71 research outputs found
Specific Absorption Rate of Assembly of Magnetite Nanoparticles with Cubic Magnetic Anisotropy
The presence of strong magnetic dipole interaction in assemblies of fractal clusters of nearly spherical magnetite nanoparticles, which arise in a biological media loaded with magnetic nanoparticles, leads to a significant decrease of the specific absorption rate of these assemblies in alternating magnetic field. However, the specific absorption rate of the assembly can be increased if the nanoparticles are covered by non magnetic shells of sufficiently large thickness comparable with the nanoparticle diameter.
Keywords: Magnetite nanoparticles, Magneto- dipole interaction, Specific absorption rate, Numerical simulatio
The role of Drosophila Merlin in spermatogenesis
<p>Abstract</p> <p>Background</p> <p><it>Drosophila </it>Merlin, the homolog of the human <it>Neurofibromatosis 2 </it>(<it>NF2</it>) gene, is important for the regulation of cell proliferation and receptor endocytosis. Male flies carrying a <it>Mer</it><sup>3 </sup>allele, a missense mutation (Met<sup>177</sup>→Ile) in the <it>Merlin </it>gene, are viable but sterile; however, the cause of sterility is unknown.</p> <p>Results</p> <p>Testis examination reveals that hemizygous <it>Mer</it><sup>3 </sup>mutant males have small seminal vesicles that contain only a few immotile sperm. By cytological and electron microscopy analyses of the <it>Mer</it><sup>3</sup>, <it>Mer</it><sup>4 </sup>(Gln<sup>170</sup>→stop), and control testes at various stages of spermatogenesis, we show that <it>Merlin </it>mutations affect meiotic cytokinesis of spermatocytes, cyst polarization and nuclear shaping during spermatid elongation, and spermatid individualization. We also demonstrate that the lethality and sterility phenotype of the <it>Mer</it><sup>4 </sup>mutant is rescued by the introduction of a wild-type <it>Merlin </it>gene. Immunostaining demonstrates that the Merlin protein is redistributed to the area associated with the microtubules of the central spindle in telophase and its staining is less in the region of the contractile ring during meiotic cytokinesis. At the onion stage, Merlin is concentrated in the Nebenkern of spermatids, and this mitochondrial localization is maintained throughout sperm formation. Also, Merlin exhibits punctate staining in the acrosomal region of mature sperm.</p> <p>Conclusion</p> <p><it>Merlin </it>mutations affect spermatogenesis at multiple stages. The Merlin protein is dynamically redistributed during meiosis of spermatocytes and is concentrated in the Nebenkern of spermatids. Our results demonstrated for the first time the mitochondrial localization of Merlin and suggest that Merlin may play a role in mitochondria formation and function during spermatogenesis.</p
Dialogue between Journalistic Generations as a Factor in the Formation of the Students- Communicative and Cultural Memory
В статье анализируется роль диалога журналистских поколений как фактора формирования коммуникативно-культурной памяти студентов. Методы и методология разработаны на основании работ Я. Ассмана, М. Халбвакса, М. Ю. Лотмана и др. Специфика исследования заключается в том, что в его основе лежит обучающий проект «Диалог журналистских поколений». Параллельно ему в течение 2017–2020 гг. проводилось анкетирование его 420 участников. Результаты исследования были обработаны соответствующими статистическими методами. Они помогли дать ответы на ряд важных вопросов, а также привели нас к выводу о том, что межпоколенческий диалог журналистов способствует социализации и формированию идентичности учащейся молодежи.In this article the authors analyze the role of dialogue between journalistic generations as a factor in the formation of the students - communicative and cultural memory. Methods and methodology are developed on the basis of the works of J. Assman, M. Halbwax, Yu. Lotman and others. The specificity of the study lies in the fact that it is based on the training project “Dialogue of Journalistic Generations”. Parallel to it during 2017-2020 questioning of its 420 participants was conducted. The results of the study were processed by appropriate statistical methods. They helped to get answers to a number of important questions, and also led us to the conclusion that the intergenerational dialogue of journalists promotes socialization and the formation of the identity of students
Achievement of maximal SARS-CoV-2 collective immunity among the Tajik population by March 2022
Despite all efforts of the world community, the COVID-19 pandemic remains one of the main epidemiological challenges of our time. Even with its widespread distribution, the infection may have certain local features due to social, geographic, and climatic factors. Objective: to study collective immunity to SARS-CoV-2 in the population of the Republic of Tajikistan.A cross-sectional, randomized study of herd immunity was carried out according to a program developed by Rospotrebnadzor and the St. Petersburg Pasteur Institute, taking into account WHO recommendations. The ethics committees of the corresponding entities approved the study: Tajik Ministry of Health and Social Protection; and the St. Petersburg Pasteur Institute (Russia). Based on questionnaire results, 4,022 people were selected, representing 0.15% (95% CI: 0.14-0.15) of the total population randomized by age and region. In subsequent laboratory analysis, 3682 people took part. The distribution and quantitative content of antibodies (Abs) to viral nucleocapsid (N Ag) and receptor binding domain (RBD Ag) were determined by ELISA. When questioned, a history of SARS-CoV-2 vaccination was indicated by 69.7% (95% CI: 68.2-71.2) of the volunteer cohort. Vector vaccines were most frequently used (50.6%; 95% CI: 48.7-52.5), with whole-virion inactivated preparations in second place (23.0%: 95% CI: 21.4-26.6) and mRNA vaccines in third place (21.0%; 95% CI:19.4-22.6).The cohort (n = 3682) featured 27.5% men and 72.5% women. The overall seroprevalence was 98.5% (95% CI: 97.7-99.2) in men and 99.4% (95% CI: 99.0-99.6) in women (differences statistically insignificant). Overall seroprevalence in the cohort was 99.2% (95% CI: 98.8-99.4) and ranged from 97.2 to 100% in certain subgroups. Asymptomatic seropositivity in the whole cohort was 98.4% (95% CI: 97.6-99.1). As a result of a mandatory vaccination program introduced in Tajikistan under a COVID-19 Emergency Project, the level of herd immunity among vaccinated individuals reached 99.5% (95% CI: 99.1-99.7), which is similar to the level reached in the cohort as a whole.The epidemic situation that developed in Tajikistan by mid-March 2022 was characterized by an almost absolute level of herd immunity, as evidenced by an absence of detected overt COVID-19 cases since the end of February (2022)
Сравнение эффектов селективной плазмофильтрации, плазмодиафильтрации с системами MARS и Prometheus при лечении печеночной недостаточности
The mortality of patients with hepatic failure remains high. Often the patient's life can be saved only with extracorporeal liver support (ELS). ELS systems – MARS® и Prometheus® have proved their efficacy but their widespread use is constrained by their very high cost. Introduction in clinical practice of new affordable ELS systems is a topical issue. The objective: to compare clinical and laboratory effects of selective plasma exchange (SPE), plasmadialfiltration (PDF) with use of the selective membrane plasma separators EvaclioTM and MARS® and Prometheus® (FPSA) systems in the treatment of liver failure. Subjects and methods: 15 extracorporeal procedures of each type were performed in 52 patients with acute liver failure (14) and acute-on-chronic liver failure (38): MARS, FPSA, PDF, SPE with use of Evaclio ЕС-2C, and ЕС-3C, ЕС-4C. The clinical and laboratory parameters (total, direct and indirect bilirubin, total protein, albumin, creatinine, urea, etc.), severity of the condition according to MELD score were determined before and after the session and the next morning. Changes, side effects and complications of procedures were assessed and compared. Results. Reduction of concentration of direct bilirubin was comparable with FPSA, PDF and SPE on Evaclio ЕС-3C20 и ЕС-4C20 (38-42%), indirect bilirubin – with PDF and SPE on Evaclio ЕС-3C20 и ЕС-4C20 (29-34%). Low-molecular metabolites (urea, creatinine) were better removed with FPSA (35-44%) and PDF (40-42%). The reduction of their concentration with SPE was insignificant. The reduction of albumin level was the highest with FPSA (10.2%) and SPE on Evaclio ЕС-4C20 (14.3%). All investigated ELS methods did not exert a significant influence on the basic parameters of blood coagulation and quantity of blood cells. No side effects and complications were observed. Conclusion: Selective plasma exchange and plasmadiafiltration are generally comparable in clinical and laboratory effects in the treatment of liver failure with MARS and Prometheus system provided significantly lower costs.Летальность пациентов c печеночной недостаточностью остается высокой. Часто спасение жизни пациента возможно только с использованием экстракорпоральной детоксикации (ЭКД). Системы экстракорпоральной поддержки печени MARS® и Prometheus® продемонстрировали свою эффективность, однако их широкому использованию препятствует очень высокая стоимость. Внедрение в клиническую практику новых, более доступных методов ЭКД является актуальной задачей. Цель: сравнение клинических и лабораторных эффектов процедур селективной плазмофильтрации (СПФ), плазмодиафильтрации (ПДФ) с использованием фракционаторов плазмы EvaclioTM, систем MARS® и Prometheus® (FPSA) при лечении печеночной недостаточности. Материалы и методы: 52 пациентам с острой (14) и декомпенсацией хронической печеночной недостаточности (38) выполнено по 15 экстракорпоральных процедур: MARS, FPSA, ПДФ, СПФ с использованием фракционаторов Evaclio ЕС-2C, ЕС-3C, ЕС-4C. До, сразу после и на следующее утро исследовались клинические и лабораторные (билирубин и фракции, общий белок, альбумин, мочевина, креатинин и др.) показатели, тяжесть состояния по шкале MELD. Оценивались и сравнивались их динамика, побочные эффекты и осложнения процедур. Результаты. Уменьшение концентрации прямого билирубина было сравнимо при FPSA, ПДФ и СПФ на Evaclio ЕС-3C20 и ЕС-4C20 (38‒42%), непрямого билирубина – при ПДФ и СПФ на Evaclio ЕС-3C20 и ЕС-4C20 (29‒34%). Низкомолекулярные метаболиты (мочевина и креатинин) лучше всего удалялись при FPSA (35‒44%) и ПДФ (40‒42%). Снижение их концентрации при СПФ было незначительным. Снижение уровня альбумина было наибольшим при FPSA (10,2%) и СПФ на Evaclio ЕС-4C20 (14,3%). Все исследованные методы ЭКД не оказывали существенного влияния на основные показатели системы свертывания и клеточный состав крови. Побочных реакций и осложнений не отмечено. Вывод. СПД и ПДФ по клиническим и лабораторным эффектам не уступают системам MARS® и Prometheus® при существенно меньшей стоимости
A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas : the PERSEUS experience
PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern
European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good
Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary
approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge
gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal
areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also
independently performed. The comparison between meta-analysis results and IAs shows similarities
for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food
web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification
of additional research themes targeting research topics that are requested to the achievement of GES.
2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.peer-reviewe
ANALYTICAL MODEL FOR LONG-TERM DEFORMATION OF A REINFORCED CONCRETE ELEMENT WITH CORROSION DAMAGE IN PLANE STRESS STATE AT THE CONTACT AREA BETWEEN CONCRETES OF VARIOUS GRADES
The paper considers the development of an analytical model for long-term deformation of a reinforced concrete element with corrosion damage in plane stress state at the contact area between concretes of various grades on the basis of known stress-strain relations and parameters for reinforced concrete in a complex stress state with cracks. The derived flexibility matrix elements allow for taking into account long-term deformation, corrosion damage and shear in contact area between concretes of various grades. The authors give an example of a layered reinforced concrete beam calculation. The results of the calculation have been compared with an experimental study data
STRENGTH CRITERIA FOR CONCRETE WITH CORROSION DAMAGE IN COMPLEX STRESS STATE
Introducing the hypothesis of colmatation conversion of concrete structure with corro- sion damage with stabilization at any ultimate depth of damage, the authors have built a strength criterion of the concrete under complex stress state. In the coordinate system of the principal normal stresses, this criterion describes the surface of the ellipsoid, the characteristic dimensions of which are primarily dependent on the kinetics of corrosion processes in time and depth of neutralization. The presented criterion can be used for solution of problems of the survivability of reinforced concrete structural systems under conditions of simultaneous mani- festation of power and environmental impacts
Kriging-boosted CR modeling for prompt infill drilling optimization
The capacitance-resistance model (CRM) has been a useful physics-based tool for obtaining production forecasts for decades. However, the model's limitations make it difficult to work with real field cases, where a lot of various events happen. Such events often include new well commissioning (NWC). We introduce a workflow that combines CRM concepts and kriging into a single tool to handle these types of events during history matching. Moreover, it can be used for selecting a new well placement during infill drilling. To make the workflow even more versatile, an improved version of CRM was used. It takes into account wells shut-ins and performed workovers by additional adjustment of the model coefficients. By preliminary re-weighing and interpolating these coefficients using kriging, the coefficients for potential wells can be determined. The approach was validated using both synthetic and real datasets, from which the cases of putting new wells into operation were selected. The workflow allows a fast assessment of future well performance with a minimal set of reservoir data. This way, a lot of well placement scenarios can be considered, and the best ones could be chosen for more detailed studies
Neutralizing antibodies to botulinum neurotoxin type A in aesthetic medicine: five case reports
Sebastian Torres,1 Mark Hamilton,2 Elena Sanches,4 Polina Starovatova,3 Elena Gubanova,3 Tatiana Reshetnikova51Di Stefano Velona Clinic, Catania, Italy; 2Hamilton Face Clinic, Dublin, Ireland; 3Preventive Medicine Clinic "Vallex M", Moscow, Russia; 4EKLAN Co Ltd Medical Center for Aesthetic Correction, Moscow, Russia; 5Department of Dermatovenereology and Cosmetology, State Medical University, Novosibirsk, RussiaAbstract: Botulinum neurotoxin injections are a valuable treatment modality for many therapeutic indications as well as in the aesthetic field for facial rejuvenation. As successful treatment requires repeated injections over a long period of time, secondary resistance to botulinum toxin preparations after repeated injections is an ongoing concern. We report five case studies in which neutralizing antibodies to botulinum toxin type A developed after injection for aesthetic use and resulted in secondary treatment failure. These results add to the growing number of reports in the literature for secondary treatment failure associated with high titers of neutralizing antibodies in the aesthetic field. Clinicians should be aware of this risk and implement injection protocols that minimize resistance development.Keywords: aesthetic medicine, botulinum neurotoxin type A, neutralizing antibody, secondary treatment failur
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