Biocompatibility of Bare Nanoparticles Based on Silicon and Gold for Nervous Cells

This work aimed to investigate the biocompatibility of bare (ligand-free) lasersynthesized nanoparticles (NPs) based on silicon (Si) and gold (Au) with primary hippocampal cultures. 1%, 5% and 7% of culture medium were replaced by 0.1 mg/mL NP solution on day 14 of culture development in vitro. Our studies revealed that the NPs caused a dose-dependent cytotoxic effect, which was manifested by an increase the number of dead cells and a decrease of the spontaneous functional calcium activity of neural networks. Au NPs revealed less pronounced cytotoxic effect than Si ones and it can be explained by larger size and better solubility of Si NPs. Keywords: bare nanoparticles, primary hippocampal cultures, neurotoxicit

Особенности совмещения классификационных систем и формирования массива ключевых слов для определения пространства знаний по микробиологии

Using various classifiers, which are thought to facilitate analytical work through structuring subject areas, in fact impedes this work. The authors present the method of combining several classification systems, namely the State Rubricator of Sci-tech Information (SRNTI); and RAS VINITI’s Rubricator of Disciplines; Universal Decimal Classification (UDC); International Patent Classification (IPC). The combination of these classification systems solves the fundamental problem which is to obtain the most detailed understanding of any scientific problem. The solution of this problem enables to determine search boundaries, filter out insignificant and irrelevant information on the subject (in this case – Microbiology). In their study, the authors selected the author's keywords and phrases. On the basis of the arrays of author’s keywords and phrases, an essential harmonized list of keywords and phrases for the basic Microbiology local rubricator was designed. Further, the selected keywords and phrases will serve as the foundation for building the ontological model of the discipline, which will enable computerized ontology building. The Microbiology draft rubricator developed by the authors comprises a three-level hierarchy. In particular, the first level is based on the classical concept of classification systems. Rubricator in Microbiology is developed on the basis of VINITI RAS classification of disciplines through the detailing method.Использование различных классификаторов, которые, казалось бы, должны содействовать аналитической работе, структурируя предметные области, на практике её частично затрудняет. В статье представлена методика совмещения различных классификационных систем: Государственного рубрикатора научно-технической информации, Рубрикатора отраслей знаний ВИНИТИ РАН, Универсальной десятичной классификации, Международной патентной классификации. Благодаря совмещению этих классификационных систем решается фундаментальная задача – получение максимально детализированного представления о научной проблеме. Решение этой задачи позволяет обозначить границы поисков, отсеивая второстепенную и неактуальную информацию по заданной теме (в данном случае – по микробиологии). В результате проведённого авторами статьи исследования были отобраны авторские ключевые слова, фразы и словосочетания. Благодаря тому, что массивы ключевых слов и фраз были приведены к единообразию, получен необходимый перечень ключевых слов и фраз для базового локального Рубрикатора по микробиологии. Отобранные ключевые слова и фразы будут впоследствии служить основой для формирования модели онтологии предметной области, обеспечивающей возможность автоматизации построения онтологии. Разработанный авторами проект Рубрикатора по микробиологии представляет собой трёхуровневую иерархию. Построение первого уровня рубрикатора основано на классической концепции создания классификационных систем. Рубрикатор по микробиологии разработан на основе классификации областей науки ВИНИТИ РАН путём детализации

The Influence of different types of upconversion nanoparticles surface coatings on neurotoxicity

The aim of the investigation was to study the effect of upconversion nanoparticles (UCNPs) with different surface coatings on viability and functional neural network activity of primary hippocampal cultures. Materials and Methods: The UCNPs with three surface coating modifications (tetramethylammonium hydroxide (TMAH), polymaleic acid octadecene and polyethyleneimine (PEI)) were synthesized by a solvothermal technique with further hydrophilization. Primary hippocampal cultures, obtained from C57BL/6 mice embryos (Е18), were incubated with tested UCNPs in the concentration of 0.8 and 8 mg/ml during 72 h. The cell viability detection, evaluation of morphological changes by immunocytochemical staining as well as the UCNPs influence on the main parameters of the functional neural network calcium activity and on the endocytosis processes were carried out. Results: Our studies revealed that UCNPs caused a dose-dependent cytotoxic effect on primary hippocampal cultures, wherein the severity of this effect directly related to the type of UCNPs surface coating. The greatest cytotoxicity was identified for UCNP–PEI, and the least — for UCNP–TMAH. UCNPs toxicity is manifested in significant morphological changes of neural networks and in the increase the number of dead cells (р<0.05) in primary hippocampal cultures. Moreover, a significant decrease (р<0.05) in the main parameters of spontaneous functional calcium activity was shown. Conclusion: A comprehensive investigation of the nanoparticles effects on primary hippocampal cultures showed that all tested UCNPs have the strong toxic effect to the nervous system cells.9 page(s