323 research outputs found

    Инструментарий минимизации риска защищенности в распределенных системах (РКС)

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    Разработана структура средств минимизации риска защищенности распределенных компьютерных систем, выполнена формализация функционирования основных блоков предложенной структуры. Предложена оценка уровня угроз безопасности, интегральная оценка ущерба вследствие атак на уязвимости, а также оценка степени риска реализации угроз безопасности в компьютерных системах. Также предложен подход к анализу риска на основе оценок степени опасности факторов угроз безопасности и вероятности реализации угроз безопасности с разделением их на соответствующие группы, а также на основе построения специальной матрицы рисков защищенности для минимизации риска защищенности.Розроблено структуру засобів мінімізації ризику захищеності розподілених комп’ютерних систем, виконано формалізацію функціонування основних блоків запропонованої структури. Запропоновано оцінку рівня загроз безпеки, інтегральну оцінку збитку внаслідок атак на вразливості, а також оцінку ступеня ризику реалізації загроз безпеки в комп’ютерних системах. Також запропоновано підхід до аналізу ризику на основі оцінок ступеня небезпеки факторів загроз безпеки та ймовірності реалізації загроз безпеки з розділенням їх на відповідні групи, а також на основі побудови спеціальної матриці ризиків захищеності для мінімізації ризику захищеності.The structure of means for security risk minimization in distributed computer systems is developed, and the functioning of the basic blocks of the suggested structure is formalized. Also, estimation of the security threat level, the integrated assessment of the damage due to attacks on to the vulnerabilities, and the risk assessment for the security threat realization are proposed. An approach to the risk analysis on the basis of estimation of the danger level of safety threat factors and the probability of safety threat realization with division of the factors into related groups is suggested, which is also based on the constructed special security risk matrix for security risk minimization

    Этноконфликт как причина агрессии: проблема национальной безопасности Украины

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    Межэтнические и межнациональные противоречия являются сегодня одной из наиболее актуальных проблем многих стран мира, в том числе и Украины. Она относится к числу полиэтнических государств, где неизбежны межэтнические и межнациональные противоречия и конфликты. Анализу последних, их причин и возможных следствий и посвящена данная статья.Міжетнічні та міжнаціональні протиріччя сьогодні є однією з найбільш актуальних проблем багатьох країн світу, у тому числі і України. Вона належить до числа поліетнічних держав, де неминучі міжетнічні та міжнаціональні протиріччя та конфлікти, аналізу яких, їх причин і можливих наслідків присвячена дана стаття.Today interethnic and international contradictions are the most topical problems of many countries of the world including Ukraine. It belongs to those polyethnic states where interethnic and international contradictions and conflicts are unavoided. This article is devoted to analysis, causes and possible consequences of the last ones

    Развитие инвестиционного кредитования в Украине

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    Free radical polymerization is often used to prepare protein and peptide-loaded hydrogels for the design of controlled release systems and molecular imprinting materials. Peroxodisulfates (ammonium peroxodisulfates (APS) or potassium peroxodisulfates (KPS)) with N,N,N,N-tetramethylethylenediamine (TEMED) are frequently used as initiator and catalyst. However, exposure to these free radical polymerization reagents may lead to modification of the protein and peptide. In this work, we show the modification of lysine residues by ammonium peroxodisulfate (APS)/TEMED of the immunostimulant thymopentin (TP5). Parallel studies on a decapeptide and a library of 15 dipeptides were performed to reveal the mechanism of modification. LC-MS of APS/TEMED-exposed TP5 revealed a major reaction product with an increased mass (+12 Da) with respect to TP5. LC-MS2 and LC-MS3 were performed to obtain structural information on the modified peptide and localize the actual modification site. Interpretation of the obtained data demonstrates the formation of a methylene bridge between the lysine and arginine residue in the presence of TEMED, while replacing TEMED with a sodium bisulfite catalyst did not show this modification. Studies with the other peptides showed that the TEMED radical can induce methyleneation on peptides when lysine is next to arginine, proline, cysteine, aspargine, glutamine, histidine, tyrosine, tryptophan, and aspartic acid residues. Stability of peptides and protein needs to be considered when using APS/TEMED in in situ polymerization systems. The use of an alternative catalyst such as sodium bisulfite may preserve the chemical integrity of peptides during in situ polymerization

    Кіноніми Кіровоградщини: особливості вибору кличок та способи їх творення

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    Стаття присвячена вивченню особливостей української кінонімії. Основну увагу зосереджено на дослідженні процесу номінації та способів словотворення кличок собак. Окремо розглянуто офіційні назви тварин, які мають родослівну.Статья посвящена изучению особенностей украинской кинонимии. Основное внимание сосредоточено на изучении процесса номинации и способах словообразования кличек собак. Отдельно рассмотрены официальные названия собак, имеющих родословную.The article is devoted to the research of the peculiarities of Ukrainian cynonymy. Most attention is taid to the research of the process of nomination and to the ways of formation of dogs' names. Special consideration is given to the official names of the animals with genealogy

    Mechanistic Study on the Degradation of Hydrolysable Core-Crosslinked Polymeric Micelles

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    Core-crosslinked polymeric micelles (CCPMs) are an attractive class of nanocarriers for drug delivery. Two crosslinking approaches to form CCPMs exist: either via a low-molecular-weight crosslinking agent to connect homogeneous polymer chains with reactive handles or via cross-reactive handles on polymers to link them to each other (complementary polymers). Previously, CCPMs based on methoxy poly(ethylene glycol)- b-poly[ N-(2-hydroxypropyl) methacrylamide-lactate] (mPEG- b-PHPMAmLac n ) modified with thioesters were crosslinked via native chemical ligation (NCL, a reaction between a cysteine residue and thioester resulting in an amide bond) using a bifunctional cysteine containing crosslinker. These CCPMs are degradable under physiological conditions due to hydrolysis of the ester groups present in the crosslinks. The rapid onset of degradation observed previously, as measured by the light scattering intensity, questions the effectiveness of crosslinking via a bifunctional agent. Particularly due to the possibility of intrachain crosslinks that can occur using such a small crosslinker, we investigated the degradation mechanism of CCPMs generated via both approaches using various analytical techniques. CCPMs based on complementary polymers degraded slower at pH 7.4 and 37 °C than CCPMs with a crosslinker (the half-life of the light scattering intensity was approximately 170 h versus 80 h, respectively). Through comparative analysis of the degradation profiles of the two different CCPMs, we conclude that partially ineffective intrachain crosslinks are likely formed using the small crosslinker, which contributed to more rapid CCPM degradation. Overall, this study shows that the type of crosslinking approach can significantly affect degradation kinetics, and this should be taken into consideration when developing new degradable CCPM platforms

    Hotel Theming in China: A Qualitative Study of Practitioners’ Views

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    Facing increasing competition, many hotels have adopted “theming” as a marketing strategy. Although still in its fledgling stage, hotel theming has already gained popularity in the growing Chinese hotel market. This study conducted focus group discussions to understand the concepts behind hotel theming in China. Respondents were 41 practitioners from the Chinese hotel industry, who were enrolled in an executive graduate program. Data revealed that hotel theming has four analytical dimensions, namely, the current state, perceived facilitators, inhibitors, and future prospective for developing such strategy in China. Results showed that the specific traits of the Chinese hotel market are highly important for the success of hotel theming in the given context

    Radioactive Holmium Acetylacetonate Microspheres for Interstitial Microbrachytherapy: An In Vitro and In Vivo Stability Study

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    Purpose The clinical application of holmium acetylacetonate microspheres (HoAcAcMS) for the intratumoral radionuclide treatment of solid malignancies requires a thorough understanding of their stability. Therefore, an in vitro and an in vivo stability study with HoAcAcMS was conducted. Methods HoAcAcMS, before and after neutron irradiation, were incubated in a phosphate buffer at 37°C for 6 months. The in vitro release of holmium in this buffer after 6 months was 0.5%. Elemental analysis, scanning electron microscopy, infrared spectroscopy and time of flight secondary ion mass spectrometry were performed on the HoAcAcMS. Results After 4 days in buffer the acetylacetonate ligands were replaced by phosphate, without altering the particle size and surface morphology. HoAcAcMS before and after neutron irradiation were administered intratumorally in VX2 tumor-bearing rabbits. No holmium was detected in the faeces, urine, femur and blood. Histological examination of the tumor revealed clusters of intact microspheres amidst necrotic tissue after 30 days. Conclusion HoAcAcMS are stable both in vitro and in vivo and are suitable for intratumoral radionuclide treatment.Radiation, Radionuclides and ReactorsApplied Science

    Holmium Nanoparticles: Preparation and In Vitro Characterization of a New Device for Radioablation of Solid Malignancies

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    # The Author(s) 2010. This article is published with open access at Springerlink.com Purpose The present study introduces the preparation and in vitro characterization of a nanoparticle device comprising holmium acetylacetonate for radioablation of unresectable solid malignancies. Methods HoAcAc nanoparticles were prepared by dissolving holmium acetylacetonate in chloroform, followed by emulsification in an aqueous solution of a surfactant and evaporation of W. Bult: R. Varkevisser: P. R. Luijten: A. D. van het Schip

    Cell delivery systems using alginate : carrageenan hydrogel beads and fibers for regenerative medicine applications

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    The present work was focused on the development and characterization of new hydrogel systems based on natural origin polymers, namely, alginate and carrageenan, into different formats and with adequate properties to sustain the viability of encapsulated cells, envisioning their application as cell delivery vehicles for tissue regeneration. Different formulations of alginate and carrageenan hydrogels and different processing parameters were considered to determine the best conditions required to achieve the most adequate response in terms of the mechanical stability, cell viability, and functionality of the developed systems. The morphology, size, and structure of the hydrogels and their degradation behavior and mechanical properties were evaluated during this study. In addition to cytotoxicity studies, preliminary experiments were carried out to investigate the ability of alginate−carrageenan beads/fibers to encapsulate chondrocytes. The results obtained indicated that the different formulations, both in the form of beads and fibers, have considerable potential as cell-carrier materials for cell delivery in tissue engineering/ regenerative medicine applications.European NoE EXPERTISSUES - NMP3-CT-2004-500283Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/64070/2009
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