60 research outputs found

    Efficacy of plasma exchange in patients with ischemia-reperfusion syndrome of the lower extremities

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    Aim. Optimization of treatment of patients with critical lower limb ischemia in ischemia-reperfusion syndrome by a combination of infusion therapy and plasma exchange. Methods. The study included 58 patients (48 men, 10 women) aged 52 to 87 years (mean age 67.1±6.2 years) operated for critical lower limb ischemia. In the postoperative period all patients received standard conservative treatment. Depending on its effectiveness, the patients were divided into two groups: group 1 (n=30) with a positive response to the treatment and group 2 (n=28) where plasma exchange was required. The indications for plasma exchange were a decrease in the rate of diuresis <0.5 ml/kg/h after the surgery for 4-6 hours, exceeding 5 times the normal values of creatine phosphokinase and 3 times the level of myoglobin. Results. In 48% of patients (group 2), deterioration of the condition was registered, which manifested by deterioration of the state, increase in shortness of breath, decrease in the rate of diuresis. In the laboratory analysis of patients of group 2, attention was drawn to an increase in the level of myoglobin to 287.8±30.1 ng/ml, creatine phosphokinase activity to 1769.3±191.8 u/l, and that of lactate to 2.2±0.3 mmol/l. These parameters exceeded not only the normal values, but also the indicators of group 1. These changes indicated the manifestation of ischemia-reperfusion syndrome and the threat of acute kidney injury. Plasma exchange was accompanied by clinical improvement (decrease in shortness of breath, increase in the rate of diuresis) and pronounced positive dynamics of laboratory parameters. The inclusion of plasma exchange into the complex therapy of ischemia-reperfusion syndrome was accompanied by an increase in the rate of diuresis by 1.7 times (p <0.05), a decrease in the level of myoglobin by 3.1 times (p <0.05) and the activity of creatine phosphokinase by 2.8 times (p <0.05). Conclusion. The use of plasma exchange during the first hours of clinical and laboratory manifestations of ischemia-reperfusion syndrome can prevent the development of fatal complications associated with the progression of this syndrome

    Pathogenesis of ischemia/reperfusion syndrome

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    Ischemia/reperfusion syndrome is a collective concept that combines various pathological conditions developing against the background of the restoration of the main blood flow in the organ or limb segment, which has long been subjected to ischemia or traumatic amputation. Intensive care physicians often see ischemia/reperfusion syndrome after restoration of blood supply in patients with critical ischemia of the lower limb. The rate of critical ischemia of the lower limbs ranges from 400 to 1000 cases per 1 million of the population. The number of lower limb amputations due to critical lower limb ischemia in economically developed countries is 13.7-32.3 cases per 100,000 of the population. The main etiological factors of critical lower limb ischemia are atherosclerosis of peripheral vessels and vascular complications of diabetes. The pathogenesis of ischemia/reperfusion syndrome is based on a complex of pathophysiological changes resulting from the restoration of blood flow in previously ischemic lower limb. Restoration of blood circulation leads to massive flow into the systemic bloodstream of anaerobic metabolism products, free myoglobin, biologically active substances and inflammatory mediators. The main sources of reperfusion damage are activated forms of oxygen, in particular, superoxide radical О2-, nitric oxide, lipid peroxidation products. In the conditions of primary ischemia, and then tissue reperfusion, excessive production of activated oxygen forms leads to damage of biological structures (lipids, proteins, deoxyribonucleic acid), which causes disruption of normal cell functioning or its death due to necrosis or apoptosis, ion pump dysfunction, adhesion of leukocytes and increased vascular permeability

    Revised Correlation between Odin/OSIRIS PMC Properties and Coincident TIMED/SABER Mesospheric Temperatures

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    The Optical Spectrograph and Infrared Imaging System (OSIRIS) instrument on board the Odin satellite detects Polar Mesospheric Clouds (PMCs) through the enhancement in the limb-scattered solar radiance. The Sounding of the Atmosphere using the Broadband Emission Radiometry (SABER) instrument on board the TIMED satellite is a limb scanning infrared radiometer that measures temperature and vertical profiles and energetic parameters for minor constituents in the mesosphere and lower thermosphere. The combination of OSIRIS and SABER data has been previously used to statistically derive thermal conditions for PMC existence [Petelina et al., 2005]. a, A.A. Kutepov, W.D. Pesnell, In this work, we employ the simultaneous common volume measurements of PMCs by OSIRIS and temperature profiles measured by SABER for the Northern Hemisphere summers of 2002-2005 and corrected in the polar region by accounting for the vibrational-vibrational energy exchange among the CO2 isotopes [Kutepov et al., 2006]. For each of 20 coincidences identified within plus or minus 1 degree latitude, plus or minus 2 degrees longitude and less than 1 hour time the frost point temperatures were calculated using the corresponding SABER temperature profile and water vapor densities of 1,3, and 10 ppmv. We found that the PMC presence and brightness correlated only with the temperature threshold that corresponds to the frost point. The absolute value of the temperature below the frost point, however, didn't play a significant role in the intensity of PMC signal for the majority of selected coincidences. The presence of several bright clouds at temperatures above the frost point is obviously related to the limitation of the limb geometry when some near- or far-field PMCs located at higher (and warmer) altitudes appear to be at lower altitudes

    Investigation of bone tissue mechanical properties in the supra-acetabular region

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    Introduction The investigation of the trabecular bone strength in the acetabular area and its dependence on age and gender may provide a theoretical basis for the development of implants for bone replacement. The purpose of this study was to determine the mechanical characteristics of the bone tissue in the supra-acetabular region in patients of different age groups. Materials and methods The cadaveric material of 60 patients was studied and included 20 young patients (age range, 18 to 44), 20 middle-aged patients (age range 45 to 59) and 20 elderly patients (age range, 60 to 74). Fragments of bone tissue 3 × 3 × 1.5 cm in size were removed from the supraacetabular region using an osteotome. Cylindrical specimens, 6 mm in diameter and 9 mm high, were produced from these fragments using a crown cutter. All samples were subjected to uniaxial compression at a loading rate of 1 mm/min. Results Comparison of male patients for each of the mechanical parameters did not reveal age differences (p > 0.05). In women of different age groups, the magnitude of elastic deformation was significantly different both by multiple analysis and in pairwise comparison of groups (p 0.05). Discussion The data obtained on the mechanical behavior of the trabecular bone and the values of the strength parameters are explained by the spatial arrangement of the fibers of structural proteins, the cross-linking profile of collagen, the degree of matrix mineralization, the structure of hydroxyapatite, and the amount of bound water. Conclusion In male patients, mechanical characteristics of the bone tissue in the supra-acetabular region do not change significantly with age. In women, the value of elastic deformation increases significantly with age. The maximum tensile strength and modulus of elasticity in women of different ages did not show any changes © Udintseva M.Yu., Zaitsev D.V., Volokitina E.A., Antropova I.P., Kutepov S.M., 202

    Magnetic state of plutonium ion in metallic Pu and its compounds

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    By LDA+U method with spin-orbit coupling (LDA+U+SO) the magnetic state and electronic structure have been investigated for plutonium in \delta and \alpha phases and for Pu compounds: PuN, PuCoGa5, PuRh2, PuSi2, PuTe, and PuSb. For metallic plutonium in both phases in agreement with experiment a nonmagnetic ground state was found with Pu ions in f^6 configuration with zero values of spin, orbital, and total moments. This result is determined by a strong spin-orbit coupling in 5f shell that gives in LDA calculation a pronounced splitting of 5f states on f^{5/2} and f^{7/2} subbands. A Fermi level is in a pseudogap between them, so that f^{5/2} subshell is already nearly completely filled with six electrons before Coulomb correlation effects were taken into account. The competition between spin-orbit coupling and exchange (Hund) interaction (favoring magnetic ground state) in 5f shell is so delicately balanced, that a small increase (less than 15%) of exchange interaction parameter value from J_H=0.48eV obtained in constrain LDA calculation would result in a magnetic ground state with nonzero spin and orbital moment values. For Pu compounds investigated in the present work, predominantly f^6 configuration with nonzero magnetic moments was found in PuCoGa5, PuSi2, and PuTe, while PuN, PuRh2, and PuSb have f^5 configuration with sizeable magnetic moment values. Whereas pure jj coupling scheme was found to be valid for metallic plutonium, intermediate coupling scheme is needed to describe 5f shell in Pu compounds. The results of our calculations show that both spin-orbit coupling and exchange interaction terms in the Hamiltonian must be treated in a general matrix form for Pu and its compounds.Comment: 20 pages, LaTeX; changed discussion on reference pape

    CLINICAL EFFICACY OF ALBUMIN DIALYSIS THERAPY FOR PATIENTS WITH HEPATORENAL SYNDROME

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    34 patients (23 male, 11 female) in the age of 41–77 years (mean age 59,7 ± 4,2 years) with 2 type hepatorenal syndrome were included in the study. All patients were divided in 3 groups. The 1st group (n = 15) was treated by medical treatment, the 2nd group (n = 12) was treated by medical treatment and hemodiafiltration and the 3rd group (n = 7) – combined treatment with MARS therapy. Outcomes showed that combined therapy with addition of MARS provides positive results in treatment of the patients with 2 type hepatorenal syndrome

    Features of high-dose intravenous immunotherapy administration in patients with reduced IgA level in neurological practice: literature review and description of a clinical case

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    Intravenous high-dose immunotherapy is one of the highly effective proven treatments for a number of autoimmune diseases of the nervous system. Nowadays there is enough knowledge about the spectrum of side effects and approaches to their prevention and monitoring. Most of them are leveled by improving the technology of the production process, but anaphylactic reactions remain one of the uncontrolled, albeit rare, undesirable reactions. The development of allergic reactions is associated with the presence of antibodies to immunoglobulin class A (IgA) in the patient, which is manifested by a decrease in the level of IgA during routine immunological examination. The article provides a review of the literature on the prevalence of IgA deficiency, its causes. A modern view of the need for routine testing of IgA level before the course of intravenous immunotherapy, approaches to reduce the risk of developing serious adverse reactions in such cases is described. A clinical case of treatment of a patient with chronic inflammatory demyelinating polyneuropathy and a reduced level of IgA is presented

    Experimental Benchmarking of Pu Electronic Structure

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    The standard method to determine the band structure of a condensed phase material is to (1) obtain a single crystal with a well defined surface and (2) map the bands with angle resolved photoelectron spectroscopy (occupied or valence bands) and inverse photoelectron spectroscopy (unoccupied or conduction bands). Unfortunately, in the case of Pu, the single crystals of Pu are either nonexistent, very small and/or having poorly defined surfaces. Furthermore, effects such as electron correlation and a large spin-orbit splitting in the 5f states have further complicated the situation. Thus, we have embarked upon the utilization of unorthodox electron spectroscopies, to circumvent the problems caused by the absence of large single crystals of Pu with well-defined surfaces. Our approach includes the techniques of resonant photoelectron spectroscopy [1], x-ray absorption spectroscopy [1,2,3,4], electron energy loss spectroscopy [2,3,4], Fano Effect measurements [5], and Bremstrahlung Isochromat Spectroscopy [6], including the utilization of micro-focused beams to probe single-crystallite regions of polycrystalline Pu samples. [2,3,6

    Electronic Structure Calculation by First Principles for Strongly Correlated Electron Systems

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    Recent trends of ab initio studies and progress in methodologies for electronic structure calculations of strongly correlated electron systems are discussed. The interest for developing efficient methods is motivated by recent discoveries and characterizations of strongly correlated electron materials and by requirements for understanding mechanisms of intriguing phenomena beyond a single-particle picture. A three-stage scheme is developed as renormalized multi-scale solvers (RMS) utilizing the hierarchical electronic structure in the energy space. It provides us with an ab initio downfolding of the global band structure into low-energy effective models followed by low-energy solvers for the models. The RMS method is illustrated with examples of several materials. In particular, we overview cases such as dynamics of semiconductors, transition metals and its compounds including iron-based superconductors and perovskite oxides, as well as organic conductors of kappa-ET type.Comment: 44 pages including 38 figures, to appear in J. Phys. Soc. Jpn. as an invited review pape

    Dynamical mean-field approach to materials with strong electronic correlations

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    We review recent results on the properties of materials with correlated electrons obtained within the LDA+DMFT approach, a combination of a conventional band structure approach based on the local density approximation (LDA) and the dynamical mean-field theory (DMFT). The application to four outstanding problems in this field is discussed: (i) we compute the full valence band structure of the charge-transfer insulator NiO by explicitly including the p-d hybridization, (ii) we explain the origin for the simultaneously occuring metal-insulator transition and collapse of the magnetic moment in MnO and Fe2O3, (iii) we describe a novel GGA+DMFT scheme in terms of plane-wave pseudopotentials which allows us to compute the orbital order and cooperative Jahn-Teller distortion in KCuF3 and LaMnO3, and (iv) we provide a general explanation for the appearance of kinks in the effective dispersion of correlated electrons in systems with a pronounced three-peak spectral function without having to resort to the coupling of electrons to bosonic excitations. These results provide a considerable progress in the fully microscopic investigations of correlated electron materials.Comment: 24 pages, 14 figures, final version, submitted to Eur. Phys. J. for publication in the Special Topics volume "Cooperative Phenomena in Solids: Metal-Insulator Transitions and Ordering of Microscopic Degrees of Freedom
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