308 research outputs found

    Mode-coupling and the pygmy dipole resonance in a relativistic two-phonon model

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    A two-phonon version of the relativistic quasiparticle time blocking approximation (RQTBA-2) represents a new class of many-body models for nuclear structure calculations based on the covariant energy density functional. As a fully consistent extension of the relativistic quasiparticle random phase approximation (RQRPA), the two-phonon RQTBA implies a fragmentation of nuclear states over two-quasiparticle and two-phonon configurations. This leads, in particular, to a splitting-out of the lowest 1^- state as a member of the two-phonon [2+3][2^+\otimes3^-] quintuplet from the RQRPA pygmy dipole mode, thus establishing a physical mixing between these three modes. The inclusion of the two-phonon configurations in the model space allows to describe the positions and the reduced transition probabilities of the lowest 1^- states in isotopes 116,120^{116,120}Sn as well as the low-energy fraction of the dipole strength without any adjustment procedures. The model is also applied to the low-lying dipole strength in neutron-rich 68,70,72^{68,70,72}Ni isotopes. Recent experimental data for 68^{68}Ni are reproduced fairly well

    Analysis of the Internal Environment of the Pharmaceutical Distributor Operation in Russia Using SWOT Analysis

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    BACKGROUND: The general directions of the organization’s development should be clearly formulated, i.e., a business strategy should be developed in order to achieve the long-term competitive advantages in the operation of a pharmaceutical distributor with its own pharmacy warehouse in Russia. AIM: Identification of strengths and weaknesses, opportunities and threats in the operation of a pharmaceutical distributor with its own pharmacy warehouse. MATERIALS AND METHODS: The SWOT analysis was used to analyze the environment, which enabled a joint study of the external and internal environment. During the study, content analysis of secondary sources of information was used (data from the Federal State Statistics Service, DSM Group marketing agency), as well as sociological analysis. RESULTS AND DISCUSSION: During the SWOT analysis, ten factors were identified that ensured the normal functioning of the pharmaceutical distributor, as well as 11 negative factors were identified that negatively affected the operation of the pharmacy warehouse. The article presents qualitative description of the strengths and weaknesses. Ten factors were attributed to the favorable opportunities for the organization’s activities; seven positions were considered as threats to the activities of the distributor. It should be noted that all factors of external environment are in a state of strong mutual influence. A change in one of the factors necessarily leads to a change in other factors. Therefore, their study and analysis should not be carried out separately, but systematically, with tracking not only the actual changes in one factor but also the process how these changes will affect other factors. After identifying strengths and weaknesses, opportunities and threats, a table was compiled and all intersections were analyzed, i.e., all possible pairwise combinations that would help determining the future strategy. At present, the strategic goal of a number of wholesale companies in the pharmaceutical market is defined as increasing return on investment. CONCLUSION: In this article, SWOT analysis has been used to provide some suggestions on overcoming weaknesses and threats in the activities of a pharmaceutical distributor, as well as on proper use of strengths and opportunities. During the study, pharmaceutical industry practitioners discussed the impact of various economic factors, strengths, opportunities, weaknesses, and threats regarding the activities of pharmaceutical distributor, as well as related problems and prospects for the future

    Rheology and porosity effect on the proliferation of preosteoblast on zirconia ceramics

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    It has been studied ZrO2(MexOy) based porous ceramics, obtained from the powders consisting of hollow spherical particles. It was shown that the structure is represented as a cellular carcass with a bimodal porosity, formed of a large pore close to a spherical shape and the pores that were not filled with the powder particles during the compaction. For such ceramics the increase of pore volume is accompanied by an increase in strain in an elastic area. It was also shown that the porous ZrO2 ceramics had no acute or chronic cytotoxicity. At the same time, ceramics possess the osteoconductive properties: adhesion support, spreading, proliferation and osteogenic differentiation of MSCs

    Certain features of using modified collagen-containing raw materials with prolonged shelf life in food technology

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    In the current circumstances, trends in nutrition of a person striving to lead a healthy life-style require intake of meat products with the reduced energy value, minimal amounts of fat, increased protein mass fraction, presence of substances improving homeostasis of the body. The synergism of the modern nutrition science and meat industry enables creating food products that satisfy consumers’ demand. Today, in the Russian Federation, a theoretical and practical base of the technology development has been collected to the full extent in the field of rational processing of secondary raw materials in the food industry, optimal use of animal secondary raw materials, study of the protein ingredients of animal and plant origin and their deep scientifically substantiated processing, improvement of technological processes and equipment, and correspondently, product range extension. The paper broadens the information about the modified collagen-containing raw materials (cattle rumen), examines physico-chemical characteristics of the collagen-containing raw material and its changes in the process of freeze-drying with a special attention paid to the study of changes in the histological structure. The presence of the relatively uniform fibrillar structure was determined, which facilitated discovering the functional potential of proteinoids that form the fibrillar matrix in the composition of products from different groups. Analysis of IR-spectra revealed several significant absorption bands linked with the state of peptide bonds. The character of bands is linked with the complex of valence and deformation vibrations of the N- and С- types. It is believed that IR-spectra reflect conformations in the protein secondary structure, which suggests preserving properties of the tropocollagen particle or collagen molecule. Freeze-dried modified collagen-containing cattle rumen was tested by the example of jellies. The obtained databank broadens information about physico-chemical properties of modified collagen-containing raw materials (cattle rumen).In the current circumstances, trends in nutrition of a person striving to lead a healthy life-style require intake of meat products with the reduced energy value, minimal amounts of fat, increased protein mass fraction, presence of substances improving homeostasis of the body. The synergism of the modern nutrition science and meat industry enables creating food products that satisfy consumers’ demand. Today, in the Russian Federation, a theoretical and practical base of the technology development has been collected to the full extent in the field of rational processing of secondary raw materials in the food industry, optimal use of animal secondary raw materials, study of the protein ingredients of animal and plant origin and their deep scientifically substantiated processing, improvement of technological processes and equipment, and correspondently, product range extension. The paper broadens the information about the modified collagen-containing raw materials (cattle rumen), examines physico-chemical characteristics of the collagen-containing raw material and its changes in the process of freeze-drying with a special attention paid to the study of changes in the histological structure. The presence of the relatively uniform fibrillar structure was determined, which facilitated discovering the functional potential of proteinoids that form the fibrillar matrix in the composition of products from different groups. Analysis of IR-spectra revealed several significant absorption bands linked with the state of peptide bonds. The character of bands is linked with the complex of valence and deformation vibrations of the N- and С- types. It is believed that IR-spectra reflect conformations in the protein secondary structure, which suggests preserving properties of the tropocollagen particle or collagen molecule. Freeze-dried modified collagen-containing cattle rumen was tested by the example of jellies. The obtained databank broadens information about physico-chemical properties of modified collagen-containing raw materials (cattle rumen)

    Dissolution kinetics of rare earth metal phosphates in carbonate solutions of alkali metals

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    Treatment of apatite raw materials is associated with the formation of large-tonnage waste – phosphogypsum. The content of rare earth metals in such waste reaches 1 %, which makes it possible to consider it a technogenic source for obtaining rare earth metals and their compounds. Up to the present moment, there are neither processing plants, nor an efficient process flow to handle phosphogypsum dumps. It is rational to use a way that involves extraction of valuable components and overall reduction of phosphogypsum dumps. Such process flow is available with carbonate conversion of phosphogypsum to alkali metal or ammonium sulfate and calcium carbonate upon the condition of associated extraction of rare earth metal (REM) compounds. Associated extraction of REM compounds becomes possible since they form strong and stable complexes with hard bases according to Pearson, which among other things include carbonate, phosphate and sulfate anions. Formation of lanthanide complexes with inorganic oxygen-containing anions is facilitated by the formation of high-energy Ln-O bonds. The study focuses on the dissolution of lanthanide phosphates in carbonate media. It was established that formation of REM carbonate complexes from their phosphates is a spontaneous endothermic process and that formation of lanthanide carbonates and hydroxides serves as thermodynamic limitation of dissolution. A shift in equilibrium towards the formation of carbonate complexes is achieved by increasing the temperature to 90-100 °C and providing an excess of carbonate. The limiting stage of REM phosphate dissolution in carbonate media is external diffusion. This is indicated by increasing rate of the process with an intensification of stirring, first order of the reaction and the value of activation energy for phosphate dissolution from 27 to 60 kJ/mol. A combination of physical and chemical parameters of the process allowed to develop an engineering solution for associated REM extraction during carbonate conversion of phosphogypsum, which included a 4-5 h conversion of phosphogypsum at temperature of 90-110 °C by an alkali metal or ammonium carbonate solution with a concentration of 2-3 mol/l. As a result, a solution with alkali metal (ammonium) sulfate is obtained, which contains REMs in the form of carbonate complexes and calcium carbonate. The rate of REM extraction into the solution reaches no less than 93 %. Rare earth metals are separated from the mother liquor by precipitation or sorption on anion exchange resins, while the excess of alkali metal or ammonium carbonate is returned to the start of the process

    The knee in galactic cosmic ray spectrum and variety in supernovae

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    The present paper deals with calculations based on a standard model of cosmic ray acceleration in Supernova remnants (SNR) and on the latest astronomical data concerning the variety in Supernovae types, energies as well as the sites of their explosions. The results obtained allow explaination of the main features of all particle cosmic ray spectrum, including the 'knee'. This conclusion is based essentially on the premise that energy of accelerated CR in the given SNR is proportional to the kinetic energy of this explosion, that stresses the input of high energy explosions and suppresses the contribution of low energy explosions to the total CR flux.Comment: LaTeX2e, 18 pages with 9 figures in eps forma

    Relativistic quasiparticle time blocking approximation. Dipole response of open-shell nuclei

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    The self-consistent Relativistic Quasiparticle Random Phase Approximation (RQRPA) is extended by the quasiparticle-phonon coupling (QPC) model using the Quasiparticle Time Blocking Approximation (QTBA). The method is formulated in terms of the Bethe-Salpeter equation (BSE) in the two-quasiparticle space with an energy-dependent two-quasiparticle residual interaction. This equation is solved either in the basis of Dirac states forming the self-consistent solution of the ground state or in the momentum representation. Pairing correlations are treated within the Bardeen-Cooper-Schrieffer (BCS) model with a monopole-monopole interaction. The same NL3 set of the coupling constants generates the Dirac-Hartree-BCS single-quasiparticle spectrum, the static part of the residual two-quasiparticle interaction and the quasiparticle-phonon coupling amplitudes. A quantitative description of electric dipole excitations in the chain of tin isotopes (Z=50) with the mass numbers A = 100, 106, 114, 116, 120, and 130 and in the chain of isotones with (N=50) 88-Sr, 90-Zr, 92-Mo is performed within this framework. The RQRPA extended by the coupling to collective vibrations generates spectra with a multitude of '2q+phonon' (two quasiparticles plus phonon) states providing a noticeable fragmentation of the giant dipole resonance as well as of the soft dipole mode (pygmy resonance) in the nuclei under investigation. The results obtained for the photo absorption cross sections and for the integrated contributions of the low-lying strength to the calculated dipole spectra agree very well with the available experimental data.Comment: 43 pages, 3 figure

    Benchmarking nuclear models for Gamow-Teller response

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    A comparative study of the nuclear Gamow-Teller response (GTR) within conceptually different state-of-the-art approaches is presented. Three nuclear microscopic models are considered: (i) the recently developed charge-exchange relativistic time blocking approximation (RTBA) based on the covariant density functional theory, (ii) the shell model (SM) with an extended "jj77" model space and (iii) the non-relativistic quasiparticle random-phase approximation (QRPA) with a Brueckner G-matrix effective interaction. We study the physics cases where two or all three of these models can be applied. The Gamow-Teller response functions are calculated for 208-Pb, 132-Sn and 78-Ni within both RTBA and QRPA. The strengths obtained for 208-Pb are compared to data that enables a firm model benchmarking. For the nucleus 132-Sn, also SM calculations are performed within the model space truncated at the level of a particle-hole (ph) coupled to vibration configurations. This allows a consistent comparison to the RTBA where ph+phonon coupling is responsible for the spreading width and considerable quenching of the GTR. Differences between the models and perspectives of their future developments are discussed.Comment: 9 pages, 2 figures, 1 table; to be published in Phys. Lett.

    Myocardial remodeling and fibroblast growth factor in patients with resistant hypertension

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    Aim. To study the prevalence and severity of left ventricular hypertrophy (LVH), its relationship with fibroblast growth factor (FGF23) in patients with resistant hypertension (RH) depending on the effectiveness of multiagent antihypertensive therapy.Material and methods. The study included 92 patients diagnosed with RH. All patients underwent 24-hour ambulatory blood pressure monitoring (ABPM), echocardiography, general laboratory tests, and the serum FGF23 level was determined.Results. According to ABPM results, patients were divided into following groups: 1st — controlled RH (n=44) and 2nd — uncontrolled (n=48) RH. The groups were comparable in sex, age, main clinical and anthropometric parameters. In group 2, the main parameters of ABPM were higher. There were no differences in general laboratory tests, In the group of uncontrolled RH, the level of FGF23 was higher — 11,7 [8,5; 15,4] pmol/ml vs 9,2 [7,1; 11,6] pmol/ml in the 1st group (p=0,0036). According to echocardiography, a comparable violation of left ventricular (LV) diastolic function, an increase in left atrial size, LV mass (LVM) and LVM index were found. In patients of the 2nd group, large values of interventricular septal thickness were revealed — 1,3 [1,2; 1,4] cm vs 1,2 [1,1; 1,3] cm in the 1st group (p=0, 0043) and relative LV wall thickness (LVWT) — 0,50 [0,48; 0,53] vs, 0,45 [0,43; 0,50] in the 1st group (p<0,0001). In the 1st and 2nd groups, concentric LVH was more common (18 (41%) patients in the 1st and 26 (54,1%) in the 2nd (p=0,044) groups) than eccentric LVH (15 (34,1%) and 13 (27,1%) patients in the 1st and 2nd groups, respectively). Correlation analysis revealed a positive relationship between pulse pressure and HTN duration (r=48, p=0,02) and FGF23 level (r=0,62, p=0,004). The LVM index was positively associated with the diastolic pressure-time index (BP) (r=51, p=0,02). A positive correlation was found between relative LVWT and pulse pressure (r=0,64, p=0,02) and a negative relationship with the duration of regular antihypertensive therapy (r=47, p=0,04), A strong relationship was found between LVEF and FGF23 levels (r=0,75, p=0,005).Conclusion. For patients with uncontrolled resistant hypertension, an increase in pulse pressure and myocardial remodeling in the form of concentric hypertrophy are more characteristic. FGF23 is significantly higher in uncontrolled RH and is positively associated with pulse pressure and relative LVWT
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