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1.
Ter Arkh ; 96(3): 212-217, 2024 Apr 16.
Article in Russian | MEDLINE | ID: mdl-38713034

ABSTRACT

AIM: To assess clinical and demographic characteristics of severe asthma (SA) patients and their management in Russian Federation. MATERIALS AND METHODS: This publication provides data for Russian part of population of the international observational study. In Phase I, retrospective analysis of medical records of patients with SA was performed with assessment of clinical and demographic data, medical history, comorbidities, treatment approaches and healthcare utilization. Phase II was a cross-sectional collection of patient-reported outcomes: level of asthma control assessed by ACT (Asthma Control Test) and health-related quality of life (HRQoL) measured using the EQ-5D-5L questionnaire. Phase I patients were enrolled into Phase II if they signed a written consent form. RESULTS: A total of 315 patients were included in Phase I of the study, 106 (33.6%) of them entered Phase II. Majority of study participants were either obese (n=103; 39.8%) or overweight (n=94; 36.3%). The most common comorbidities were cardiovascular diseases (n=217; 71.4%), followed by chronic respiratory diseases (n=198; 68.8%). There were 268 (85.1%) patients who had at least one exacerbation during last 12 months. Data for blood eosinophil count were available in 176 patients; 81.3% of them (n=143) had only one test in the last 12 months. The mean (SD) last available blood eosinophil count was 161.2 (181.2) cells/mm3. Serum Immunoglobulin E (IgE) value was known for 88 patients, and the mean (SD) last measured IgE value was 254.3 (249.7) ng/mL. Only 4.7% of Phase II participants had ACT scores indicative of controlled asthma (>20). As much as 74.5% had scores ≤15 suggesting uncontrolled disease. Most patients also had impaired HRQoL. CONCLUSION: Most SA patients had poor disease control with frequent exacerbations and high number of comorbidities. Blood eosinophils and IgE level measurements were not evaluated routinely which might be a barrier for appropriate phenotyping and treatment selection.


Subject(s)
Asthma , Quality of Life , Humans , Asthma/epidemiology , Asthma/therapy , Russia/epidemiology , Female , Male , Middle Aged , Adult , Cross-Sectional Studies , Severity of Illness Index , Retrospective Studies , Comorbidity , Cost of Illness , Surveys and Questionnaires
2.
Ter Arkh ; 96(3): 240-245, 2024 Apr 16.
Article in Russian | MEDLINE | ID: mdl-38713038

ABSTRACT

AIM: To assess effectiveness and safety of biological therapy in patients with severe asthma during 5 yr follow-up. MATERIALS AND METHODS: We recruited 129 adult outpatients (29% males) aged 18-81 yrs with severe asthma were followed up during 5 yrs and were examined for every 3-6 months. Eighty five patients were treated by conventional therapy (ICS/LABA ± tiotropium, montelukast, OCS) only and 44 pts additionally received biologicals (оmalizumab - 9 pts, мepolizumab - 8 pts, benralizumab - 11 pts, dupilumab - 16 pts). Pulmonary function tests were measured by dry spirometer (2120, Vitalograph Ltd., UK). Eosinophil count in blood was assessed by automatic haemoanalyser. Fraction of exhaled nitric oxide was measured by a chemiluminescence analyzer (LR4100; Logan Research, UK). Asthma control and quality of life were assessed by using Russian versions of ACQ-5 and SGRQ. RESULTS: The use of biologicals led to a more significant reduction of exacerbations and OCS use, improvement of lung function, asthma control and quality of life, decrease of eosinophil and fraction of exhaled nitric oxide than conventional therapy of severe asthma (p<0.05). Systemic side effects were not registered, frequency of local adverse reactions (edema, hyperemia and itching at injection site) was 14%. CONCLUSION: Long-term use of biologicals added to conventional therapy in patients with severe asthma is characterized by high effectiveness and favorable safety profile.


Subject(s)
Asthma , Humans , Asthma/drug therapy , Asthma/physiopathology , Male , Female , Middle Aged , Adult , Antibodies, Monoclonal, Humanized/administration & dosage , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/therapeutic use , Anti-Asthmatic Agents/administration & dosage , Anti-Asthmatic Agents/adverse effects , Anti-Asthmatic Agents/therapeutic use , Severity of Illness Index , Quality of Life , Respiratory Function Tests/methods , Treatment Outcome , Aged , Biological Therapy/methods , Biological Therapy/adverse effects , Young Adult , Adolescent
3.
Ter Arkh ; 96(3): 292-297, 2024 Apr 16.
Article in Russian | MEDLINE | ID: mdl-38713046

ABSTRACT

Chronic obstructive pulmonary disease is now one of the most common noncommunicable diseases and the main causes of morbidity, disability and mortality in the world. In recent years, new approaches to epidemiology, diagnosis, classification (categorization), evaluation of phenotypes, as well as characterization and assessment of the severity of сhronic obstructive pulmonary disease exacerbations have emerged. Modern approaches to starting and subsequent drug therapy have changed significantly. This is largely due to the results of recently conducted major clinical trials, demonstrated high efficacy of triple fixed combinations, including inhaled glucocorticosteroids, long-acting beta-agonists and long-acting anticholinergic drugs. The use of non-medication methods (smoking cessation, physical activity and respiratory rehabilitation) and modern approaches to the treatment of respiratory failure and antibiotic therapy remain important. In terms of their significance, all these updates have a significant impact on real clinical practice and can be considered as a novel paradigm of the approaches to the diagnosis and management of this disease.


Subject(s)
Practice Guidelines as Topic , Pulmonary Disease, Chronic Obstructive , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/therapy , Pulmonary Disease, Chronic Obstructive/drug therapy , Pulmonary Disease, Chronic Obstructive/physiopathology , Humans , Disease Management , Cholinergic Antagonists/therapeutic use , Bronchodilator Agents/therapeutic use
4.
Gene ; 882: 147639, 2023 Oct 05.
Article in English | MEDLINE | ID: mdl-37473971

ABSTRACT

Last data demonstrated that exonic variants of LRRK2 (p.G2019S, p.M1646T) may affect the catalytic activity of lysosomal enzyme glucocerebrosidase (GCase) probably through the phosphorylation of Rab10 protein. We aimed to evaluate an association of LRRK2 exonic variants previously associated with alteration of phosphorylation levels for Rab10Thr73 with PD risk in Russian population and analyze an impact of p.G2019S mutation and selected LRRK2 variants on lysosomal hydrolase activities. LRRK2 variants were determined by full sequencing of LRRK2 in 508 PD patients and 470 controls from Russian population. Activity of lysosomal enzymes (glucocerebrosidase (GCase), alpha-galactosidase A (GLA), acid sphingomyelinase (ASMase) and concentrations of their corresponded substrates (hexosylsphingosine (HexSph), globotriaosylsphingosine (LysoGb3), lysosphingomyelin (LysoSM), respectively) were estimated in 211 PD patients and 179 controls by liquid chromatography with tandem mass spectrometry (LC-MS-MS) in dry blood spots. p.M1646T and p.N2081D were associated with PD (OR = 2.33, CI 95%: 1.1215 to 4.8253, p = 0.023; OR = 1.89, 95%CI: 1.0727 to 3.3313, p = 0.028, respectively) in Russian population. An increased LysoGb3 concentration was found in p.G2019S and p.N2081D LRRK2 carriers among PD patients compared to both PD patients and controls (p.G2019S: p = 0.00086, p = 0.0004, respectively; p.N2081D: p = 0.012, p = 0.0076, respectively). A decreased ASMase activity in p.G2019S LRRK2 carriers among PD patients (p = 0.014) was demonstrated as well. Our study supported possible involvement of LRRK2 dysfunction in an alteration of sphingolipid metabolism in PD.


Subject(s)
Parkinson Disease , Humans , Parkinson Disease/genetics , Glucosylceramidase/genetics , Glucosylceramidase/metabolism , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/genetics , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/metabolism , Mutation , Sphingolipids , Lysosomes
5.
Ter Arkh ; 94(4): 524-529, 2022 May 26.
Article in Russian | MEDLINE | ID: mdl-36286803

ABSTRACT

Asthma and chronic obstructive pulmonary disease remain major problems of medicine, and still there is need to improve the level and quality of diagnosis of these diseases. Primary care physicians (general practitioners, therapists) should be involved widely and actively in this process. To simplify the diagnosis, special questionnaires have been developed, they can be used in a real clinical practice. Only this approach will bring statistical data closer to the true prevalence of these diseases and improve quality of their treatment.


Subject(s)
Asthma , Pulmonary Disease, Chronic Obstructive , Humans , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/epidemiology , Pulmonary Disease, Chronic Obstructive/therapy , Asthma/diagnosis , Asthma/epidemiology , Asthma/therapy , Surveys and Questionnaires , Prevalence , Russia/epidemiology
6.
Sci Rep ; 12(1): 7090, 2022 Apr 30.
Article in English | MEDLINE | ID: mdl-35490169

ABSTRACT

A new mechanism of charge transport inside a thundercloud is suggested and numerically investigated. The considered mechanism can be called "relay" because it is provided by a dynamical network of a relatively small amount of continuously decaying and arising conducting plasma formations. It manifests itself in two consecutive modes corresponding to pre-streamer and streamer/leader stages of thundercloud development. The first one is provided by dynamics of conducting ionic spots recently described by Iudin et al.1 that prepare conditions for initiation of positive streamers. The second mode relies on dynamical network of streamer/leader discharges and finally results in the formation of a compact well-conducting structure that bridges an area of strong electric field inside a thundercloud and can be associated with a lightning "seed". The effectiveness of relay charge transport strongly depends on the relative proportion of conductive elements (plasma formations) and drastically increases in the field-dependent case.

7.
Mol Neurobiol ; 59(4): 2277-2287, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35066761

ABSTRACT

The synucleinopathies are a group of neurodegenerative diseases characterized by the oligomerization of alpha-synuclein protein in neurons or glial cells. Recent studies provide data that ceramide metabolism impairment may play a role in the pathogenesis of synucleinopathies due to its influence on alpha-synuclein accumulation. The aim of the current study was to assess changes in activities of enzymes involved in ceramide metabolism in patients with different synucleinopathies (Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA)). The study enrolled 163 PD, 44 DLB, and 30 MSA patients as well as 159 controls. Glucocerebrosidase, alpha-galactosidase, acid sphingomyelinase enzyme activities, and concentrations of the corresponding substrates (hexosylsphingosine, globotriaosylsphingosine, lysosphingomyelin) were measured by liquid chromatography tandem-mass spectrometry in blood. Expression levels of GBA, GLA, and SMPD1 genes encoding glucoceresobridase, alpha-galactosidase, and acid sphingomyelinase enzymes, correspondently, were analyzed by real-time PCR with TaqMan assay in CD45 + blood cells. Increased hexosylsphingosine concentration was observed in DLB and MSA patients in comparison to PD and controls (p < 0.001) and it was associated with earlier age at onset (AAO) of DLB (p = 0.0008). SMPD1 expression was decreased in MSA compared to controls (p = 0.015). Acid sphingomyelinase activity was decreased in DLB, MSA patients compared to PD patients (p < 0.0001, p < 0.0001, respectively), and in MSA compared to controls (p < 0.0001). Lower acid sphingomyelinase activity was associated with earlier AAO of PD (p = 0.012). Our data support the role of lysosomal dysfunction in the pathogenesis of synucleinopathies, namely, the pronounced alterations of lysosomal activities involved in ceramide metabolism in patients with MSA and DLB.


Subject(s)
Lewy Body Disease , Multiple System Atrophy , Parkinson Disease , Synucleinopathies , Ceramides , Humans , Lewy Body Disease/metabolism , Multiple System Atrophy/pathology , Parkinson Disease/pathology , Sphingolipids , Sphingomyelin Phosphodiesterase , alpha-Galactosidase , alpha-Synuclein/metabolism
8.
Kardiologiia ; 62(12): 23-29, 2022 Dec 31.
Article in Russian, English | MEDLINE | ID: mdl-36636973

ABSTRACT

Aim      To evaluate functional changes in the heart in the long-term following COVID-19 in patients with chronic heart failure (CHF).Material and methods  Case reports of 54 patients aged 69.1±9.7 years who had COVID-19 from January 2021 through January 2022 and had been previously diagnosed with NYHA functional class II-III CHF were studied. Two comparison groups were isolated: HF with LV EF >50 % (n=39) and <50 % (n=15). Echocardiography was used to evaluate changes in LV EF and pulmonary artery systolic pressure (PASP) 5-6 months following COVID-19.Results In all CHF patients after COVID-19 at 5.8 months on average, LV EF decreased (median difference, 2.5 %; 95 % confidence interval (CI): 6.99×10-5- 4.99) and PASP increased (median difference, 8 mm Hg; 95 % CI: 4.5-12.9). In the HF group with LV EF <50 %, the decrease in EF was greater than in the group with LV EF >50 % (6.9 and 0.7 %, respectively; p=0.037); furthermore, the CHF phenotype did not influence the change in PASP (p=0.4). The one-factor regression analysis showed that the dynamics of LV EF decrease was significantly influenced by the baseline decrease in LV EF, whereas the change in PASP was influenced by the dynamics of LV EF decrease, presence of dyslipidemia, and statin treatment. Furthermore, the multifactorial analysis showed that prognostically significant factors for long-term changes in LV EF following COVID-19 were male gender (odds ratio (OR), 5.92; 95 % CI: 1.31-26.75; p=0.014), LV EF at baseline <50 % (OR, 0.88; 95 % CI: 0.8-0.96; p<0.001); changes in PASP depended on the presence of dyslipidemia (OR, 0.08; 95 % CI: 0.01-0.84; p=0.018).Conclusion      This study showed that COVID-19 in the long term can influence the course of CHF; in this process, HF patients with EF <50 % have progression of systolic dysfunction and PASP, whereas patients with EF >50 % have an isolated increase in PASP.


Subject(s)
COVID-19 , Heart Failure , Male , Female , Humans , Stroke Volume , COVID-19/complications , Heart Failure/diagnosis , Heart Failure/epidemiology , Chronic Disease , Ventricular Function, Left
9.
Acta Naturae ; 13(2): 70-78, 2021.
Article in English | MEDLINE | ID: mdl-34377557

ABSTRACT

Parkinson's disease (PD) is a multifactorial neurodegenerative disease. To date, genome-wide association studies have identified more than 70 loci associated with the risk of PD. Variants in the GBA gene encoding glucocerebrosidase are quite often found in PD patients in all populations across the world, which justifies intensive investigation of this gene. A number of biochemical features have been identified in patients with GBA-associated Parkinson's disease (GBA-PD). In particular, these include decreased activity of glucocerebrosidase and accumulation of the glucosylceramide substrate. These features were the basis for putting forward a hypothesis about treatment of GBA-PD using new strategies aimed at restoring glucocerebrosidase activity and reducing the substrate concentration. This paper discusses the molecular and genetic mechanisms of GBA-PD pathogenesis and potential approaches to the treatment of this form of the disease.

10.
Mol Biol (Mosk) ; 55(2): 338-345, 2021.
Article in Russian | MEDLINE | ID: mdl-33871446

ABSTRACT

Parkinson's disease (PD) is the second most common neurodegenerative disorder. Alpha-synuclein misfolding and aggregation resulting in neurototoxicity is a hallmark of PD. The prion properties of alpha-synuclein are still under discussion. Exosomes (extrcellular vesicles 40-100 nm in size) can play a key role in the transport of pathogenic forms of alpha-synuclein. The most frequent inherited forms of the disease are PD associated with mutation in the leucine-rich repeat kinase 2 (LRRK2-PD) and glucocerebrosidase (GBA-PD) genes. The aim of our work is to evaluate the concentration and size of exosomes derived from blood plasma of patients with GBA-PD, asymptomatic GBA mutation carriers, and the effect of GBA and LRRK2 mutations on alpha-synuclein level in exosomes derived from peripheral blood plasma. Plasma extracellular vesicles were isolated via chemical precipitation and sequential ultracentrifugation and characterized by transmission electron microscopy, nanoparticle tracking analysis (NTA), and flow cytometry. Total alpha-synuclein level in plasma exosomes was estimated by enzyme-linked immunosorbent assay. Patients with sporadic PD, PD with dementia, patients with inherited PD (GBA-PD, LRRK2-PD), and GBA mutation carriers were included in the study. The concentration on plasma exosomes was higher in GBA-PD patients that in sporadic PD patients, asymptomatic carriers of mutations on GBA gene, and control (p = 0.004, 0.019 and 0.0001 respectively). The size of plasma exosomes was higher in GBA-PD patients compared to asymptomatic carriers of GBA mutations and control (p = 0.009 and 0.0001, respectively). No significant difference was found for exosomal alpha-synuclein levels in the studied groups. Our results allowed us to suggest that a decrease in GBA activity may affect the pool of plasma exosomes, and mutations in the LRRK2 and GBA genes do not influence the level of plasma exosomal alpha-synuclein.


Subject(s)
Exosomes , Parkinson Disease , Exosomes/genetics , Glucosylceramidase/genetics , Humans , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/genetics , Mutation , Parkinson Disease/genetics , Plasma
11.
Parkinsonism Relat Disord ; 84: 112-121, 2021 03.
Article in English | MEDLINE | ID: mdl-33609962

ABSTRACT

Mutations in the glucocerebrosidase gene (GBA) encoding the lysosomal enzyme glucocerebrosidase (GCase) cause Gaucher disease (GD) and are the most commonly known genetic risk factor for Parkinson disease (PD). Ambroxol is one of the most effective pharmacological chaperones of GCase. Fourteen GD patients, six PD patients with mutations in the GBA gene (GBA-PD), and thirty controls were enrolled. GCase activity and hexosylsphingosine (HexSph) concentration were measured in dried blood and macrophage spots using liquid chromatography coupled with tandem mass spectrometry. The effect of ambroxol on GCase translocation to lysosomes was assessed using confocal microscopy. The results showed that ambroxol treatment significantly increased GCase activity in cultured macrophages derived from patient blood monocytic cell (PBMC) of GD (by 3.3-fold) and GBA-PD patients (by 3.5-fold) compared to untreated cells (p < 0.0001 and p < 0.0001, respectively) four days after cultivation. Ambroxol treatment significantly reduced HexSph concentration in GD (by 2.1-fold) and GBA-PD patients (by 1.6-fold) (p < 0.0001 and p < 0.0001, respectively). GD macrophage treatment resulted in increased GCase level and increased enzyme colocalization with the lysosomal marker LAMP2. The possible binding modes of ambroxol to mutant GCase carrying N370S amino acid substitution at pH 4.7 were examined using molecular docking and molecular dynamics simulations. The ambroxol position characterized by minimal binding free energy was observed in close vicinity to the residue, at position 370. Taken together, these data showed that PBMC-derived macrophages could be used for assessing ambroxol therapy response for GD patients and also for GBA-PD patients.


Subject(s)
Ambroxol/pharmacology , Enzyme Inhibitors/pharmacology , Gaucher Disease/drug therapy , Glucosylceramidase/drug effects , Macrophages/drug effects , Molecular Chaperones/pharmacology , Parkinson Disease/drug therapy , Translocation, Genetic/drug effects , Adult , Aged , Aged, 80 and over , Cells, Cultured , Female , Glucosylceramidase/antagonists & inhibitors , Humans , Male , Middle Aged
12.
Neurosci Lett ; 741: 135509, 2021 01 10.
Article in English | MEDLINE | ID: mdl-33227372

ABSTRACT

Lysosomal integral membrane protein-2 (LIMP-2), encoded by the SCARB2 gene, is the specific lysosomal receptor for glucocerebrosidase enzyme. Association between rs6812193 and rs68250047 of SCARB2 with PD has been shown in genetic studies, including large genome-wide association studies. The aim of the current study was to determine whether rs6812193 and rs8475 are associated with PD in Russia. rs6812193 and rs8475 were genotyped in a total of 604 PD patients (65 PD patients with positive (fPD) and 539 PD patients with negative family history (sPD)) and 413 controls and also in 17 patients with PD associated with GBA mutations (PD-GBA) and 18 asymptomatic GBA mutation carriers (GBA-Carriers). SCARB2 expression was measured by real-time PCR in CD45+ blood cells in part of individuals in the studied groups. No linkage disequilibrium was shown between rs6812193 and rs8475 in Russian population. Increased PD risk for TT variant of rs8475 (OR = 2.02; p < 0.001) was found in sPD patients but not in fPD. rs6812193 and rs8475 were not associated with age at onset (AAO) of PD. SCARB2 expression level was decreased in GBA-PD patients and GBA-Carriers compared to PD patients (padjusted = 0.02, padjusted = 0.003, respectively) and GBA-Carriers compared to controls (padjusted = 0.013) with no significant difference in PD patients and controls. SCARB2 expression was not modified with rs6812193 and rs8475. In conclusion, rs8475 was associated with PD status. rs6812193 and rs8475 are not genetic modifier of AAO of PD and do not influence on SCARB2 mRNA level in CD45+ blood cells in studied groups. SCARB2 expression could be modified with GBA mutations and is independent of PD status.


Subject(s)
Lysosomal Membrane Proteins/genetics , Parkinson Disease/genetics , Parkinson Disease/pathology , Receptors, Scavenger/genetics , Adult , Aged , Aged, 80 and over , Female , Genetic Predisposition to Disease , Genetic Variation , Genotype , Humans , Male , Middle Aged , Mutation , Parkinson Disease/blood , Polymorphism, Single Nucleotide , Russia
13.
Ter Arkh ; 93(8): 986-990, 2021 Aug 15.
Article in Russian | MEDLINE | ID: mdl-36286897

ABSTRACT

Allergic rhinitis (AR) is one the most common allergic diseases affecting from 10 to 40% of the population in different countries, including Russia. AR is a risk factor of bronchial asthma, other upper airway disease and may decrease patient quality of life, their productivity, increase probability of occupational traumatism, depression and anxiety. AR also presents a substantial economic burden. The rationale to use fixed dose combination of intranasal steroids and topical H1 antihistamines includes suboptimal control of symptoms by monotherapy, its complementary pharmacologic activity and the results of clinical trials. This review focused on fixed dose combination of intranasal mometasone furoate and olopataine. Double blind placebo-controlled and open clinical trials have confirmed that this combination decreased severity of nasal and ocular symptoms of seasonal and perennial AR, improved patient quality of life and had a good tolerability. Its efficacy was higher than those of monotherapy. Fast onset of action and sustainable effect on symptoms (during 1 yr) may improve adherence patients to the treatment and control of symptoms of AR.


Subject(s)
Anti-Allergic Agents , Rhinitis, Allergic, Seasonal , Rhinitis, Allergic , Humans , Anti-Allergic Agents/adverse effects , Quality of Life , Mometasone Furoate/therapeutic use , Rhinitis, Allergic/diagnosis , Rhinitis, Allergic/drug therapy , Histamine Antagonists/therapeutic use , Randomized Controlled Trials as Topic
14.
Neural Netw ; 134: 64-75, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33291017

ABSTRACT

This work is aimed to study experimental and theoretical approaches for searching effective local training rules for unsupervised pattern recognition by high-performance memristor-based Spiking Neural Networks (SNNs). First, the possibility of weight change using Spike-Timing-Dependent Plasticity (STDP) is demonstrated with a pair of hardware analog neurons connected through a (CoFeB)x(LiNbO3)1-x nanocomposite memristor. Next, the learning convergence to a solution of binary clusterization task is analyzed in a wide range of memristive STDP parameters for a single-layer fully connected feedforward SNN. The memristive STDP behavior supplying convergence in this simple task is shown also to provide it in the handwritten digit recognition domain by the more complex SNN architecture with a Winner-Take-All competition between neurons. To investigate basic conditions necessary for training convergence, an original probabilistic generative model of a rate-based single-layer network with independent or competing neurons is built and thoroughly analyzed. The main result is a statement of "correlation growth-anticorrelation decay" principle which prompts near-optimal policy to configure model parameters. This principle is in line with requiring the binary clusterization convergence which can be defined as the necessary condition for optimal learning and used as the simple benchmark for tuning parameters of various neural network realizations with population-rate information coding. At last, a heuristic algorithm is described to experimentally find out the convergence conditions in a memristive SNN, including robustness to a device variability. Due to the generality of the proposed approach, it can be applied to a wide range of memristors and neurons of software- or hardware-based rate-coding single-layer SNNs when searching for local rules that ensure their unsupervised learning convergence in a pattern recognition task domain.


Subject(s)
Neural Networks, Computer , Neuronal Plasticity , Pattern Recognition, Automated/methods , Algorithms , Models, Neurological , Neuronal Plasticity/physiology , Neurons/physiology
16.
Materials (Basel) ; 13(1)2020 Jan 04.
Article in English | MEDLINE | ID: mdl-31947948

ABSTRACT

Diamond films are advanced engineering materials for various industrial applications requiring a coating material with extremely high thermal conductivity and low electrical conductivity. An approach for the synthesis of diamond films via high-speed jet deposition of thermally activated gas has been applied. In this method, spatially separated high-speed flows of methane and hydrogen were thermally activated, and methyl and hydrogen radicals were deposited on heated molybdenum substrates. The morphology and structure of three diamond films were studied, which were synthesized at a heating power of 900, 1700, or 1800 W, methane flow rate of 10 or 30 sccm, hydrogen flow rate of 1500 or 3500 sccm, and duration of the synthesis from 1.5 to 3 h.The morphology and electronic state of the carbon on the surface and in the bulk of the obtained films were analyzed by scanning electron microscopy, Raman scattering, X-ray photoelectron, and near-edge X-ray absorption fine structure spectroscopies. The diamond micro-crystals with a thick oxidized amorphous sp2-carbon coating were grown at a heating power of 900 W and a hydrogen flow rate of 1500 sccm. The quality of the crystals was improved, and the growth rate of the diamond film was increased seven times when the heating power was 1700-1800 W and the methane and hydrogen flow rates were 30 and 3500 sccm, respectively. Defective octahedral diamond crystals of 30 µm in size with a thin sp2-carbon surface layer were synthesized on a Mo substrate heated at 1273 K for 1.5 h. When the synthesis duration was doubled, and the substrate temperature was decreased to 1073 K, the denser film with rhombic-dodecahedron diamond crystals was grown. In this case, the thinnest hydrogenated sp2-carbon coating was detected on the surface of the diamond crystals.

17.
Ter Arkh ; 92(12): 86-90, 2020 Dec 15.
Article in Russian | MEDLINE | ID: mdl-33720579

ABSTRACT

Hereditary angioedema (HAE) with normal C1-inhibitor level is a rare potentially life-threatening disorder with autosomal dominant inheritance which was first described in 2000. Its clinical presentation is similar to HAE with C1-deficiency. The review is summarized data about its prevalence, mechanisms, genetics and diagnostic criteria. Different subtypes and treatment options (on demand, short term and long-term prophylaxis) are discussed. We describe family clinical cases of 2 female patients with normal C1-inhibitor and plasminogen gene mutation. Their features were late diagnosis (in 10 and 25 years after the onset of symptoms), family history (similar genetic mutation in 3 female members of the same family, including 1-asymtomatic) and combination of face, tongue, larynx and abdominal angioedema in patient and her sibling.


Subject(s)
Angioedema , Angioedemas, Hereditary , Angioedemas, Hereditary/diagnosis , Angioedemas, Hereditary/drug therapy , Angioedemas, Hereditary/genetics , Female , Humans , Mutation , Plasminogen
18.
Nanotechnology ; 31(4): 045201, 2020 Jan 17.
Article in English | MEDLINE | ID: mdl-31578002

ABSTRACT

Neuromorphic systems consisting of artificial neurons and memristive synapses could provide a much better performance and a significantly more energy-efficient approach to the implementation of different types of neural network algorithms than traditional hardware with the Von-Neumann architecture. However, the memristive weight adjustment in the formal neuromorphic networks by the standard back-propagation techniques suffers from poor device-to-device reproducibility. One of the most promising approaches to overcome this problem is to use local learning rules for spiking neuromorphic architectures which potentially could be adaptive to the variability issue mentioned above. Different kinds of local rules for learning spiking systems are mostly realized on a bio-inspired spike-time-dependent plasticity (STDP) mechanism, which is an improved type of classical Hebbian learning. Whereas the STDP-like mechanism has already been shown to emerge naturally in memristive devices, the demonstration of its self-adaptive learning property, potentially overcoming the variability problem, is more challenging and has yet to be reported. Here we experimentally demonstrate an STDP-based learning protocol that ensures self-adaptation of the memristor resistive states, after only a very few spikes, and makes the plasticity sensitive only to the input signal configuration, but neither to the initial state of the devices nor their device-to-device variability. Then, it is shown that the self-adaptive learning of a spiking neuron with memristive weights on rate-coded patterns could also be realized with hardware-based STDP rules. The experiments have been carried out with nanocomposite-based (Co40Fe40B20) х (LiNbO3-y )100-х memristive structures, but their results are believed to be applicable to a wide range of memristive devices. All the experimental data were supported and extended by numerical simulations. There is a hope that the obtained results pave the way for building up reliable spiking neuromorphic systems composed of partially unreliable analog memristive elements, with a more complex architecture and the capability of unsupervised learning.


Subject(s)
Algorithms , Nanocomposites , Neural Networks, Computer , Computers , Nanocomposites/chemistry , Neurons/physiology
19.
Chemosphere ; 241: 125083, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31683425

ABSTRACT

The increasing inflow of nitrogen (N) substrates into marine nearshore ecosystems induces proliferation of harmful algal blooms (HABs) of dinoflagellates, such as potentially toxic invasive species Prorocentrum minimum. In this study, we estimated the influence of NO3-, NH4+ and urea on transcription levels and urea transporter dur3 and nitrate transporter nrt2 genes expression in these dinoflagellates. We identified dur3 and nrt2 genes sequences in unannotated transcriptomes of P. minimum and other dinoflagellates presented in MMETSP database. Phylogenetic analysis showed that these genes of dinoflagellates clustered to the distinct clade demonstrating evolutionary relationship with the other known dur3 and nrt2 genes of microalgae. The evaluation of expression levels of dur3 and nrt2 genes by RT-qPCR revealed their sensitivity to input of the studied N sources. Dur3 expression levels were downregulated after the supplementation of additional N sources and were 1.7-2.6-fold lower than in the nitrate-grown culture. Nrt2 expression levels decreased 1.9-fold in the presence of NH4+. We estimated total RNA and DNA synthesis rates by the analysis of incorporation of 3H-thymidine and 3H-uridine in batch and continuous cultures. Addition of N compounds did not affect the DNA synthesis rates. Transcription levels increased up to 12.5-fold after the N supplementation in urea-limited treatments. Investigation of various nitrogen sources as biomarkers of dinoflagellate proliferation due to their differentiated impact on expression of dur3 and nrt2 genes and transcription rates in P. minimum cells allowed concluding about high potential of the studied parameters for future modeling of HABs under global N pollution.


Subject(s)
Dinoflagellida/genetics , Nitrogen/metabolism , Anion Transport Proteins , Dinoflagellida/metabolism , Ecosystem , Harmful Algal Bloom/physiology , Membrane Transport Proteins , Nitrate Transporters , Nitrates/metabolism , Phylogeny , Urea/metabolism , Urea Transporters
20.
Infect Agent Cancer ; 14: 46, 2019.
Article in English | MEDLINE | ID: mdl-31827597

ABSTRACT

ABSTRACT: Earlier we suggested a new hypothesis of the possible evolutionary role of hereditary tumors (Kozlov, Evolution by tumor Neofunctionalization, 2014), and described a new class of genes - tumor specifically expressed, evolutionarily novel (TSEEN) genes - that are predicted by this hypothesis (Kozlov, Infect Agents Cancer 11:34, 2016). In this paper we studied evolutionarily novel genes expressed in fish tumors after regression, as a model of evolving organs. As evolutionarily novel genes may not yet have organismal functions, we studied the acquisition of new gene functions by comparing fish evolutionarily novel genes with their human orthologs. We found that many genes involved in development of progressive traits in humans (lung, mammary gland, placenta, ventricular septum, etc.) originated in fish and are expressed in fish tumors and tumors after regression. These findings support a possible evolutionary role of hereditary tumors, and in particular the hypothesis of evolution by tumor neofunctionalization. RESEARCH HIGHLIGHTS: Earlier we described a new class of genes that are tumor-specifically expressed and evolutionarily novel (TSEEN). As the functions of TSEEN genes are often uncertain, we decided to study TSEEN genes of fishes so that we could trace the appearance of their new functions in higher vertebrates. We found that many human genes which are involved in development of progressive traits (placenta development, mammary gland and lung development etc.,) originated in fishes and are expressed in fish tumors.

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