Phase Composition and Microstructure of Ti-Nb Alloy Produced by Selective Laser Melting

The phase composition and microstructure of Ti-Nb alloy produced from composite titanium and niobium powder by selective laser melting (SLM) was studied. Produced monolayered Ti-Nb alloy enhanced the formation of fine-grained and medium-grained zones with homogeneous element composition of 36-38% Nb mass interval. Alloy phase composition responded to [beta]-alloy substrate phase (grain size was 5-7 pm) and non-equilibrium martensite [alpha]"- phase (grain size was 0.1-0.7 [mu]m). [alpha]"-phase grains were found along [beta]-phase grain boundaries and inside grains, including decreased niobium content. Alloy microhardness varied within 4200-5500 MPa

Peculiarities of electronic heat capacity of thulium cuprates in pseudogap state

Precise calorimetric measurements have been carried out in the 7 - 300 K temperature range on two ceramic samples of thulium 123 cuprates TmBa2Cu3O6.92 and TmBa2Cu3O6.70. The temperature dependence of the heat capacity was analyzed in the region where the pseudogap state (PGS) takes place. The lattice contribution was subtracted from the experimental data. The PGS component has been obtained by comparing electronic heat capacities of two investigated samples because the PGS contribution for the 6.92 sample is negligible. The anomalous behavior of the electronic heat capacity near the temperature boundary of PGS was found. It is supposed that this anomaly is due to peculiarities in N(E) function where N is the density of electronic states and E is the energy of carriers of charge.Comment: 12 pages, 3 Postscript figure

NMR Structures of Apo L. casei Dihydrofolate Reductase and Its Complexes with Trimethoprim and NADPH: Contributions to Positive Cooperative Binding from Ligand-Induced Refolding, Conformational Changes, and Interligand Hydrophobic Interactions

bS Supporting Information The enzyme dihydrofolate reductase (DHFR; 5,6,7,8-tetra-hydrofolate:NADPH oxidoreductase, EC 1.5.1.3) catalyzes the reduction of 7,8-dihydrofolate (DHF) to 5,6,7,8-tetrahydro-folate (THF) using NADPH as coenzyme.1 Since THF and its metabolites are precursors of purine and pyrimidine bases, the normal functioning of this enzyme is essential for proliferating cells. This makes DHFR an excellent target for antifolate drugs such as methotrexate (anticancer), pyrimethamine (antimalarial), and trimethoprim (antibacterial). Such agents act by inhibiting the enzyme in parasitic or malignant cells.1,2 The cooperative binding of ligands to DHFR plays an important role not only in the enzyme catalytic cycle (negative cooperativity in THF/ NADPH binding)3 but also in enzyme inhibition (positive cooperativity in antifolate/NADPH binding).4 The effects of positive cooperative binding in controlling enzyme inhibition ar

Хронические болезни легких: от педиатра к терапевту

The article demonstrates results of paediatricians’ and the rapeutists’ joint work assessing peculiarities of course and outcome of chronic lung diseases in different ages (a child — an adolescent — an adult). It was revealed that various form s of chronic lung pathology (chronic bronchitis, bronchiectasia, primary ciliary dyskinesia, bronchial asthma) start in childhood and, as a rule, go on in maturity. Factors effecting the disease outcome are analyzed.В статье представлены результаты совместной работы педиатров и терапевтов по оценке особенностей течения и исходов хронических заболеваний легких на различных возрастных этапах (ребенок — подросток — взрослые). Показано, что различные формы хронической патологии легких (хронический бронхит, бронхоэктазия, первичная цилиарная дискинезия, бронхиальная астма), начавшись у детей, как правило, продолжаются у больных, зрелого возраста. Рассмотрены факторы, влияющие на исход заболевания

Right heart condition in patients with COVID-19 pneumonia

Aim. To assess right heart condition in patients with coronavirus disease 2019 (COVID-19) pneumonia.Material and methods. One hundred and five patients with COVID-19 pneumonia were divided into 3 groups depending on the involvement of lung parenchyma: group I — 0-25%, II — 25-50%, III — 50-75%. The clinical status of patients was assessed using the NEWS2 and SHOKS-COVID scales. A complete blood count and biochemical blood tests were performed to determine the level of N-terminal pro-brain natriuretic peptide (NT-proBNP) and troponin I. Echocardiography was performed to assess the right heart structural, hemodynamic and functional parameters.Results. In patients with COVID-19 pneumonia, with an increase in lung parenchyma involvement, the intensity of systemic inflammatory response increased: C-reactive protein, group I — (4 [1,9; 35] mg/l), in III — (70,5 [33; 144] mg/l) (pI-III=0,012); myocardial stress marker level increased: NT-proBNP, group I — 77 [48; 150] ng/l, group III — 165 [100; 287] ng/l (pI-III=0,047). The dependence of NT-proBNP on C-reactive protein level was revealed (r=0,335, p=0,03). Intergroup comparison did not reveal significant differences between the main right heart functional parameters: TAPSE, Tei index (PW and TDI), FAC of the right ventricle (RV) (p>0,05). However, differences in the tricuspid annular peaks were found as follows: group I — 0,14 [0,12; 0,14] m/s, group II — 0,14 [0,12; 0,15] m/s, group III — 0,16 [0,14; 0,17] m/s (pI-II=0,012, pI-III=0,014) and RV global longitudinal strain: group I — 19,63±7,72%, group III — 27,4±5,93% (pI-III=0,014). The relationship between the RV global longitudinal strain and SHOKS-COVID score was confirmed (r=0,381; p=0,024).Conclusion. Patients with COVID-19 pneumonia showed no signs of right heart dysfunction. The development of RV hyperfunction was noted. Most likely, this is a compensatory mechanism in response to acute RV afterload. NT-proBNP increase under conditions of an inflammatory response may indicate myocardial stress. The results obtained allow to expand our understanding of the right heart condition in patients with COVID-19 pneumonia

The commensal infant gut meta-mobilome as a potential reservoir for persistent multidrug resistance integrons

Despite the accumulating knowledge on the development and establishment of the gut microbiota, its role as a reservoir for multidrug resistance is not well understood. This study investigated the prevalence and persistence patterns of an integrase gene (int1), used as a proxy for integrons (which often carry multiple antimicrobial resistance genes), in the fecal microbiota of 147 mothers and their children sampled longitudinally from birth to 2 years. The study showed the int1 gene was detected in 15% of the study population, and apparently more persistent than the microbial community structure itself. We found int1 to be persistent throughout the first two years of life, as well as between mothers and their 2-year-old children. Metagenome sequencing revealed integrons in the gut meta-mobilome that were associated with plasmids and multidrug resistance. In conclusion, the persistent nature of integrons in the infant gut microbiota makes it a potential reservoir of mobile multidrug resistance

Comparative analysis of anxiety-depressive spectrum disorders in patients with rheumatic diseases

Research objective - comparative analysis of incidence and structure of anxiety-depressive spectrum disorders (ADD) in patients with various rheumatic diseases (RD). Materials and methods. 613 patients with RD were enrolled in the study: 180 with a reliable diagnosis of systemic lupus erythematosus (SLE), 128 with rheumatoid arthritis (RA), 110 with systemic sclerosis (SSc), 115 with Behcet's disease (BD), 80 with primary Sjögren's syndrome (pSS). Female prevailed in all groups (95% of patients with pSS, 88,2% - SSc, 87,2% - RA, 85,5% of SLE) except BD patients (70% male). The mean age was 42.3±1.54 years and was lower in patients with BD (33.3±0.98 years) and SLE (34.6±0.93 years) compared to patients with SSc (49.9±2.47 years), RA (47.4±0.99 years) and pSS (46.2±2.3 years). The mean RD duration was 130,0±8,65 months and was more at BD - 148,5±10,4 months, pSS - 141,6±8,92 months, RA - 138,4±10,1months, and less at SLE - 134,9±8,8 months and SSc - 87,0±5,04 months. The mean SLE activity index SLEDAI was 9,13±0,63 points (high), RA (DAS28) - 5,26±0,17 points (high), BD (BDCAF) - 3,79±0,2 points (moderate) and SSc by G. Valentini - 1,1±0,20 points (moderate). Glucocorticoids took 100% of patients with pSS, 91,1% - SLE, 90% - SSc, 87% - BD and 67,2% - RA patients; conventional disease modifying anti-rheumatic drugs (cDMARDs) took 90% of patients with SSc, 84% - BD, 79,6% - RA, 68% - pSS, 40,6% - SLE. Biologic DMARDs took 32% of patients with RA, 17,4% - BD, 7,3% - SSc and 7,2% - SLE. Mental disorders were diagnosed by psychiatrist as a result of screening by the hospital anxiety and depression scale (HADS) and in semi-structured interview in accordance with the ICD-10/ DSM-IV. The severity of depression was evaluated by Montgomery-Asberg Depression Rating Scale (MADRS) and anxiety - by Hamilton Anxiety Rating Scale (HAM-A). Projective psychological methods were used for cognitive impairment detection. Results. Screening of depressive disorders (HADS-D≥8) was positive in 180 (29,4%) patients with RD, including 74 (41%) patients with SLE, 38 (35%) - SSc, 29 (23%) - RA, 23 (20%) - BD and 16 (20%) - pSS; anxiety disorders (HADS-A≥8) - in 272 (44,4%) patients, including 66 (52%) patients with RA, 40 (50%) - pSS, 77 (43%) - SLE, 45 (41%) - SSc and 44 (38%) - BD. In accordance with the ICD-10/ DSM-IV depressive disorders have been identified in 389 (63%) patients, including 94 (73%) patients with RA, 71 (64,5%) - SSc, 69 (60%) - BD, 90 (50%) - SLE and 39 (49%) - pSS; anxiety disorders - in 377 (61,5%) patients, including 20 (25%) patients with pSS, 44 (24,5%) - SLE, 29 (23%) - RA, 20 (17%) - BD and 7 (6,4%) - SSc. Conclusion. Anxiety-depressive spectrum disorders are typical for most patients with RA, SLE, SSc, pSS and BD. ADDs diagnosis in RD patients with the use of the HADS did not reveal a significant proportion. To obtain objective data on the frequency and structure of ADDs, psychopathological and clinical psychological diagnosis is necessary

Results of a Joint Epizootiological Survey of Transboundary Natural Plague Foci of the Russian Federation and Potentially Focal Territories of the Republic of Kazakhstan in 2019–2022

Consolidation of the efforts in implementation of epidemiological surveillance and control over plague and other dangerous natural-focal infections is an essential aspect in ensuring epidemiological well-being as regards particularly dangerous infectious diseases in the territory of natural plague foci and potentially focal territories located within the borders of the Russian Federation and the Republic of Kazakhstan. The aim of the work was to carry out a joint epizootiological survey of the transboundary territories of the Volga-Ural sandy natural plague focus and the territory of the East Kazakhstan region of the Republic of Kazakhstan (RK) potentially focal for plague over the period of 2019–2022. Materials and methods. Samples of field materials, collected during the epizootiological survey of the territory of Kazakhstan, were studied using bacteriological, molecular-genetic, and immune-serological methods. Results and discussion. We have obtained the current evidence on the spatial-biocenotic structure, the circulation of pathogens of dangerous natural-focal infectious diseases in the transboundary territories of Eastern and Western Kazakhstan. It has been established that the conditions that contribute to the possibility of human infection with plague and other dangerous infectious diseases in case of the aggravation of epizootic situation in the foci or importation of the pathogens into the territory are in place