Efficacy and safety of Chondroxide ointment in combine therapy of osteoarthritis patients

Objective. To assess the efficace and safety of Chondroxide ointment in OA pts. Methods. 27 OA pts were included in clinical investigation. All the pts used Chondroxide preparation as a topical application. Results. Considerable and marced improvement were achieved in 18 OA pts (66,6%). In 9 cases the efficacy of treatment was abcent. Conclusion. Chondroxide ointment is highly effective and safe preparation in OA pts treatmen

Цифровые образовательные практики студентов в условиях локдауна

 Introducing digital technologies in education is a priority task of the current stage of the country’s development, which relevance and significance has been manifested during the pandemic. The education system found itself in a situation of a total forced transition to the online learning format. This transition revealed a whole range of problems related to online learning. Organizational, technical, methodological, psychological problems faced the participants of the educational process. Forced digitalization became a test for the education system, which is aimed with training personnel for the digital economy. The discussion on ways to digitalize education was expanding in the context of a lockdown by assessing the experience gained during this period. It becomes obvious that digitalization is possible provided both by technical readiness of the system, and the psychologically prepared key participants in the educational process. The authors turn to the research of students’ readiness for online learning, digital methods of acquiring knowledge using the experience of online learning in a pandemic. The study methodological basis is the digital sociology theses on the role and significance of digital technologies as intermediaries in social interaction (F. Nitsevich). Digital technologies change the patterns of social interaction, social relationships, and human self- image. The study objective is to identify the innovative potential of students, their readiness to master and use digital technologies in the educational process, and to online learning. The main hypothesis of the study is online education requires the formed digital competencies of students, equipment availability, students’ internal readiness to study online, however, the previous educational experience of students does not provide them with digital learning skills determining the difficulties of online education in the pandemic. Based on a questionnaire survey of the technical university students the with online learning experience carried out by the authors, the paper identifies the students’ attitudes to (1) readiness for the transition to distance educational technologies; (2) continuing such practices after lifting the quarantine restrictions, using information and communication technologies for distance learning tech- nologies; (3) assessing the organization of the university and personal digital educational environ (availability of devices and software, access to the Internet), evaluating student involvement in the educational process in the context of online learning; (4) estimating the digital skills and competencies (user and professional) of students. Results: The study reveals a range of problems faced students during the period of distant learning; gives a characteristic of students’ readiness to use digital educational technologies. The work practical significance is the results obtained can be used to improve online learning methods, procedures for involving students in the educational process, and assessing their educational results.Внедрение цифровых технологий в образование – это одна из приоритетных задач современ- ного этапа развития страны, актуальность и значимость которой проявилась в период пандемии. В этот период система образования оказалась в ситуации тотального вынужденного перехода к формату онлайн-обучения. Форсированный переход проявил целый комплекс проблем, связанных с онлайн-обучением. Организационные, технические, методические, психологические проблемы – круг проблем, с которыми столкнулись участники образовательного процесса. Форсированная цифровизация стала испытанием для системы образования, на которую возложена задача подготовки кадров для цифровой экономики. Дискуссия о путях цифровизации образования расширяется в условиях локдауна оценками опыта, полученного в этот период. Становится очевидным, что цифровизация возможна не только при условии технической готовности системы, но и при условии психологической готовности к ней ключевых участников образовательного процесса. Авторы обращаются к исследованию готовности студентов к онлайн-обучению, к цифровым способам получения знаний, используя опыт онлайн-обучения в период пандемии. Методологической основой исследования стали положения цифровой социологии о роли и значении цифровых технологий как посредников в социальном взаимодействии (Ф. Ницевич). Цифровые технологии изменяют модели социального взаимодействия, социальные отношения и представления человека о самом себе. Цель исследования – выявить инновационный потенциал студентов, их готовность к освоению и использованию цифровых технологий в образовательном процессе и к онлайн-обучению. Основная гипотеза исследования сводилась к тому, что образование онлайн требует сформированных цифровых компетенций студентов, наличия технической оснащенности, внутренней готовности студента обучаться онлайн, однако предшествующий образовательный опыт, имеющийся у студентов, не обеспечивает им навыков цифрового обучения, что определило сложности образования онлайн в период пандемии. Позиции студентов (1) о готовности к переходу на дистанционные образовательные технологии; (2) отношение к продолжению таких практик после отмены карантинных ограничений и использованию информационно- коммуникативных технологий для дистанционных образовательных технологий; (3) оценки организации цифровой образовательной среды вуза и личной цифровой образовательной среды (наличие устройств и ПО, доступ к интернету); (4) оценки вовлеченности студентов в образовательный процесс в условиях онлайн-обучения; (5) оценки цифровых навыков и компетенций (пользовательских и профессиональных) студентов выявлены на основании проведенного авторами анкетного опроса студентов отраслевого вуза. Результаты: выявлен круг проблем, с которыми столкнулись студенты в период обучения с применением дистанционных технологий, дана характеристика готовности студентов к использованию цифровых образовательных технологий. Практическая значимость работы состоит в том, что полученные результаты могут быть использованы для совершенствования методик онлайн-обучения, процедур вовлечения студентов в образовательный процесс и оценивания их образовательных результатов

Quantitative localized proton-promoted dissolution kinetics of calcite using scanning electrochemical microscopy (SECM)

Scanning electrochemical microscopy (SECM) has been used to determine quantitatively the kinetics of proton-promoted dissolution of the calcite (101̅4) cleavage surface (from natural “Iceland Spar”) at the microscopic scale. By working under conditions where the probe size is much less than the characteristic dislocation spacing (as revealed from etching), it has been possible to measure kinetics mainly in regions of the surface which are free from dislocations, for the first time. To clearly reveal the locations of measurements, studies focused on cleaved “mirror” surfaces, where one of the two faces produced by cleavage was etched freely to reveal defects intersecting the surface, while the other (mirror) face was etched locally (and quantitatively) using SECM to generate high proton fluxes with a 25 μm diameter Pt disk ultramicroelectrode (UME) positioned at a defined (known) distance from a crystal surface. The etch pits formed at various etch times were measured using white light interferometry to ascertain pit dimensions. To determine quantitative dissolution kinetics, a moving boundary finite element model was formulated in which experimental time-dependent pit expansion data formed the input for simulations, from which solution and interfacial concentrations of key chemical species, and interfacial fluxes, could then be determined and visualized. This novel analysis allowed the rate constant for proton attack on calcite, and the order of the reaction with respect to the interfacial proton concentration, to be determined unambiguously. The process was found to be first order in terms of interfacial proton concentration with a rate constant k = 6.3 (± 1.3) × 10–4 m s–1. Significantly, this value is similar to previous macroscopic rate measurements of calcite dissolution which averaged over large areas and many dislocation sites, and where such sites provided a continuous source of steps for dissolution. Since the local measurements reported herein are mainly made in regions without dislocations, this study demonstrates that dislocations and steps that arise from such sites are not needed for fast proton-promoted calcite dissolution. Other sites, such as point defects, which are naturally abundant in calcite, are likely to be key reaction sites

Directed emission of CdSe nanoplatelets originating from strongly anisotropic 2D electronic structure

ntrinsically directional light emitters are potentially important for applications in photonics including lasing and energy-efficient display technology. Here, we propose a new route to overcome intrinsic efficiency limitations in light-emitting devices by studying a CdSe nanoplatelets monolayer that exhibits strongly anisotropic, directed photoluminescence. Analysis of the two-dimensional k-space distribution reveals the underlying internal transition dipole distribution. The observed directed emission is related to the anisotropy of the electronic Bloch states governing the exciton transition dipole moment and forming a bright plane. The strongly directed emission perpendicular to the platelet is further enhanced by the optical local density of states and local fields. In contrast to the emission directionality, the off-resonant absorption into the energetically higher 2D-continuum of states is isotropic. These contrasting optical properties make the oriented CdSe nanoplatelets, or superstructures of parallel-oriented platelets, an interesting and potentially useful class of semiconductor-based emitters

Wave instabilities in the presence of non vanishing background in nonlinear Schrodinger systems

We investigate wave collapse ruled by the generalized nonlinear Schroedinger (NLS) equation in 1+1 dimensions, for localized excitations with non-zero background, establishing through virial identities a new criterion for blow-up. When collapse is arrested, a semiclassical approach allows us to show that the system can favor the formation of dispersive shock waves. The general findings are illustrated with a model of interest to both classical and quantum physics (cubic-quintic NLS equation), demonstrating a radically novel scenario of instability, where solitons identify a marginal condition between blow-up and occurrence of shock waves, triggered by arbitrarily small mass perturbations of different sign

Multi-photon absorption limits to heralded single photon sources

This work was supported in part by the Centre of Excellence (CUDOS, project number CE110001018), Laureate Fellowship (FL120100029) and Discovery Early Career Researcher Award (DE120102069, DE130101148, and DE120100226) programs of the Australian Research Council (ARC), EPSRC UK Silicon Photonics (Grant reference EP/F001428/1), EU FP7 GOSPEL project (grant no. 219299), and EU FP7 COPERNICUS (grant no. 249012).Single photons are of paramount importance to future quantum technologies, including quantum communication and computation. Nonlinear photonic devices using parametric processes offer a straightforward route to generating photons, however additional nonlinear processes may come into play and interfere with these sources. Here we analyse spontaneous four-wave mixing (SFWM) sources in the presence of multi-photon processes. We conduct experiments in silicon and gallium indium phosphide photonic crystal waveguides which display inherently different nonlinear absorption processes, namely two-photon (TPA) and three-photon absorption (ThPA), respectively. We develop a novel model capturing these diverse effects which is in excellent quantitative agreement with measurements of brightness, coincidence-to-accidental ratio (CAR) and second-order correlation function g((2))(0), showing that TPA imposes an intrinsic limit on heralded single photon sources. We build on these observations to devise a new metric, the quantum utility (QMU), enabling further optimisation of single photon sources.Publisher PDFPeer reviewe

Enhanced spectral sensitivity of a chip-scale photonic-crystal slow-light interferometer

We experimentally demonstrate that the spectral sensitivity of a Mach–Zehnder (MZ) interferometer can be enhanced through structural slow light. We observe a 20-fold resolution enhancement by placing a dispersion-engineered, slow-light, photonic-crystal waveguide in one arm of a fiber-based MZ interferometer. The spectral sensitivity of the interferometer increases roughly linearly with the group index, and we have quantified the resolution in terms of the spectral density of interference fringes. These results show promise for the use of slow-light methods for developing novel tools for optical metrology and, specifically, for compact high-resolution spectrometers

Hyperpolarizability of Plasmonic Meta-Atoms in Metasurfaces

Plasmonic metasurfaces are promising as enablers of nanoscale nonlinear optics and flat nonlinear optical components. Nonlinear optical responses of such metasurfaces are determined by the nonlinear optical properties of individual plasmonic meta-atoms. Unfortunately, no simple methods exist to determine the nonlinear optical properties (hyperpolarizabilities) of the meta-atoms hindering the design of nonlinear metasurfaces. Here, we develop the equivalent RLC circuit (resistor, inductor, capacitor) model of such meta-atoms to estimate their second-order nonlinear optical properties, that is, the first-order hyperpolarizability in the optical spectral range. In parallel, we extract from second-harmonic generation experiments the first-order hyperpolarizabilities of individual meta-atoms consisting of asymmetrically shaped (elongated) plasmonic nanoprisms, verified with detailed calculations using both nonlinear hydrodynamic-FDTD and nonlinear scattering theory. All three approaches, analytical, experimental, and computational, yield results that agree very well. Our empirical RLC model can thus be used as a simple tool to enable an efficient design of nonlinear plasmonic metasurfaces. © 2020 American Chemical Society