The results obtained by determining the flux density of neutrons produced with energies of up to 20 MeV upon the irradiation of a beryllium target 1.3 mm thick with a beam of 21.3-MeV protons are ...presented. The proton flux density was determined by means of standard instruments and was controlled with the aid of the monitoring reactions
Cu
Zn and
Cu
Zn, while the neutron flux density was determined using the reactions
Al
Mg and
Al
Na. The proton and neutron spectra at the center of experimental samples were calculated using the PHITS code.
The ice-gouging topography of bed of the southwestern Kara Sea is the result of the impact of icebergs and sea ice. During cruise 52 of the R/V
Akademik Nikolaj Strakhov
using a multibeam echo ...sounder, we collected representative data on the key parameters of ice scours (location, orientation, depth, width) for the first time, which allows us to draw conclusions on a regional scale. We revealed regularities in the spatial and temporal distribution of ice scours and their density in different parts of the seabed. It was revealed that the maximum dimensions of the ice scours decrease with distance from the sources of iceberg calving from NW to SE. The orientation of the ice scours correlates with the main drift directions of icebergs. Most of the ice scours are located at depths up to 220 m and could have formed both at the modern and lower sea levels (in postglacial time). We identified a high degree of seabed transformation by ice-gouging processes in the southwestern Kara Sea.
The graphite in marbles from Oltrek, an uninhabited island on Lake Baikal, has been investigated by micro‐Raman spectroscopy using visible and near‐ultraviolet wavelength excitation. All graphite ...samples exhibit a sharp first‐order Raman band at about 1,580 cm−1 with a width from 10 to 19 cm−1, and sometimes a D1 band with very low intensity, which is occasionally absent. Using Raman spectra data it was estimated that the temperature of graphite formation in the Oltrek marbles is about 530–650°C and possibly even higher. This evaluation is in good agreement with the temperatures (about 700°C) determined by a graphite isotope geothermometer of the graphite–calcite pair. Scanning electron microscopy images have recorded a сonical graphite morphology on the surface of plate crystals of graphite. Raman spectra of samples with cones about 200–400 nm sizes showed that the graphite was associated with nontronite in the specimens studied. Natural nontronite, a clay mineral of the smectite group, has not been well characterized using Raman spectroscopy. Here, the Raman spectra of the Oltrek nontronite were compared with the spectrum of nontronite from the weathered crust of the Salair Ridge, Russia. The formation of hexagonal–pyramidal structures on the surface of graphite with the participation of clay and bio‐organic matter in marble is discussed.
Micro‐Raman spectra of the high quality plate graphite and graphite cones on its surface show that the latter was associated with clay mineral nontronite in the specimens studied. The Raman spectrum of the Oltrek nontronite was compared with the spectrum of nontronite from the weathered crust of the Salair Ridge, Russia. The formation of hexagonal–pyramidal structures on the surface of the graphite with the participation of clay and bio‐organic matter in marble is discussed.
Abstract
Current–voltage characteristics (
EJ
curves) and magnetic field dependences of the critical current have been calculated for a superconductor with artificial pinning in the form of ...submicron-sized holes and tilted radiation defects. Calculations have been performed within the framework of the three-dimensional model of a layered HTS by means of the Monte Carlo method. S-shaped features of the
EJ
curves have been observed for a sample with a rectangular lattice of holes. Such features have not occurred in calculations for HTSs with non-magnetic pinning centers before, but they have been observed in experimental studies. In this paper, the features occurred in magnetic fields close to 290 Gs (which is the lower critical field for the Bi
2
Sr
2
CaCu
2
O
8-
δ
superconductor at 1 K) and they were sensitive to the magnitude of the external magnetic field. In addition, the features were more prominent at temperatures below 30 K and in samples with weak intrinsic pinning, and they were connected with matching-like effects in the vortex system (i. e. a certain number of vortices being pinned on each hole, screening new vortices from entering the sample). For samples with tilted radiation defects, decreasing field dependences of the critical current have been obtained, showing weak maxima near the lower critical field of the superconductor. Calculations have shown that, at a fixed value of the external field, the critical current decreases with the increasing tilt angle of the defects.
Dental caries stands as a highly common chronic ailment affecting individuals globally, with susceptibility to this condition spanning their entire lifespan. Consequently, the search for novel ...medications aimed at treating and preventing dental caries holds significant importance in the field of pharmacy.
The aim of the work was to study the antioxidant, antimicrobial, and antifungal activity of the obtained oral tablets “Сaсhisept” for resorption in the oral cavity for the treatment and prevention of dental caries.
Materials and methods. The obtained tablets “Сaсhisept” with green tea leaf extract were the object of investigation. Antioxidant activity was established by the potentiometric method, and antimicrobial and antifungal activity was assessed by the agar well diffusion method.
Results. The level of antioxidant activity for tablets “Сaсhisept” was 110.00 ± 2.20 mmol-eqv./mdry res, the obtained tablets had a high level of antioxidant activity according to Maslov’s conditional classification. Staphylococcus aureus (25.33 ± 0.50 mm), Baсillus subtilis (25.33 ± 0.50 mm) and Streptococcus mutans (25.33 ± 0.50 mm) were the most sensitive to the obtained “Сaсhisept” tablets, and the least – Proteus vulgaris (20.67 ± 0.50 mm), and it was observed strong growth inhibition in relation to the fungus Candida albicans (20.00 ± 0.50 mm).
Conclusions. The presented study has found that “Сaсhisept” tablets have a high level of antioxidant activity, and also have a high antimicrobial and antifungal effect against all investigated Gram-positive, Gram-negative bacteria, and the Candida albicans fungus. Thus, “Сaсhisept” tablets can be recommended for the treatment and prevention of dental caries.
The features of diffraction on silver nanoparticles located in channels of mesoporous silicate SBA-15 are analyzed. A computer simulation of diffraction patterns is performed for crystallites with ...different sizes, the cubic structure, and stacking faults. The experimental diffraction patterns are compared with simulated ones. Together with the stacking fault concentration, the average crystallite sizes are determined in the direction normal to the close packed layers and along the layers in the crystal structure.
The article is dedicated to the 500th anniversary of the birth of the greatest physician and scientist of the 16 th century Gabriele Falloppio (Fallopius), a revolutionary morphologist who made ...an invaluable contribution to the development of science, and one of the founders of fundamental anatomy. Although Falloppio is primarily known as an anatomist who described the uterine (“fallopian”) tubes, his range of interests was much wider, and his contribution to anatomy was substantially more significant. Fallopius made many important discoveries in anatomy, and a number of anatomical structures bear his name. Also, Gabriele Falloppio was a talented teacher and a renowned medical practitioner, surgeon and pharmacist. It should be especially noted that Fallopius considered himself an apprentice of Andreas Vesalius. There is no data confirming the fact of their personal acquaintance, but there is documentary evidence of short-term correspondence between Fallopius and Vesalius. In his famous work “Anatomical observations” (“Observationes anatomicae”, 1561), Fallopius pointed out Vesalius’ mistakes and inaccuracies in anatomical descriptions, subjecting his “De humani corporis fabrica” to correct criticism. Vesalius’ reply with compliments to Fallopius as a scientist has been preserved. In any case, the undoubted fact is that Fallopius was an adherent of Vesalius’ methods in applied science and the teaching of anatomy, and consistently introduced them into practice throughout his life.
Magnetic, acoustic, and thermophysical phenomena in magnetic fluid systems have found application in the design of magnetic fluid seals, shock absorbers, sensitive three-axis accelerometers, density ...meters, and a number of other advanced devices. This explains the interest in studying these effects. Lately, due to the rapid development of microfluidics, more and more works have appeared that deal with magnetic fluid dynamics in channels of various shapes when various external physical fields affect them. However, several aspects have only been studied superficially, although they are potentially of great scientific and practical interest; these are levitating gas cavity properties and magnetic, acoustic and thermophysical phenomena accompanying dynamic gas cavity and bubble displacement in a magnetic fluid. This paper investigates the dynamics of bubble trapping in magnetic fluid located in the so-called magnetic vacuum region of an annular magnet. We obtained data on effects of centrifugation and magnetic fluid structure on the strength of magnetic fluid bridges subjected to external pressure. This information may be useful for developing a test bench for magnetic fluids used in seals, where fluids undergo similar effects. We used two samples of magnetic fluid to perform an experiment which involved compressing the air cavity, eventually leading to gas bubbles detaching from the samples. We draw conclusions concerning the effects of physical parameters of magnetic fluids and magnetic field configuration on the diameter of the resulting bubbles.
REHABILITATION OF PATIENTS AFTER CARDIAC SURGERY Romaniuk, T. V.; Moroz, V. S.; Maslii, S. M. ...
International journal of medicine and medical research,
04/2022, Letnik:
7, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Background. Patients undergoing cardiac surgery are under a high risk of post-operative reductions in respiratory muscle strength and pulmonary function as well as lowered functional capacity. ...In-hospital physical inactivity and inappropriate rehabilitation increases the chances for development of these complications and affects patients’ future independence in daily routine. Cardiac rehabilitation is crucial in preventing complications and assisting the early function recovery. However, despite the evidences for its benefits and strong guideline recommendations, the uptake of cardiac rehabilitation remains poor. Objective. this study is aimed at promotion of cardiac rehabilitation and sharing successful experience of using it. Methods. Post-surgical treatment and rehabilitation of 387 patients with cardiovascular pathology in the Department of Vascular and Cardiac Surgery of Municipal Non-Commercial Enterprise “Ternopil Regional Clinical Hospital” of Ternopil Regional Council has been analysed. Results. The experience of successful post-surgical treatment and rehabilitation allowed establishing the basic approaches to perioperative management of patients with cardiovascular surgical pathology. Key principles include minimized ICU stay and artificial ventilation time, early verticalization and beginning of physical activities, early removed drainage tubes, tracheobronchial tree drainage, nutritional balance, lymphatic drainage massage, application of elastic jersey on the lower extremities, early transferring to the surgery ward and returning to the regular daily activities, circumstantial health education, complex work of a multidisciplinary team. Conclusions. This set of rehabilitation measures helps prevent complications after cardiac surgery as well as provide a faster patient’s daily routine.
An analysis of a number of samples from the Tomtor deposit of Nb and rare-earth elements (Republic of Saha (Yakutia)) by X-ray diffractometry, IR spectroscopy, and Raman spectroscopy makes it ...possible to cover the structural organization of minerals and their components from the long-range to the mid- and short-range orders. The apatites present in the samples are characterized by a large variety of anion and cation substitutions (including rare-earth elements) in various structural sites. Raman microspectroscopy revealed some specific features, inherent in molecular biomarkers (specifically, a band due to double bonds –C=C– in the central part of the polyene chain of carotenoids, which characterize cyanobacteria associated with apatite), which is a direct proof of participation of microorganisms in the formation of apatites in rocks of this deposit.
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