Morphology of Camellia Sinensis L. leaves as marker of white tea authenticity

Received: February 1st, 2021 ; Accepted: April 24th, 2021 ; Published: August 18th, 2021 ; Correspondence: [email protected] is one of the most common drinks in the world. Classic tea is obtained by brewing the leaves of the Camellia sinensis L plant in hot water. However, even the leaves collected from the same branch of the same tea bush can have completely different anatomical, biochemical and taste characteristics. White tea is the youngest, immature apical leaves of the tea bush (fleshes) together with leaf buds (tips) which are is considered the most valuable parts of teaplant. The chemical composition of tea is studied in sufficient detail, however, there are still no uniform criteria for determining the authenticity of white tea leaves, which creates great preconditions for falsifying this most valuable type of raw material. The aim of this study was to study the macroand microstructure of white tea leaves from different manufacturers and to determine the morphological markers of the authenticity of white tea leaves. The objects of research were white tea from the Nandana Tea Factory (Sri Lanka) and white tea from an unknown manufacturer, purchased from a local tea shop. The study of raw materials was carried out in accordance with the requirements of GF XIV OFS 1.5.1.0003.15 ‘Leaves’ and OFS 1.5.3.0003.15 ‘Technique of microscopic and microchemical examination of medicinal plants and herbal medicinal products.’ The work was carried out on the basis of the laboratories of the Department of Food Technologies of FGBOU VO Saratov GAU named after N.I. Vavilov, and the Department of General Biology, Pharmacognosy and Botany, Saratov State Medical University named after V.I. Razumovsky Ministry of Health of Russia. Studies of the structure of white tea leaves from various manufacturers have shown that the structure and presence of morphological elements of leaves, such as hairs, stomata, leaf edge, druses, sclereids, differ markedly and can serve as reliable markers for identifying the variety of tea

THE ROLE OF SMALL RNAS IN CONTROLLING EXPRESSION OF GENES INVOLVED IN THE IMPLEMENTATION OF VIBRIO CHOLERAE PATHOGENICITY

Currently, bacterial small RNAs with regulatory functions are characterized as a heterogeneous claster of highly structured single-stranded RNAs which usually would not be translated into proteins. A large group of small RNAs consists of small regulatory RNAs functioning through the mechanism of complementary interaction between small regulatory RNA bases and bacterial messenger RNAs (mRNA). The review provides the description of direct participation of small RNA mechanisms in realization of pathogenic properties, biofilm formation and virulence regulation in V. cholerae strains. In particular, the Hfq-dependent small RNAs that control the expression of genes responsible for virulence and biofilm formation of V. choleraе, and the impact of small RNA on the secretion system of VI type are presented. We also characterized the small RNAs–controlled process of V. cholerae vesicles formation, which have a great significance for colonization ability of cholera vibrios. In addition, such method of regulation at RNA level as “riboswitches”, (RNA switches) is described

Media Image as One of the Components for Formation of Media Aesthetic Code of the Region

Статья поступила в редакцию 12.01.2023 г.В статье рассматривается медиаобраз как одна из составляющих формирования медиаэстетического кода региона. Анализ научной литературы, посвященной данному вопросу, показал, что в последнее время интерес исследователей различных направлений и научных школ к вопросу изучения медиаобраза регионов возрастает. В то же время исследований, рассматривающих медиаобраз региона в контексте его медиаэстетического кода, нами не обнаружено. Статья направлена на восполнение этого пробела, в чем и заключается актуальность и новизна исследования. Авторы показывают, что образ, конструируемый в медиапространстве региона, служит основой формирования медиаэстетического кода данного региона. На основе анализа материалов, опубликованных в средствах массовой информации (сайт 1obl.ru), делается вывод о некотором несоответствии между вербальным и визуальным контентом. Из-за этого создается отрицательный медиаобраз города, что негативно сказывается на формировании медиаэстетического кода города и региона. В статье сформулированы универсальные рекомендации по оптимизации изовербального контента, которые могут быть экстраполированы на деятельность других локальных редакций.The article considers the media image as one of the components of the formation of the media aesthetic code of the region. An analysis of the scientific literature devoted to this issue has shown that recently the interest of researchers from various fields and scientific schools in the study of the media image of the regions has been increasing. At the same time, we have not found any studies that consider the media image of the region in the context of its media aesthetic code. The proposed article is aimed at filling this gap, which is the relevance and novelty of the proposed study. The authors show that the image constructed in the media space of the region serves as the basis for the formation of the media aesthetic code of the region. Based on the analysis of materials published in the media (website 1obl.ru), a conclusion is made about some discrepancy between verbal and visual content. Because of this, a negative media image of the city is created, which negatively affects the formation of the media aesthetic code of the city and region. The article formulates universal recommendations for optimizing isoverbal content, which can be extrapolated to the activities of other local editorial offices

Construction of Polymeric Antigenic Diagnosticum Based on <i>Vibrio cholera</i> О1 Lipopolysaccharide

Representatives of the genus Vibrio cholerae differ in the structure of lipopolysaccharide, in particular, its O-polysaccharide chains (O-antigen), which determines the serological specificity of vibrios. Currently, the water-phenolic method is used to obtain the lipopolysaccharide preparation. However, this technique relates to harsh chemical methods, leads to a change in original molecular organization of biopolymer, violating its structure and biological properties. Modern technologies in the development of diagnostic kits for the immunosuspension reaction of volume agglomeration allow for obtaining synthetic carriers with different reaction groups on the particle surface capable to bind antigens/antibodies. The aim of this study was to construct cholera antigenic polymeric diagnostic kit based on the lipopolysaccharide of Vibrio cholerae O1 serogroup. Materials and methods. The lipopolysaccharide was used as a sensitizer obtained through the author's modification of enzymatic purification from the cell membranes of Vibrio cholerae using ultrasonic disintegration. Results and discussion. The resulting sensitin contains small impurities of protein (1.5 %) and nucleic acids (0.1 %). Diagnosticum is characterized by high analytical sensitivity in agglomeration reaction with commercial and experimental rabbit serum to Vibrio cholerae O1 serogroup (1:640 - 1:5120) and analytical specificity (the diagnosticum does not interact with heterologous sera, with serums to pathogens of acute intestinal infections, as well as with sera from healthy donors). A polymeric antigenic cholera diagnosticum designed to detect antibodies to lipopolysaccharide of Vibrio cholerae in the blood serum of patients who were ill, suspected of the disease or vaccinated people has been constructed

Polimeric Immunoglobulin Diagnosticum for Detection of Cholera Toxin and Assessing the Level of Its Production by Vibrios

A marker of the epidemic significance of Vibrio cholerae is their toxigenicity. Therefore, much attention is currently paid to the creation of diagnostic preparations for the detection of cholera toxin and assessment of the level of its production. The volumetric immunosuspension agglomeration reaction, carried out with the help of latex diagnosticums, is an analogue of the indirect hemagglutination reaction, an affordable and technically simple method, since it does not require special equipment and can be used when conducting research in the field. The aim of the study was to design a polymeric immunoglobulin diagnosticum for determining cholera toxin and the level of its production by vibrio strains. Materials and methods. Cholera toxin was obtained from the producer strain Vibrio cholerae Classical 569 B. Rabbit serum to the toxin was obtained according to the method selected by the authors. A polymeric diagnostic immunoglobulin antitoxic drug was obtained through sensitizing immunoglobulins from cholera antitoxic rabbit serum on the surface of polyacrolein microspheres with a size of (1±0.1) μm. Results and discussion. The analytical sensitivity of the developed diagnostic preparation with control cholera toxin is 100 ng/ml. It detects cholera toxin in toxigenic strains of Vibrio cholerae in a titer of 1:16 – 1:512, gives negative results with non-toxigenic strains of V. cholerae O1, V. Cholerae nonO1/nonO139, with samples of heterologous cultures, LPS preparations, liquid nutrient medium used for the cultivation of V. cholerae. Thus, a polymeric immunoglobulin diagnosticum has been constructed to detect and quantify the production of cholera toxin by vibrio strains, and its analytical sensitivity and specificity have been established

The Role of Vesicles in Transporting of Cholera Toxin

The review reports on the secretion pathways of the main virulence factor of Vibrio cholerae, cholera toxin, both through the two-stage Sec-dependent type 2 secretion system and with the help of vesicles of the outer membrane of V. cholerae. The ways of toxin transfer into the host organism, depending on its form, are discussed. The well-studied free soluble cholera toxin is secreted extracellularly and transmitted in a GM1-dependent manner through cholesterolrich lipid rafts. The transfer of cholera toxin associated with vesicles has advantages over free toxin, because substances inside the outer membrane vesicles are protected from external proteases and host antibodies by the membrane that forms the vesicle. Vesicular transporting of cholera toxin into the target cell occurs via clathrin-dependent, caveolin-dependent and lipid raft-dependent endocytosis. The specific transport route is determined by the structure of the vesicles. Clathrindependent endocytosis is described for V. cholerae strains cultivated at low osmolarity of the medium, whose outer membrane vesicles contain the cholera toxin subunit A inside. Lipid raft-dependent endocytosis is characteristic of vesicles in which cholera toxin is located on the surface. In addition, endocytosis of V. cholerae outer membrane vesicles through structures known as caveolae is presented

Пенолиты – новый тип эндогенных горных пород (о. Бельковский, Россия)

The results of a comprehensive study of a slag-like sideritolite, a representative of a previously unknown genetic type of rock, are summarized. The nano- microstructural features, chemical composition, trace elements, the constitution and the spectroscopic properties of the pore-forming and accessory minerals were investigated. Using the mineralogical and ontogenetic method, the history of rock formation was defined. Penoliths, the slag-like sideritolite, may be identified as a new genetic type of endogenous rocks formed directly in the bubbly foam.Обобщены результаты комплексного изучения шлакоподобного сидеритолита – представителя ранее неизвестного генетического типа горных пород. Исследованы наномикроструктурные особенности, химический состав, микроэлементы, конституция и спектроскопические свойства породообразующих и акцессорных минералов. С использованием минералого-онтогенического метода расшифрована история образования породы, сделан вывод о том, что шлакоподобный сидеритолит может быть определен как представитель нового генетического типа эндогенных горных пород – пенолитов, образующихся непосредственно в пузыристой пене

Analysis of Multiple Infection in Ixodic Ticks <i>Dermacentor reticulatus</i> in a Combined Natural Focus of Vector-Borne Infections in the Tomsk Region

The aim of the study was to characterize mono- and mixed infection with causative agents of vector-borne infections in Dermacentor reticulatus ticks inhabiting one of the anthropourgic foci of the Tomsk Region. Materials and methods. D. reticulatus ticks were collected from vegetation “on the flag” in the forest park zones of the southern part of Tomsk in August and September, 2020–2021. To isolate nucleic acids from homogenates of mites and subsequent PCR diagnostics, kits of the RealBest series (“Vector-Best”, Novosibirsk) were used. 184 individual samples of nucleic acids were examined for the presence of molecular-genetic markers of tick-borne encephalitis virus (TBEV), pathogenic borrelia, babesia, rickettsia, anaplasma, and ehrlichia. Results and discussion. The spectrum of pathogens detected through PCR assay of ticks collected in one of the anthropurgic foci of the Tomsk Region in 2020 and 2021 includes TBEV, pathogenic borrelia, rickettsia, and babesia. The highest rate of D. reticulatus infection has been established in relation to candidate pathogens of tick-borne rickettsioses (Rickettsia sp.) and babesioses (Babesia sp.). The overall frequency of co-infection in D. reticulatus was 12.88 %. Seven different associations of pathogens infecting D. reticulatus have been identified. The majority (88.24 %) of the detected cases of mixed infection were rickettsia associations. Double infection has been registered in 94 % of the total number of mixed variants. Markers of four tick-borne infection pathogens simultaneously (Rickettsia species DNA, Babesia species DNA, Borrelia burgdorferi s.l. DNA and TBEV RNA) have been found in one sample. Changes in areal of the D. reticulatus against the background of an increase in their numbers, determines the need to analyze the epidemiological significance of the ticks of this species in combined foci of tick-borne infections, especially in the zone of sympatry with ixodic ticks of other species

Evaluation of Biological Properties of New Selective Differential Medium for Cholera Vibrios Isolation Based on the Results of Laboratоry Trials

Previously developed selective differential medium for V. cholerae growth was modernized. The modernized medium called SDMV-M was shown to possess the required sensitivity and germination index. The growth of E. coli was entirely inhibited, that of P. vulgaris was inhibited considerably. The medium possessed good differentiating ability: orange V. cholerae colonies were clearly distinguished from concomitant microorganisms. In the laboratory trials SDMV-M demonstrated some advantages as regards V. cholerae isolation from contaminated faeces in comparison with the reference medium TCBS