67 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
Forming of Students Valeological Culture in Studying of Natural-Science Disciplines (by Example of Physics Course)
The article is devoted to the problem of valeological culture education in the process of studying of natural-science disciplines at school. The importance of developing skills aimed at the development of a healthy lifestyle in the process of realization of intersubject links on the example of studying of a school course of physics is noted. It is shown that in explaining to students the physical laws of nature, phenomena and processes the most appropriate is the use of specific examples, including the area of valeology, which not only broaden pupils’ outlook, but also affect the development of their culture of health. The article focuses on pedagogical techniques, allowing the teacher to develop individual abilities of students and create an atmosphere of success for each student both in the classroom and in extracurricular time in self-preparation for classes. Different forms of work are described that students can fulfill implementing interdisciplinary links between valeology and physics: self-dependent development of physics tasks using valeology material, writing essays, making presentations, preparing reports, making visual teaching aids, etc. It is concluded that this work allows the learner not only to accumulate knowledge about health care, but also to apply them in practice
ПЕРВЫЙ КЛИНИЧЕСКИЙ ОПЫТ ПРИМЕНЕНИЯ КОЛОНОК ДЛЯ ЛПС-АДСОРБЦИИ «ТОКСИПАК» В ЛЕЧЕНИИ ПАЦИЕНТОВ С СЕПСИСОМ
Endotoxicosis is one of the main factors of the pathogenesis of multiple organic dysfunctions in gram-negative sepsis, induced by the accumulation of lipopolysaccharides - wall components of gram-negative bacteria. In vitro removal of them (LPS-adsorption) promotes better treatment outcomes in sepsis patients. Development and introduction of the Russian tools for LPS-adsorption becomes more crucial. Objective: to evaluate the efficiency and safety of the column of Toxipak for endotoxin removal, manufactured by POCARD Ltd. Materials and methods: 7 adult sepsis patients who had LPS-adsorption were included into the study. The changes of the following parameters were monitored in the patients: temperature, pulse, arterial pressure, respiration rate, central venous pressure, oxygen saturation, hourly rate of diuresis, oxygenation index was calculated, hematologic and biochemical blood parameters were tested as well as coagulation system rates, endotoxin level, C-reactive protein (CRP), procalcitonin, and interleukins (IL) 1, 6, 8. Criteria of the system inflammatory response and SOFA score were used for the comprehensive evaluation of clinical status. The adverse events, duration of stay in the intensive care ward and 18- and 24-day mortality were followed up during manipulations. Results: the studied column provided no negative effect on the cellular and biochemical composition, main parameters of clotting system and acid-base balance of blood. Its use resulted in the reduction of endotoxin (LPS) (by 64%), CRP (by 14%), IL-1 (by 38%) in blood, increase of oxygenation index, and renal function improvement. LPS adsorption promoted the reduction of clinical and laboratory signs of system inflammatory response, and severity of organ dysfunction (from 6.0 to 3.0 as per SOFA score) in patients with sepsis and septic shock. Conclusion: Toxipak column is safe and efficient for removal of endotoxins from blood. Одним из основных факторов патогенеза множественной органной дисфункции при грамотрицательном сепсисе является эндотоксикоз, обусловленный накоплением липополисахаридов – компонентов стенки грамотрицательных бактерий. Их экстракорпоральное удаление (ЛПС-адсорбция) способствует улучшению результатов лечения пациентов с сепсисом. Разработка и внедрение в практику отечественных устройств для ЛПС-адсорбции является актуальной задачей. Цель: провести оценку эффективности и безопасности колонок «Токсипак» для удаления эндотоксинов производства ЗАО НПФ «ПОКАРД». Материал и методы: в исследование включено 7 взрослых пациентов с сепсисом, которым выполнено 10 ЛПС-адсорбций. У пациентов в динамике измеряли температуру тела, пульс, артериальное давление, частоту дыхания, центральное венозное давление, сатурацию кислорода, почасовой темп диуреза, рассчитывали индекс оксигенации, в крови определяли гематологические и биохимические показатели, показатели системы свертывания, уровень эндотоксина, С-реактивного белка (СРБ), прокальцитонина, интерлейкинов (ИЛ) 1, 6, 8. Для интегральной оценки клинического статуса использовали критерии системной воспалительной реакции и шкалу SOFA. Оценивали нежелательные явления в ходе проведения процедур, длительность пребывания в отделении реанимации и интенсивной терапии, 14- и 28-дневную летальность. Результаты: изученные колонки не оказывали отрицательного влияния на клеточный и биохимический состав крови, основные показатели системы свертывания и кислотно-основное состояние крови. В результате их использования в крови достоверно уменьшилась концентрация эндотоксинов (ЛПС) (на 64%), СРБ (на 14%) и ИЛ-1 (на 38%), повысился индекс оксигенации, улучшилась функция почек. ЛПС-адсорбция способствовала ослаблению клинических и лабораторных проявлений системной воспалительной реакции, снижению выраженности органной дисфункции (с 6,0 до 3,0 баллов по шкале SOFA) у пациентов с сепсисом и септическим шоком. Вывод: колонки «Токсипак» эффективно удаляют из крови эндотоксины и являются безопасными.
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
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
Evolution of waves induced by periodic variations of pressure in a bounded basin of variable depth
Possibilities of boron neutron capture therapy in the treatment of malignant brain tumors
Boron neutron capture therapy (BNCT) that is of the highest attractiveness due to its selective action directly on malignant tumor cells is a promising approach to treating cancers. Clinical interest in BNCT focuses in neuro-oncology on therapy for gliomas, glioblastoma in particular, and BNCT may be used in brain metastatic involvement. This needs an epithermal neutron source that complies with the requirements for BNCT, as wellas a 10B-containing agent that will selectively accumulate in tumor tissue. The introduction of BNCT into clinical practice to treat patients with glial tumors will be able to enhance therapeutic efficiency
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