190 research outputs found

    Study of the Effect of γ-Irradiation on Copper Single Crystals by Etching Technique

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    The effect of γ-irradiation with low energies on samples of copper single crystals with oriented surfaces of (111), (100) and (621) was studied by etching technique. The etch pits show a formation of glide bands, polygonized walls and Blisters as result to irradiation

    Validated RP-HPLC method for the simultaneous determination of glucosamine sulphate and curcumin in cream formulation: A novel stability-indicating study

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    Purpose: To develop and validate a stability-indicating reverse phase-high performance liquid chromatography (RP-HPLC) method for the simultaneous determination of glucosamine sulphate (GS) and curcumin (Cur) in drug solution and formulation.Methods: The optimized chromatographic conditions were achieved by passing various compositions of mobile phases over  different reverse phase chromatographic columns. Various validation parameters, including linearity, range, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, specificity and system suitability were performed and evaluated. Stability studies under stressed conditions were done to evaluate the effects of acid, alkali, oxidation, heat and degradation by UV light.Results: The validated method was linear over the concentration range of 0.094 to 1.5 mg/mL for GS and 0.125 to 1.5 mg/mL for Cur, with a correlation coefficient > 0.999. The Intra and inter-day precision were 1.9 % for GS and 0.5 % for Cur, while accuracy was 96 and 102 % for GS and Cur, respectively. Stability studies showed that GS was highly sensitive to acid, alkali and oxidation and less sensitive to heat and UV. Cur was stable against acid, heat and oxidation but sensitive to alkali and UV.Conclusion: The developed and validated method was precise and accurate for both GS and Cur and can potentially be utilized for their identification and quantification at industrial, research and quality control laboratories

    РЕАКТОРНЫЕ И ПОСЛЕРЕАКТОРНЫЕ ИСПЫТАНИЯ И ИССЛЕДОВАНИЯ НА БЫСТРЫХ КРИТИЧЕСКИХ СБОРКАХ ВЫСОКОПЛОТНОГО НИЗКООБОГАЩЕННОГО УРАН-ЦИРКОНИЕВОГО КАРБОНИТРИДНОГО ТОПЛИВА

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    UZrCN fuel is a high-density, high-temperature fuel that has potential for application in different type reactors. In the past, reactor tests using UZrCN HEU (96% U-235) fuel have been performed to low burnup. However, reactor-testing data are still needed at high burnup to confirm the optimal performance of this-type fuel. The SM-3 research reactor, which is a high-flux reactor located at the State Scientific Center – Research Institute of Atomic Reactors, Dimitrovgrad, Russia, will be used to test a UZrCN LEU (19.73% U-235) fuel to ~40% of burnup. The fuel will then be examined to determine its performance during irradiation.On the “Giacint” and “Kristal” critical facilities located at the Joint Institute for Power and Nuclear Research – SOSNY of the National Academy of Sciences of Belarus, Minsk, Belarus, criticality experiments on multiplying systems modeling physical features of cores with UZrCN LEU (19.75% U-235) fuel have been prepared for use in works on fast reactors with gaseous and liquid-metal coolants. Critical assemblies represent uniform hexagonal lattices of fuel assemblies, each of which consists of 7 fuel rods and has no clad. The active fuel length is 500 mm. Clad material is stainless steel or Nb. Three types of fuel assemblies with different matrix material (air, aluminum and lead) are investigated. These are side radial, top and bottom reflectors – beryllium (internal layer) and stainless steel (external layer).This article desribes the design of the experiment that will be performed in the SM-3 reactor and discusses the results of different calculations that have been performed to show that the experiment design will meet all objectives. The description of construction and composition of critical assemblies with UZrCN fuel and the calculation results are also presented. Топливо UZrCN представляет собой высокоплотное высокотемпературное топливо, которое может применяться в реакторах различных типов. В прошлом реакторные испытания ВОУ (96% U-235) UzrCN-топлива были выполнены только с низким выгоранием. Вместе с тем данные реакторных испытаний необходимы при высоком выгорании для подтверждения оптимальных характеристик этого типа топлива. Высокопоточный исследовательский реактор СМ-3, расположенный в Государственном научном центре – Научно-исследовательский институт атомных реакторов (г. Димитровград, Россия), будет использоваться для испытания НОУ (19,73% U-235) UzrCN-топлива до ~40 % выгорания. Затем топливо будет исследоваться для определения его характеристик после облучения.На критических стендах «Гиацинт» и «Кристал» в Объединенном институте энергетических и ядерных исследований – Сосны Национальной академии наук Беларуси (г. Минск, Беларусь) осуществляется подготовка к экспериментам по критичности на размножающих системах, моделирующих физические особенности активных зон с НОУ (19,75% U-235) UzrCN-топливом для использования в работах по новому поколению быстрых реакторов с газообразными и жидкометаллическими теплоносителями. Критические сборки представляют собой однородные гексагональные решетки топливных сборок, каждая из которых состоит из семи топливных стержней и не имеет оболочки. Длина активной части топливного стержня составляет 500 мм. Материал оболочки – нержавеющая сталь или ниобий. Будут исследованы три типа топливных сборок с различным материалом матрицы в них (воздух, алюминий и свинец). Боковой радиальный, верхние и нижние отражатели – бериллий (внутренний слой) и нержавеющая сталь (внешний слой).В настоящей статье описываются проектные данные эксперимента, который будет осуществлен на реакторе СМ-3, и обсуждаются результаты расчетов, призванные показать, что эксперимент будет отвечать всем поставленным целям. Также представлены описания конструкции и состава критических сборок с топливом UZrCN и результаты их расчетов.

    An analytical approach for prediction of elastohydrodynamic friction with inlet shear heating and starvation

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    An analytical friction model is presented, predicting the coefficient of friction in elastohydrodynamic (EHD) contacts. Three fully formulated SAE 75W-90 axle lubricants are examined. The effect of inlet shear heating (ISH) and starvation is accounted for in the developed friction model. The film thickness and the predicted friction are compared with experimental measurements obtained through optical interferometry and use of a mini traction machine. The results indicate the significant contribution of ISH and starvation on both the film thickness and coefficient of friction. A strong interaction between those two phenomena is also demonstrated, along with their individual and combined contribution on the EHD friction

    Trypan Blue Dye Enters Viable Cells Incubated with the Pore-Forming Toxin HlyII of Bacillus cereus

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    Trypan blue is a dye that has been widely used for selective staining of dead tissues or cells. Here, we show that the pore-forming toxin HlyII of Bacillus cereus allows trypan blue staining of macrophage cells, despite the cells remaining viable and metabolically active. These findings suggest that the dye enters viable cells through the pores. To our knowledge, this is the first demonstration that trypan blue may enter viable cells. Consequently, the use of trypan blue staining as a marker of vital status should be interpreted with caution. The blue coloration does not necessarily indicate cell lysis, but may rather indicate pore formation in the cell membranes and more generally increased membrane permeability

    IlsA, A Unique Surface Protein of Bacillus cereus Required for Iron Acquisition from Heme, Hemoglobin and Ferritin

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    The human opportunistic pathogen Bacillus cereus belongs to the B. cereus group that includes bacteria with a broad host spectrum. The ability of these bacteria to colonize diverse hosts is reliant on the presence of adaptation factors. Previously, an IVET strategy led to the identification of a novel B. cereus protein (IlsA, Iron-regulated leucine rich surface protein), which is specifically expressed in the insect host or under iron restrictive conditions in vitro. Here, we show that IlsA is localized on the surface of B. cereus and hence has the potential to interact with host proteins. We report that B. cereus uses hemoglobin, heme and ferritin, but not transferrin and lactoferrin. In addition, affinity tests revealed that IlsA interacts with both hemoglobin and ferritin. Furthermore, IlsA directly binds heme probably through the NEAT domain. Inactivation of ilsA drastically decreases the ability of B. cereus to grow in the presence of hemoglobin, heme and ferritin, indicating that IlsA is essential for iron acquisition from these iron sources. In addition, the ilsA mutant displays a reduction in growth and virulence in an insect model. Hence, our results indicate that IlsA is a key factor within a new iron acquisition system, playing an important role in the general virulence strategy adapted by B. cereus to colonize susceptible hosts

    Association of Health Literacy with Complementary and Alternative Medicine Use: A Cross-Sectional Study in Adult Primary Care Patients

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    <p>Abstract</p> <p>Background</p> <p>In the United States, it is estimated that 40% of adults utilize complementary and alternative medicine (CAM) therapies. Recently, national surveys report that over 90 million adults have inadequate health literacy. To date, no study has assessed health literacy and its effect on CAM use. The primary objective of this study was to assess the relationship between health literacy and CAM use independent of educational attainment. Second objective was to evaluate the differential effect of health literacy on CAM use by race.</p> <p>Methods</p> <p>351 patients were recruited from an outpatient primary care clinic. Validated surveys assessed CAM use (I-CAM-Q), health literacy (REALM-R), and demographic information. We compared demographics by health literacy (adequate vs. inadequate) and overall and individual CAM categories by health literacy using chi square statistics. We found a race by health literacy interaction and ran sequential logistic regression models stratified by race to test the association between health literacy and overall CAM use (Model 1), Model 1 + education (Model 2), and Model 2 + other demographic characteristics (Model 3). We reported the adjusted effect of health literacy on CAM use for both whites and African Americans separately.</p> <p>Results</p> <p>75% of the participants had adequate literacy and 80% used CAM. CAM use differed by CAM category. Among whites, adequate health literacy was significantly associated with increased CAM use in both unadjusted (Model 1, OR 7.68; p = 0.001) and models adjusted for education (Model 2, OR 7.70; p = 0.002) and other sociodemographics (Model 3, OR 9.42; p = 0.01). Among African Americans, adequate health literacy was not associated with CAM use in any of the models.</p> <p>Conclusions</p> <p>We found a race by literacy interaction suggesting that the relationship between health literacy and CAM use differed significantly by race. Adequate health literacy among whites is associated with increased CAM use, but not associated with CAM use in African Americans.</p
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