СТРУКТУРА И МЕХАНИЧЕСКИЕ СВОЙСТВА СЛИТКОВ И ПРОФИЛЕЙ ИЗ АЛЮМИНИЕВОГО СПЛАВА НА ОСНОВЕ СИСТЕМЫ AL-MG-MN

Commercial ingots and hot-pressed rolled sections of Al-Mg-Mn alloy doped with zinc, scandium, zirconium, chromium, and vanadium have been studied using optical microscopy, thermal analysis, electron microscopy, and electron-probe microanalysis. The compositions of the phase constituents and aluminum matrix of the alloy are determined. The sensitivity of the alloy to the formation of complex intermetallic compounds during solidification is revealed. The mechanical properties of ingots and rolled sections are determined. © 2013 Pleiades Publishing, Ltd

Effectiveness of mindfulness-based therapy, stress reduction in hypertension and prehypertension: a systematic review

Aim. To collect and analyze currently available clinical studies on the effectiveness of mindfulness-based stress reduction (MBSR) for lowering blood pressure in individuals with normal, high normal blood pressure and hypertension.Material and methods. The systematic review was prepared according to the PRISMA algorithm with minor modifications. The search algorithm included articles in Russian and English, indexed in the Pubmed/MEDLINE and Cochrane Library databases. The study included studies on the impact of mindfulness interventions on blood pressure levels in individuals aged ≥18 years with an established diagnosis of hypertension, with normal (120-129/80-84 mm Hg) and high normal office blood pressure (130-139/85-89 mm Hg).Results. A total of 4785 publications were identified and included in the study, of which, after a multistage sampling, including screening of articles, 6 studies were included in a qualitative systematic review.Conclusion. Qualitative synthesis of the results of clinical studies revealed that the evidence currently available indicates a possible positive effect of mindfulness interventions on blood pressure levels in individuals with normal, high normal blood pressure and hypertension. However, further studies with larger samples and measurement of more primary and secondary endpoints are required

Mobile applications for anxiety and stress reduction: potential for preventing noncommunicable diseases

The article discusses using mobile applications for smartphones as tools to reduce anxiety and stress. The modern views on pathogenesis of the relationship between stress, anxiety disorders and cardiovascular disease are considered. Based on a review of some representative studies, a methodology for evaluating the characteristics and functions of mobile applications for managing anxiety and stress symptoms is proposed. The applications selected for analysis were tested according to this methodology. There are following key features of the Russianlanguage field of mobile applications for anxiety and stress reduction: a small number of applications, high prevalence of using breathing exercises, meditations and sound therapy, an extremely low disease specificity and focus mainly on helping with general symptoms of anxiety

Влияние состояния атмосферы на взаимодействие вихревых и конденсационных следов воздушных судов

Currently, much emphasis is given to the environmental problems. This article is not an exception. It is devoted to the issue of propagation and interaction of vortex and condensation trails that form behind aircraft when flying in the atmosphere, depending on its state. A vortex trail is an area of disturbed air flow behind an aircraft formed as a result of its motion. A condensation trail is a product of the aviation fuel combustion in the engine and represents condensed moisture in the form of ice crystals, which is generated under certain ambient conditions. As the numerous studies and observations have shown, condensation trails can affect the heat exchange processes in the atmosphere, contributing to the greenhouse effect, deteriorate the environment. It is especially relevant for the area where numerous transitional airways pass. Therefore, it is essential to understand behind what aircraft type the condensation trail, interacting with the vortex one, dissipates in the atmosphere, and the substances composing the condensation trail lose their concentration. And on the contrary, behind what aircraft type the condensation trail does not dissipate for a long term, and the substances, composing the contrail, retain concentration for a long time. It should also be noted that the contrail, while interacting with the vortex wake, can reveal its structure and visualize the processes of propagation and attenuation of the vortex wake. This paper uses a special computational software application, based on the discrete vortex method, to study the interaction of condensation and vortex trails. It considers the flight weight, aircraft speed and altitude, its in-flight configuration, atmospheric conditions, axial velocity in the vortex core and some other factors, when calculating the vortex wake performance. This complex passed the required testing and state registration. Several procedures were executed to validate and verify the developed complex, confirming its program efficiency and the reliability of the results obtained. The Airbus A320 and A380 were selected as the research object of this article. The flight mode and atmospheric conditions are similar for all aircraft. The results obtained allow us to understand how atmospheric conditions affect the propagation of contrails behind aircraft of different classes, provided their interaction with vortex trails.В настоящее время много внимания уделяется экологическим проблемам. Данная работа не исключение. Она посвящена проблеме распространения и взаимодействия вихревых и конденсационных следов, образующихся за воздушными судами при полете в атмосфере в зависимости от ее состояния. Вихревой след – это область возмущенного воздушного потока за самолетом, образующаяся в результате его движения. Конденсационный след является продуктом сгорания авиационного топлива в двигателе и представляет собой сконденсированную влагу в виде ледяных кристаллов, которая образуется при определенных состояниях атмосферы. Как показали многочисленные исследования и наблюдения, конденсационные следы могут влиять на теплообменные процессы в атмосфере и, способствуя парниковому эффекту, ухудшать экологию. Особенно это актуально для местности, где проходят многочисленные воздушные транзитные трассы воздушных судов. Поэтому важно понимать, за какими воздушными судами конденсационный след, взаимодействуя с вихревым, рассеивается в атмосфере, а вещества, входящие в состав конденсационного следа, теряют свою концентрацию. И, наоборот, за какими воздушными судами конденсационный след долго не рассеивается, а вещества, входящие в состав конденсационного следа, длительное время сохраняют концентрацию. Отметим также, что конденсационный след, взаимодействуя с вихревым следом, может выявлять его структуру, а также визуализировать процессы распространения и затухания вихревого следа. В данной статье для исследования взаимодействия конденсационных и вихревых следов был использован специальный расчетно-программный комплекс, базирующийся на методе дискретных вихрей. В нем при расчете характеристик вихревого следа учитываются полетный вес, скорость и высота полета самолета, его полетная конфигурация, атмосферные условия, осевая скорость в ядре вихря и некоторые другие факторы. Этот комплекс прошел необходимую апробацию и государственную регистрацию. Был выполнен ряд мероприятий по валидации и верификации разработанного комплекса, подтверждающих работоспособность программ, входящих в него, и достоверность получаемых результатов. В данной статье в качестве объектов исследования были выбраны воздушные суда А-320 и А-380. Режим полета и атмосферные условия для всех самолетов выбраны одни и те же. Получены результаты, которые позволяют понять, как влияют атмосферные условия на распространение конденсационных следов за воздушными судами разного класса при условии их взаимодействия с вихревыми следами

Этиотропная терапия COVID-19: критический анализ и перспективы

The COVID-19 outbreak started in December 2019 in China has spread over all countries of the world within few month acquiring a pandemic nature, the incident population counting millions. The pathogenic mechanisms of the new coronaviral infection caused by never-before-seen virus SARS-CoV2 are yet to be studied. Various drugs are used for COVID-19 treatment and guidelines are continuously revised as new experience is acquired. In the current pandemic situation, it is important to provide specialists with latest information concerning efficacy and safety drugs for COVID-19 patients and promising research in this field.The purpose of the review is to critically analyze published data on outcomes of COVID-19 treatment with various drugs including potentially promising drugs.The search has been carried out through such databases as PubMed, Scopus, Cyberleninka, https://www.globalclinicaltrialsdata.com, https://clinicaltrials.gov, Cochrane Library; mostly, randomized clinical trials-2020 and papers dedicated to candidate drugs have been considered. The paper is structured based on the drug’s action mechanism and contains parts dedicated to antiviral, immunomodulatory, and antibacterial therapies. Looking for a new promising target in COVID-19 treatment, the authors focus their attention on matrix metalloproteinases (MMP), which abundance results in the destruction of extracellular matrix, epithelial and endothelial basal membranes and leads to secondary lung tissue injury. The paper provides a theoretic justification of MMP inhibitor use by an example of doxycycline and offers an efficacy study protocol for the new approach to COVID-19 therapy.Conclusion: as of now, there are no drugs which efficacy for COVID 19 has been proven. Drugs possessing multiple mechanisms of action are employed beside their specified indications, often in combinations; in this situation, additive side effects with adverse consequences for the patient can hardly be avoided. Administration of drugs with unproven efficacy may be justified only in clinical trials followed by subsequent analysis and publication of findings demonstrating that in case of success, recommendations for a majority of COVID-19 patients could be confidently issued.Эпидемия COVID-19, начавшаяся в декабре 2019 года в Китае, за несколько месяцев распространилась на все страны мира, приняв характер пандемии, число заболевших исчисляется миллионами. Механизмы патогенеза новой коронавирусной инфекции, вызванной неизвестным ранее вирусом SARS-CoV2, остаются недостаточно изученными. Для лечения COVID-19 применяют препараты разных групп, по мере появления опыта рекомендации регулярно пересматриваются. В условиях текущей пандемии важно предоставить специалистам актуальную информацию об эффективности и безопасности лечебных препаратов, применяемых для лечения пациентов с COVID-19, и о перспективных исследованиях в этой области. Цель обзора — критический анализ опубликованных результатов лечения COVID-19 с использованием различных групп препаратов для выбора наиболее перспективных лекарственных средств.Поиск источников провели по базам данных PubMed, Scopus, Cyberleninka, Clinical Trials, Cochrane Library и др., рассматривали преимущественно рандомизированные клинические исследования 2020 года, а также работы по изучению препаратов-претендентов. Материал статьи структурирован по механизму действия препаратов, содержит разделы противовирусной, иммуномодулирующей, антибактериальной терапии. В поиске новой перспективной мишени в лечении COVID-19 концентрировали внимание на матриксных металлопротеиназах (ММР), избыток которых ведет к разрушению внеклеточного матрикса, базальных мембран эпителия и эндотелия, способствует вторичному повреждению легочной ткани. В работе теоретически обосновали применение ингибиторов MMP на примере доксициклина, предложили протокол исследования для оценки эффективности нового подхода к лечению COVID-19.Заключение. Лекарственных средств с доказанной эффективностью в отношении COVID 19 в настоящее время нет. Препараты с разными механизмами действия применяются не по показаниям, часто в комбинациях, в этих условиях трудно избежать суммирования побочных эффектов с неблагоприятными последствиями для пациента. Применение препаратов с недоказанной эффективностью оправдано лишь в рамках клинических исследований с последующим анализом и публикацией результатов, чтобы в случае успеха с уверенностью рекомендовать их большинству пациентов с COVID-19. Ключевые слова: COVID-19; противомалярийные средства; ингибиторы вирусных протеаз; противопаразитарные препараты; ингибиторы интерлейкинов; ингибиторы янус-киназ; интерфероны; плазма реконвалесцентов; кортикостероиды; прокальцитонин; антибиотики; новая мишень; матриксные металлопротеиназы, доксициклин

CHANGING ETIOLOGICAL STRUCTURE AND OUTCOMES OF BACTERIEMIA IN SURGICAL PATIENTS AS A RESULT OF MONITORING AND MANAGEMENT OF ANTIBIOTIC RESISTANCE IN MULTIDISCIPLINARY HOSPITAL

Objective. Evaluate the change of etiological structure and clinical outcomes of bacteremia in surgical patients after the implementation the system of monitoring and control antibiotic resistance in a multidisciplinary hospital.Materials and methods. Interventional study with historical controls. The intervention: antibiotic stewardship program, including a group of experts on antimicrobial therapy, antimicrobial therapy and prophylaxis protocols, infection control, improving hospital bacteriological laboratory, educational programs, internal audit. Study onset: June 2013. Analysis of pre-intervention (Jan. 2011-June 2013) and intervention (July 2013-Dec. 2015) periods was carried out. We assessed incidence of bacteremia caused by methicillin-resistant S. aureus (MRSA), vancomycin-resistant Enterococci (VRE), ESBL-producing Enterobacteriaceae, MDR Gram-negative nonfermenting bacteria (MDR-NFGB), incidence of candidemia, hospital length of stay (LOS) and mortality of surgical patients with bacteremia.Results. In the intervention period a significant decrease in the incidence of bacteremia caused by MDR-NFGB from 50 (14,8%) to 16 (4,7%), р<0,0001, VRE from 10 (3,0%) to 0, р=0,0008 and incidence of candidemia from 29 (8,6%) to 13 (2,8%), р=0,011, was detected. The frequency of bacteremia caused by ESBL-producing Enterobacteriae did not significantly change [103 (30,6%) vs. 86 (25,1%), р=0,124]. Number of MRSA bacteremias remained low [5 (1,5%) vs. 1 (0,3%), р=0,121]. There was a significant reduction of mortality from 36,8% до 22,3%, р<0,007 in the group of surgical patients with bacteremia. The LOS did not change significantly [34 (IQI 21-64) days и 34 (IQI 17,25-60,75) days, р=0,415].Conclusion. Implementation of system monitoring and control antimicrobial resistance in multidisciplinary hospital allows to significantly reduce mortality in surgical patients with bloodstream infections due to changes in etiological structure of bacteremia, reduction of the incidence of candidemia and bacteremia caused by MDR-NFGNB and VRE, which may be the result of improving the quality of antimicrobial therapy of severe infections

Geometric and Statistical Properties of the Mean-Field HP Model, the LS Model and Real Protein Sequences

Lattice models, for their coarse-grained nature, are best suited for the study of the ``designability problem'', the phenomenon in which most of the about 16,000 proteins of known structure have their native conformations concentrated in a relatively small number of about 500 topological classes of conformations. Here it is shown that on a lattice the most highly designable simulated protein structures are those that have the largest number of surface-core switchbacks. A combination of physical, mathematical and biological reasons that causes the phenomenon is given. By comparing the most foldable model peptides with protein sequences in the Protein Data Bank, it is shown that whereas different models may yield similar designabilities, predicted foldable peptides will simulate natural proteins only when the model incorporates the correct physics and biology, in this case if the main folding force arises from the differing hydrophobicity of the residues, but does not originate, say, from the steric hindrance effect caused by the differing sizes of the residues.Comment: 12 pages, 10 figure

Landscape science: a Russian geographical tradition

The Russian geographical tradition of landscape science (landshaftovedenie) is analyzed with particular reference to its initiator, Lev Semenovich Berg (1876-1950). The differences between prevailing Russian and Western concepts of landscape in geography are discussed, and their common origins in German geographical thought in the late nineteenth and early twentieth centuries are delineated. It is argued that the principal differences are accounted for by a number of factors, of which Russia's own distinctive tradition in environmental science deriving from the work of V. V. Dokuchaev (1846-1903), the activities of certain key individuals (such as Berg and C. O. Sauer), and the very different social and political circumstances in different parts of the world appear to be the most significant. At the same time it is noted that neither in Russia nor in the West have geographers succeeded in specifying an agreed and unproblematic understanding of landscape, or more broadly in promoting a common geographical conception of human-environment relationships. In light of such uncertainties, the latter part of the article argues for closer international links between the variant landscape traditions in geography as an important contribution to the quest for sustainability