Effect of dioxane on the binding of competitive inhibitor proflavin and catalytic activity of bovine pancreatic α-chymotrypsin

The binding of competitive inhibitor proflavin by α-chymotrypsin in water-dioxane mixtures over the entire range of thermodynamic activities of water a w was studied. The data on the degree of binding of proflavin were compared to the results on the catalytic activity of the enzyme preliminary incubated in water-dioxane mixtures. An analysis of the behavior of the concentration dependences of these characteristics demonstrated that, at low a w values, the behavior of the interprotein contacts in the enzyme formed during its drying largely governs its functional properties, while at high a w values, they are determined by the interaction of the enzyme with the organic solvent. Interplay of these two factors is responsible for the observed complex shape of the isotherm of binding of proflavin, with the maximum degree of binding being attained at moderate a w values. © 2007 Pleiades Publishing, Ltd

Кинетика окисления полиизопрена в присутствии активных добавок

Analysis of changes in the structure and properties of polyisoprene films was carried out. The samples contained chemically active additives (antioxidants, antiscorchings) and were subsequenly warmed up.Проведен анализ изменения структуры и свойств пленок полиизопрена, содержащих химически активные добавки (противостарители, антискорчинги) с последующим прогревом образцов

SYSTEM OF ANAESTHETIC SUPPORT AT LARGE JOINT REPLACEMENT SURGERIES

The operation of total endoprosthesis replacement of large joints is associated with several anesthetic problems. Solving these problems ensures the safety of these highly traumatic operations and requires the solution of the following anesthetic tasks in the perioperative period: high degree of antinociceptive protection of patients with effective relaxation of the surgical intervention area; prevention of fatty hyperglobulinemia; decrease in the volume of perioperative hemorrhage and prophylaxis of thrombogenic complications. We developed our own program of anesthetic maintenance at major joints replacement. The components of the program are: the type of anesthesia - spinal anesthesia preservation of spontaneous respiration; our method of fat globulinemia prevention, based on maintaining the functional stability of the hepatocyte; our own method of replacement of peri-operative blood loss, based on the additional principle of "normalization of the oncotic blood pressure". Before the operation, patients receive a solution of tranexamic acid at a dose of 10 mg/kg of body mass to inhibit proteolysis (blood preservation technology). This method provides a "dry" operating field, reducing intraoperative hemorrhage. In the early postoperative period (5 hours after the surgery), under the control of whole blood clotting time, patients receive low molecular weight heparin Clexane at a therapeutic dosage of 1 mg/kg of body weight. This provides effective prevention of thrombogenic complications. The application of the developed technique shows its high clinical effectiveness. Over the past 5 years, 5,800 operations for large joint prosthetics have been performed, including 3,200 total hip replacement operations, 2,600 total knee replacement operations. There were no complications with a fatal outcome, in 5 cases fatty hyperglobulinemia was noted, which was stopped by the own method of treatment. There are no thrombogenic complications

Элемент согласования волноводной линии передачи с диодом

The article deals with the issues of matching a waveguide transmission line with millimeter wave diodes. The implementation of the transition of a rectangular waveguide to a microstrip switching line in the form of a line of the fin-line type is described. The computer simulation results of the transmission coefficient module of the developed element and the standing wave coefficient by voltage separately for the transition from a rectangular waveguide to a microstrip transmission line and as part of an amplitude detector are shown. A joint application of the developed element with a microstrip detector based on a Schottky diode in the frequency range from 118.1 to 178.4 GHz is proposed. The results of measuring its parameters and the results of determining the sensitivity are given, as well as the evaluation of the results obtained is performed. The obtained results proved the possibility of using the matching element of a waveguide transmission line with a diode in the millimeter wavelength range. Рассмотрены вопросы согласования волноводной линии передачи с диодами миллиметрового диапазона длин волн. Описана реализация перехода с прямоугольного волновода на микрополосковую линию передачи в виде линии типа фин-лайн. Показаны результаты компьютерного моделирования модуля коэффициента передачи разработанного элемента и коэффициента стоячей волны по напряжению отдельно перехода с прямоугольного волновода на микрополосковую линию передачи и в составе амплитудного детектора. Представлена реализация совместного применения разработанного элемента с микрополосковым детектором на базе диода Шоттки в диапазоне частот от 118,1 до 178,4 ГГц. Приведены результаты измерения его параметров и определения чувствительности. При оценке полученных данных подтверждена возможность применения разработанного элемента согласования волноводной линии передачи с диодом в миллиметровом диапазоне длин волн

Effect of dioxane on the binding of competitive inhibitor proflavin and catalytic activity of bovine pancreatic α-chymotrypsin

The binding of competitive inhibitor proflavin by α-chymotrypsin in water-dioxane mixtures over the entire range of thermodynamic activities of water a w was studied. The data on the degree of binding of proflavin were compared to the results on the catalytic activity of the enzyme preliminary incubated in water-dioxane mixtures. An analysis of the behavior of the concentration dependences of these characteristics demonstrated that, at low a w values, the behavior of the interprotein contacts in the enzyme formed during its drying largely governs its functional properties, while at high a w values, they are determined by the interaction of the enzyme with the organic solvent. Interplay of these two factors is responsible for the observed complex shape of the isotherm of binding of proflavin, with the maximum degree of binding being attained at moderate a w values. © 2007 Pleiades Publishing, Ltd

Effect of dioxane on the binding of competitive inhibitor proflavin and catalytic activity of bovine pancreatic α-chymotrypsin

The binding of competitive inhibitor proflavin by α-chymotrypsin in water-dioxane mixtures over the entire range of thermodynamic activities of water a w was studied. The data on the degree of binding of proflavin were compared to the results on the catalytic activity of the enzyme preliminary incubated in water-dioxane mixtures. An analysis of the behavior of the concentration dependences of these characteristics demonstrated that, at low a w values, the behavior of the interprotein contacts in the enzyme formed during its drying largely governs its functional properties, while at high a w values, they are determined by the interaction of the enzyme with the organic solvent. Interplay of these two factors is responsible for the observed complex shape of the isotherm of binding of proflavin, with the maximum degree of binding being attained at moderate a w values. © 2007 Pleiades Publishing, Ltd

Influence of cure activator on the structure and properties of rubbers

The influence of vulcanization activator type on the properties of the compositions and elastic-strength characteristics of rubber was studied. Found that the modification of zinc oxide as the basis of actual formation curing vulcanization agents leads to an increase of vulcanization active centers, providing an increase in the velocity of rubber vulcanization and improvement of physical and mechanical rubber’s properties

Kinetics of polyisoprene oxidation in the presence of active chemical additives

Analysis of changes in the structure and properties of polyisoprene films was carried out. The samples contained chemically active additives (antioxidants, antiscorchings) and were subsequenly warmed up

Features of rubber crosslinking in the presence of composite vulcanization activators

The features of curing polydienes by vulcanizing system based on composite curing activators was studied. Based on analysis of the investigating results of cure and elastic-strength properties rubbers was found that the modification of zinc oxide as a basis of the formation of actual curing agents increases of the active sites of vulcanization and as a consequence, increases the rate of vulcanization and improving physical and mechanical properties of rubbers