“Sometimes the biography of a scholar is similar to an adventure novel”: Some notes on publishing a new book

The article discusses a book by the well-known St. Petersburg scholar and Doctor of History, Professor Petr Bazanov that explores the life and activity of the Russian émigré historian and thinker Nikolay Uljanov (1904–1985). This book was published in 2018 in St. Petersburg by Vladimir Dal Publishing as part of the series “Russia at the Turning Point.””. The authors show that this monograph is a result of a long period of work by Bazanov, whose first studies on Uljanov were published at the beginning of 1990s. The authors stress that an analysis of this monograph demonstrates Bazanov’s excellent knowledge of scholarship devoted to Uljanov. The archival foundation for this book includes materials from numerous Russian and foreign archives. This article discusses how Bazanov’s monograph characterizes Uljanov’s way of life. Uljanov’s life was connected with pupils and comrades of V. E. Meyerhold, and he was the last pupil of academician S. F. Platonov and a comrade of Sergey Melgunov. The authors show that using different historical sources and scholarship, Bazanov characterizes all nuances of Uljanov’s fate. The authors conclude that this monograph makes a serious contribution to the Russian historiography, and this book would be interesting not only for professional historians, but also for people interested in the history of Russian culture and Russian thought. © 2019 Saint-Petersburg State University. All rights reserved

MECHANISMS OF EPIDURAL CATHETER KNOTTING

The objective of the study: to determine factors and mechanisms of the epidural catheter knotting. Three clinical cases of the epidural catheter knotting have been studied, and 80 bench tests of catheters made of polyamide and polyether block amide have been run. It has been found out that the extension of the length in the inserted catheter and the speed of its extraction result in the higher risk of knotting. Polyether block amide catheters versus polyamide ones are safer respective the potential knotting, A certain algorithm of actions for a doctor has been offered in order to prevent knotting and breakage of the catheter

Solving stiff problems using generalized picard iteration

The main point of the talk is an alternative approach to the construction of numerical methods for stiff problems. It can be interpreted as a generalization of fixed-point iterations for implementation of implicit collocation methods. The algorithms proposed combine easy implementation and low cost of iterations with superior convergence properties on stiff problems compared to conventional Picard iteration

AFM and FTIR Investigation of the Effect of Water Flow on Horseradish Peroxidase

Atomic force microscopy (AFM)-based fishing is a promising method for the detection of low-abundant proteins. This method is based on the capturing of the target proteins from the analyzed solution onto a solid substrate, with subsequent counting of the captured protein molecules on the substrate surface by AFM. Protein adsorption onto the substrate surface represents one of the key factors determining the capturing efficiency. Accordingly, studying the factors influencing the protein adsorbability onto the substrate surface represents an actual direction in biomedical research. Herein, the influence of water motion in a flow-based system on the protein adsorbability and on its enzymatic activity has been studied with an example of horseradish peroxidase (HRP) enzyme by AFM, attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) and conventional spectrophotometry. In the experiments, HRP solution was incubated in a setup modeling the flow section of a biosensor communication. The measuring cell with the protein solution was placed near a coiled silicone pipe, through which water was pumped. The adsorbability of the protein onto the surface of the mica substrate has been studied by AFM. It has been demonstrated that incubation of the HRP solution near the coiled silicone pipe with flowing water leads to an increase in its adsorbability onto mica. This is accompanied by a change in the enzyme’s secondary structure, as has been revealed by ATR-FTIR. At the same time, its enzymatic activity remains unchanged. The results reported herein can be useful in the development of models describing the influence of liquid flow on the properties of enzymes and other proteins. The latter is particularly important for the development of biosensors for biomedical applications—particularly for serological analysis, which is intended for the early diagnosis of various types of cancer and infectious diseases. Our results should also be taken into account in studies of the effects of protein aggregation on hemodynamics, which plays a key role in human body functioning

Effect of Spherical Elements of Biosensors and Bioreactors on the Physicochemical Properties of a Peroxidase Protein

External electromagnetic fields are known to be able to concentrate inside the construction elements of biosensors and bioreactors owing to reflection from their surface. This can lead to changes in the structure of biopolymers (such as proteins), incubated inside these elements, thus influencing their functional properties. Our present study concerned the revelation of the effect of spherical elements, commonly employed in biosensors and bioreactors, on the physicochemical properties of proteins with the example of the horseradish peroxidase (HRP) enzyme. In our experiments, a solution of HRP was incubated within a 30 cm-diameter titanium half-sphere, which was used as a model construction element. Atomic force microscopy (AFM) was employed for the single-molecule visualization of the HRP macromolecules, adsorbed from the test solution onto mica substrates in order to find out whether the incubation of the test HRP solution within the half-sphere influenced the HRP aggregation state. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) was employed in order to reveal whether the incubation of HRP solution within the half-sphere led to any changes in its secondary structure. In parallel, spectrophotometry-based estimation of the HRP enzymatic activity was performed in order to find out if the HRP active site was affected by the electromagnetic field under the conditions of our experiments. We revealed an increased aggregation of HRP after the incubation of its solution within the half-sphere in comparison with the control sample incubated far outside the half-sphere. ATR-FTIR allowed us to reveal alterations in HRP’s secondary structure. Such changes in the protein structure did not affect its active site, as was confirmed by spectrophotometry. The effect of spherical elements on a protein solution should be taken into account in the development of the optimized design of biosensors and bioreactors, intended for performing processes involving proteins in biomedicine and biotechnology, including highly sensitive biosensors intended for the diagnosis of socially significant diseases in humans (including oncology, cardiovascular diseases, etc.) at early stages