Effects of Protein Content on Pickering-assisted Interfacial Enzyme Catalysis

In recent years, water-in-oil Pickering emulsions have been introduced as promising reaction systems for multiphase enzyme catalysis, in particular lipase-catalyzed esterification and transesterification. Here, we for the first time gained insight into the effects that the presence of the proteins exert on the fineness and stability of the emulsion system and thus, the catalytic performance. We demonstrated a distinct, concentration-and enzyme-dependent decrease of droplet sizes in the dispersed phase, accompanied by decreasing stability against coalescence. This was due to a probably quantitative adsorption of lipases at the interphase intercalating the solid particles. Destabilization was reduced slightly at increased particle content and increased volume portion of the dispersed phase, respectively. However, the low tolerable lipase concentrations in the reaction system considerably limited its productivity. Thus, our study points at the enzyme content, or rather enzyme location, in Pickering emulsions being the crucial parameter for optimizing catalytic performance

The effect of boron on mechanical and functional properties in the ironbased alloy

The mechanical properties and superelastic behavior were studied on [001]-single crystals of Fe-28%Ni-17%Co-11.5%Al-2.5% Х (at. %) (X=Ta, TaВ) alloy. It is shown that boron affects on the mechanical and functional properties in the iron-based alloy

Rsn-2-mediated directed foam enrichment of β-lactamase

Today, the availability of methods for the activity-preserving and cost-efficient downstream processing of enzymes forms a major bottleneck to the use of these valuable tools in technical processes. A promising technology appears to be foam fractionation, which utilizes the adsorption of proteins at a gas–liquid interface. However, the employment of surfactants and the dependency of the applicability on individual properties of the target molecules are considerable drawbacks. Here, we demonstrate that a reversible fusion of the large, surface-active protein Ranaspumin-2 (Rsn-2) to a β-lactamase (Bla) enabled both surfactant-free formation of a stable foam and directed enrichment of the enzyme by the foaming. At the same time, Bla maintained 70% of its catalytic activity, which was in stark contrast to the enzyme without fusion to Rsn-2. Rsn-2 predominantly mediated adsorption. Comparable results were obtained after fusion to the structurally more complex penicillin G acylase (PGA) as the target enzyme. The results indicate that using a surface-active protein as a fusion tag might be the clue to the establishment of foam fractionation as a general method for enzyme downstream processing

Lipase-Mediated Conversion of Protecting Group Silyl Ethers: An Unspecific Side Reaction

Silyl ether protecting groups are important tools in organic synthesis, ensuring selective reactions of hydroxyl functional groups. Enantiospecific formation or cleavage could simultaneously enable the resolution of racemic mixtures and thus significantly increase the efficiency of complex synthetic pathways. Based on reports that lipases, which today are already particularly important tools in chemical synthesis, can catalyze the enantiospecific turnover of trimethylsilanol (TMS)-protected alcohols, the goal of this study was to determine the conditions under which such a catalysis occurs. Through detailed experimental and mechanistic investigation, we demonstrated that although lipases mediate the turnover of TMS-protected alcohols, this occurs independently of the known catalytic triad, as this is unable to stabilize a tetrahedral intermediate. The reaction is essentially non-specific and therefore most likely completely independent of the active site. This rules out lipases as catalysts for the resolution of racemic mixtures of alcohols through protection or deprotection with silyl groups

Получение и изучение медико-биологических свойств меченного технецием-99м противомикробного препарата норфлоксацина гидрохлорида

Проведены исследования по созданию стандартного реагента для получения меченного 99mТс норфлоксацина гидрохлорида (НФГ). Оценку влияния компонентов реакционной смеси на радиохимическую чистоту получаемого препарата проводили методом тонкослойной хроматографии. На экспериментальных животных (кроликах) с моделью воспаления различной локализации показана функциональная пригодность меченого антибиотика для диагностики воспалительных процессов

Совершенствование процесса производства электрических машин с помощью инструментов бережливого производства

Объектом исследования работы является АО "Томский электротехнический завод". Предметом исследования являются производственные процессы предприятия. Цель исследования – повысить производительность труда за счет применения инструментов бережливого производства. В соответствии с целью были поставлены следующие задачи: 1.Изучить основные инструменты бережливого производства. 2.Проанализировать деятельность завода и его производственные процессы. 3.Внедрить улучшения на пилотном участке. 4.Оценить эконмическую эффективность внедренных методов. 5.Разработать рекомендации для дальнейшего улучшения работы АО "ТЭТЗ".The object of the study is Tomsk Electrotechnical Plant . The subject of the research is the production processes of the enterprise. The purpose of the study is to increase labor productivity through the use of lean manufacturing tools. In accordance with the goal, the following tasks were set: 1. Learn the basic tools of lean manufacturing. 2. Analyze the activities of the plant and its production processes. 3. Implement improvements at the pilot site. 4. Assess the economic efficiency of the implemented methods. 5. Develop recommendations for further improving the work of TETZ