Sensitivity analysis and simulation of a multiserver queueing system with mixed service time distribution

The motivation of mixing distributions in communication/queueing systems modeling is that some input data (e.g., service time in queueing models) may follow several distinct distributions in a single input flow. In this paper, we study the sensitivity of performance measures on proximity of the service time distributions of a multiserver system model with two-component Pareto mixture distribution of service times. The theoretical results are illustrated by numerical simulation of the M/G/c systems while using the perfect sampling approach

Contraction (Retraction) of blood clots in patients with ischemic stroke

© 2016, Media Sphera. All rights reserved.Objective: To study a possible pathogenetic role of the blood clot contraction and its disturbances in the acute stage of ischemic stroke (IS). Material and methods: Using a new instrumental technique to study the dynamics of clot contraction in vitro, the authors have determined quantitative parameters of clot contraction (the extent and rate of contraction, duration of the lag-period) in the blood of 85 patients with acute IS. Results and Conclusion: The contractile activity of blood clots was substantially reduced compared to the blood of healthy subjects. Correlations between hemostatic and contractile parameters suggest that the reduced clot contraction in stroke is due to the lower platelet count and impaired platelet functionality, higher levels of fibrinogen and antithrombin III as well as higher hematocrit and hemoglobin contents, leukocytosis, and changes in the biochemical blood composition. The results show that the reduced ability of clots may be a novel pathogenic mechanism that aggravates the course and outcomes of IS

XXI Century: Creativity in Demand

В статье обсуждается влияние таких трендов мирового развития как цифровизация и автоматизация на рост востребованности креативной деятельности человека, развития его креативного потенциала. Цифровые технологии открывают новые возможности для творческой самореализации людей. Цифровые технологии становятся сегодня платформой необычайного всплеска креативности, что в экономической сфере выражается в появлении нового типа инноваций, получивших название «открытых инноваций», или инноваций, инициируемых пользователями. Инновации, инициируемые пользователями, реализуются в различных секторах экономики. Более того, их процент достаточно высок, что говорит в пользу необходимости разработки и реализации политики инклюзивного инновационного роста в интересах всего общества. Глубокие преобразования экономики, производства и общества ожидаются также в связи с нарастающими процессами автоматизации и роботизации. Пессимистический сценарий развития связывают со скачкообразным ростом безработицы и появлением большого количества «лишних людей». Оптимистические сценарии опираются на возрастающее значение креативности и предпринимательских компетенций как главного условия формирования новых рабочих мест.The article discusses the impact of such global development trends as digitalization and automation on the growth in demand for human creative activity, the development of its creative potential. Digital technologies open up new opportunities for creative self-realization of people. Digital technologies are today becoming the platform for an extraordinary surge of creativity, which in the economic sphere is expressed in the emergence of a new type of innovation, called “open innovation”, or user-initiated innovation. User- initiated innovations are being implemented in various sectors of the economy. Moreover, their percentage is quite high, which speaks in favor of the need to develop and implement an inclusive innovative growth policy in the interests of the whole society. Deep transformations of the economy, production and society are also expected in connection with the growing processes of automation and robotization. The pessimistic development scenario is associated with an abrupt increase in unemployment and the emergence of a large number of "extra people". Optimistic scenarios are based on the growing importance of creativity and entrepreneurial competencies as the main condition for the formation of new jobs

A case of arterial thrombosis with formation of an atypical fibrin-rich thrombus

Aim. To describe a case of arterial thrombosis with a thrombus that had atypical composition due to profound pathological changes in the cellular and protein composition of the blood. Methods. Scanning electron microscopy of an ex vivo thrombus extracted from the common femoral artery. Results. In the absence of platelets and leukocytes there was a significant prevalence of fibrin over other blood components in all layers of the arterial thrombus. There were no morphological signs of intravital contraction (retraction) characteristic for thrombi: single erythrocytes were not exposed compressive deformation, redistribution of fibrin and platelets within the thrombus toward the periphery. Formation of the atypical arterial thrombus in the vessel with atherosclerotic vessel damage is probably due to association with severe hyperfibrinogenemia and thrombocytopenia. Conclusion. The structure of a thrombus depends not only on its vascular location (arterial or venous), but also on the cellular and protein composition of the blood. These factors support diversification of antithrombotic therapy, considering composition and properties of thrombi irrespective of the place and hemodynamic conditions of their formation

Interaction of 4 allotropic modifications of carbon nanoparticles with living tissues

Environmental pollution and technological progress lead to carbon nanoparticles that pose a serious health risk. They are present in soot, dust, and printing toner and can also be formed during grinding and cutting. Human neutrophils are able to sequester foreign material by formation of neutrophil extracellular traps (NETs), a process that can cause a strong inflammatory response. In the current work we compared proinflammatory properties of different carbon-based nanostructures: nanodiamonds, graphene oxide, fullere­nes C60 and carbon dots. We tested adjuvant properties of carbon nanoparticles in a murine immunization model by investigating humoral (specific IgG and IgM antibodies) and cellular (delayed type hypersensitivity) immune responses. The ability of NETs to sequester nanoparticles was analyzed in a mouse air pouch model and neutrophil activation was verified by in vivo tracking of near-infrared labeled nanodiamonds and ex vivo fluorescent assays using human blood-derived neutrophils. All carbon nanoparticles exhibited proinflammatory adjuvant-like properties by stimulating production of specific IgG but not IgM antibodies (humoral immune response). The adjuvant-like response decreased in this order: from nanodiamonds, graphene oxide, fullerenes C60 to carbon dots. None of the studied carbon nanoparticles triggered a delayed type hypersensitivity reaction (cellular immune response). Nanodiamonds and fullerenes C60 were sequestrated in the body by NETs, as confirmed in the air pouch model and by in vivo fluorescent tracking of near-infrared labeled nanodiamonds

Optical properties of melanin in the skin and skin-like phantoms

ABSTRACT Experimental study and computer modeling were used to investigate the optical properties of melanin in the skin and skinlike phantoms. To investigate light scattering by melanosomes in skin we made skin-like phantoms on the base of gelatin with different content of melanin particles. Spectra of total transmittance and diffuse reflectance of the phantoms were obtained in the wavelength range from 400 to 800 nm. Absorption and reduced scattering coefficients of melanin were calculated. Mie theory was used to estimate the optical properties ofmelanin particles. Wavelength dependence of refractive indices of eumelanin particles (isolated and purified from the ink of the cuttlefish Sepia officinalis) and synthetic melanin particles was estimated

ИСПОЛЬЗОВАНИЕ ЭКСТРАКТОВ РАСТЕНИЙ КАК РЕГУЛЯТОРОВ КАЧЕСТВЕННЫХ ПОКАЗАТЕЛЕЙ ПЛОДОВ МОМОРДИКИ (MOMORDICA CHARANTIA L.)

Momordica (Momordica charantia L.) is unconventional crop of the Cucurbitaceae family for the central regions of the Russian. Fruits of this crop have anti-inflammatory and immunomodulatory effect. The influence of promising growth regulators from plants on the qualitative composition of fruits momordika has been studied. The positive effect of leaf extract yakon as phytoregulator on productivity increasing and fruit quality of momordika is shown.Момордика (Momordica charantia L.) – нетрадиционное для центральных регионов России растение семейства тыквенные. Плоды культуры обладают противовоспалительным, инсулиностимулирующим и иммуномодулирующим эффектом. Изучено влияние перспективных регуляторов роста из растительного сырья на качественный состав плодов момордики. Показано положительное влияние экстракта листьев якона, как фиторегулятора, на увеличение продуктивности и качество плодов момордики

A Case of Medullary Carcinoma of the Jejunum Combined with the Intestinal Lymphangiectasia Accompanied by the Malabsorption Syndrome

Aim: to present a clinical and morphological observation of an extremely rare combination of medullary carcinoma of the jejunum and intestinal lymphangiectasia in a 33-year-old patient with clinical features of malabsorption syndrome over the 10 years.Key points. An autopsy revealed a tumor formation spreading from the wall of the jejunum to the mesentery, with metastases to the mesenteric lymph nodes. The medullary carcinoma with positive expression of СD117, DOG1, EMA, PanCK, PDL-1, vimentin, mosaic non-intense expression of CA19-9, calretinin, CD10, CDX2, CEA, MUC-5AC, SATB2, and negative reaction to ALK, CD3, CD8, CD20, CD30, CD31, CD34, CD45, CD56, chromogranin, CK7, CK20, desmin. The proliferative index was high: Ki-67 > 80 %. Moreover, during the histological examination of the intestinal wall, intestinal lymphangiectasia complicated by the malabsorption syndrome was revealed.Conclusion. The uniqueness of this clinical and morphological case is in the combination of medullary carcinoma of the jejunum metastasized to the mesenteric lymph nodes with the underlying intestinal lymphangiectasia accompanied by the development of malabsorption syndrome

Clonal structure and the specificity of vaccine-induced T cell response to SARS-CoV-2 Spike protein

Adenovirus vaccines, particularly the COVID-19 Ad5-nCoV adenovirus vaccine, have emerged as promising tools in the fight against infectious diseases. In this study, we investigated the structure of the T cell response to the Spike protein of the SARS-CoV-2 virus used in the COVID-19 Ad5-nCoV adenoviral vaccine in a phase 3 clinical trial (NCT04540419). In 69 participants, we collected peripheral blood samples at four time points after vaccination or placebo injection. Sequencing of T cell receptor repertoires from Spike-stimulated T cell cultures at day 14 from 17 vaccinated revealed a more diverse CD4+ T cell repertoire compared to CD8+. Nevertheless, CD8+ clonotypes accounted for more than half of the Spike-specific repertoire. Our longitudinal analysis showed a peak T cell response at day 14, followed by a decline until month 6. Remarkably, multiple T cell clonotypes persisted for at least 6 months after vaccination, as demonstrated by ex vivo stimulation. Examination of CDR3 regions revealed homologous sequences in both CD4+ and CD8+ clonotypes, with major CD8+ clonotypes sharing high similarity with annotated sequences specific for the NYNYLYRLF peptide, suggesting potential immunodominance. In conclusion, our study demonstrates the immunogenicity of the Ad5-nCoV adenoviral vaccine and highlights its ability to induce robust and durable T cell responses. These findings provide valuable insight into the efficacy of the vaccine against COVID-19 and provide critical information for ongoing efforts to control infectious diseases

Contraction (Retraction) of blood clots in patients with ischemic stroke

© 2016, Media Sphera. All rights reserved.Objective: To study a possible pathogenetic role of the blood clot contraction and its disturbances in the acute stage of ischemic stroke (IS). Material and methods: Using a new instrumental technique to study the dynamics of clot contraction in vitro, the authors have determined quantitative parameters of clot contraction (the extent and rate of contraction, duration of the lag-period) in the blood of 85 patients with acute IS. Results and Conclusion: The contractile activity of blood clots was substantially reduced compared to the blood of healthy subjects. Correlations between hemostatic and contractile parameters suggest that the reduced clot contraction in stroke is due to the lower platelet count and impaired platelet functionality, higher levels of fibrinogen and antithrombin III as well as higher hematocrit and hemoglobin contents, leukocytosis, and changes in the biochemical blood composition. The results show that the reduced ability of clots may be a novel pathogenic mechanism that aggravates the course and outcomes of IS