Ultrasound in the Intensification of the Concentration of Lead and Cadmium on Sorbents

Показано, що використання одночасної дії ультразвуку високої та низької частот дає змогу покращити стабільність суспензії та метрологічні характеристики отриманих результатів. Розроблено безпечну (без використання токсичних розчинників) методику електротермічного атомно-абсорбційного визначення свинцю і кадмію із чутливістю визначення 0,05 і 0,001 мг/кг відповідно. It is shown that the use of the simultaneous action of ultrasonic high-frequency and low Koi can improve the stability of the suspension and improve the metrological characteristics of the results. Designed without-Pasni (without the use of toxic solvents) method in electro-cal atomic-absorption determination of lead and cadmium sensitivity of the determination of 0.05 and 0.001 mg / kg, respectively.Роботу виконано на кафедрі охорони праці та інженерної педагогіки УІП

Metal-insulator transition induced by 16O -18O oxygen isotope exchange in colossal negative magnetoresistance manganites

The effect of 16O-18O isotope exchange on the electric resistivity was studied for (La(1-y)Pr(y))0.7Ca0.3MnO3 ceramic samples. Depending on y, this mixed perovskite exhibited different types of low-temperature behavior ranging from ferromagnetic metal (FM) to charge ordered (CO) antiferromagnetic insulator. It was found that at y=0.75, the substitution of 16O by 18O results in the reversible transition from a FM to a CO insulator at zero magnetic field. The applied magnetic field (H >= 2 T) transformed the sample with 18O again to the metallic state and caused the increase in the FM transition temperature Tc of the 16O sample. As a result, the isotope shift of Tc at H = 2 T was as high as 63 K. Such unique sensitivity of the system to oxygen isotope exchange, giving rise even to the metal-insulator transition, is discussed in terms of the isotope dependence of the effective electron bandwidth which shifts the balance between the CO and FM phases.Comment: 5 pages (RevTeX), 2 eps figures included, to appear in J. Appl. Phys. 83, (1998

Low molecular weight thymic factor inhibits histamine release from basophils

Low molecular weight thymic factor stimulates the suppressor function of T-lymphocytes, increases cAMP content (but not cGMP) in lymphocytes and inhibits histamine release from sensitized basophils. The mechanisms of LTF action are discussed

Pathogenic characteristics of intracellular infection in chlamydiosis

This review analyzes scientific data and systematized information regarding microbiological aspects and pathogenesis of chlamydia infection. Chlamydia are obligate intracellular microorganisms that are sensitive to any human cells where energy parasitism is possible: various types of epithelium, fibrocytes, histiocytes, glial and muscle cells, squamous epithelium of the meninges and eyeball, neurons, monocytes, macrophages. Structure, chemical composition and enzymatic activity of Chlamydia closely resemble those in Gram-negative bacteria, as they retain their morphological identity throughout the life cycle, possess cell wall, ribosomes, DNA, RNA, biochemical elements of glycolysis, tissue respiration, peptose production being sensitive to some broad-spectrum antibiotics, and are able to vegetative form division. In recent decades, the pathogenesis and clinical symptoms of chlamydial lesions in the urogenital tract, nervous, cardiovascular, musculoskeletal and bronchopulmonary systems have been actively studied, and new approaches and treatment schemes for chlamydia-infected patients are still developing. Over many decades, Chlamydia infection has been an important and urgent problem, not only due to its high prevalence, but also because of high rate of complications negatively affecting populational health and related demographic parameters. Chlamydia causes multiple diseases resulting in chronization of inflammatory process in all human organs and systems, and affects reproduction of population. Mandatory statistical recording of chlamydiosis cases introduced as early as in 1994 in the Russian Federation does not reflect the actual incidence rate. A rise in number of inflammatory diseases of the upper respiratory tract caused by Chlamydia undoubtedly increases its etiological importance, but data regarding etiopathogenetic role of Chlamydia in ENT pathology are ambiguous and contradictory. Available publications describe a large range of variation in rate of detected Chlamydia due to poor awareness of doctors about the microbiological properties of chlamydia, pathogenetic and clinical features of clinical signs of this infection, and lack of common and clear understanding on the algorithms for identifying and treating chlamydiosis. Since the majority of chlamydia-associated nosological forms are asymptomatic, knowing pathogenetic features of related will allow to prevent the spread of the infection and reduce subsequent socio-economic consequences

Structural and Semantic Features of Euphemisms and Dysphemisms (based on the materials of German-languSage articles on the topic of coronavirus)

В статье рассматриваются явления эвфемиии и дисфемии, часто встречающиеся в публицистическом дискурсе. Структурно-семантические особенности эвфемизмов и дисфемизмов позволяют рассматривать их как оценочную лексику, воздействующую на формирование общественного мнения.The article discusses the phenomena of euphemia and dysphemia, which are often found in journalistic discourse. The structural and semantic features of euphemisms and dysphemisms allow us to consider them as evaluative vocabulary affecting the formation of public opinion

Evaluation of the effectiveness of the implementation of the new legislation on control and supervisory activities in the Northern Yekaterinburg department of the Department of Rospotrebnadzor in the Sverdlovsk region

The purpose of the study is to assess the effectiveness of implementation of the new legislation on control and supervisory activities.Цель исследования – провести оценку эффективности реализации нового законодательства о контрольной (надзорной) деятельности

About Possibility of Using Nanoparticles Based on Gadolinium Compounds in Preparations for Diagnostics of Oncological Diseases

The work was supported by D. Mendeleev University of Chemical Technology of Russia (Project № 013-2018)

Non-Perturbative Production of Multi-Boson States and Quantum Bubbles

The amplitude of production of $n$ on-mass-shell scalar bosons by a highly virtual field $\phi$ is considered in a $\lambda \phi^4$ theory with weak coupling $\lambda$ and spontaneously broken symmetry. The amplitude of this process is known to have an $n!$ growth when the produced bosons are exactly at rest. Here it is shown that for $n \gg 1/\lambda$ the process goes through `quantum bubbles', i.e. quantized droplets of a different vacuum phase, which are non-perturbative resonant states of the field $\phi$. The bubbles provide a form factor for the production amplitude, which rapidly decreases above the threshold. As a result the probability of the process may be heavily suppressed and may decrease with energy $E$ as $\exp (-const \cdot E^a)$, where the power $a$ depends on the number of space dimensions. Also discussed are the quantized states of bubbles and the amplitudes of their formation and decay.Comment: 20 pages in LaTeX + 3 figures (fugures not included, hardcopy available on request), TPI-MINN-93/20-

Поведение морфолина и его триметилсилилпроизводного в реакциях с триметилсилилизоцианатом

Objectives. To study the patterns of behavior of morpholine and its trimethylsilyl derivative in reactions with trimethylsilyl isocyanate.Methods. The study employed infrared and nuclear magnetic resonance spectroscopy, as well as elemental analysis.Results. The formation of mixtures of tautomeric forms of silicon-containing urea—N-(trimethylsilyl) morpholine-4-carboxamide and trimethylsilylmorpholine-4-carboximidoate—was established.Conclusions. It is shown that the composition and structure of the resulting products are determined both by the presence of a morpholine substituent at the nitrogen atom and by the type of isocyanate used. Unlike the trimethylsilyl derivative of morpholine, morpholine itself reacts with trimethylsilyl isocyanate to form a mixture of tautomeric forms.Цели. Изучить закономерности поведения морфолина и его триметилсилилпроизводного в реакциях с триметилсилилизоцианатом.Методы. В исследовании использовались методы инфракрасной спектроскопии, спектроскопии ядерного магнитного резонанса и элементного анализа.Результаты. Установлено образование смеси таутомерных форм кремнийсодержащей мочевины: N-(триметилсилил)морфолин-4-карбоксамида и триметилсилилморфолин -4-карбоксимидоата.Выводы. Установлено, что состав и строение образующихся продуктов определяется как наличием заместителя при атоме азота морфолина, так и типом используемого изоцианата. Показано, что, в отличие от триметилсилильного производного морфолина, сам морфолин взаимодействует с триметилсилилизоцианатом с образованием смеси таутомерных форм

Analysis of model for assessing the road train movement stability

In this paper, we conduct a mathematical analysis of the model of ensuring the road trains movement stability by changing the design of coupling devices to determine the critical characteristic parameters of the road trains, which result in the loss of en-route directional stability under external action. The concept of the model was to separate the process of yawing of the road trains and its elements (due to external perturbing action) on the highway into several typical stages. The main parameters of the stages (the displacement amplitude and rotation angle of the road trains elements in relation to the driving direction) were determined based on the initial conditions of the road trains movement, the force and duration of the external action. The most dangerous areas of external action application to the road trains were determined in this paper. The maximum permissible exposure limit should not exceed 0.5-1.0% of the road trains trailer momentum, with duration having the greater effect than the amount of impact. The results obtained can be used in mechanical engineering to improve the road trains performance. © Published under licence by IOP Publishing Ltd