The characteristics of the effect of inert gases on tissue respiration in vivo]

Helium-oxygen and argon-oxygen gaseous mixtures have been studied for their effect on tissue respiration. It is shown that 1-hour exposition of animals induces an increase in the oxygen consumption of the liver tissue (more essential in the presence of helium in the gaseous mixture).     

Consciousness, its criteria and the possible mechanisms]

Consciousness is characterized by the objective and subjective criteria. Accordingly, this is the ability to operation with knowledge, its transmission to other people in abstract form and the feeling of "ego" as a subject of these actions. Objective and subjective signs of the consciousness are provided with the mechanism based on the synthesis of information coming from organs of sensation extracted from memory and coming from the centers of emotions and motivations. As a result of this synthesis the sensation of "ego", appears, and information estranged from it and offered for others is determined. An important role in the informational synthesis is played by the dynamic cortical structures--foci of interaction. In the process of perception they are localized mostly in projective zones of analyzers, at thinking--in associative zones of the cortex. Realization is closely connected with communication and formation of foci of interaction in the verbal zones of the left hemisphere.     

The opposing physiological effects of high pressures and inert gases.

The physiological effects on mammals of elevated pressures (approximately 100 atmospheres) must be considered in the context of the inert gases breathed. The most striking effect of pressure per se is a central hyperexcitability manifest at first by trembling of the entremities and finally by convulsions. Paralysis and death occur at higher pressures. The primary effects of the inert gases breathed are inert gas narcosis and general anesthesia. The exciting effects of pressure per se and the depressive effects of the inert gases tend to oppose each other. Thus consciousness may be restored to anesthetized mice by raising the pressure, and conversely the threshold pressure that causes convulsions is elevated in the presence of anesthetics. These mutually antagonistic effects can be rationalized in terms of model which proposes that both anesthetics and pressure non-specifically perturb thelipid bilayer regions of neutral membranes. This model is termed the critical volume hypothesis. Anthesthetics dissolve in and expand these lipid bilayer regions, while pressure causes mechanical compression. Expansion leads to anesthesia and compression to convulsions if a critical degree of change is achieved. At elevated partial pressures of inert gas the gas-induced expansion is opposed by the compression of pressure per se. With very insoluble gases, such as helium, this expansion is so small that net compression results and the effects of helium differ little from those of pressure per se. With more soluble gases, such as nitrogen, net expansion results in inert gas narcosis and anesthesia. The critical volume hypothesis enables "safe" mixtures of "expanding" and "compressing" gases to be defined. These enable higher pressures to be better tolerated by mammals.     

Grading criteria for assessing the ovarian development of Athetis lepigone and its use in forecasting

对室内饲养的二点委夜蛾Athelis lepigone(Moschler)雌成虫分时段进行解剖,观察其卵巢的结构及发育进程.结果显示二点委夜娥具有1对卵巢,各由4个卵巢小管组成.发育进程可分为5个阶段:透明期、卵黄沉积期、成熟待产期、产卵盛期和产卵末期.河北省石家庄地区2011年7月下旬至8月上旬田间卵巢发育的监测结果显示,Ⅰ级卵巢在整个发生期所占比例较高,Ⅳ级卵巢所占比例较低,推测其下一代幼虫的发生量将较低,并与田间调查结果吻合,因此卵巢解剖分级法可以用于二点委夜蛾的预测预报工作.     

二点委夜蛾卵巢发育分级及在预测预报中的应用

对室内饲养的二点委夜蛾Athelis lepigone(Moschler)雌成虫分时段进行解剖,观察其卵巢的结构及发育进程。结果显示二点委夜蛾具有1对卵巢,各由4个卵巢小管组成。发育进程可分为5个阶段:透明期、卵黄沉积期、成熟待产期、产卵盛期和产卵末期。河北省石家庄地区2011年7月下旬至8月上旬田间卵巢发育的监测结果显示,Ⅰ级卵巢在整个发生期所占比例较高,Ⅳ级卵巢所占比例较低,推测其下一代幼虫的发生量将较低,并与田间调查结果吻合,因此卵巢解剖分级法可以用于二点委夜蛾的预测预报工作。     

Mathematical model of the dynamics of transport of inert gases in the microcirculatory system

A mathematical model imitating transport of inert gases in the system of microcirculation under increased pressures was constructed. It has been shown that saturation of microareas nucleus of the brain cortex of average dimensions proceeds in about 90 sec. Effect of the blood flow velocity, gases tension in arterial blood and density of the capillary net on the dynamics of mass transfer of gases in a tissue was investigated.     

The effect of inert gases on the intensity of lipid peroxidation in the rat liver

The presence of helium and argon in gas mixtures increases the peroxidation rate of lipids in homogenates and has no influence on this index in the mitochondrial and microsomal fractions of the rat liver. An assumption is advanced that the realization of effects of the inactive gases in question is realized via the plasma membranes of cells.     

Determination of the distribution of ventilation-perfusion ratios: technic of elimination of multiple inert gases

The multiple inert gas elimination technique (MIGT) facilitates the estimation of the distributions of ventilation-perfusion (VA/Q) ratios in the experimental and clinical setting. The most relevant technical aspects and equipment and operational requirements needed to measure a mixture of inert gases in both the gas phase and the blood phase using gas chromatography are overviewed with detail. Results obtained in 3 dogs and 4 syringe-homogeneous lung models were entirely consistent with data formerly reported in the literature. Particular attention is paid to the linearity of the gas chromatograph detectors, reproducibility of inert gases sampling, and analysis of brands of heparin to detect acetone content. The errors of measurement (coefficients of variation) in blood were: 1.4 for sulfur hexafluoride; 1.8% for ethane; 2% for cyclopropane and halothane, each; 2.4% for diethyl ether; and, 3.6% for acetone. Important practical points are also emphasized in order to draw attention to potential problems and issues that should be concentrated upon to minimize the error in the measurements. It is concluded that the setting up of the MIGT is well established and validated.     

Conditions controlling the development of distant intercellular interactions during ultraviolet radiation]

The study is concerned with ascertaining the role of UV radiation in distant intercellular interactions (DII) and the conditions resulting in "MIRROR" CYTOPATHIC EFFECT ("M" CPE). It has been found that the UV radiation-induced extreme state of the cells in a radiant culture produces distantly in an intact detector culture, which has only an optic contact with it, the cytopathic effect (CPE) as a repercussion of a specificity of morphological manifestations imprinted in the affected culture. UV preparadiation of the detector cells aids in manifestation of the "mirror" CPE.     

New criteria for evaluation of soil bacterial complexes

The initial concentration of prokaryotic microorganisms, the type of their growth, doubling time, and the growth dynamics of bacteria and actinomycetes in three types of soil (meadow, chestnut, and soddy forest) were evaluated by the luminescence microscopic analysis of soil samples incubated in a humid chamber for 1 day. Soddy forest and chestnut soils differed in most of the parameters analyzed. Meadow soil was close to soddy forest soil in some parameters and to chestnut soil in other parameters. All soil suspensions exhibited high growth rates of bacteria and actinomycetes, indicating that the fraction of viable microorganisms in the soils was high.     

Activation of polyvinyl chloride sheet surface for covalent immobilization of oxalate oxidase and its evaluation as inert support in urinary oxalate determination

Polyvinyl chloride (PVC) sheets are a promising material for enzyme immobilization owing to the PVC’s properties such as being chemically inert, corrosion free, weather resistant, tough, lightweight, and maintenance free and having a high strength-to-weight ratio. In this study, this attractive material surface was chemically modified and exploited for covalent immobilization of oxalate oxidase using glutaraldehyde as a coupling agent. The enzyme was immobilized on activated PVC surface with a conjugation yield of 360 μg/cm². The scanning electron micrographs showed the microstructures on the PVC sheet surface revealing the successful immobilization of oxalate oxidase. A colorimetric method was adopted in evaluating enzymatic activity of immobilized and native oxalate oxidase. The immobilized enzyme retained 65% of specific activity of free enzyme. Slight changes were observed in the optimal pH, incubation temperature, and time for maximum activity of immobilized oxalate oxidase. PVC support showed no interference when immobilized oxalate oxidase was used for estimation of oxalic acid concentration in urine samples and showed a correlation of 0.998 with the values estimated with a commercially available Sigma kit. The overall results strengthen our view that PVC sheet can be used as a solid support for immobilization of enzymes and in the field of clinical diagnostics, environmental monitoring and remediation.     

On the theory of blood-tissue exchange of inert gases: VI. Validity of approximate uptake expressions

It is shown that the equation of inert gas uptake by a distinct parallel tissue-blood arrangement coincides, under certain conditions, with two formulations which neglect the possible existence of a blood-tissue barrier. The first of these approximations is the classic von Schrötter equation in continuous form, whereas the second is the empirical one frequently used by contemporary authors. The condition for coincidence is that the product of permeability and blood-tissue exchange surface greatly exceed the rate of blood flow to the tissue. It is difficult to examine this condition at present because of a dearth of gas permeability measurement and because apparently there exist no measurements of surface and flow on the same tissue. A compilation is made of such values as are available, and it is found that on the assumption that gas permeabilities are of the order of 1×10^?3 cm sec^?1, the conditions for neglecting the blood-tissue barrier may be met in many cases and certainly not met in many others. It is concluded that under these circumstances the more exact equations, taking into account the barrier, should be employed, at least until precise independent measurements justifying the approximations become available.