378 research outputs found

    Sorption Properties of Clay and Pectin-Containing Hydrogels

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    As is known, polymeric polyelectrolyte hydrogels are superabsorbents that are capable of absorbing moisture in amounts many times greater than their own mass. Numerous studies have shown that besides water absorption and retention, they can also be effectively used as sorbents to purify water from heavy metals. In many works, attempts are made to improve the sorption properties of polyelectrolyte hydrogels by creating polymer composites based on them. Organic/inorganic composite materials frequently exhibited desired hybrid performance superior to their individual components and cost-efficient characteristics. The composites derived from natural polysaccharides and inorganic clay minerals are of special interest by virtue of their unique commercial and environmental advantages, which means that the design and development of environmentally friendly superabsorbents, introducing natural ingredients, have long been necessary. In this paper, we consider polymer hydrogels based on a copolymer of acrylic acid and acrylamide filled with pectin and bentonite. The aim of this study is to investigate the influence of chemical conditions on hydrogels and their composites, kinetic, and absorption behavior toward metal ions in the presence of the chelating agent. In this chapter, an investigation of the kinetic patterns of swelling, deswelling, and sorption of the hydrogels and their composites will be presented

    Статистическое изучение конъюнктуры валютного рынка

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    The authors attempted to conduct a statistical study of foreign exchange market and its environment, determined the theoretical basis of the study and aspects of practical application of the obtained results. To achieve this goal, the authors defined the subject of the statistical study of the foreign exchange market environment, structured scorecard to assess the state of the foreign exchange market, indicated the sources of information for the statistical analysis of the foreign exchange market environment in various areas. In the process of writing the article, the authors also used relevant materials on the topic of the research developed and published by the authorized organizations, including the international ones. In the study of the currency market and its situation in various areas the authors identified its importance for the financial stability of the national economy, the relationship with other segments of the fi nancial market, and the impact on macroeconomic indicators of economic development. Special attention was paid to the system of indicators to characterize the currency market environment, which is the methodological basis of the study and analysis of phenomena and processes occurring in the foreign exchange market. The authors compiled and structured a system of statistical indicators for the analysis of the status and development of the currency market in various areas in accordance with the available sources of information. This article discusses the issues related to deriving statistical data about the currency market from offi cial and alternative sources, the assessment of the completeness and reliability of statistical information was conducted, directions to improve statistical monitoring of the foreign exchange segment of the fi nancial market were determined. In the article, considerable attention is paid to the methodology of calculating separate indicators, including derivatives, in accordance with national and international statistical standards. In the study the authors came to the conclusion that currently, primary foreign exchange statistical information is suffi cient for calculating the recommended indicators characterizing the foreign exchange market environment, including supply and demand, and their correlation. In addition, the Bank of Russia has enough statistics to study the current situation with the sources of currency supply and demand in a relatively longer term. The indicators of the currencies turnover, its detailed structure, currency exchange rates, their fluctuations, and the business activity indicators are calculated fully or have the necessary reliable information for their assessment.Авторы статьи предприняли попытку статистического исследования валютного рынка и его конъюнктуры, определили теоретические основы его изучения и аспекты практического применения полученных результатов. Для достижения поставленной цели авторы определили предмет статистического изучения конъюнктуры валютного рынка, структурировали систему показателей для оценки состояния валютного рынка, обозначили источники информации для проведения статистического анализа конъюнктуры валютного рынка по различным направлениям. В процессе работы над статьей авторы широко применяли актуальные материалы по теме исследования, которые разрабатывают и публикуют уполномоченные организации, в том числе международные. В рамках изучения валютного рынка и его конъюнктуры по различным направлениям авторы определили его значение для финансовой стабильности национальной экономики, связь с другими сегментами финансового рынка, влияние на макроэкономические индикаторы развития экономики. Особое внимание было уделено системе показателей для характеристики конъюнктуры валютного рынка, являющейся методологической основой исследования и анализа явлений и процессов, происходящих на валютном рынке. Авторы обобщили и структурировали систему статистических показателей для анализа состояния и развития валютного рынка по различным направлениям в соответствии с имеющимися источниками информации. В статье подробно рассмотрены вопросы, связанные с получением статистических данных о валютном рынке из официальных и альтернативных источников, проведена оценка полноты и достоверности статистической информации, определены направления совершенствования статистического наблюдения за валютным сегментом финансового рынка. В статье значительное внимание уделено методологии расчета отдельных показателей, в том числе производных, в соответствии с национальными и международными статистическими стандартами. В результате проведенного исследования авторы пришли к выводу, что в настоящее время для расчета рекомендуемых показателей, характеризующих конъюнктуру валютного рынка, в том числе спроса и предложения, их соотношения, достаточно имеющейся первичной биржевой статистической информации. Кроме того, в распоряжении Банка России достаточно статистики для исследования складывающейся ситуации с источниками предложения и спроса валюты в относительно более долгосрочной перспективе. Показатели же оборота валют, его детальной структуры, валютных котировок, их колебаний, а также показатели деловой активности рассчитаны полно или есть необходимая достоверная информация для их оценки

    The effectiveness of biofilm formation of daily cultures of clinically significant strains of opportunistic bacteria

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    Background. The formation of biofilm structures by microorganisms living in the hospital environment is a serious medical problem. To conduct correct experimental studies, it is necessary to know the speed and efficiency of biofilm formation by clinically significant species of opportunistic bacteria.   Aim: to study the kinetics of plankton culture growth and the rate of biofilm formation by clinically significant pathogens of infections associated with medical care to substantiate the methodology of further research.   Materials and methods. The strains from the working collection of the Laboratory for Microbiome and Microecology of the Scientific Сentre for Family Health and Human Reproduction Problems were used. Experiments were carried out with conditionally pathogenic microorganisms of the Enterobacteriaceae family and non-fermenting gram-negative bacteria. The optical density was measured, the total microbial number of the cell suspension was determined, and the morphological structure of the biofilm was evaluated using a light microscope on sterile cover glasses for thespecies Pseudomonas aeruginosa, Klebsiella pneumoniae and Serratia marcescens.   Results. The duration of the lag phase of the kinetic curve of cell growth varied in isolates of S. marcescens, P. aeruginosa and K. pneumoniae from 1 to 4 and 6 hours of cultivation, respectively. Despite this, the exponential growth phase was the same for all tested isolates and amounted to 4 hours. Thus, isolates of clinically significant species entered the stationary growth phase after 5–10 hours of cultivation and were characterized as fast-growing. On abiotic surfaces, after 8 hours of incubation of the tested cultures, the initial stages of the formation of biofilm structures were observed, after 20 hours the formed multilayer biofilm was visualized, after 24 hours succession occurred, new single cells were attached to the place of the detached structures.   Conclusion. The data obtained on the duration of the main stages of growth kinetics compared with the visualization of the formation of biofilm structures on abiotic surfaces should be taken into account when studying the effects of disinfectants, antiseptics and antibacterial drugs on planktonic cells and biofilm associations of clinically significant opportunistic microorganisms

    Influence on the autonomic cardiovascular system regulation in the treatment of hypertension, arrhythmias and heart failure

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    Cardiovascular diseases are widespread and are the leading death cause in most countries, despite the creation and improvement of strategies to reduce cardiovascular risk. A significant role in the development and evolution of cardiovascular diseases belongs to sympathetic nervous system hyperactivity, and therefore the methods of effecting it are relevant for the prevention and treatment of cardiovascular pathology. The article discusses modern approaches to interventional and conservative regulation of the autonomic nervous system and neuromodulation in the prevention and treatment of hypertension, heart failure, tachyarrhythmias, as well as reflects a conjoint expert judgment on these issues

    2020 Clinical practice guidelines for Myocarditis in adults

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    Russian Society of Cardiology (RSC)With the participation: Eurasian Association of Therapists (EUAT), Society of Specialists in Heart Failure (OSSN), Russian Scientific Medical Society of Therapists (RNMOT), Russian Society of Pathologists, Russian Society of Radiologists and Radiologists (RSR)Endorsed by: Research and Practical Council of the Ministry of Health of the Russian Federatio

    ШЕСТИЛЕТНИЙ ОПЫТ ТРАНСПЛАНТАЦИИ СЕРДЦА В ФГБУ «СЕВЕРО-ЗАПАДНЫЙ ФЕДЕРАЛЬНЫЙ МЕДИЦИНСКИЙ ИССЛЕДОВАТЕЛЬСКИЙ ЦЕНТР ИМЕНИ В.А. АЛМАЗОВА»

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    Aim. To estimate the results of 6-year experience of heart transplantation (HT) in Federal Almazov North-West Medical Research Centre. Methods. From 2010 to 2015 we have performed 65 HT. Mean age was 44.3 ± 14 years old (from 10 to 64 years old). We used biventricular assist device (BIVAD, Berlin Heart Excor) support in 7 heart transplant candidates before HT. 19 patients (29%) received thymoglobulin, whereas 46 patients (71%) had basiliximab to induce immunosuppression.Results. Extracorporeal membrane oxygenation machines were implanted in 5 patients (7.7%) after HT due to acute right ventricular failure. Suture annuloplasty (the Batista procedure) for tricuspid valve repair was carried out in 3 cases (4.6%). Venovenous hemodiafi ltration was used in 11 patients (16.9%). A total of 598 endomyocardial biopsies (EMB) were performed after HT. Evidence of cellular rejection (R1 and R2) was presented in 286 biopsies (48%). The 30-day in-hospital mortality rate was 3.1%. The 6-month survival rate after HT was 92%, 1-year – 91% and overall survival for the 6-year period of observation – 89.2%. Maximum observation period was 71 months.Conclusions. The 6-year experience of HT in our Center has shown a high level of survival. BIVAD Excor support can be effectively used as a «bridge» to HT. Prevention of graft loss due to acute rejection in heart transplant recipients can be achieved only through regular EMB monitoring. The rate of viral infection increased in 2 months after HT.Цель исследования. Оценить результаты трансплантаций сердца (ТС), выполненных в ФГБУ «Северо-Западный федеральный медицинский исследовательский центр имени В.А. Алмазова» за шесть лет.Материалы и методы. В период с 2010-го по 2015 год в Центре было выполнено 65 ТС. Средний возраст реципиентов составил 44,3 ± 14 лет (от 10 до 64 лет). В качестве «моста» к ТС у 7 пациентов перед пересадкой были имплантированы устройства вспомогательного кровообращения (УВК) Excor. Для индукции иммуносупрессивной терапии у 19 пациентов (29%) применялся антитимоцитарный иммуноглобулин, у 46 пациентов (71%) – базиликсимаб.Результаты. У 5 (7,7%) пациентов, в связи с тяжелой правожелудочковой недостаточностью, в раннем периоде после ТС была установлена система ЭКМО. У 3 (4,6%) больных ввиду развития трикуспидальной недостаточности была выполнена пластика трикуспидального клапана по Батиста. Проведение сеансов заместительной почечной терапии после ТС потребовалось у 11 (16,9%) реципиентов. Всего за шестилетний период наблюдения у всех пациентов было выполнено 598 эндомиокардиальных биопсий (ЭМБ). В 286 (48%) случаях диагностировано клеточное отторжение трансплантата стадии R1 или R2. 30-дневная госпитальная летальность составила 3,1% (2 пациента). Выживаемость в отдаленном периоде составила: через 6 месяцев – 92%, через 1 год – 91%, общая выживаемость за 6 лет наблюдения – 89%. Максимальный срок наблюдения – 71 месяц.Заключение. Шестилетний опыт ТС в нашем Центре показал высокий уровень выживаемости после операции. Имплантация УВК является «мостом» к ТС у больных с терминальной стадией ХСН. ЭМБ остается единственным эффективным методом диагностики острого отторжения трансплантата сердца. Через два месяца после ТС в структуре инфекционных осложнений увеличивается частота вирусной инфекции

    Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF

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    M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe

    Studies of new Higgs boson interactions through nonresonant HH production in the b¯bγγ fnal state in pp collisions at √s = 13 TeV with the ATLAS detector

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    A search for nonresonant Higgs boson pair production in the b ¯bγγ fnal state is performed using 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes and expands upon the previous nonresonant ATLAS results in this fnal state based on the same data sample. The analysis strategy is optimised to probe anomalous values not only of the Higgs (H) boson self-coupling modifer κλ but also of the quartic HHV V (V = W, Z) coupling modifer κ2V . No signifcant excess above the expected background from Standard Model processes is observed. An observed upper limit µHH < 4.0 is set at 95% confdence level on the Higgs boson pair production cross-section normalised to its Standard Model prediction. The 95% confdence intervals for the coupling modifers are −1.4 < κλ < 6.9 and −0.5 < κ2V < 2.7, assuming all other Higgs boson couplings except the one under study are fxed to the Standard Model predictions. The results are interpreted in the Standard Model efective feld theory and Higgs efective feld theory frameworks in terms of constraints on the couplings of anomalous Higgs boson (self-)interactions

    Measurement of ZZ production cross-sections in the four-lepton final state in pp collisions at √s = 13.6 TeV with the ATLAS experiment

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    Electron and photon energy calibration with the ATLAS detector using LHC Run 2 data

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    This paper presents the electron and photon energy calibration obtained with the ATLAS detector using 140 fb−1 of LHC proton-proton collision data recorded at root(s) = 13 TeV between 2015 and 2018. Methods for the measurement of electron and photon energies are outlined, along with the current knowledge of the passive material in front of the ATLAS electromagnetic calorimeter. The energy calibration steps are discussed in detail, with emphasis on the improvements introduced in this paper. The absolute energy scale is set using a large sample of Z-boson decays into electron-positron pairs, and its residual dependence on the electron energy is used for the first time to further constrain systematic uncertainties. The achieved calibration uncertainties are typically 0.05% for electrons from resonant Z-boson decays, 0.4% at ET tilde 10 GeV, and 0.3% at ET tilde 1 TeV; for photons at ET tilde 60 GeV, they are 0.2% on average. This is more than twice as precise as the previous calibration. The new energy calibration is validated using J/psi -> ee and radiative Z-boson decays
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