54 research outputs found
Oil and gas presence perspectives of weathering layer reservoir of Nurol'ka mega-basin according to data of geothermics
Oil perspective areas of the Nurol'ka mega-basin (south-east of Western Siberia) through the M formation (Permian-Triassic weathering crust) on the basis of the results application of geothermometry were identified. Accumulating power distribution and quality of the M formation collectors were taken into account. The priority area for research are weathering layer reservoirs and its development that cover the South beads of Kulan-Igayskaya and Tamradskaya basins and its insulation joint were proposed. Glukhov's oil field that is located in this area approve its high prospectivity
Changes in the antigenic and genetic structure of influenza viruses: analysis of surveillance data of influenza A and B in Russia in 2006-2013
The goal of this research project was to study the natural variability of human influenza A and B viruses based on the analysis of the population structure of influenza viruses, circulating in Russia in 2006-2013, in order to determine the direction of their genetic and antigenic drift by comparison to the WHO reference strains. Our results proved that during that period significant changes occurred in the genetic structure of influenza viruses, their phylogenetic affiliation, as well as their sensitivity to antiviral drugs. According to the surveillance data, the percentage of influenza A(H1N1) viruses among patients with influenza-like illness or acute respiratory infection gradually decreased from 42% of the total number of influenza viruses in 2006-2007 to 19% in 2008- 2009. Influenza A(H1N1) viruses are characterized by «silent» variability that manifests in the gradual accumulation of amino acid substitutions in the minor undetectable group of viruses.The share of influenza A(H3N2) viruses varied from 10% in the 1st post pandemic year to approx. 60% in 2008-2009 and 2011- 2012 epidemic seasons. All of the influenza A strains isolated during the last years of the period, covered in this study, were found to be susceptible to neuraminidase inhibitors and resistant to adamantane antivirals.Influenza B viruses of both Yamagata and Victoria lineages circulated in Russia in the period from 2006 to 2013. The vast majority of these influenza B viruses belonged to the Victoria lineage. Phylogenetic and antigenic analyses of influenza B viruses have demonstrated a gradual drift of Russian isolates from the reference strains. No changes leading to resistance to oseltamivir or zanamivir were found in influenza B strains isolated until 2013.The goal of this research project was to study the natural variability of human influenza A and B viruses based on the analysis of the population structure of influenza viruses, circulating in Russia in 2006-2013, in order to determine the direction of their genetic and antigenic drift by comparison to the WHO reference strains. Our results proved that during that period significant changes occurred in the genetic structure of influenza viruses, their phylogenetic affiliation, as well as their sensitivity to antiviral drugs. According to the surveillance data, the percentage of influenza A(H1N1) viruses among patients with influenza-like illness or acute respiratory infection gradually decreased from 42% of the total number of influenza viruses in 2006-2007 to 19% in 2008- 2009. Influenza A(H1N1) viruses are characterized by «silent» variability that manifests in the gradual accumulation of amino acid substitutions in the minor undetectable group of viruses. The share of influenza A(H3N2) viruses varied from 10% in the 1st post pandemic year to approx. 60% in 2008-2009 and 2011- 2012 epidemic seasons. All of the influenza A strains isolated during the last years of the period, covered in this study, were found to be susceptible to neuraminidase inhibitors and resistant to adamantane antivirals. Influenza B viruses of both Yamagata and Victoria lineages circulated in Russia in the period from 2006 to 2013. The vast majority of these influenza B viruses belonged to the Victoria lineage. Phylogenetic and antigenic analyses of influenza B viruses have demonstrated a gradual drift of Russian isolates from the reference strains. No changes leading to resistance to oseltamivir or zanamivir were found in influenza B strains isolated until 2013
Structural features and formation of lower Cretaceous AV[1] layer in the Soviet oil field (Tomsk Oblast)
The analysis of the collected geological and geophysical information on AV[1] layer known as Ryabchik formation is carried out. The facial conditions of this formation which define structural features of "Ryabchik" sandstones formations are considered. Maps characterizing permeability and porosity of reservoir are plotted. Areal tracking technique of sand streaks is given
Поражения сердца у детей на фоне течения COVID-19
Ongoing research on SARS-CoV-2 showed the ability of a pathogen to affect cardio-vascular system in the form of myocarditis, dysrhythmia, cardiac failure, etc. According to an infectious diseases hospital in Omsk, changes in the heart were recorded in 3.3% of children hospitalized with COVID-19. Authors conducted a retrospective study of 24 children aged 1—17 years 11 months with a new coronavirus infection who recieved treatment in an infectious diseases hospital at the Budgetary Healthcare Institution of Omsk Oblast City Children's Clinical Hospital №3 in Omsk from October 2020 to December 2021. It was found that heart lesions were more often recorded in children over 10 years old, all males. In most patients, cardiac lesions developed in presence of concomitant pathology and were combined with lung damage. Clinical manifestations indicating involvement in the pathological process of the cardiovascular system appeared in addition to respiratory infection. They were mild and nonspecific.Продолжающиеся исследования в отношении SARS-CoV-2 показали возможность возбудителя поражать сердечно-сосудистую систему в виде миокардитов, нарушений ритма, сердечной недостаточности и др. По данным инфекционного стационара г. Омска, изменения со стороны сердца регистрировались у 3,3% госпитализированных детей с COVID-19. Материалы и методы. Было проведено ретроспективное исследование историй болезни 24 детей в возрасте от 1 года до 17 лет 11 месяцев с новой коронавирусной инфекцией, находившихся на лечении в инфекционном стационаре БУЗОО ГДКБ №3 г. Омска в период с октября 2020 года по декабрь 2021 г. Результаты. Было выявлено, что поражения сердца чаще регистрируются в группе детей старше 10 лет, мужского пола. У большинства пациентов поражения сердца развивались на фоне сопутствующей патологии и сочетались с поражением легких. Клинические проявления, свидетельствующие о вовлечении в патологический процесс сердечно-сосудистой системы, появлялись на фоне респираторной инфекции, были слабо выражены и неспецифичны
Consistency in fruit preferences across the geographical range of the frugivorous bats Artibeus , Carollia and Sturnira (Chiroptera)
The mechanisms of antibiotic resistance in major pathogens of purulent-inflammatory complications in cancer patients
The problem of microbial antibiotic resistance and investigation of its underlying mechanisms is of paramount importance for all fields of clinical medicine, including oncology. The aim of the study was to examine the mechanisms of antibiotic resistance for major pathogens causing purulent-inflammatory complications in cancer patients. Materials and methods. In 2012—2015 there was conducted a prospective examination of 184 cancer patients, including 67 patients at the Department of Surgery no. 1 and 117 patients at the Intensive Care Unit of the Krasnoyarsk Regional Clinical Oncology Center named after A.I. Kryzhanovsky. For this, we collected bronchoalveolar lavage fluid, wound discharge and investigated the material by using bacteriological method, as well as MALDI-TOF. Antibiotic sensitivity was studied as follows: disco-diffusion, double disc method, carbapenem inactivation method, staphylococcal sensitivity — by screening method, PCR, E-test method, and serial dilutions in Muller-Hinton broth. Genotyping and antibiotic resistance mechanisms study were performed by using PCR, M-PCR, and sequencing. The WHONET program (WHO) was used, with significance level set at p < 0.05. Results. Microbiological examination of bronchoalveolar lavage fluid and wound discharge samples allowed to uncover prevalent associations of multi-resistant (MDR) and extremely resistant pathogens (XDR). The microflora of the lower respiratory tract and in the wound secretion in cancer patients were found to be dominated by non-fermenting Gram-negative bacteria reaching up to 44.5% and 48%, respectively; as well as order Enterobacteriales found in 24% and 34.9%, respectively; Gram-positive bacteria — 24% and 17.1%, respectively. Imipenem- and/or meropenem-resistant P. aeruginosa and A. baumannii, K. pneumoniae strains, were assessed for MBL production phenotypically, as well as the genes of the most common VIM, IMP types, whereas A. baumannii — for OXA-23, OXA-40, and OXA-58; and K. pneumoniae — for OXA-48. 20 strains and 16 strains of P. aeruginosa and A. baumannii, respectively, were studied by PCR. It was found that A. baumannii strains formed no MBL, but 56.3% of A. baumannii isolates (9 strains) produced OXA-23 and OXA-40 carbapenemases. Among P. aeruginosa strains there were three of them which possessed VIM (15.0%), whereas the remaining strains formed no MBL, but were resistant to carbapenems being associated with other resistance mechanisms, e.g. efflux, decreased permeability of cell wall etc. Among 6 isolates of K. pneumoniae, 1 strain produced OXA-48. In cancer patients, the percentage of methicillin-resistant strains among all members of the genus Staphylococcus was 48.9% (4 strains belonged to MRSA). PVL- MRSA strains belonged to the clones ST239/spa3(t037)/SCCmecIIIA/tst,sek,seq+ (75%) and ST8/ spa1(t008)/SCCmecIVc/sea+ (25%). MRSA ST239 showed multiple antibiotic resistance: to aminoglycosides (aacA-aphD, aadD genes were detected), linkcosamides/macrolides (the ermA gene was detected), fluoroquinolones (mutations in the GyrA gene — Ser84Leu; in GrlA- Ser80Phe), rifampicin (MIC more than 128 gg/ml; mutations in the rpoB gene are His481Asn, Ile527Met), sulfamethoxazole, tetracycline (tetM gene), and chloramphenicol (66.7% of isolates, the cat gene encoding chloramphenicol acetyl transferase was detected); but sensitive to vancomycin (MIC 1.0 gg/ ml), linezolid in 100% of cases. MRSA ST8 are resistant to aminoglycosides (aacA-aphD, aadD genes), lincosamides/macrolides (ermC gene), tetracyclines (tetK gene), chloramphenicol (cat gene); and 100% sensitive to fluoroquinolones, rifampicin (MIC 0.006 gg/ml), sulfamethaxazole, vancomycin (MIC 1.0 gg/ml), daptomycin (MIC 0.094 gg/ml), linezolid (MIC 0.75 gg/ml). Conclusion. Thus, it was found that members of the order Enterobacteriales, A. baumannii, P. aeruginosa and MRSA retain high resistance to a large number of antibacterial drugs of almost all classes. These data should be taken into account while choosing proper antibiotic therapy, as well as controlling spread of nosocomial infections caused by multiresistant microorganisms
Phyllostomidae assemblage (Chiroptera: Mammalia) in altitudinal forests at the Parque Estadual do Ibitipoca, Southeast of Minas Gerais, Brazil
Антигенное разнообразие вирусов гриппа А и В, выделенных от детей в г. Санкт-Петербурге в период с 2013 по 2015 г.
Purpose of the study: study of the circulation, isolation and antigenic analysis of influenza viruses A and B in St.-Petersburg in the children aged 0–18 in the seasons 2013–2015.Materials: nasal swabs from children-inpatients from Saint-Petersburg.Methods: virus isolation in MDCK cell culture and chicken embryos, antigenic analysis with the hemagglutination inhibition (HAI) test with the set of hyper-immune rat antisera to the epidemic and reference strains, antigenic cartography.Results: The epidemic seasons 2013–2015 were characterized by the co-circulation in children in St.-Petersburg of influenza sub-types А(H1N1)pdm09, A(H3N2), and B of Yamagata lineage (B yam). In the season 2014–2015 the low activity of epidemic process was observed with the predominant sub-type A(H3N2) and in the next season – 2014–2015 with the more pronounced epidemic activity – the pre-dominance of B yam viruses. Antigenic analysis of influenza viruses А(H1N1)pdm09 which circulated in children revealed their antigenic homogeneity and full correspondence with vaccine strain A/California/07/09. As for А(H3N2) viruses, two antigenic groups were established: strains similar to A/St.-Petersburg/80/14 (sub-clade 3C.2a) and strains similar to A/Switzerland/9715293/13 (sub-clade 3C.3a). А(Н3N2) strains of the season 2013-2014 were similar to the vaccine strain. However isolates of the season 2014-2015 did not fit to the vaccine strain because in the children were predominant strains similar to the evolution branch A/St.-Petersburg/80/14 while according the WHO recommendations the influenza vaccine contained the strain A/Texas/50/12. Antigenic analysis of influenza viruses B showed their homogeneity and all they were B/Phuket/3073/13-like. Influenza strains B also incompletely corresponded to the vaccine strain – B/Massachusetts/2/12 belonging to the different genetic sub-clade. That might be the reason of enhanced morbidity of children with influenza B in the last season.Conclusion: The obtained results stress the urgency for the wide coverage of human population with the epidemic studies, virus isolation in different time periods and geographic regions and their etiological studies with the modern techniques. Only in these conditions we can assure high efficiency of flu seasonal vaccines.Цель исследования: особенности циркуляции, выделение и антигенный анализ вирусов гриппа А и В в Санкт-Петербурге в 2013–2015 гг. от детей от 0 до 18 лет.Материалы исследования: назальные мазки от детей из стационаров и закрытых детских учреждений Санкт-Петербурга.Методы: выделение вирусов на культуре клеток MDCK и куриных эмбрионах, антигенный анализ методом реакции торможения гемагглютинации (РТГА) с набором гипериммунных крысиных антисывороток к эталонным и эпидемическим штаммам гриппа, антигенная картография.Результаты: в эпидемические сезоны 2013–2015 гг. в г. Санкт-Петербурге среди детей была выявлена совместная циркуляция вирусов гриппа А(H1N1)pdm09, A(H3N2), B Ямагатской линии (B yam), причем в сезоне 2013–2014 гг. при общей невысокой активности эпидемического процесса преобладали вирусы A(H3N2), а в следующем эпидемическом сезоне – 2014–2015 гг. – при более высокой интенсивности эпидемии – вирусы В yam. Антигенный анализ вирусов А(H1N1)pdm09, циркулировавших среди детей, выявил их антигенную однородность и полное соответствие вакцинному штамму А/Калифорния/07/09. Зафиксирован антигенный дрейф вирусов А(H3N2), выявлены 2 антигенные группы: вирусы, подобные А/Санкт-Петербург/80/14 (генетическая подгруппа 3С.2а) и вирусы, подобные А/Швейцария/9715293/13 (подгруппа 3С.3а). Вирусы А(Н3N2) сезона 2013–2014 гг. были подобны вакцинному штамму. В то же время изоляты сезона 2014–2015 гг. не соответствовали вакцинному штамму, поскольку среди детей в основном выявлены штаммы, подобные эволюционной ветви А/Санкт-Петербург/80/14, а в вакцину по рекомендации ВОЗ был включен штамм А/Техас/50/12. Антигенный анализ вирусов гриппа В yam показал их однородность, они были подобны эталонному вирусу В/Пхукет/3073/13. Вирусы В также антигенно не полностью соответствовали вакцинному компоненту, поскольку данные вирусы были подобны штамму В/Пхукет/3073/13, а в состав вакцины входил штамм В/Массачусетс/2/12, принадлежащий к другой генетической подгруппе, что могло привести к повышению заболеваемости детей гриппом типа В в данном сезоне. Заключение: для своевременного правильного выбора штаммов, входящих в состав сезонных противогриппозных вакцин, по-прежнему актуальной остается задача как можно более широкого охвата населения эпидемиологическими исследованиями, выделения вирусов в разные периоды эпидемического сезона и в разных географических регионах, их антигенный и генетический анализ современными методами
The Missing Part of Seed Dispersal Networks: Structure and Robustness of Bat-Fruit Interactions
Mutualistic networks are crucial to the maintenance of ecosystem services. Unfortunately, what we know about seed dispersal networks is based only on bird-fruit interactions. Therefore, we aimed at filling part of this gap by investigating bat-fruit networks. It is known from population studies that: (i) some bat species depend more on fruits than others, and (ii) that some specialized frugivorous bats prefer particular plant genera. We tested whether those preferences affected the structure and robustness of the whole network and the functional roles of species. Nine bat-fruit datasets from the literature were analyzed and all networks showed lower complementary specialization (H2' = 0.37±0.10, mean ± SD) and similar nestedness (NODF = 0.56±0.12) than pollination networks. All networks were modular (M = 0.32±0.07), and had on average four cohesive subgroups (modules) of tightly connected bats and plants. The composition of those modules followed the genus-genus associations observed at population level (Artibeus-Ficus, Carollia-Piper, and Sturnira-Solanum), although a few of those plant genera were dispersed also by other bats. Bat-fruit networks showed high robustness to simulated cumulative removals of both bats (R = 0.55±0.10) and plants (R = 0.68±0.09). Primary frugivores interacted with a larger proportion of the plants available and also occupied more central positions; furthermore, their extinction caused larger changes in network structure. We conclude that bat-fruit networks are highly cohesive and robust mutualistic systems, in which redundancy is high within modules, although modules are complementary to each other. Dietary specialization seems to be an important structuring factor that affects the topology, the guild structure and functional roles in bat-fruit networks
Local and Landscape Factors Determining Occurrence of Phyllostomid Bats in Tropical Secondary Forests
Neotropical forests are being increasingly replaced by a mosaic of patches of different successional stages, agricultural fields and pasture lands. Consequently, the identification of factors shaping the performance of taxa in anthropogenic landscapes is gaining importance, especially for taxa playing critical roles in ecosystem functioning. As phyllostomid bats provide important ecological services through seed dispersal, pollination and control of animal populations, in this study we assessed the relationships between phyllostomid occurrence and the variation in local and landscape level habitat attributes caused by disturbance. We mist-netted phyllostomids in 12 sites representing 4 successional stages of a tropical dry forest (initial, early, intermediate and late). We also quantitatively characterized the habitat attributes at the local (vegetation structure complexity) and the landscape level (forest cover, area and diversity of patches). Two focal scales were considered for landscape characterization: 500 and 1000 m. During 142 sampling nights, we captured 606 individuals representing 15 species and 4 broad guilds. Variation in phyllostomid assemblages, ensembles and populations was associated with variation in local and landscape habitat attributes, and this association was scale-dependent. Specifically, we found a marked guild-specific response, where the abundance of nectarivores tended to be negatively associated with the mean area of dry forest patches, while the abundance of frugivores was positively associated with the percentage of riparian forest. These results are explained by the prevalence of chiropterophilic species in the dry forest and of chiropterochorous species in the riparian forest. Our results indicate that different vegetation classes, as well as a multi-spatial scale approach must be considered for evaluating bat response to variation in landscape attributes. Moreover, for the long-term conservation of phyllostomids in anthropogenic landscapes, we must realize that the management of the habitat at the landscape level is as important as the conservation of particular forest fragments
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