250 research outputs found

    LIGHT SCATTERING IN RESEARCH AND QUALITY CONTROL OF DEUTERIUM DEPLETED WATER FOR PHARMACEUTICAL APPLICATION

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    Objective: Development of a methodology for measuring the deuterium content in water for pharmaceutical purposes by laser light scattering based on ideas about the cluster structure of water. Methods: Samples of industrially manufactured drinking water from different manufacturers with varying deuterium content from 10 ppm to 115 ppm. For the titration of laboratory samples of deuterium depleted water in increments of 5 ppm the following reagents were used: Water, deuterium-depleted (≤1 ppm (D2O, Aldrich, USA); Deuterium oxide/Heavy water/Water-d2 (99.9 atom % D, Aldrich, USA); water Milli-Q (specific resistance 18.2 µS·sm at 25 оС, ТОС ≤ 5 ppb, Merck Millipore). The determination of deuterium content in samples of industrially manufactured water and water obtained in a laboratory manner was carried out by the method of low-angle laser light scattering (LALLS) at the Mastersizer (Malvern Instruments) analyzer and using a working measuring tool–laser dispersion meter/MDL («Cluster-1», Russia/Ukraine). The statistical methods–packages OriginPro®9. Results: It was found that the content of isotopologies in water leads to physicochemical water’s properties changes and morphology changes of giant heterogeneous clusters (GHC). The results of low-angle laser light scattering (LALLS) in the water samples under investigation showed the dependence of the water GHC "dispersibility" expressed in the differentiation of curves of the volume size distribution ("size spectra"), the volume concentration, w%, the laser obscuration values (I ‒I0) as the function of the water isotopic composition variations. The laser diffraction method results correlate with two-dimensional (2D) multi-descriptor mathematical analysis. Conclusion: When identifying deuterium depleted water, it should be considered not only the indicators that determine its pharmacopoeial quality, but also the D/H ratio, because even small changes in the natural isotopic composition of water lead to significant biological effects. Our proposed approach using laser diffraction in combination with mathematical apparatus of (2D) multi-descriptor laser scattering analysis makes possible the exact calculation of individual signs of deuterium depleted water as the pharmaceutical object of study

    Strong 3D correlations in vortex system of Bi2212:Pb

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    The experimental study of magnetic flux penetration under crossed magnetic fields in Bi2212:Pb single crystal performed by magnetooptic technique (MO) reveals remarkable field penetration pattern alteration (flux configuration change) and superconducting current anisotropy enhancement by the in-plane field. The anisotropy increases with the temperature rise up to Tm=54±2KT_m = 54 \pm 2 K. At T=TmT = T_m an abrupt change in the flux behavior is found; the correlation between the in-plane magnetic field and the out-of-plane magnetic flux penetration disappears. No correlation is observed for T>TmT > T_m. The transition temperature TmT_m does not depend on the magnetic field strength. The observed flux penetration anisotropy is considered as an evidence of a strong 3D - correlation between pancake vortices in different CuO planes at T<TmT < T_m. This enables understanding of a remarkable pinning observed in Bi2212:Pb at low temperatures.Comment: 8 pages, 9 figure

    Commemorative Project “Kovalevsky Forest”: Conflicts of Mnemonic Actors and Strategies for Resolving Them (2001–2022)

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    Статья поступила в редакцию 01.04.2024; одобрена после рецензирования 15.04.2024; принята к публикации 30.04.2024.The article was submitted 01.04.2024; approved after reviewing 15.04.2024; accepted for publication 30.04.2024.В статье рассматриваются конфликты между мнемоническими акторами вокруг коммеморативного проекта Ковалевского леса как места увековечения памяти жертв красного террора 1920-х гг. Опираясь на идеи О. Двейера и Д. Альдермана об изучении мемориальных объектов, анализируются столкновения между акторами по поводу степени их вовлеченности в формирование проекта и включаемых в него фигур. Автор приходит к выводам о том, что мнемонические акторы, заинтересованные в преодолении забвения красного террора, стремились создать в Ковалевском лесу мифологизированную версию прошлого для посетителей, для которых память о репрессиях, терроре и его жертвах вынесена за черту города. В процессе развития проекта Ковалевский лес становится гибким пространством, в котором выделяется место для многих мифов. Для успешной реализации проекта акторы были готовы выстраивать свои отношения как взаимно принимающие и соглашались с включением в него многих нарративов.The article examines the conflicts between mnemonic actors regarding the commemorative project of the Kovalevsky Forest as a place to perpetuate the memory of the victims of the Red Terror of the 1920s. Based on the ideas of O. Dwyer and D. Alderman on the study of memorial objects, the author in the article analyzes the conflicts between actors regarding the level of their involvement in the formation of the project and the figures included in it. The author comes to the conclusion that mnemonic actors interested in overcoming the oblivion of the Red Terror sought to create a mythologized version of the past in the Kovalevsky Forest for visitors for whom the memory of repression, terror and its victims was carried outside the city borders. In the process of development of the project, the Kovalevsky Forest becomes a flexible space with many myths. To successfully implement the project, the actors were ready to build their relationships as mutually accepting and agreed to include many narratives in it

    PREPARATION, CHARACTERIZATION AND STUDIES OF PHYSICOCHEMICAL AND BIOLOGICAL PROPERTIES OF DRUGS COATING LACTOSE IN FLUIDIZED BEDS

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    Objective: Study physicochemical properties and activity of biotechnological drugs coating lactose particles in fluidized beds for the development of a prospective approach of their identification. Methods: Lactose monohydrate as pharmaceutical excipient; affinity-purified polyclonal rabbit antibodies to recombinant human interferon-gamma as a drug substance; Pilotlab fluid bed apparatus was used for lactose powder saturation with solutions of pharmaceutical substances to the point of granulation (pelletizing); inverse light scattering method (2D-LS) for analysis of micron vibrations frequency spectra of samples surfaces for light intensity distribution in time by values of d1, d2, d3 primary descriptors; low angel and dynamic laser light scattering (LALLS, DLS) methods for distribution of lactose-water (LW) supramolecular complexes into volume fractions (micron "size spectra"), using the Master Sizer 2000 instrument and Zeta Sizer Nano ZS instrument in the nanoscale; Spirotox method for research of biological activity to determine the activation energy (Ea) values of cell death in solutions of tested samples. Results: Changes in 2D-LS scattering time on sample surfaces, described by topological descriptors, made it possible to clearly differentiate the intact lactose from fluidized samples by specific corridors in coordinates di=F(t). The calculated activation energy (Ea) values of cell biosensor death process in solutions of drugs coating lactose allow to characterize the biological activity of it in the initial (by Ea increase) and activated state (by Ea decrease) after the creation of intra-laboratory transmucosal conditions. A unique dimensional spectrum of LW complexes in the nanoscale range was obtained by DLS. The differences between samples in the distribution of LW complexes in the size range from 1 µm to 125 µm was showed by LALLS. Conclusion: The developed approach, including Сhemometrics, laser and biotesting methods can be used for qualitative the analysis tasks as well as for analytical control of the fluidization process in cases where identifiable pharmaceutical substances are not distinguishable by traditional analytical methods

    VASCULAR DEMENTIA

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    The review gives data on the epidemiology, terminology, diagnostic criteria, and standards for the examination and treatment of patients with vascular cognitive disorders and vascular dementia (VD). The heterogeneity of vascular cognitive disorders, concurrence of vascular and neurodegenerative diseases are discussed. Data from studies of specific therapy for VD are given

    POLARIMETRY AND DYNAMIC LIGHT SCATTERING IN QUALITY CONTROL OF CARDIOTONIC AND HYPOTENSIVE TINCTURES

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    Objective: To substantiate the possibility of using polarimetry to control the quality of tinctures as an additional pharmacopoeial method. Methods: The polarimetric method (POL-1/2, Atago, Japan, the measurement accuracy of±0.002 °) was used to measure the optical activity (α °) of motherwort, valerian and hawthorn tinctures. The dynamic light scattering method (DLS; Zetasizer Nano ZS, Malvern, UK) was used to assess the stability of alcoholic and aqueous dilutions of tinctures according to the intensity of dynamic light scattering dependent on the size (d, nm) of the dispersed phase particles and the values of the electrokinetic potential (ξ, mV). Results: For the first time in this investigation, the polarimetry approach was proposed to evaluate the cardiotonic and hypotensive tinctures' quality and for their identification. Valerian tincture, dilution 1:40,-0.10°&lt;α°&lt;-0.89°; motherwort, tincture-dilution 1:10,-0.10°&lt;α°&lt;-2.21°; hawthorn, tincture without dilution,-0.76°&lt;α°&lt;-1.55°-these are the acceptable ranges of optical activity (α°) of their alcohol dilutions. Beyond these intervals, the use of the polarimetric approach is impossible. Values of optical activity below 0.1 correspond to too low a content of optically active components. Tinctures with optical activity above the upper value of the interval were unstable dispersed systems with low values of the electrokinetic potential (|ξ|≪25mV) and micron particle sizes. Reference tinctures were made from raw materials (Leonurus cardiaca L.) to verify the results. The quality parameters: optical activity (α°), spectra of dynamic light scattering by intensity, volume, and number ("I-d"; "V-d"; "N-d"), electrokinetic potential (ξ) values, and photon pulse count per second (Count Rate, kcps) corresponded to the results obtained for pharmaceutical dosage forms. Conclusion: The permissible intervals of optical activity (α°) of their ethanol dilutions, as well as their relationships with the particle size of the dispersed phase and the values of the electrokinetic potential, were established for the first time to evaluate the quality of tinctures. The obtained results show that polarimetry can be recommended as an additional pharmacopoeial quality control method for tinctures

    Sorption Properties of Clay and Pectin-Containing Hydrogels

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    As is known, polymeric polyelectrolyte hydrogels are superabsorbents that are capable of absorbing moisture in amounts many times greater than their own mass. Numerous studies have shown that besides water absorption and retention, they can also be effectively used as sorbents to purify water from heavy metals. In many works, attempts are made to improve the sorption properties of polyelectrolyte hydrogels by creating polymer composites based on them. Organic/inorganic composite materials frequently exhibited desired hybrid performance superior to their individual components and cost-efficient characteristics. The composites derived from natural polysaccharides and inorganic clay minerals are of special interest by virtue of their unique commercial and environmental advantages, which means that the design and development of environmentally friendly superabsorbents, introducing natural ingredients, have long been necessary. In this paper, we consider polymer hydrogels based on a copolymer of acrylic acid and acrylamide filled with pectin and bentonite. The aim of this study is to investigate the influence of chemical conditions on hydrogels and their composites, kinetic, and absorption behavior toward metal ions in the presence of the chelating agent. In this chapter, an investigation of the kinetic patterns of swelling, deswelling, and sorption of the hydrogels and their composites will be presented

    PHYSICOCHEMICAL PROPERTIES AND BIOLOGICAL ACTIVITY OF THE NEW ANTIVIRAL SUBSTANCE

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    Objective: To develop a set of quality control procedures for the promising antiviral pharmaceutical substance L-histidyl-1-adamantylethylamine dihydrochloride monohydrate, a derivative of rimantadine. Methods: Substances and solvents: synthesized in laboratory L-histidyl-1-adamantylethylamine dihydrochloride monohydrate (H-His-Rim•2HCl•H2O), rimantadine hydrochloride (Rim•HCl), 99%, ethanol 96%, N, N-dimethylformamide (DMF) anhydrous, 99.8% and n-hexane anhydrous, 95%, deionized high-resistance water (18.2 MΩ•cm at 25 °C, Milli-Q system), silver nitrate. Infrared (IR) Spectroscopy–Cary 630 Fourier Transform IR Spectrometer, elemental analysis–elemental composition analyzer CHNS-O EuroEA3000, ultraviolet (UV) spectrometry–Cary-60 spectrophotometer, polarimetry–POL-1/2 polarimeter with an external Peltier module, granulometric analysis by optical microscopy (Altami BIO 2 microscope) and low-angle laser light scattering (LALLS)–Master Sizer 3600, measurement of potential for hydrogen–potentiometer PB-11, Spirotox method–the study of temperature dependences of Spirostomum ambiguum lifetime to characterize the biological activity of the studied compounds. Results: The substance H-His-Rim•2HCl•H2O is an amorphous yellowish powder, slightly soluble in water, soluble in ethanol, freely soluble in N, N-dimethylformamide, and practically insoluble in n-hexane. A study of the elemental composition has confirmed the authenticity of H-His-Rim•2HCl•H2O. Comparison of the spectral characteristics of H-His-Rim•2HCl•H2O and Rim•HCl by IR spectroscopy and UV spectrometry confirmed the authenticity of the substance. The racemic form of the substance Rim•HCl with an insignificant amount of impurity of the levorotatory enantiomer was proved polarimetrically: α =-0.0126±0.0003 (1% aqueous solution, 20±0.5 °С). The specific optical rotation of 1% aqueous solution H-His-Rim•2HCl•H2O . In 1% ethanol solution -10.32±0.12. Using the method of laser light diffraction for a substance H-His-Rim•2HCl•H2O, the dimensional spectra «fraction of particles, %-d, μm» were characterized, the maximum of which in hexane is in the region of 40–50 μm. Arrhenius’s kinetics on the Spirotox model established statistically significant differences in ligand-receptor interactions, which are characterized by values of observed apparent activation energy °bsEa, kJ/mol: 132.36±1.55 for H-His-Rim•2HCl•H2O and 176.15±0.48 for Rim•HCl. Conclusion: The developed set of methods for assessment of physical and chemical properties and biological activity of a new antiviral substance H-His-Rim•2HCl•H2O is the basis for establish of regulatory documentation

    Inter- and intragrain currents in bulk melt-grown YBaCuO rings

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    A simple contactless method suitable to discern between the intergrain (circular) current, which flows in the thin superconducting ring, and the intragrain current, which does not cross the weakest link, has been proposed. At first, we show that the intergrain current may directly be estimated from the magnetic flux density B(±z0)B(\pm z_0) measured by the Hall sensor positioned in the special points ±z0\pm z_0 above/below the ring center. The experimental and the numerical techniques to determine the value z0z_0 are discussed. Being very promising for characterization of a current flowing across the joints in welded YBaCuO rings (its dependencies on the temperature and the external magnetic field as well as the time dissipation), the approach has been applied to study corresponding properties of the intra- and intergrain currents flowing across the aa-twisted grain boundaries which are frequent in bulk melt-textured YBaCuO samples. We present experimental data related to the flux penetration inside a bore of MT YBaCuO rings both in the non-magnetized, virgin state and during the field reversal. The shielding properties and their dependence on external magnetic fields are also studied. Besides, we consider the flux creep effects and their influence on the current re-distribution during a dwell.Comment: 13 pages, 16 figures (EPS), RevTeX4. In the revised version, corrections to perturbing effects near the weak links are introduced, one more figure is added. lin
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