The choice of analytes’ powder-carrier for preparing calibration samples when analyzing welding fumes using X-ray fluorescence

Введение. Рассмотрены процессы образования твердой составляющей сварочных аэрозолей (ТССА); показано, что частицы ТССА отличаются фазовым и химическим составом, дисперсностью в зависимости от свариваемых материалов и условий сварки; основными фазами является магнетит Fe₃O₄ и железомарганцевая шпинель MnFe₂O₄. Проблема. Определение градуировочных характеристик недеструктивных методик рентгенофлуоресцентного анализа (РФА) и проверка правильности методик количественного химического анализа ТССА осложнены отсутствием стандартных образцов. Создание аттестованных смесей, адекватных реальным пробам ТССА, собранным на фильтр, затруднено из-за сложности их физико-химических свойств. Эксперимент. Приготовлены синтетические образцы в виде тонкой органической пленки, содержащей порошковые соединения элементов, контролируемых в ТССА. Проведены исследования по выбору порошкового носителя аналитов для создания аттестованных смесей. Оценено максимальное значение размера зерен порошка, когда эффектом микроабсорбционной неоднородности можно пренебречь на фоне случайной погрешности изготовления пленочных аттестованных смесей. Экспериментально доказано, что в качестве порошка-носителя аналитов при создании градуировочных образцов для недеструктивных методик РФА проб ТССА допустимо применять любые соединения аналитов, если размер их частиц менее 4 мкм. Результаты. Создан комплект пленочных аттестованных смесей, которые можно рекомендовать в качестве градуировочных образцов для недеструктивных методик РФА; погрешность их изготовления характеризуется коэффициентом вариации 5-6 %.The processes of forming the solid component of welding fumes (SCWF) are considered; the particles of SCWF are shown to differ in phase and chemical composition, and dispersion depending on welding materials and welding conditions; the magnetite Fe₃O₄ and the iron-manganese spinel MnFe₂O₄ are the main phases. The determination of calibration characteristics of non-destructive techniques and the validation of the techniques for quantitative chemical analysis of SCWF are complicated by the lack of certified reference materials. The development of certified mixtures, appropriate to real samples of SCWF collected on a filter, is difficult because of the complexity of their physical and chemical properties. The synthetic samples were prepared in the form of an organic thin film containing the powder compounds of elements controlled in the SCWF. The studies were conducted to choose the powder-carrier of analytes for developing the certified mixtures. The maximum size value of powder grains were estimated when the effect of micro absorption heterogeneity can be neglected on the background of random error in preparing film certified mixtures. It is experimentally proven that any analyte compounds are suitable for use as a powder-carrier of analytes in developing the calibration samples for the non-destructive techniques of X-ray fluorescence analysis (XRF) of SCWF samples if their particle sizes are less than 4 microns. A set of film certified mixtures was developed, which can be recommended as the calibration samples for the non-destructive XRF techniques; the error in their preparation is characterized by the variation coefficient of 5-6 %

Visualization of microtubule growth in cultured neurons via the use of EB3-GFP (end-binding protein 3-green fluorescent protein)

Several microtubule binding proteins, including CLIP-170 (cytoplasmic linker protein-170), CLIP-115, and EB1 (end-binding protein 1), have been shown to associate specifically with the ends of growing microtubules in non-neuronal cells, thereby regulating microtubule dynamics and the binding of microtubules to protein complexes, organelles, and membranes. When fused to GFP (green fluorescent protein), these proteins, which collectively are called +TIPs (plus end tracking proteins), also serve as powerful markers for visualizing microtubule growth events. Here we demonstrate that e

Efficiency in a forced contribution threshold public good game

We contrast and compare three ways of predicting efficiency in a forced contribution threshold public good game. The three alternatives are based on ordinal potential, quantal response and impulse balance theory. We report an experiment designed to test the respective predictions and find that impulse balance gives the best predictions. A simple expression detailing when enforced contributions result in high or low efficiency is provided

Ethylene supports colonization of plant roots by the mutualistic fungus Piriformospora indica

The mutualistic basidiomycete Piriformospora indica colonizes roots of mono- and dicotyledonous plants, and thereby improves plant health and yield. Given the capability of P. indica to colonize a broad range of hosts, it must be anticipated that the fungus has evolved efficient strategies to overcome plant immunity and to establish a proper environment for nutrient acquisition and reproduction. Global gene expression studies in barley identified various ethylene synthesis and signaling components that were differentially regulated in P. indica-colonized roots. Based on these findings we examined the impact of ethylene in the symbiotic association. The data presented here suggest that P. indica induces ethylene synthesis in barley and Arabidopsis roots during colonization. Moreover, impaired ethylene signaling resulted in reduced root colonization, Arabidopsis mutants exhibiting constitutive ethylene signaling, -synthesis or ethylene-related defense were hyper-susceptible to P. indica. Our data suggest that ethylene signaling is required for symbiotic root colonization by P. indica

Potential health impacts of heavy metals on HIV-infected population in USA.

Noninfectious comorbidities such as cardiovascular diseases have become increasingly prevalent and occur earlier in life in persons with HIV infection. Despite the emerging body of literature linking environmental exposures to chronic disease outcomes in the general population, the impacts of environmental exposures have received little attention in HIV-infected population. The aim of this study is to investigate whether individuals living with HIV have elevated prevalence of heavy metals compared to non-HIV infected individuals in United States. We used the National Health and Nutrition Examination Survey (NHANES) 2003-2010 to compare exposures to heavy metals including cadmium, lead, and total mercury in HIV infected and non-HIV infected subjects. In this cross-sectional study, we found that HIV-infected individuals had higher concentrations of all heavy metals than the non-HIV infected group. In a multivariate linear regression model, HIV status was significantly associated with increased blood cadmium (p=0.03) after adjusting for age, sex, race, education, poverty income ratio, and smoking. However, HIV status was not statistically associated with lead or mercury levels after adjusting for the same covariates. Our findings suggest that HIV-infected patients might be significantly more exposed to cadmium compared to non-HIV infected individuals which could contribute to higher prevalence of chronic diseases among HIV-infected subjects. Further research is warranted to identify sources of exposure and to understand more about specific health outcomes

АНАЛІЗ НЕСПРИЯТЛИВИХ ПОДІЙ ПІСЛЯ ІМУНІЗАЦІЇ ВАКЦИНАМИ ПРОТИ SARS CoV-2

Although the WHO-recommended coronavirus vaccines are safe and effective, vaccines provide new information to healthcare professionals about the extent and nature of adverse reactions to these drugs. The aim of the study is supplementing the available data on adverse reactions of vaccines on the example of the experience of vaccination of the teaching staff of the Cherkasy Medical Academy with vaccines COVISHIELD and COMIRNATY. Information for this study was collected retrospectively through a survey of 72 employees of the Cherkasy Medical Academy who were vaccinated with the COVISHIELD vaccine (first dose); 67 workers vaccinated with AstraZeneca (second dose); 54 workers who were vaccinated with COMIRNATY vaccine (first dose); 52 people vaccinated with this vaccine (second dose). The study confirmed that among the local side effects, the most common were pain at the injection site, among the systemic - fever, weakness, fatigue and drowsiness, headache, muscle pain, chills. Most of the side effects were most pronounced in young people, more often in women than in men.Although the WHO-recommended coronavirus vaccines are safe and effective, vaccines provide new information to healthcare professionals about the extent and nature of adverse reactions to these drugs. The aim of the study is supplementing the available data on adverse reactions of vaccines on the example of the experience of vaccination of the teaching staff of the Cherkasy Medical Academy with vaccines COVISHIELD and COMIRNATY. Information for this study was collected retrospectively through a survey of 72 employees of the Cherkasy Medical Academy who were vaccinated with the COVISHIELD vaccine (first dose); 67 workers vaccinated with AstraZeneca (second dose); 54 workers who were vaccinated with COMIRNATY vaccine (first dose); 52 people vaccinated with this vaccine (second dose). The study confirmed that among the local side effects, the most common were pain at the injection site, among the systemic - fever, weakness, fatigue and drowsiness, headache, muscle pain, chills. Most of the side effects were most pronounced in young people, more often in women than in men

Анализ инновационных технологий гидрогелей из уронатных полисахаридов и биодеградирующих пленок на их основе

The article is devoted to the analysis of the state and dynamics of scientific developments in the field of creating products for life and health, based on hydrogels from uronate polysaccharides (HUP). The article is reflected the results of the global scientific research monitoring and their changes in the field of technologies for the creation and use of HUP. The results of a retrospective analysis of existing technologies based on poorly studied in the field of food technologies uronic acids, as glucuronic, idouronic, hyaluronic were presented. The study showed, that nowadays the industry of products with their content is acquiring market traits, although it has insufficient scientific substantiation. Development segments with widely used uronate polysaccharides – pectins and alginates – according to the types of hydrogels (swollen hydrogel, cross-linked hydrogel, xerogel) were developed. The article presents examples and identified the required properties of substances intended for immobilization or encapsulation in the hydrogel matrix of uronate polysaccharides. The basic principles of uronate polysaccharides crosslinking chains in the hydrogel phase are determined. Possible methods of biologically active substances (BAS) retention in the matrix of uronate polysaccharides to reduce the risk of premature oxidation, destruction, decomposition, decomposition, evaporation were described. The search for information allowed us to identify key technological areas for the development of scientific research on the creation and use of HUP to improve people's lives and health. The archives of the world's leading publications in the field of food chemistry, biotechnology, food engineering, chemistry of new materials, food polymers and hydrocolloids were analyzed. The authors used in their work the resources of the Science Direct search system, which made it possible to determine the most promising and modern lines of development of HUP technologies and products based on them. The analysis of technologies has shown that existing innovative technologies are formed on “basic” technologies for producing solutions of high-molecular compounds under various conditions. Active modernization is carried out in the direction of creating products with immobilized biologically active substances, as well as in attempts to compose a composition with other polysaccharides and/or peptide components. The article notes that existing technologies allow developing other technologies with the help of which it is possible to expand the field of HUP application.Статья посвящена анализу состояния и динамике научных разработок в области создания продуктов для жизни и здоровья на основе гидрогелей из уронатных полисахаридов (ГУП). В статье отражены результаты мониторинга мировых научных исследований и их изменений в области технологий создания и применения ГУП. Авторы представили результаты ретроспективного анализа существующих технологий на основе малоизученых в области пищевых технологий уроновых кислот: глюкуроновая, идоуроновая, гиалуроновая. Исследование показало, что на сегодня индустрия продуктов с их содержанием приобретает вполне рыночные черты, хотя и имеет недостаточно полное научное обоснование. Сформированы сегменты разработок с широко используемыми уронатными полисахаридами - пектинами и альгинатами – по видам гидрогелей (гидрогель набухший, гидрогель сшитый, ксерогель). В статье представлены примеры и выявлены требуемые свойства веществ, предназначенных для иммобилизации или инкапсуляции в матрицу гидрогеля из уронатных полисахаридов. Определены основные принципы сшивания цепочек уронатных полисахаридов в фазе гидрогеля. Описаны возможные способы удержания биологически активных веществ (БАВ) в матрице уронатных полисахаридов для снижения риска преждевременного окисления, деструкции, разложения, распада, испарения. Поиск информации позволил определить ключевые технологические области развития научных исследований по созданию и применению ГУП для улучшения жизни и здоровья людей. Проанализированы архивы ведущих мировых изданий в области пищевой химии, биотехнологии, пищевой инженерии, химии новых материалов, пищевых полимеров и гидроколлоидов. Авторы использовали в работе ресурсы поисковой системы Science Direct, что позволило определить наиболее перспективные и современные направления развития технологий ГУП и продуктов на их основе. Анализ технологий показал, что существующие инновационные технологии сформированы на “базисных” технологиях получения растворов высокомолекулярных соединений при различных условиях. Активная модернизация проводится в направлении создания продуктов с иммобилизированными БАВ, а также в попытках составить композицию с другими полисахаридами и/или пептидными составляющими. В работе отмечается, что существующие технологии позволяют развивать другие технологии, с помощью которых возможно расширить сферы применения ГУП