[A two-stage technology for bacterial and chemical leaching of copper-zinc raw materials by Fe3+ ions with their subsequent regeneration by chemolithotrophic bacteria].

A two-stage technology for bacterial and chemical leaching of nonferrous metals in a specifically designed laboratory unit has been proposed. At the first stage of leaching, ferric iron formed during the second stage of oxidation of Fe2+ ions by mesophilic chemolithotrophic microorganisms was used. The optimal parameters of the first stage of the process (flow rate, temperature, and the process duration) were 2 l/h, 75 degrees C, and 2 h, respectively. The results of testing of the two-stage technology for leaching copper-zinc raw materials indicated that the depth of zinc and copper leaching can be increased from 70 to 93% and from 40 to 58.8%, respectively, and the process duration can be reduced from 120 to 24 h as compared to the commonly used one-stage technology.

[The dynamics of oxidase activity during cultivation of basidiomycetes from the genus Trametes Fr].

Twenty strains of the wood-degrading fungi from the genus Trametes Fr., capable of synthesizing laccases, were screened according to the changes in the oxidase activity in a submerged culture. The range of maximal efficiency of various species with respect to extracellular oxidase activity was determined. The absence of correlation between the oxidase activity in a submerged culture and the size of colored zone on agar media (Bavendamm reaction) was demonstrated. The most efficient strains, T. hirsita 56 and T. ochracea 92-78, were used to produce laccases, homogeneous according to SDS electrophoresis data. A number of biochemical parameters characteristic of these enzymes were determined.

[Biological oxidation of sulfide raw material using a culture of Thiobacillus ferrooxidans under various conditions of leaching]. / Biookislenie sul'fidnogo syr'ia kul'turoi Thiobacillus ferrooxidans pri razlichnykh usloviiakh vyshchelachivaniia.

Major parameters of the first stage of leaching of a copper-zinc sulfide product by a culture of Thiobacillus ferrooxidans have been studied, including the effects of solid phase concentration, Fe2+ and Fe3+ ions, pH, and the intensity of mixing. The first stage of leaching of the sulfide raw material is optimum under the following conditions: pH of the original leaching solution equal to 1.6; Fe3+ concentration of order of 10 g/l; and vigorous mixing of the suspension at solid phase concentrations of 30-35%. A theoretical substantiation of the observed dependences is proposed.

[Application of clexane in urosepsis: necessity or the issue of fashion]. / Primenenie kleksana pri urosepsise: neobkhodimost' ili dan' mode.

Results of comparative studying of influence of low-molecular weight heparin clexane (enoxaparine sodium) and nonfractionized heparin on coagulational properties of blood in patients with uncomplicated urosepsis are presented. It was established that application of clexane promotes an effective prophylaxis of thromboembolic complications without rising of the hemorrhage occurrence risk.

[Conditions for forming ethanol during bioconversion of cellulose-containing raw material]. / Usloviia obrazovaniia tanola pri biokonversii tselliulozosoderzhashchego syr'ia.

Several natural associations composed by thermophilic anaerobic bacteria capable of utilizing various cellulose materials at 60 +/- 2 degrees C and pH 6.0-7.0 were isolated from the sludge of Kamchatka geothermal springs. The rate of ethanol production (up to 1.7 g/l per day) and the concentration of ethanol in the medium (up to 1.2%), as well as the fermentation period (10-15 days) were determined under anaerobic conditions in the presence of cellulose, coniferous sawdust, newsprint, or paper pulp as a carbon source. Microorganisms were found that inhibited the production of ethanol. The initial pH value was found to influence both the ethanol production rate and ethanol/acetate ratio. A pH decrease from 7.0 to 5.0 led to 6.7-fold increased the ethanol production and caused a 23.8-fold increase in the ethanol/acetate ratio.

[Selection of a mixed culture of cellulosolytic thermophilic anaerobes from various natural sources]. / Selektsiia smeshannoi kul'tury tselliulozoliticheskikh termofil'nykh anaérobov iz raznykh prirodnykh istochnikov.

Microbial associations capable of converting cellulose-containing substrates to ethanol and organic acids were isolated from natural sources. The resulting mixed cultures utilized cellulose, cellobiose, glucose, maize residue, cotton, and flax boon producing ethanol (up to 0.9 g/l) and acetic acid (up to 0.8 g/l). The most complete conversion of cellulose-containing substrates occurred at 60 degrees C, pH 7.0. The selected association of thermophilic anaerobic bacteria produced 0.64 g ethanol per g substrate utilized at the ethanol/acetate ratio 4.7:1.

[Clexane and regional anesthesia. Contraindication or possible combination?]. / Kleksan i regionarnaia anesteziia. Protivopokazanie ili vozmozhnoe sochetanie?

Results of the efficacy and safety analysis of low-molecular weight heparine clexane (sodium enoxaparine) in patients with urological diseases were adduced. Postoperative usage of clexane along with epidural anesthesy had prevented occurrence of hypercoagulation as well as epidural and spinal hematoma.

[Disorders of the ventilation-diffusion correlations and of the gas-transport function of the blood in the acute period of burn trauma in children]. / Narushenie ventiliatsionno-diffuzionnykh vzaimootnoshenii i gazotransportnoi funktsii krovi v ostryi period ozhogovoi travmy u detei.

External respiration and blood gas composition were examined in 187 children aged 1 to 14 years during the acute period of burn disease (burn shock and toxemia). The patients were divided into three groups with different area of thermal injury to the skin. Group 1 were children with burns of up to 10% of body surface area. The ventilation parameters in this group were changed just negligibly, and the diffusion capacity of the lungs and gas composition of arterial blood were within the normal range of values both during shock and toxemia. In patients with burns involving 11 to 20% of body surface the ventilation parameters were changed appreciably and did not compensate for each other, as was observed in group 1. The diffusion capacity of the lungs and blood gas composition values were moderately decreased. During toxemia the minute-consumption of oxygen was decreased and alveolar oxygen tension remained unchanged. As a result of this, the diffusion capacity of the lungs and blood gas parameters continued to decrease. The most dynamic changes were observed in children with burns involving 21 to 45% of body surface. The ventilation-diffusion disorders and blood gas composition were altered, particularly so during toxemia; the changes consisted in a decrease of the minute ventilation volume and oxygen tension in arterial blood and a moderate increase of alveolar oxygen tension, which led to further decrease of the diffusion capacity of the lungs. In parallel with the disorders in the above parameters, x-ray changes in the lungs were observed, which were characterized by a vascular-interstitial pattern in group 2 and infiltrative changes in group 3. In children with burn wounds of 35 to 45% of body surface these changes presented as the developing lung edema.

[An evaluation of the effect of magnetic-laser therapy on external respiratory function in complicated forms of acute pneumonia in children]. / Otsenka vliianiia magnitnolazernoi terapii na funktsiiu vneshnego dykhaniia pri oslozhnennykh formakh ostroi pnevmonii u detei.

The authors studied the effects of magnetic laser therapy (MLT) on external respiration, blood transport of gas and clinical course of acute destructive pneumonia in children aged 1-12 years. It was established that energy of infrared laser combined with magnetic field reduces the severity of acute respiratory insufficiency, treatment course, prevents destructive complications in children with infiltrative acute destructive pneumonia.

[Study of the conditions for reproducing the processes of antibiotic biosynthesis. Determining the limiting stage of the process of mass transfer of oxygen]. / Issledovanie uslovii vosproizvodimosti protsessov biosinteza antibiotikov. Opredelenie limitiruiushchei stadii protsessa massoperedachi kisloroda.

A theoretical method for estimating limiting stage of oxygen mass transfer is proposed. The method is based on calculation and comparison of particular resistance of separate stages of mass transfer: mass transfer through the gas-liquid boundary, oxygen transport in the liquid phase, mass transfer through the liquid-cell boundary and oxygen consumption by microbial cells. With the proposed method, particular resistance was calculated and conditions for oxygen mass transfer were analyzed in the biosynthesis of sisomicin as an example. As a result the conditions for reproducibility of the process in apparatus of various size were determined.

[Study of the conditions for reproducing the processes of antibiotic biosynthesis. Calculating the process of sisomycin biosynthesis]. / Issledovanie uslovii vosproizvodimosti protsessov biosinteza antibiotikov. Masshtabirovanie protsessa biosinteza sizomitsina.

Conditions were experimentally studied for reproducing sisomicin biosynthesis by up-to-down scaling. It was shown that respiration intensity as a parameter of antibiotic biosynthesis scaling-down had certain limitations connected with multistage oxygen mass transfer. The parameter could be used only when the limiting stages of oxygen mass transfer coincided. It was confirmed experimentally that it was possible to apply the previously proposed theoretical method to estimation of the limiting stage of oxygen mass transfer.

[Theoretical analysis of the continuous two-stage process of the biosynthesis of a metabolic product]. / Teoreticheskii analiz nepreryvnogo dvukhstadiinogo protsessa biosinteza produkta metabolizma.

A mathematical model for continuous biosynthesis of a metabolite in a battery of two apparatuses with ideal agitation is described and analysed. In the first apparatus of the battery it is advisable to maintain a high specific rate of culture growth for continuous accumulation of young active biomass while in the second apparatus a low growth rate is expedient which provides a change in the culture metabolism to biosynthesis of the required product. To make the continuous two-stage process efficient, it is necessary to add an extremely concentrated solution of the nutrients to the second apparatus of the battery. Influence of the oxygen transport velocity on the maximum attainable concentration of the biomass and the process capacity by the required product was studied.

[Effect of partial pressure of solute oxygen on the intensity of respiration of cultures of antibiotic producers]. / Vliianie partsial'nogo davleniia rastvorennogo kisloroda na intensivnost' dykhaniia kul'tur-produtsentov antibiotikov.

It was shown possible to use feeding of hydrogen peroxide as a method for investigating the impact of dissolved oxygen concentrations on growth and development of microorganisms. The influence of pO2 on the respiration intensity was studied in penicillin- and erythromycin-producing cultures and it was found that dependence of the respiration intensity on pO2 had the form of a curve with saturation, at pO2 equal to zero the value of the culture respiration intensity being different from zero. A mathematical model accounting for the presence in the fermentation broth of microbial agglomerates with the average size depending on the agitation conditions is proposed for describing the relationships.

[Branching defects and mucosal diverticulosis of the bronchi in children as factors predisposing to the development of chronic inflammatory processes in the lungs]. / Poroki vetvleniia i divertikulez slizistoi obolochki bronkhov u detei kak faktory, predraspolagaiushchie k razvitiiu khronicheskikh vospalitel'nykh protsessov v legkikh.

Clinical and bronchographic data were juxtaposed with the results of selective histological examination of the resected parts of lungs from 3 to 14-year-old children suffering for several years from persistent cough and recurrent pneumonias. The defects of small and mean bronchi branching are found in 66% of cases (out of 50) and in 64% there was diverticulosis of the mucous membrane of large and small bronchi that is followed by pseudopoliposis and the development of deep "pouches". All this is followed by bronchus-associated lymphoid tissue hyperplasia, development of peribronchial pneumonia foci, chronic bronchitis, obturation syndrome.