlAs central barrier have been investigated for different well widths and Si doping levels. The transport parameters are determined by resistivity measurements in the temperature range 4-300 K and magnetotransport in magnetic fields up to 12 T. The (subband) carrier concentrations and mobilities are extracted from the Hall data and Shubnikov-de Haas oscillations. We find that the transport parameters are strongly affected by the insertion of the AlAs central barrier. Photoluminescence spectra, measured at 77 K, show an increase of the transition energies upon insertion of the barrier. The transport and optical data are analyzed with help of self-consistent calculations of the subband structure and envelope wave functions. Insertion of the AlAs central barrier changes the spatial distribution of the electron wave functions and leads to the formation of hybrid states, i.e. states which extend over the InGaAs and the delta-doped layer quantum wells.Comment: 14 pages, pdf fil

Distribution and physiological state of microorganisms in petrochemical oily sludge

The occurrence, vertical distribution, and the physiological state of microorganisms in a petrochemical oily sludge deposit were studied. The total number and the number of viable microbial cells at depths of 0.2 and 3 m were about 10 and 108 cells/g dry wt. sludge. Most microbial cells taken from the middle (1 m deep) and the bottom (3 m deep) sludge horizons showed a delayed colony-forming ability, which suggested that the cells occurred in a hypometabolic state. The relative number of microaerobic denitrifying microorganisms steeply increased with depth. The amount of microorganisms tolerant to 3, 5, and 10% NaCl and capable of growing at 7 and 40°C varied from 102 to 108 CFU/g dry wt. sludge. Petrochemical oily sludge was found to maintain the growth of heterotrophs, among which the degraders of oily sludge and ten different individual polycyclic aromatic hydrocarbons were detected. The occurrence of highly adaptable microorganisms with an adequate metabolic potential in the petrochemical oily sludge deposit implies that its bioremediation is possible without introducing special microorganisms

Distribution and physiological state of microorganisms in petrochemical oily sludge

The occurrence, vertical distribution, and physiological state of microorganisms in a petrochemical oily sludge deposit were studied. The total number and the number of viable microbial cells at depths of 0.2 and 3 m were about 1010 and 108 cells/g dry wt sludge. Most microbial cells taken from the middle (l m deep) and the bottom (3 m deep) sludge horizons showed a delayed colony-forming ability, which suggested that the cells occurred in a hypometabolic state. The relative number of microaerobic denitrifying microorganisms steeply increased with depth. The amount of microorganisms tolerant to 3, 5, and 10% NaCl and capable of growing at 7 and 40 °C varied from 102 to 108 CFU/g dry wt sludge. Petrochemical oily sludge was found to maintain the growth of heterotrophs, among which the degraders of oily sludge and ten different individual polycyclic aromatic hydrocarbons were detected. The occurrence of highly adaptable microorganisms with an adequate metabolic potential in the petrochemical oily sludge deposit implies that its bioremediation is possible without introducing special microorganisms

ELECTRICAL CONDUCTIVITY OF TUNGSTEN PHOSPHATE GLASSES

Glasses of different compositions xWO3–(100-x)P2O5 (х = 70, 75, 80, 82 mol. %) have been obtained and investigated. Measurements have been made on electrical conductivity by various electrochemical methods. The maximum value of conductivity in this system at room temperature is 6,7·10-7 S/cm for the composition 82WO3–18P2O5.В данной работе получены и исследованы стёкла системы xWO3–(100-x)P2O5 (при х = 70, 75, 80, 82 мол. %). Изучены их проводящие свойства разными электрохимическими методами. Показано, что состав 82WO3–18P2O5 имеет наибольшую электропроводность при комнатной температуре, которая составляет 6,7·10-7 См/см

INFLUENCE OF SiO2 ON THERMAL PROPERTIES OF TUNGSTEN-PHOSPHATE GLASSES

In this work, the thermal properties of 70WO3–хSiO2–(100 – x)P2O5 glasses at х = 0, 10, 15 mol. % were studied by the DSC. The amorphous state of the obtained samples was monitored using XRD. It was found that the SiO2 addition increases the tendency of tungsten-phosphate glasses to crystallize.В работе исследованы термические свойства стекол 70WO3– хSiO2–(100 – x)P2O5 при х = 0, 10, 15 мол. % методом дифференциальной сканирующей калориметрии (ДСК). Аморфное состояние полученных образцов контролировали с помощью рентгенофлуоресцентного анализа (РФА). Установлено, что введение оксида кремния увеличивает склонность вольфрамофосфатных стекол к кристаллизации

Nonlinearization and waves in bounded media: old wine in a new bottle

We consider problems such as a standing wave in a closed straight tube, a self-sustained oscillation, damped resonance, evolution of resonance and resonance between concentric spheres. These nonlinear problems, and other similar ones, have been solved by a variety of techniques when it is seen that linear theory fails. The unifying approach given here is to initially set up the appropriate linear difference equation, where the difference is the linear travel time. When the linear travel time is replaced by a corrected nonlinear travel time, the nonlinear difference equation yields the required solution

Efficient optical-to-terahertz conversion in large-area InGaAs photo-Dember emitters with increased indium content

Optical-to-terahertz (THz) conversion of 800 nm femtosecond laser pulses in large-area bias-free InGaAs emitters based on photo-Dember (PD) and lateral photo-Dember (LPD) effects is experimentally investigated. We use metamorphic buffers to grow submicro-meter thick InxGa1-xAs layers with indium mole fractions x=0.37, 0.53, and 0.70 on a GaAs substrate. A strong enhancement of THz output energy with an increase of indium content is observed. On the surface of the sample providing the strongest emission (x=0.7), we have fabricated a 1.5 cm2 area of asymmetri-cally shaped metallic grating for LPD emission. This LPD emitter allows achieving high conversion efficiency of 0.24 . 10-3 and a broad generation band-width of up to 6 THz. We also demon-strate that there is no significant differ-rence in the conversion efficiency when operating at 1 and 200 kHz repetition rates. Our results show that large area LPD emitters give a convenient, competitive way to generate intense high-repetition-rate THz pulses