Structural transformations and their impact on the mechanical and antifriction properties in the process of alloying graphitized hypereutectoid steel with copper

The purpose of the work is to develop a cast antifriction material based on an iron-carbon alloy with a high copper content for use in large, heavy duty sliding friction units. Using the casting method in self-hardening liquid glass mixtures, two specimens of hypereutectoid graphitized steel with different copper contents (0.09 and 8.76 wt.%) were produced. To obtain graphite in the steel structure, modification with the silicocalcium (SiCa) was used. The microstructural examination was carried out using optical metallography, SEM and TEM methods. The impact of copper on the structure as well as the mechanical and antifriction properties of graphitized hypereutectoid steel was studied. It was found that adding 8.76 wt.% of copper to the steel composition leads to an increase in the Brinell hardness level of the material from 250 to 300 HB, ultimate tensile strength from 250 to 380 MPa and compressive strength from 1050 to 1200  MPa, which is associated with an increase in the microhardness of pearlite from 350 to 420 HV. To assess the impact of copper on the sliding friction coefficient of graphitized hypereutectoid steel, a curve of sliding friction coefficient vs applied load was plotted; the experiment was carried out according to the liner-on-disk scheme. The wear resistance of materials under sliding friction conditions was also assessed using this method. Copper alloying has a positive effect on the wear resistance of graphitized hypereutectoid steel by increasing the mechanical properties of the material and also by reducing the level of the sliding friction coefficient under boundary lubrication conditions

Plaster Mask from the Oglakhty Cemetery Grave no. 1/2021: Comprehensive Study Experience

Статья представляет результаты изучения женской погребальной маски из захоронения таштыкской культуры на Оглахтинском грунтовом могильнике 2–3 вв.н.э. Основным в нашей работе был материаловедческий подход к изучению маски и связанных с ней остатков. Исследование предпринято с использованием ряда (комплекса) аналитических методов: оптической и сканирующей электронной микроскопии, 3D‑микротомографии, ИК‑рефлектографии и ИК‑микроспектроскопии, рентгенофлюоресцентного анализа и др. Среди основных пигментов росписи – киноварь и гематит, первая была нанесена по сырому гипсу. В качестве добавки в гипсовую смесь впервые идентифицированы оболочки зерен проса обыкновенного (Panicum miliaceum L.). Отпечатки текстиля у глазниц маски проанализированы с точки зрения вида и структуры оставившей их ткани. «Наглазники» были выполнены из шелка простого прямого переплетения с оснóвным настилом, что подтвердилось и сравнением отпечатков на маске с фрагментами шелковых тканей из оглахтинских погребений. Впервые обнаружены и изучены скопления микроскопических волокон вблизи описанных отпечатковThe paper deals with a study of a death mask from the Tashtyk culture grave at the Oglakhty cemetery, 2nd‑3rd centuries AD, and presents its results. Our main approach was that of material science. The study was undertaken using a series of analytical methods such as optical microscopy, scanning electron microscopy (SEM), 3D microtomography, IR reflectography, IR spectroscopy, Raman spectroscopy, UV luminescence, X‑ray reflectometry. Cinnabar and hematite were identified as the main pigments of the painting; the former was applied on raw plaster, whereas the latter above dry plaster surface. Shells of the grains of common millet (Panicum miliaceum L.) turned out to be an additive to the gypsum mixture. Textile imprints near the eye sockets were analyzed to get an insight of the type and structure of the fabric. Clusters of tiny fibers near the textile imprints were noticed and studied for the first time. They are explained as remains of the silk pieces with unhemmed borders, “cought” by liquid plaster in the process of applying it to the person’s face. The fibers could be preserved inside the plaster due to the absence of air and mechanical influence

C9ORF72 hexanucleotide repeat expansion in ALS patients from the Central European Russia population

Cohorts of amyotrophic lateral sclerosis (ALS) patients and control individuals of Caucasian origin from the Central European Russia (Moscow city and region) were analyzed for the presence of hexanucleotide repeat GGGGCC expansion within the first intron of the C9ORF72 gene. The presence of a large (>40) repeat expansion was found in 15% of familial ALS cases (3 of 20 unrelated familial cases) and 2.5% of sporadic ALS cases (6 of 238) but in none of control cases. These results suggest that the frequency of C9ORF72 hexanucleotide repeats expansions in the Central Europea

Использование низкобелковых обогащенных крахмаломучных продуктов в диетотерапии больных фенилкетонурией детей в возрасте старше 1 года

Background. The nutrition of children with phenylketonuria includes specialized starch-based products, the range of which is constantly expanding. Our aim was to study the safety of the composition of starchy flakes enriched with a complex of fat-soluble vitamins, natural fruit and berry additives used in the food of children with phenylketonuria. Methods. The study included children under the age of 14 years who were compliant with the previously conducted hypophenylalanine diet, without acute infectious, severe somatic or neurological diseases. The investigated products (starch-rye, wheat, and wheat fruit flakes with a complex of provitamin A and vitamin E) were prescribed instead of previously used low-protein confectionery products in the amount of 20–25 g/day for children under 6 years, 30–40 g — for children aged 6 years and over. The products were given with the recommendation to use alternately, with a duration of at least 10 days, totally for 30 days of the study. The safety of the products was assessed by phenylalanine concentration in the blood (determined by the fluorimetric method). In addition, we assessed the organoleptic qualities of the products and the dynamics of physical development of children. Results. The study included 15 children, mean age 4.4 ± 1.9 years. The initial concentration of phenylalanine in the blood varied from 1.6 to 3.9 mg%, the median — 2.2 mg% (2.0; 2.8). In 30 days after inclusion of starchy flakes in the diet, the content of phenylalanine in the blood did not change and was 2.5 mg% (2.2; 2.7); p = 0.859. The organoleptic properties of the products were rated «excellent» by all patients and their parents (in children under 6 years, only according to the parents’ assessment). The indicators of physical development did not change. There was no adverse events (allergic reactions, dyspepsia, refusal to take food). Conclusion. Introduction of new functional products — low-protein starchy flakes enriched with a vitamin complex and natural fruit and berry additives — in the diet of children with phenylketonuria allows to maintain the level of phenylalanine in the blood at the level of reference values.Обоснование. В питании детей с фенилкетонурией широко используют специализированные продукты на основе крахмалов, ассортимент которых постоянно расширяется.Цель исследования — изучить безопасность состава хлопьев крахмаломучных, обогащенных комплексом жирорастворимых витаминов, натуральными плодовыми и ягодными добавками, используемых в пище детей с фенилкетонурией.Методы. В исследование включали детей в возрасте до 14 лет, комплаентных к ранее проводимой гипофенилаланиновой диете, без острых инфекционных, тяжелых соматических или неврологических заболеваний. Исследуемые продукты — крахмалоржаные, пшеничные и пшеничные плодово-ягодные хлопья с комплексом провитамина А и витамина Е — назначали взамен применявшихся ранее низкобелковых кондитерских изделий в количестве 20–25 г/сут детям младше 6 лет, по 30–40 г — детям, достигших возраста или старше 6 лет. Продукты выдавали с рекомендацией использовать поочередно, продолжительностью не менее 10 сут, всего на 30 сут исследования. Безопасность продуктов оценивали по концентрации фенилаланина в крови (определяли флюориметрическим методом). Дополнительно оценивали органолептические качества продуктов и динамику физического развития детей.Результаты. В исследование включили 15 детей, средний возраст 4,4±1,9 года. Исходная концентрация фенилаланина в крови варьировала от 1,6 до 3,9 мг%, медиана — 2,2 мг% (2,0; 2,8). Через 30 сут после включения в рацион крахмаломучных хлопьев содержание фенилаланина в крови не изменилось и составило 2,5 мг% (2,2; 2,7); р=0,859. Органолептические свойства продуктов были оценены на «отлично» всеми пациентами и их родителями (у детей в возрасте до 6 лет — только согласно оценке родителей). Показатели физического развития не изменились. Нежелательные явления (аллергические реакции, диспепсии, отказ от приема продуктов) не зафиксированы.Заключение. Введение в рацион детей с фенилкетонурией новых функциональных продуктов — хлопьев крахмаломучных низкобелковых, обогащенных витаминным комплексом и натуральными плодовыми и ягодными добавками, позволяет сохранять уровень фенилаланина в крови на уровне референсных значений.ИСТОЧНИК ФИНАНСИРОВАНИЯ Работа выполнена при поддержке гранта Федерального государственного научного учреждения «Всероссийский научно-исследовательский институт крахмалопродуктов» Федерального агентства научных организаций (Московская область). Для целей исследования использовались продукты, безвозмездно предоставленные производителем (опытное производство ФГНУ «ВНИИК» ФАНО).КОНФЛИКТ ИНТЕРЕСОВ Т.Э. Боровик, Н.Н. Семёнова, О.Л. Лукоянова, Н.Г. Звонкова, Т.В. Бушуева, Т.Н. Степанова, В.А. Скворцова — проведение научно-исследовательских работ при поддержке компаний Heinz, Semper, Хипрока Нутришион Ист Лимитед. И.М. Гусева, Е.А. Рославцева, А.К. Геворкян, С.Т. Быкова, Т.Г. Калинина, С.Г. Калиненкова подтвердили отсутствие конфликта интересов.ВЫРАЖЕНИЕ ПРИЗНАТЕЛЬНОСТИ Выражаем благодарность к.м.н. С.Г. Калиненковой (Московский областной научно-исследовательский клинический институт им. М.Ф. Владимирского) за участие в выполнении лабораторной части данного исследования. 

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Profit optimization with a power-law adjustable coefficient for zero ending inventories dynamic pricing model, stochastic demand, and fixed lifetime product

We consider a single product with a fixed lifetime and price sensitive intensity of a Poisson customers flow. A model with a power adjustable coefficient of a dynamic retail price control through the intensity of the demand is considered providing almost surely zero ending inventories at the end of the product's lifetime. To obtain probabilistic characteristics of the selling process and the expected profit, the diffusion approximation of the stock level process is used. The task of the expected profit maximization with respect to the adjustable coefficient for a linear approximation of the intensity-ofprice dependence is solved. Copyright (C) 2022 The Authors

Price-to-quality ratio dependent demand: keeping the intensity of demand constant

We consider a deterministic model of an inventory system that consists of a single type of perishable product, which is periodically replenished, and a demand depends on price-to-quality ratio (PQR). The product quality decays linearly over time. To keep an intensity of the demand constant we change the price proportionally to the decreasing quality of the product. Exponential and linear dependences of the demand’s intensity of PQR are considered and optimal values of lot size and PQR maximizing the profit per unit time are obtained