713 research outputs found
Features of structural and functional state of the heart in patients with chronic heart failure with comorbid hypertension
The aim - to identify structural and functional features of cardiac remodeling in patients with chronic heart failure associated with hypertension.
Materials and Methods. Hemodynamic, structural and functional changes have been studied in 77 patients (21 women and 56 men) with chronic heart failure with preserved left ventricular ejection fraction using echocardiography. The first group consisted of 46 patients with heart failure and hypertension, the second group included 31 patients with CHF without hypertension. All groups were comparable to age and sex.
Results. In patients with heart failure and a history of hypertension remodeling processes were characterized by increase in LAV (17.8%, p<0.05), LVPWd (16.3%, p<0.05), IVSd (12.7%, p<0.05), RWT (22.4%, p<0.05) and ejection fraction (13.3%, p<0.05), compared with patients without hypertension, with a predominance of eccentric and concentric hypertrophy and diastolic dysfunction by type of abnormal relaxation.
Conclusions. In CHF patients with hypertension remodeling processes are characterized by walls thickening, increase in left atrium volume, left ventricular myocardial mass, left ventricular ejection fraction with a predominance of eccentric and concentric hypertrophy and diastolic dysfunction by type of abnormal relaxation that are reasonable to use in practice of medical and social expertise
The problem of cognitive-semantic grounds for verbs polysemy in English
The given article considers the problem of the cognitive and semantic basis for polysemanticism of verbs in English as one of the main mental processes that promotes changes and development of the meaning of words, the verbs in particula
Ergatic dynamic control systems
Synthesis and analysis of systems containing a man in their control circuits are considered. The concepts of ergonomics and ergatic systems are defined, and tasks and problems of ergonomics are outlined. The synthesis of the structure of an astronautic ergatic organism is presented, as well as the synthesis of nonstationary ergatic systems. Problems of selecting the criteria for complex systems are considered, and the results are presented from a study of ergatic control systems with any degree of human participation
Investigation on the origin of magnetization in plastically deformed Ni51Ti49 alloy
The article deals with the investigation of structure and magnetic properties of plastically deformed Ni51Ti49 alloy. The magnetic hysteresis loops confirm the presence of ferromagnetic properties in the alloy. The transmission electron microscopy (TEM) detects the appearance of lenticular crystals with bending contours which indicate the large distortion of the crystal lattice. The crystal lattice curvature occurs due to the large atom displacement. As a result, icosahedral clusters with the Frank-Kasper (FK) structure can be formed. The spin-polarized density of electron states and the magnetic moments for both non-deformed (near-spherical structure) and deformed (elongated by 5% along the Z-axis) Ni7Ti5 (FK-12), Ni8Ti5 (FK-13), and Ni10Ti6 (FK-16) clusters are calculated for the explanation of possibility of magnetization appearance in Ni51Ti49 alloy. The calculations show the increase in the magnetic moments for the deformed clusters. The calculated spectra demonstrate the high density of electron states near the Fermi level which is a characteristic feature of ferromagnetic alloys
ІНФОРМАЦІЙНА ТЕХНОЛОГІЯ КОРОТКОСТРОКОВОГО ПРОГНОЗУВАННЯ ПЕРВИННОЇ ІНВАЛІДНОСТІ В УКРАЇНІ
The information technology of primary disability forecasting in Ukraine is developed. It is based on combined using of short-term forecasting adapt methods.Разработана информационная технология прогнозирования первичной инвалидности в Украине на основе комплексного применения адаптивных методов краткосрочного прогнозирования.Розроблено інформаційну технологію прогнозування первинної інвалідності в Україні на базі комплексного застосування адаптивних методів короткострокового прогнозування
Morphological features of bovine placenta in case of viral, bacterial and protozoal infections
The problem of the intrauterine infection of fetus is one of the most critical ones in veterinary obstetrics and in perinatology due to the high level of infection in pregnant cows, the risk of developmental disorder of fetus and the birth of sick calves. Complications of pregnancy occur in case of viral, bacterial and protozoal infections, when the pathogen enters the uterus in an ascending or descending way with further transplacental infection of the fetus. Morphological studies of placenta of Black Pied cattle infected with bovine viral diarrhea, chlamydia and neosporosis were carried out. The presence of the pathogen was confirmed by serological and molecular genetic methods. The material used for histological studies was the fetal part of placenta. After sampling, the material was fixed in a 10% neutral formalin solution, then xylene-free method for histological preparation was used. Afterwards, samples were embedded in paraffin. In order to study morphological structures, samples were sectioned at 5–6 µm, and stained with hematoxylin and eosin. Histological sections were analyzed using a Leica DM 1000 light microscope at a magnification of 100×, 200×, 400×, 630×. On the basis of the conducted studies, it was established that bovine viral diarrhea-associated morphofunctional changes in the “mother – placenta – fetus” system are characterized by involutive-dystrophic changes with microcirculation disorders and the development of an immunity-associated inflammatory process. Chlamydia abortus intrauterine infection in the “mother – placenta – fetus” system in cows causes a complex of destructive morphological and functional changes of an infectious and toxic nature with a pronounced inflammatory reaction, involvement of blood vessels in the pathological process, and endothelial dysfunction development, alongside with tissue necrosis in case of a chronic process. The presence of cellular structures in the placenta and the inner part of the umbilical cord is a pathognomonic sign of chlamydia. The role of transplacental transmission of Neospora caninum in cattle was confirmed, the Neospora parasites subjected to basophilic staining were detected not only in the tissues of the placenta, but also in histological sections of the fetus heart and liver. The main characteristic diagnostic sign is the presence of basophilic stained Neospora parasites in the organs of the mother and fetus, placenta, and intervillous space. As part of the study morphological features of placenta, one of the most unique histohematic barriers and the basic element of the intrauterine infectious process, were determined
Autowave Processes in Magnetic Fluid: Electrically Controlled Interference
The chapter considers autowaves that were observed in the thin near-electrode layer of concentrated magnetic fluid. Autowave process is a unique object for the study of self-organization. We observed pacemakers (leading centers), reverberators (spiral waves), and wave diffraction. A mechanism for the appearance of an autowave process has been developed; its mathematical model has been proposed and realized by means of computer simulation. As a basic method of observation, we used electrically controlled interference. This method watches the changes in the spectrum of reflected light from a two-layer structure with variable thickness: “conductive ITO coating—a layer of concentrated magnetic fluid” in an electric field
Магнитные свойства в пластически деформированном никель-титановом сплаве
Ni–Ti alloy has been intensively studied over the past decades. The unique properties of the alloy have allowed using it as a structural material for the creation of instruments and devices in various fields of science and technology, including mechanical engineering, aerospace, instrumentation. Measuring magnetic hysteresis loop is shown that after the deformation of the alloy having ferromagnetic properties. According to the equilibrium phase diagram, the alloys of Ni–Ti at a Ti content above 10 at. % is non-ferromagnetic. Due to lowering of the crystal phase symmetry with a cubic lattice the magnetization appears. In this work we have investigated the magnetic properties and the structure of deformed Ni51Ti49 samples by electron microscopy and X-ray diffraction methods. In Ni51Ti49 samples after plastic deformation the lenticular crystals containing bending contours with a high concentration of internal stresses were found. Bending contours indicate a large distortion of the crystal lattice. The curvature of the crystal lattice occurs due to the large displacements of the atoms. As a result, it can be formed and icosahedral cluster with the structure of the Frank–Kasper. An icosahedron is a twelve vertex polyhedron, which is denoted by FK-12. Furthermore, the crystal can be formed in other Frank–Kasper structures, e. g., FK-16. FK-16 is a sixteen vertex polyhedron with atom located in the center of the cluster. Indexing paintings electron diffraction and X-ray showed that the alloy phase of the Ni–Ti coexist with the structure Ti2Ni and Ni4Ti3. For explaining the possibility of the appearance of magnetization in Ni–Ti alloy samples spin-polarized electron density of states and magnetic moments Ni10Ti6 clusters (FK-16), Ni7Ti5 (FK-12) alloy Ni51Ti49 for electrons with different spin projections: “up” and “down” was calculated. The calculation by the scattered waves (RF) was performed. The results of calculation can be seen that the total electron density of nickel tends to zero faster than the density of titanium. Also shows that nickel becomes negative spin density in the area of r = 3.25–6.7 a. u. and titanium for r > 4.5 a. u. This may result depending on the value of the interatomic distances and to the effects ferromagnetism and antiferromagnetic in order to establish a magnetic clusters. The spectra show a high density of states near the Fermi level that is a characteristic feature of metals, besides there is an increase in the magnetization of the alloy during deformation. The calculations showed that the investigated clusters, not susceptible to deformation, also have a magnetic moment (the average magnetic moment per atom cluster FK-12, is about 1,0 μB, and for the FK-16 is about 0.3 μB. Overall, however, the average magnetic moment is zero, due to the absence of a preferred direction (the chaotic distribution of clusters) for the alloy. However, if the cluster is subjected to tension, the compensation of the magnetic moments of clusters occurs in the alloy, since there is allocated for all atoms direction due to deformation. At the same time, the average magnetic moments of the atoms in the cluster for the Deformed increase to 1.6 μB and 0.8 μB respectively for the FK-12 and FK-16
Optical coherence tomography angiography for choroidal neovascularization in pathological myopia and neovascular age-related macular degeneration in combination with axial myopia in comparative analysis
Background. Optical coherence tomography angiography (OCTA) is currently an important method of visualization and assessment of fundus pathology in various diseases. The study of combined pathologies is not well covered.The aim: to compare OCTA features during choroidal neovascularization (CNV) in pathological myopia (PM) and in neovascular age-related macular degeneration in combination with axial myopia (nAMD + M) against the background of anti-VEGF therapy.Materials and methods. A prospective study included 70 eyes with active CNV. Comparative analysis of parameters was carried out between two groups: with PM – 47 eyes; with nAMD + M – 23 eyes.Results. 4 OCTA patterns were established in both groups: dense, loose, mixed and unidentifi able. With PM, dense pattern was found in 28 (59.57 %) eyes, loose pattern – in 16 (34.04 %), mixed pattern– in 2 (4.26 %), unidentifi able pattern – in 1 (2.13 %). In the nAMD + M group, dense pattern was rare – in 1 (4.35 %) eye, loose pattern – in 7 (30.44 %), mixed pattern – in 9 (39.13 %), unidentifi able pattern – in 6 (26.08 %). The fi rst group was characterized by a dense pattern that was found at a younger age, the second group was characterized by dense and mixed patterns. The greatest area and density of CNV were found with a loose pattern in both groups (p < 0.05). The observation period until the stabilization of CNV was achieved was longer in the loose and mixed patterns in the PM group, and in the loose and unidentifi able – in the nAMD + M group (p < 0.05). Loose and unidentifi able patterns require more injections. The halo was determined by the presence of intraretinal fluid in the retina. Conclusion. OCTA showed common features and distinctive features in the course of CNV in patients with PM and nAMD + M during anti-VEGF therapy. OCTA can be useful in assessing CNV activity and predicting the eff ect of treatment
Elongation of confined ferrofluid droplets under applied fields
Ferrofluids are strongly paramagnetic liquids. We study the behavior of
ferrofluid droplets confined between two parallel plates with a weak applied
field parallel to the plates. The droplets elongate under the applied field to
reduce their demagnetizing energy and reach an equilibrium shape where the
magnetic forces balance against the surface tension. This elongation varies
logarithmically with aspect ratio of droplet thickness to its original radius,
in contrast to the behavior of unconfined droplets. Experimental studies of a
ferrofluid/water/surfactant emulsion confirm this prediction.Comment: 12 pages, 7 figures. Submitted to Phys. Rev.
- …