94 research outputs found
Synthesis and Characterization of Large Stereoregular Organosiloxane Cycles
The large stereoregular phenyltrimethylsiloxysiloxane macrocycles of general formula [PhSi(OSiMe3)O]n (n=6 and 12) have been selectively obtained with high yields by trimethylsilylation of cage-like oligophenylmetallasiloxanes (OPMS) which we described earlier. The compounds 3 (n=6) and 4 (n=12) have been characterized by NMR-spectroscopy method and by single crystal X-ray analysis. This investigation showed unambiguously that the siloxane macrocycles keep their size and configuration (the same as in the initial OPMS) during the trimethylsilylation. Thus a synthetic route for obtaining large stereoregular siloxane macrocycles has been developed
Socially-engaged narrative in contemporary Hindi poetry
The influence of Marxist ideology has played a peculiar role in the formation of Hindi literature. Many writers believed that a literary word, illuminating the problems of inequality and oppression, could awake effective political, social and economic actions that could change an ordinary person’s life. In contemporary Hindi poetry there is the rise of young poets’ interest in socially-engaged narrative, which they clarify with the concept of “socialist”. It is aimed at criticizing the world order surrounding them and the desire to point out the problems of social peace. The authors discuss and translate for the first time the poems of the 21st century - Hindi poets of the left wing Alokadhanva and Avinash Mishra. They, drawing the reader's attention to the fact that the art of the word is given to them from above, raise acute social issues with realistic poems and simple language, hiding their powerlessness behind rhetorical appeals calling for an active struggle. Special attention is paid to the artistic techniques, which are practically not used in this poetry. It is concluded that poets create their own metapoetics focused on revising literature’s mission as a way of exposing the modern society’s vices
Role of coupling delay in oscillatory activity in autonomous networks of excitable neurons with dissipation
We study numerically the effects of time delay in networks of delay-coupled
excitable FitzHugh Nagumo systems with dissipation. The generation of periodic
self-sustained oscillations and its threshold are analyzed depending on the
dissipation of a single neuron, the delay time, and random initial conditions.
The peculiarities of spatiotemporal dynamics of time-delayed bidirectional
ring-structured FitzHugh-Nagumo neuronal systems are investigated in cases of
local and nonlocal coupling topology between the nodes, and a first-order
nonequilibrium phase transition to synchrony is established. It is shown that
the emergence of oscillatory activity in delay-coupled FitzHugh-Nagumo neurons
is observed for smaller values of the coupling strength as the dissipation
parameter decreases. This can provide the possibility of controlling the
spatiotemporal behavior of the considered neuronal networks. The observed
effects are quantified by plotting distributions of the maximal Lyapunov
exponent and the global order parameter in terms of delay and coupling
strength.Comment: 14 pages, 17 figure
ВИПАДОК СИНДРОМУ КОРНЕЛІЇ ДЕ ЛАНГЕ (КЛІНІЧНЕ СПОСТЕРЕЖЕННЯ).
The article is devoted to rare syndrome of uncertain course of succession. Describes the etiology, phenotypic characteristics, symptoms, based on which a pediatrician and geneticist may suspect the Amsterdam dwarfism. Principles of treatment summarize the general. Clinical observation of the child V. 6 years old with multiple organ failure was conducted.Статья посвящена редкому синдрому с неясным ходом наследования. Описываются этиология, фенотипические признаки, симптомы, на основаниикоторых педиатр и генетик могут заподозрить амстердамскую карликовость. Кратко изложены общие принципы лечения. Приведено клиническое наблюдение у ребенка А. в возрасте 6 лет с полиорганным поражением.Стаття присвячена рідкісному синдрому з неясним ходом успадкування. Описуються етіологія, фенотипічні ознаки, симптоми, на підставі яких педіатр і генетик можуть запідозрити амстердамську карликовість. Стисло викладені загальні принципи лікування. Наведено клінічне спостереження в дитини А. віком 6 років з поліорганним ураженням
Beginner adaptive swimming model for psychophysical progress of children with down syndrome
Objective of the study was to develop and test benefits of a new beginner adaptive swimming model for children with Down syndrom
In-hospital outcomes of ST elevation myocardial infarction in post-COVID-19 patients
Aim. To study clinical and anamnestic data, as well as inhospital outcomes in patients with ST elevation myocardial infarction (STEMI) with prior coronavirus disease 2019 (COVID-19) compared with previously uninfected STEMI patients.Material and methods. This prospective study included 181 patients treated for STEMI. The patients were divided into 2 groups, depending on the anti-SARS-CoV-2 IgG titer as follows: the main group included 62 seropositive patients, while the control group — 119 seronegative patients without prior COVID-19. Anamnesis, clinical and paraclinical examination, including electrocardiography, echocardiography, coronary angiography, were performed. Mortality and incidence of STEMI complications at the hospital stage were analyzed.Results. The mean age of the patients was 62,6±12,3 years. The vast majority were men (69,1% (n=125)). The median time from the onset of COVID-19 manifestations to STEMI was 60,00 [45,00; 83,00] days. According to, the patients of both groups were comparable the severity of circulatory failure (p>0,05). Coronary angiography found that in patients of the main group, Thrombolysis In Myocardial Infarction (TIMI) score of 0-1 in the infarct-related artery was recorded much less frequently (62,9% (n=39) vs, 77,3% (n=92), p=0,0397). Patients of the main group demonstrated a lower concentration of leukocytes (9,30*109/l [7,80; 11,40] vs 10,70*109/l [8,40; 14,00], p=0,0065), higher levels of C-reactive protein (21,5 mg/L [9,1; 55,8] vs 10,2 mg/L [5,1; 20,5], p=0,0002) and troponin I (9,6 ng/mL [2,2; 26,0] vs 7,6 ng/mL [2,2; 11,5], p=0,0486). Lethal outcome was recorded in 6,5% (n=4) of cases in the main group and 8,4% (n=10) in the control group (p=0,6409). Both groups were comparable in terms of the incidence of complications (recurrent myocardial infarction, ventricular fibrillation, complete atrioventricular block, stroke, gastrointestinal bleeding) during hospitalization (p>0,05).Conclusion. Patients with STEMI after COVID-19, despite a more burdened history and higher levels of C-reactive protein and troponin I, compared with STEMI patients without COVID-19, did not differ significantly in clinical status, morbidity, and inhospital mortality
Characterization and luminescence dynamics of MgF2:W ceramics
This study delves into the synthesis and characterization of luminescent ceramics based on tungstenactivated magnesium fluoride (MgF 2 ) complemented with varying concentrations of lithium hydroxide
(LiOH). Utilizing a distinctive sintering process conducted in an open-air milieu under robust radiation conditions, we successfully synthesized a series of tungsten-activated ceramics. Study revealed that the
resultant ceramics prominently display luminescent properties, which can be excited by UV radiation in the spectrum of 200-300 nm, as well as by high-energy electron fluxes. The spectral characteristics of
these ceramics, in terms of band position, half-width, and excitation spectra, are strikingly analogous to those observed in LiF crystals activated by tungsten and titanium ions. This observation led to the
conclusion that luminescent centers, similar to those in LiF crystals, are formed during the ceramic synthesis
Identification of geographically distributed sub-populations of Leishmania (Leishmania) major by microsatellite analysis
<p>Abstract</p> <p>Background</p> <p><it>Leishmania </it>(<it>Leishmania</it>) <it>major</it>, one of the agents causing cutaneous leishmaniasis (CL) in humans, is widely distributed in the Old World where different species of wild rodent and phlebotomine sand fly serve as animal reservoir hosts and vectors, respectively. Despite this, strains of <it>L. (L.) major </it>isolated from many different sources over many years have proved to be relatively uniform. To investigate the population structure of the species highly polymorphic microsatellite markers were employed for greater discrimination among it's otherwise closely related strains, an approach applied successfully to other species of <it>Leishmania</it>.</p> <p>Results</p> <p>Multilocus Microsatellite Typing (MLMT) based on 10 different microsatellite markers was applied to 106 strains of <it>L. (L.) major </it>from different regions where it is endemic. On applying a Bayesian model-based approach, three main populations were identified, corresponding to three separate geographical regions: Central Asia (CA); the Middle East (ME); and Africa (AF). This was congruent with phylogenetic reconstructions based on genetic distances. Re-analysis separated each of the populations into two sub-populations. The two African sub-populations did not correlate well with strains' geographical origin. Strains falling into the sub-populations CA and ME did mostly group according to their place of isolation although some anomalies were seen, probably, owing to human migration.</p> <p>Conclusion</p> <p>The model- and distance-based analyses of the microsatellite data exposed three main populations of <it>L. (L.) major</it>, Central Asia, the Middle East and Africa, each of which separated into two sub-populations. This probably correlates with the different species of rodent host.</p
Tungsten Activated Ceramics Based on Metal Fluorides
This work is aimed at establishing the possibility of introducing W ions into ceramics based on alkaline earth metal fluorides by the radiation synthesis method, which differs significantly in the totality of processes from the currently used thermal methods
Na,K-ATPase Acts as a Beta-Amyloid Receptor Triggering Src Kinase Activation
Beta-amyloid (Aβ) has a dual role, both as an important factor in the pathology of Alzheimer’s disease and as a regulator in brain physiology. The inhibitory effect of Aβ42 oligomers on Na,K-ATPase contributes to neuronal dysfunction in Alzheimer’s disease. Still, the physiological role of the monomeric form of Aβ42 interaction with Na,K-ATPase remains unclear. We report that Na,K-ATPase serves as a receptor for Aβ42 monomer, triggering Src kinase activation. The co-localization of Aβ42 with α1- and β1-subunits of Na,K-ATPase, and Na,K-ATPase with Src kinase in SH-SY5Y neuroblastoma cells, was observed. Treatment of cells with 100 nM Aβ42 causes Src kinase activation, but does not alter Na,K-ATPase transport activity. The interaction of Aβ42 with α1β1 Na,K-ATPase isozyme leads to activation of Src kinase associated with the enzyme. Notably, prevention of Na,K-ATPase:Src kinase interaction by a specific inhibitor pNaKtide disrupts the Aβ-induced Src kinase activation. Stimulatory effect of Aβ42 on Src kinase was lost under hypoxic conditions, which was similar to the effect of specific Na,K-ATPase ligands, the cardiotonic steroids. Our findings identify Na,K-ATPase as a Aβ42 receptor, thus opening a prospect on exploring the physiological and pathological Src kinase activation caused by Aβ42 in the nervous system
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