2,127 research outputs found
Elaboration of the Model of Formation of Readiness of Future Primary School Teachers to the Use of Learning-playing Technologies
The study characterizes the structural-functional model of formation of readiness of students of the specialty “Primary education” to using learning-playing technologies in the educational process. Among general modeling forms there was chosen the combined model (graphic descriptive scheme) of the structural-functional type. There was substantiated the main idea of modeling of the process of formation of future primary school teachers' readiness to using learning-playing technologies, especially, elaboration of such structural-functional model that would allow to improve the effectiveness of this process, to make it correspondent to social requirements and expectations from realization of New Ukrainian school principles. It was determined, that the object of modeling is the process of formation of readiness to using learning-playing technologies, realized within the general system of the professional training of future primary school teachers. The aim of the model creation was formulated: elaboration of the schematic construction that embodies the abstract structure and the real projected process and result. The theoretical-methodological approaches to the model projecting process were separated, namely: system, activity, personally oriented, competence. The main blocs of the elaborated structural-functional model were separated, especially, target, content, procedural and resulting
Development of Meta-Geosystems of Tourist and Recreational Clusters
The study aims to find a key to the problem of managing cultural heritage systems in the example of the Temnikov-Sanaksar cluster located in Eastern Europe. This area is situated between the forest-steppe of the layered-tier Volga upland and the forest geosystems of the layered Oka-Don lowland. The article applies an interdisciplinary approach to solving the problem of optimizing inter-component relationships in the meta-geosystems of tourist and recreational clusters. The sustainable development of meta-geosystems should be based on multifactorial information support, which implements the most important condition for the effective economic development of landscapes through the formation of the regions’ spatial data infrastructure. In order to consistently optimize meta-geosystems of different hierarchical levels, it is necessary to solve several emerging issues, such as assessing the strength and nature of inter-component connections in geosystems, determination of factors describing the territorial variation of the properties of geosystems, interpreting and substantiation the semantics of the selected basic factors
Expression of estrogen and progesterone receptors in subcutaneous endometriosis
Endometriosis is a clinical disorder defined by the presence of functional endometrial tissue outside the uterine cavity. Depending on the localization of the endometrial tissue related to the pelvis, the endometriosis can be classified either as intrinsic or extrinsic. The prevalence of endometriosis is difficult to determine. Statistical data show that endometriosis could be associated both with female infertility (20%) and pelvic pains (24%), while in 4.1% of affected women, endometriosis has asymptomatic forms. The total prevalence of endometriosis is estimated to be between 5-10%. A 35-year-old woman from Knic, Serbia, was admitted to the Obstetrics and Gynecology Clinic of the Clinical Center in Kragujevac for surgical treatment of a suspicious swelling in the pubic region. Following surgical intervention, a nut-sized tumor was removed and sent for both pathohistological and immunohistochemical analysis. The results confirmed the presence of subcutaneous endometriosis positive for both estrogen and progesterone receptors. Endometriosis is usually described as a steroid hormone-dependent change that resembles the eutopic endometrial tissue characteristic for the presence of both glandular and stromal tissues. Given the fact that endometrial lesions are estrogen-dependent tumors, a crucial factor in the development of endometriosis is a late exposure to the hormone, mostly estrogen. Spontaneous subcutaneous endometriosis is rarely observed, but it could be assumed if there is recurrent pelvic pain which intensifies during menstruation. Given the fact that endometriosis coexists with different autoimmune diseases, multidisciplinary approaches are required for its proper diagnosis
Sonochemical synthesis of up-converting β-NaYF4: Yb, Er nanoparticles
Up-converting nanoparticles (UCNPs) with unique ability to convert NIR to VIS light (anti-Stokes process) have a wide application in optoelectronics, forensic, security labeling and biomedicine. Over the past few years different methods (like co-precipitation, thermal decomposition, hydro/solvothermal synthesis, etc.) are used for synthesis of β-NaYF4: Yb/Er phase, mainly from toxic organic precursors. In this work we explore conditions for stabilization of β-NaYF4: Yb/Er phase in nanoparticles applying sonochemistry synthesis of common inorganic precursor. The XRPD analysis showed that pure β phase is possible to obtained after 120 min of ultrasonification, while for shorter processing time (30-90min), cubic α-NaYF4: Yb/Er or orthorhombic YF3 : Yb,Er phase were founded too. The SEM and TEM analysis reveal presence of elongated nanoparticles self-assembled in spindles long up to 500 nm. Evolution of particle morphological and particle composition are analysed and correlated further with intensity of green emission (2H11/2,4S3/2→4I15/2) intensity measured under excitation of 978 nm
Sonochemical synthesis of up-converting β-NaYF4: Yb, Er nanoparticles
Up-converting nanoparticles (UCNPs) with unique ability to convert NIR to VIS light (anti-Stokes process) have a wide application in optoelectronics, forensic, security labeling and biomedicine. Over the past few years different methods (like co-precipitation, thermal decomposition, hydro/solvothermal synthesis, etc.) are used for synthesis of β-NaYF4: Yb/Er phase, mainly from toxic organic precursors. In this work we explore conditions for stabilization of β-NaYF4: Yb/Er phase in nanoparticles applying sonochemistry synthesis of common inorganic precursor. The XRPD analysis showed that pure β phase is possible to obtained after 120 min of ultrasonification, while for shorter processing time (30-90min), cubic α-NaYF4: Yb/Er or orthorhombic YF3 : Yb,Er phase were founded too. The SEM and TEM analysis reveal presence of elongated nanoparticles self-assembled in spindles long up to 500 nm. Evolution of particle morphological and particle composition are analysed and correlated further with intensity of green emission (2H11/2,4S3/2→4I15/2) intensity measured under excitation of 978 nm
Sonochemical synthesis of optically active fluorides
Up-conversion is the optical property of materials which have ability to convert low energy photons (usually from infrared spectrum) into higher energy photons (from visible spectrum). Such compounds, usually lanthanide doped oxides or fluorides, have many applications in photoluminescence science and technology today. Currently, (β) NaYF4:Yb,Er polymorph is considered to be the most efficient up-converting material. Its synthesis usually includes the usage of toxic solvents, long-term heating, high pressures, controlled gas atmosphere, etc. The aim of this work was to utilize rarely applied sonochemical synthesis for the stabilization of (β) NaYF4:Yb,Er phase under mild and environmental friendly conditions. For this purpose, we performed ultrasonic treatment of common nitrate precursors and sodium fluorine for a different time. The obtained powders were analyzed in order to determine their phase composition and thermal stability, morphology, dopants distribution, particles surface purity and luminescent characteristics. Owing to this, the chemical and crystal phase transformations that occurred in specified periods of synthesis time are explained in detail. Moreover, it was shown that obtaining of uniformly doped (β) NaYF4:Yb,Er mosocrystalline particles is possible after 2h of sonication
Sonochemical synthesis of optically active fluorides
Up-conversion is the optical property of materials which have ability to convert low energy photons (usually from infrared spectrum) into higher energy photons (from visible spectrum). Such compounds, usually lanthanide doped oxides or fluorides, have many applications in photoluminescence science and technology today. Currently, (β) NaYF4:Yb,Er polymorph is considered to be the most efficient up-converting material. Its synthesis usually includes the usage of toxic solvents, long-term heating, high pressures, controlled gas atmosphere, etc. The aim of this work was to utilize rarely applied sonochemical synthesis for the stabilization of (β) NaYF4:Yb,Er phase under mild and environmental friendly conditions. For this purpose, we performed ultrasonic treatment of common nitrate precursors and sodium fluorine for a different time. The obtained powders were analyzed in order to determine their phase composition and thermal stability, morphology, dopants distribution, particles surface purity and luminescent characteristics. Owing to this, the chemical and crystal phase transformations that occurred in specified periods of synthesis time are explained in detail. Moreover, it was shown that obtaining of uniformly doped (β) NaYF4:Yb,Er mosocrystalline particles is possible after 2h of sonication
Statistička analiza rezultata ispitivanja fizičko-mehaničkih svojstava kontrolnih betonskih kocki
Cilj ovog istraživanja je prikupljanje, obrada i statistička analiza rezultata ispitivanja uzoraka betonskih kocki koji su ispitani u Laboratoriji za materijale Građevinskog fakulteta u Beogradu prema standardu SRPS ISO 4012:2000 u periodu od 2012. do 2017. godine. Za potrebe analize, preuzeti su podaci iz Izveštaja o ispitivanju kontrolnih betonskih kocki, prepoznate su i klasifikovane osnovne karakteristike očvrslog betona. Izvršena je statistička analiza datuma betoniranja, starosti uzoraka, sastava betona, zapreminske mase, čvrstoće pri pritisku, zahtevane marke betona itd. Statistika je pokazala da su najčešće upotrebljavani cementi sledećih oznaka: CEM II A-M (V-L), CEM II A-M (S-L), CEM II A-S, a da najveće učešće imaju marke betona MB 30 sa 66,8% i MB 40 sa 14,3% udela
Role of Polyamine-Induced Dimerization of Antizyme in Its Cellular Functions
Funding: This work was supported by grants from the Russian Science Foundation (grant # 17-74-20049—synthesis of C-methylated Spd analogues, ITC studies of dimerization of OAZ1, and frameshifting experiments), the Russian Science Foundation (grant # 19-74-10086—isolation of OAZ1, electrophoresis studies of dimerization of OAZ1), and the Academy of Finland (grants # 292574 and # 315487). Acknowledgments: The authors thank A. Karppinen, A. Korhonen, T. Reponen, M. Salminkoski, and S.D. Negrya for their skillful technical assistance.Peer reviewedPublisher PD
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