In Vitro Cytotoxicity of CdSe/ZnS Quantum Dots and Their Interaction with Biological Systems

Semiconductor nanocrystals (quantum dots, QDs) have a wide range of potential application in multiplexed tissue and cell imaging, and for in vivo molecular diagnostics and therapy. Therefore studying of the toxicity of QDs and their influence on various cellular processes in vitro is necessary to understand their interaction with living systems.; The paper presents the results of studies on the evaluation of CdSe/ZnS QD cytotoxicity, as well as the results of studying their interaction with freshly prepared human monocytes in vitro. Keywords: Quantum dots, semiconductor nanocrystals, cytotoxicity, in vitro models, monocytes

Cytotoxicity of Polyelectrolyte Microcapsules Encoded with Semiconductor Nanocrystals

Polyelectrolyte microcapsules are promising carriers of drugs and diagnostic agents for designing targeted and controlled delivery systems design. The use of quantum dots (QDs) as fluorescent labels in bioimaging is a promising approach to bioimaging tool development. The potential toxicity of QDs makes their applicability as fluorescent labels in vivo questionable. Therefore, the cytotoxicity of polyelectrolyte microcapsules encoded with semiconductor nanocrystals has been investigated. Keywords: Polyelectrolyte microcapsules, semiconductor nanocrystals, cytotoxicity, theranostic agents

The first notes on taxonomic diversity of leaf-mining micromoths, Gracillariidae (Insecta, Lepidoptera) in Omskaya Oblast, Russia

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Мобильное приложение Quizlet как средство обучения лексической компетенции студентов-лингвистов

Целью проведенного исследования является изучение возможностей мобильного приложения Quizlet как инструмента формирования лексической компетенции студентов-лингвистов, определение готовности использовать данное мобильное приложение на аудиторных занятиях, направленных на усвоение иноязычной лексики в ВУЗе. Анкетирование, проведённое среди студентов бакалавриата направления 45.03.02 «Лингвистика» УрФУ им. Б. Н. Ельцина показывает позитивное отношение обучающихся к мобильным приложениям и готовность к их использованию на занятиях.The purpose of this study is to study the capabilities of the Quizlet mobile application as a tool for the development of lexical competence of linguists, to determine the readiness to use this mobile application in classroom training aimed at mastering foreign language vocabulary at the university. A survey conducted among undergraduate students of the 45.03.02 "Linguistics" major of the B. N. Yeltsin UrFU shows a positive attitude of students to mobile applications and readiness to use them in the classroom

Chronobiological approach to study microsymbiont catalase activity in female reproductive tract

Catalase is a heme-containing enzyme belonging to protection factors that destroys peroxide compounds. The presence of catalase activity is an important ability of microorganisms that allows them to be protected from unfavorable factors as well as adapt to macroorganism conditions. Catalase along with superoxide dismutase plays an important role in pathogen resistance to phagocyte oxygen-dependent bactericidal mechanisms. The aim of the study was to investigate microsymbiont catalase activity from female reproductive tract in normocenosis and candidiasis dysbiosis using the chronobiological approach. The study was conducted on clinical isolates, isolated from female reproductive tract microsymbiocenosis. The catalase activity was determined by spectrophotometry based on 24 hour-long hydrogen peroxide reduction with 3-hours interval in winter season. Dynamic hydrogen peroxide was assessed in 3–5 experiment replicates. In some Lactobacillus spp., catalase was found containing no heme group — pseudocatalase. Chronobiological approach allowed to reveal enzyme activity from all microsymbionts. The dominant and associative microbiota isolated from healthy females was characterized by circadian (24 hours) rhythms of catalase activity early in the morning — 5 a.m. (р 0.05). Hydrogen peroxide decomposes spontaneously or via non-enzymatic catalysts, and microorganisms cope with this situation under such conditions. In microsymbionts characteristic of female reproductive tract dysbiosis, and usually found in large numbers along with decreased Lactobacillus spp. ultradian rhythms with 12- and 8-hour harmonics of catalase activity with acrophase were recorded in the morning (8 a.m.) and evening hours (8 p.m.). The minimum values of enzyme production in all cultures were recorded at 12 p.m. and 5 p.m. Therefore, the contribution of the rhythm of the studied parameter at varying degree of vaginal sterility reflects the adaptive pathogen capabilities to the conditions of existence and can be the basis for studying related regulatory mechanisms. Mesor and amplitude phase stability are universal rhythmometric parameters used to evaluate patient’s condition independent of species assignment

Chronobiological approach to study the physiological activity of <i>Candida</i> species

Rythmometric markers can be identified within a day during the study of biological characteristics in order to be used for differential diagnostics of pathogens of different patients’ physical condition. These principles are based on analysis of clinical isolates С. albicans, С. tropicalis and C. krusei allocated from the vaginal microbiota at Candida dysbiosis condition. Control examples were the master samples from the American Type Culture Collection (ATCC). Detailed research was conducted on physiological characteristics through the formation of biofilms by yeast pathogens. Biological activity of Candida sp. biofilming was observed within 2 days with 4 hours interval in winter. Daily cultures were used for the experiment to correspond to their maximum adhesion to the glass surface. It was important to obtain 6 measurements per day with 3-5 times repetition of experiment conditions during the specified timeline. In order to determine the periodicity of the parameters studied, the data was statistically processed by Student’s t-test, using Mann–Whitney criteria and nonparametric method of least square method.It was found out that biofilming activity during 24 hours (р &lt; 0.05) of fungi exists and that all species have many principles in common. It was attested that the main rhythmometric parameters of diagnostic significance are the rhythm period and amplitude-phase stability. It was found that the daily dynamics of C. albicans 24433 biofilm formation from American Type Culture Collection was characterized by an ultradian (about 12-hours) contribution of the rhythm in the morning – 4 A.M and in the evening – 4 P.M. Significant circadian (approx. daily) rhythms of adhesion glass surface activity were revealed in C. non-albicans from American Type Culture Collection. The dynamic of biofilm formation isolates of yeast from female reproductive organs with Candida pathology was characterized by reliable ultradian (about 12-hour) harmonics which biological significance defines resistance to external impact and the ability to adaptively respond to periodic stimuli.To sum up, implementation of the chronobiological approach has opened up new prospects for studying the physiology of Сandida sp., as it enables us to predict the dynamics of microbial states and takes into account the specificity of emergency and long-term adaptation to different environmental factors. The detection of the circadian rhythm of biofilm formation activity of different Candida sp. strains provides the possibility to manage the vitality of the Society of Bacteria and Fungi and predicts its resistance to various antibiotics