212 research outputs found

    The Development of Model and Measuring Tool for Specialists Accreditation in Area of Public Health Services

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    The main purpose of the paper is to present some theoretical approaches and some methods providing assessment optimization in specialists' accreditation in area of public health services. The results of research presented in this paper, include the model of multistage adaptive measurements and two methods for reliability and validity analysis, providing high justice decisions in accreditation and corresponding to requirements in High-Stakes Testing procedures. The assessment optimization intends for minimization time of assessment and for reliability and validity data increasing. For optimization the special model of measurements based on multistage adaptive testing is offered. The using of offered model in assessment design allows to realize the advantages of traditional adaptive testing and linear testing, while minimizing their disadvantages. So, this model is recommended as dominating for assessment in accreditation

    Magnetostimulated Chandges of Microhardness in Potassium Acid Phthalate Crystals

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    A decrease in microhardness along the (010) cleavage in potassium acid phthalate single crystals by 15--18% after the application of a permanent magnetic field was revealed for the first time. It is shown that the effect revealed is of the volume character. The role of interlayer water in the processes stimulated by a magnetic field is studied., Interlayer water plays does not cause the observed changes it only plays the part of an indicator of these changes in potassium acid phthalate crystals in a magnetic field. It is established that microhardness in the (100) plane of the crystal in an applied a magnetic field first increases by 12--15% and then remains constant in time within the accuracy of the experiment. The possibility of varying the crystal structure of potassium acid phthalate crystals by applying magnetic fields inducing rearrangement in the system of hydrogen bonds or in the defect structure is discussed.Comment: 6 pages, 7 figure

    СОВРЕМЕННЫЙ КОМПЛЕКСНЫЙ ПОДХОД К ХИРУРГИЧЕСКОМУ ЛЕЧЕНИЮ ЛЕГОЧНОЙ АРТЕРИАЛЬНОЙ ГИПЕРТЕНЗИИ, АССОЦИИРОВАННОЙ С ВРОЖДЕННЫМИ ПОРОКАМИ СЕРДЦА

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    Pulmonary arterial hypertension (PAH) is a common complication of congenital heart disease (CHD) occurring in left-to-right shunt. The progression of PAH is associated with delayed diagnosis and surgical treatment of congenital heart disease. An uncorrected left-to-right shunt in patients with CHD lead to histological changes of pulmonary vessels and reversal of the shunt may arise, with the development of Eisenmenger’s syndrome. Until recently, the surgical treatment of patients thought to be impossible, and few attempts to perform radical correction were associated with high in-hospital mortality. The main causes of the in-hospital mortality included acute right ventricular failure, pulmonary hypertension crisis and cardiac arrhythmias. The long-term survival of these patients was low, directly associated with the progression of residual pulmonary hypertension. The novel technique of a fenestrated double patch has been widely used abroad, but very rarely in Russia. Moreover, there is no standardized algorithm for selecting surgical approach in these patients as well as common approaches to the preoperative management and anesthetic protocol. The efficiency of specific therapies for residual pulmonary hypertension is poorly understood. Lack of research and experience in applying the fenestrated double patch in Russia for a population of children and adolescents who require combined treatment (surgical and specific therapy for pulmonary arterial hypertension) proved our research to be pivotal.Легочная артериальная гипертензия (ЛАГ) является частым осложнением врожденных пороков сердца (ВПС) с лево-правым сбросом. Развитие этого осложнения связано с несвоевременной диагностикой и хирургической коррекцией врожденной патологии сердца. Длительное существование врожденного порока сердца с лево-правым шунтом приводит к стадийному гистологическому изменению сосудов легких и формированию комплекса Эйзенменгера, появлению «перекрестного» сброса крови. До недавнего времени хирургическое лечение таких пациентов считалось невозможным, а немногочисленные попытки радикальной коррекции сопровождались высокой госпитальной летальностью. Основными причинами госпитальной летальности являлись: острая правожелудочковая недостаточность, кризы легочной гипертензии и нарушения ритма сердца. Отдаленная выживаемость таких пациентов была невысокой и обусловливалась прогрессированием резидуальной легочной гипертензии. Оригинальная методика двойной заплаты с фенестрой применялась за рубежом, но не нашла широкого распространения в России. Кроме того, до сих пор не существует стандартизированного алгоритма выбора хирургической тактики у таких пациентов, отсутствуют единые подходы к предоперационной подготовке, не разработан общепринятый протокол анестезиологического пособия, до конца не изучена эффективность специфической терапии резидуальной легочной гипертензии. Отсутствие публикаций и опыта применения методики двойной заплаты с фенестрой в России при наличии популяции детей и подростков, нуждающихся в комбинированном, хирургическом и специфическом лечении легочной артериальной гипертензии, постулировало наше исследование

    Характеризация наночастиц кристаллического кремния, легированного железом, и их модификация цитрат-анионами для использования in vivo

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    Objectives. This paper presents data on the development and study of the structural properties of iron-doped crystalline silicon (nc-Si/SiOx/Fe) nanoparticles obtained using the plasma-chemical method for application in magnetic resonance imaging diagnostics and treatment of oncological diseases. This work aimed to use a variety of analytical methods to study the structural properties of nc-Si/SiOx/Fe and their colloidal stabilization with citrate anions for in vivo applications.Methods. Silicon nanoparticles obtained via the plasma-chemical synthesis method were characterized by laser spark emission spectroscopy, atomic emission spectroscopy, Fouriertransform infrared spectroscopy, and X-ray photoelectron spectroscopy. The hydrodynamic diameter of the nanoparticles was estimated using dynamic light scattering. The toxicity of the nanoparticles was investigated using a colorimetric MTT test for the cell metabolic activity. Elemental iron with different Fe/Si atomic ratios was added to the feedstock during loading.Results. The particles were shown to have a large silicon core covered by a relatively thin layer of intermediate oxides (interface) and an amorphous oxide shell, which is silicon oxide with different oxidation states SiOx (0 ≤ x ≤ 2). The samples had an iron content of 0.8–1.8 at %. Colloidal solutions of the nanoparticles stabilized by citrate anions were obtained and characterized. According to the analysis of the cytotoxicity of the modified nanosilicon particles using monoclonal K562 human erythroleukemia cells, no toxicity was found for cells in culture at particle concentrations of up to 5 µg/mL.Conclusions. Since the obtained modified particles are nontoxic, they can be used in in vivo theranostic applications.Цели. В работе приводятся данные по разработке и изучению структурных свойств полученных плазмохимическим методом наночастиц кремния nc-Si/SiOx/Fe, легированных железом. Цель работы – исследование свойств наночастиц кремния, легированных железом, комплексом аналитических методов и их стабилизация цитрат-анионами для применения в диагностике методом магнитно-резонансной томографии и лечении онкологических заболеваний.Методы. Наночастицы кремния, полученные плазмохимическим методом синтеза, были охарактеризованы лазерно-искровым эмиссионным методом, методом атомной эмиссионной спектроскопии, Фурье-ИК-спектроскопией, рентгеновской фотоэлектронной спектроскопией. Гидродинамический диаметр наночастиц оценивали методом динамического светорассеяния. Исследование токсичности наночастиц проводили с помощью колориметрического МТТ теста на метаболическую активность клеток. В исходное сырье при загрузке добавляли элементарное железо с разным атомным соотношением Fe/Si.Результаты. Было показано, что частица имеет кремниевое ядро с аморфной оксидной оболочкой, представляющей собой оксиды кремния с разной степенью окисления SiO x (0 ≤ x ≤ 2). Содержание железа в образцах составило от 0.8 до 1.8 ат. %. Были получены и охарактеризованы коллоидные растворы наночастиц, стабилизированные цитрат-анионами. Анализ цитотоксичности модифицированных частиц нанокремния с использованием моноклонизированных клеток эритролейкоза человека К562 показал отсутствие токсичности для клеток в культуре при концентрации частиц до 5 мкг/мл.Выводы. Полученные модифицированные частицы не обладают токсичностью, поэтому их можно рекомендовать для использования в in vivo приложениях для тераностик

    Translation initiation and its deregulation during tumorigenesis

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    Regulation of protein synthesis at the level of translation initiation is fundamentally important for the control of cell proliferation under normal physiological conditions. Conversely, misregulation of protein synthesis is emerging as a major contributory factor in cancer development. Most bulk protein synthesis is initiated via recognition of the mRNA 5′ cap and subsequent recognition of the initiator AUG codon by a directional scanning mechanism. However, several key regulators of tumour development are translated by a cap-independent pathway. Here we review eukaryotic translation initiation, its regulation and the ways in which this regulation can break down during tumorigenesis

    The influence of the degree fibrotic changes in the liver on the effectiveness of antiviral therapy in patients with chronic hepatitis C with genotype 1 (preliminary data)

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    На теперішній час багато уваги приділяється виявленню факторів, що впливають на ефективність противірусної терапії (ПВТ) хронічного гепатиту С (ХГС). У дослідженнях останніх років активно обговорюється зв'язок процесів фіброгенезу печінки та ефективності ПВТ ХГС. За результатами більшості досліджень ступінь вираженості фібротичних змін у печінці є незалежним фактором прогнозу відповіді на ПВТ. У то й же час дані щодо впливу фіброзу печінки на ефективність ПВТ при наявності 1 генотипу вірусу обмежені

    Analysis of natural variants of the hepatitis C virus internal ribosome entry site reveals that primary sequence plays a key role in cap-independent translation

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    The HCV internal ribosome entry site (IRES) spans a region of ∼340 nt that encompasses most of the 5′ untranslated region (5′UTR) of the viral mRNA and the first 24–40 nt of the core-coding region. To investigate the implication of altering the primary sequence of the 5′UTR on IRES activity, naturally occurring variants of the 5′UTR were isolated from clinical samples and analyzed. The impact of the identified mutations on translation was evaluated in the context of RLuc/FLuc bicistronic RNAs. Results show that depending on their location within the RNA structure, these naturally occurring mutations cause a range of effects on IRES activity. However, mutations within subdomain IIId hinder HCV IRES-mediated translation. In an attempt to explain these data, the dynamic behavior of the subdomain IIId was analyzed by means of molecular dynamics (MD) simulations. Despite the loss of function, MD simulations predicted that mutant G266A/G268U possesses a structure similar to the wt-RNA. This prediction was validated by analyzing the secondary structure of the isolated IIId RNAs by circular dichroism spectroscopy in the presence or absence of Mg2+ ions. These data strongly suggest that the primary sequence of subdomain IIId plays a key role in HCV IRES-mediated translation

    Peroxiredoxin 6 in human brain: molecular forms, cellular distribution and association with Alzheimer’s disease pathology

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    Peroxiredoxin 6 is an antioxidant enzyme and is the 1-cys member of the peroxiredoxin family. Using two-dimensional electrophoresis and Western blotting, we have shown for the first time that, in human control and brain tissue of patient’s with Alzheimer’s disease (AD), this enzyme exists as three major and five minor forms with pIs from 5.3 to 6.1. Using specific cellular markers, we have shown that peroxiredoxin 6 is present in astrocytes with very low levels in neurons, but not detectable in microglia or oligodendrocytes. In control brains, there was a very low level of peroxiredoxin 6 staining in astrocytes that was confined to a “halo” around the nucleus. In AD, there were marked increases in the number and staining intensity of peroxiredoxin 6 positive astrocytes in both gray and white matter in the midfrontal cortex, cingulate, hippocampus and amygdala. Confocal microscopy using antibodies to Aβ peptide, tau and peroxiredoxin 6 showed that peroxiredoxin 6 positive astrocytes are closely involved with diffuse plaques and to a lesser extent with neuritic plaques, suggesting that plaques are producing reactive oxygen species. There appeared to be little astrocytic response to tau containing neurons. Although peroxiredoxin 6 positive astrocytes were seen to make multiple contacts with tau positive neurons, there was no intraneuronal colocalization. In brain tissue of patients with AD, many blood vessels exhibited peroxiredoxin 6 staining that appeared to be due to the astrocytic foot processes. These results suggest that oxidative stress conditions exist in AD and that peroxiredoxin 6 is an important antioxidant enzyme in human brain defenses

    Enhancement of carotenoids biosynthesis in Chlamydomonas reinhardtii by nuclear transformation using a phytoene synthase gene isolated from Chlorella zofingiensis

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    The isolation and characterization of the phytoene synthase gene from the green microalga Chlorella zofingiensis (CzPSY), involved in the first step of the carotenoids biosynthetic pathway, have been performed. CzPSY gene encodes a polypeptide of 420 amino acids. A single copy of CzPSY has been found in C. zofingiensis by Southern blot analysis. Heterologous genetic complementation in Escherichia coli showed the ability of the predicted protein to catalyze the condensation of two molecules of geranylgeranyl pyrophosphate (GGPP) to form phytoene. Phylogenetic analysis has shown that the deduced protein forms a cluster with the rest of the phytoene synthases (PSY) of the chlorophycean microalgae studied, being very closely related to PSY of plants. This new isolated gene has been adequately inserted in a vector and expressed in Chlamydomonas reinhardtii. The overexpression of CzPSY in C. reinhardtii, by nuclear transformation, has led to an increase in the corresponding CzPSY transcript level as well as in the content of the carotenoids violaxanthin and lutein which were 2.0- and 2.2-fold higher than in untransformed cells. This is an example of manipulation of the carotenogenic pathway in eukaryotic microalgae, which can open up the possibility of enhancing the productivity of commercial carotenoids by molecular engineering

    Outbreak of Pneumonic Plague in 2017 on Madagascar

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    The causes of emergence and development of pneumonic plague outbreak in 2017 on Madagascar were analyzed. Summarized were the literature data, characterizing the spatial and biocoenotic structure of natural plague focus on Madagascar, assessed were the risk factors of plague infection among rural and urban population of the island, as well as the properties of Yersinia pestis strains isolated there in the XX century. It is substantiated that the distinctive type of plague outbreaks on Madagascar is a rural one. It is demonstrated that one of the main causes of wide spread of plague in 2017 is importation of the infection from central regions of the Republic of Madagascar into big cities with further formation of multiple epidemic foci. Confirmed was the circulation of Y. pestis strains that belong to the third branch of irradiation of oriental biovar (1.ORI3). Discussed are the issues of diagnostics and treatment of plague in epidemic foci in the territory of the Republic of Madagascar. The evidence is provided to the fact that the plague outbreak in 2017 on Madagascar is the consequence of a lower surveillance level, first and foremost undervaluation of specific and non-specific prophylaxis capacities regarding this infection
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