99 research outputs found

    Role of coupling delay in oscillatory activity in autonomous networks of excitable neurons with dissipation

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    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).

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    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

    In-hospital outcomes of ST elevation myocardial infarction in post-COVID-19 patients

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    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

    Tungsten Activated Ceramics Based on Metal Fluorides

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    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

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    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

    Characterization of Leishmania spp. causing cutaneous leishmaniasis in Manaus, Amazonas, Brazil

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    In the State of Amazonas, American tegumentary leishmaniasis is endemic and presents a wide spectrum of clinical variability due to the large diversity of circulating species in the region. Isolates from patients in Manaus and its metropolitan region were characterized using monoclonal antibodies and isoenzymes belonging to four species of the parasite: Leishmania (Viannia) guyanensis, 73% (153/209); Leishmania (Viannia) braziliensis, 14% (30/209); Leishmania (Leishmania) amazonensis, 8% (17/209); and Leishmania (Viannia) naiffii, 4% (9/209). The most prevalent species was L. (V.) guyanensis. The principal finding of this study was the important quantity of infections involving more than one parasite species, representing 14% (29/209) of the total. The findings obtained in this work regarding the parasite are further highlighted by the fact that these isolates were obtained from clinical samples collected from single lesions

    Долгосрочное влияние нетакимаба на качество жизни, боль в спине и работоспособность пациентов с анкилозирующим спондилитом: результаты международного многоцентрового рандомизированного двойного слепого клинического исследования III фазы BCD-085-5/ASTERA

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    The article contains the data obtained during the 156-week follow-up of patients with ankylosing spondylitis (AS) in the ASTERA phase III study.Objective: to evaluate the effect impact of netakimab (NTK) on quality of life (QoL), back pain and work capacity in patients with active AS.Material and methods. The study enrolled 228 patients with active AS who were randomized 1:1 to receive NTK 120 mg or placebo. At week 52, patients in Group 1 (NTK) who achieved ASAS20 continued therapy (NTK at a dose of 120 mg once every 2 weeks) until week 156. Patients in Group 2 (placebo/NTK) received the study drug at a dose of 120 mg subcutaneously every 2 weeks from week 20 until week 68, after which the efficacy of therapy was determined (by achieving an ASAS20 response). Patients who achieved ASAS20 received treatment (NTK at a dose of 120 mg once every 2 weeks) until week 172.Results and discussion. Under NTK therapy, a significant improvement in QoL was observed in the assessment of the physical and psychological components of the SF-36 questionnaire, which was maintained during the three years of therapy: increase in indicator by 12.68±9.92; 13.27±10.14; 12.92±10.03; 14.10±10.35; 14.76±9.77 and 6.10±11.59; 5.50±11.82; 6.32±11.01; 5.87±11.45; 5.25±11.98 points at week 52, 76, 104, 128 and 156, respectively. During the extended therapy period, a reduction in the proportion of working hours missed for health reasons, an improvement in work capacity and work efficiency and an increase in daily activity were observed. Back pain (BASDAI question 2) and nocturnal back pain decreased steadily during the entire follow-up period compared to the screening values.Conclusion. NTK is an effective therapy for active AS that improves QoL scores, significantly reduces pain intensity and improves work productivity.В статье приведены данные, полученные в ходе 156 нед наблюдения за пациентами с анкилозирующим спондилитом (АС) в исследовании III фазы ASTERA.Цель исследования – оценить влияние нетакимаба (НТК) на качество жизни (КЖ), боль в спине и работоспособность пациентов с активным АС.Материал и методы. В исследование включено 228 больных активным АС, которые были рандомизированы в соотношении 1:1 в группу НТК 120 мг или группу плацебо. На неделе 52 пациенты группы 1 (НТК), достигшие ASAS20, продолжили получать терапию (НТК в дозе 120 мг 1 раз в 2 нед) до недели 156. Пациенты группы 2 (плацебо/НТК), начиная с недели 20, использовали исследуемый препарат в дозе 120 мг подкожно 1 раз в 2 нед до недели 68, после которой у них была определена эффективность терапии (по достижению ответа ASAS20). Пациенты, достигшие ASAS20, получали лечение (НТК в дозе 120 мг 1 раз в 2 нед) до недели 172.Результаты и обсуждение. На фоне лечения НТК наблюдалось значимое улучшение КЖ при оценке физического и психологического компонентов опросника SF-36, которое сохранялось на протяжении 3 лет терапии: повышение показателя на 12,68±9,92; 13,27±10,14; 12,92±10,03; 14,10±10,35; 14,76±9,77 и 6,10±11,59; 5,50±11,82; 6,32±11,01; 5,87±11,45; 5,25±11,98 балла на неделях 52, 76, 104, 128, 156 соответственно. В течение продленного периода терапии было выявлено снижение доли рабочего времени, пропущенного по состоянию здоровья, улучшение работоспособности и эффективности труда, а также повышение повседневной активности. Боль в спине (вопрос 2 BASDAI) и ночная боль в спине стойко уменьшались на протяжении всего периода наблюдения по сравнению с их показателями на момент скрининга.Заключение. НТК является эффективным методом терапии активного АС. Под действием НТК улучшаются показатели КЖ, в том числе значимо снижается интенсивность боли и улучшается производительность труда
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