Magnetomechanical stimulation of bone tissue regeneration

The aim of the research. To assess the ability of superparamagnetic nanoparticles functionalized with the RGD peptide to accelerate bone tissue recovery aft er transverse osteotomy under the infl uence of a low-frequency alternating magnetic fi eld. Material and methods. We used superparamagnetic nanoparticles ferroarabinogalactans (FeAG) functionalized with the RGD peptide for targeted binding to integrins. Th e model for assessing the ability of FeAG-RGD to accelerate bone regeneration was the transverse osteotomy of the radius of the ICR mice. To induce the process of bone tissue regeneration aft er the injection of FeAG-RGD particles, mice were placed in an alternating magnetic fi eld (50 Hz 100 Oe) for 60 min. Th e therapy was performed daily for 5 days. Results. Th e paper tested the hypothesis about the acceleration of bone tissue regeneration by the method of magnetomechanical therapy using superparamagnetic FeAG-RGD nanoparticles. It has been established that FeAG-RGD under conditions of an alternating magnetic fi eld (50 Hz 100 Oe) are able to change their orientation in space and, thus, cause mechanical stress in the proteins of the cell membrane – integrins, which trigger the process of osteogenic diff erentiation. Th e research results showed that 5 procedures of magnetomechanical therapy lead to complete restoration of bone tissue at the site of the transverse osteotomy, while in the group of control animals no fusion of bones is observed. Conclusion. Th e use of the method of magnetomechanical therapy using ferroarabinogalactans functionalized with the targeting ligand RGD for binding to integrins of osteogenic cells is a promising technology for bone tissue regeneration

Comparison of clinical, electroencephalographic and tomographic data in children with epilepsy with controlled and uncontrolled seizures

The article presents the results of a examination of 124 children with epilepsy aged 1 month to 18 years to detect clinical electroencephalographic (EEG) and tomographic correlations in patients with controlled and uncontrolled seizures. It was shown that clinical manifestations (seizure types) are not always correlated with local changes on EEG and focus on MRI. In children, especially with uncontrolled seizures, even in the case of a focal onset of the seizure, secondary generalization is often observed, which is due to the functional immaturity of the brain and the tendency to rapid generalization of the epileptic potential. In general, the coincidence between the EEG data and morphological MRI is determined in 66 % of patients, when performing high-fi eld magnetic resonance tomography (on devices with a magnetic fi eld of 1.5 T or more) in the "Epilepsy" mode — in 71 %, and using MR-spectroscopy rises to 73 %. Key words: children, epilepsy, EEG, MRI

Study of magnetohydrodynamic effects for the richtmyer-meshkov instability

This work presents experimental and computational studies of the Richtmyer-Meshkov (RM) instability with Magnetohydrodynamic (MHD) effects. The experimental work does not consider the instability or its growth, but rather developes an atmospheric plasma jet for use in future magnetohydrodynamic experiments. The operating conditions of the torch are explored to optimize the ionized length of the plasma jet by varying the voltage-current characteristics and the gas low rates. Probe, spectral, and visual diagnostics are also developed in an effort to characterize the plasma. The probe diagnostics were unsuccessful but discussions are included to help improve the technique. The visual Mie-Scattering like technique is able to capture qualitative images of the plasma flow field and are ready for use in future hydrodynamic experiments where the qualitative growth is of interest. Simulations utilized the hydrocode FLAG, developed at Los Alamos National Laboratory, are performed on a 2D shock cylinder plasma-air interface where MHD effects work to remove vorticity from the interface and suppress RM growth. To study this magnetic field orientation, magnetic field strength, and incident Mach number are all varied in this study. It was found that the orientation of the magnetic fi eld relative to the shock wave direction causes different morphology and can effect the amount of observable RM suppression. Similarly, increasing the magnetic field strength reduces the effects of the baroclinic vorticity, responsible for RM growth, by generating strong MHD waves which carry the vorticity away from the interface quicker. Increasing the Mach number can also cause varying qualitative effects, with greater Mach numbers showing greater interfacial compression. But comparing the MHD RM to the RM instability at a single Mach number still shows suppresion of the instability. Finally a 3D cylindrical interface is simulated using the hydrocode ARES. These simulations compare the cylindrical Richtmyer-Meshkov to two cases of the MHD-RM instability; one with a parallel and one with a perpendicular magnetic fi eld of 500 Guass. As per literature, the magnetic cases exhibit suppression through decreased enstrophy, vorticity, and mixedness with respect to time in addition to the clear morphological differences.

Forecasting the course of occupational chronic fl uorine intoxication by means of univariate analysis

Relevance. In contemporary occupational pathology, diagnosis of occupational fluorosis is based on locomotory apparatus disorder such as fluorine osteopathy. Other significant consequences of negative effects of fluorine compounds are deactivation of enzymatic systems, metabolic disorders — that results in pathologic involvement of many organs and systems (hepato-biliary, cardiovascular, respiratory, nervous, endocrine, gastrointestinal). Topical issue is search of a complex of factors influencing development of the occupational disease, to optimize management of occupational fluorine intoxication risk.Objective. To determine spectrum of factors that promote development of occupational fl uorine intoxication in workers exposed to inorganic fl uorine compounds, for forecasting the disease outcome and selecting main trends of preventive measures.Materials and methods.Single-factor analysis methods helped to carry retrospective cohort study of occupational fl uorine intoxication development in 201 workers of aluminum production in Ural region. Th e study covered infl uence of main occupational factors and somatic health parameter s on occupational fl uorosis development.Results.Findings are reliable infl uence of age (k=0.532, p<0.001), length of service in hazardous work conditions (p<0.001), hydrofl uoride level (p<0.001) and constant magnetic fi eld (p=0.005). Besides that, analysis of immune and metabolic state of the workers revealed signifi cant infl uence of disordered lipid, carbohydrate, purine metabolism, altered immune parameters on occupational fl uorosis development. Other evidence was reliable dependence between concomitant cardiovascular diseases and period of occupational chronic fl uorine intoxication development.Conclusion.Using single-factor analysis helped to determine wide spectrum of factors associated with the workers’ health state and work conditions, that signifi cantly infl uence development of fl uorine intoxication. Th e authors proved that period of occupational chronic fl uorine intoxication is notably infl uenced by occupational factors (length of service, hydrofl uoride level, fl uorine load degree, magnetic fi eld) and somatic state characteristics as age, parameters of carbohydrate, lipid, purine metabolism, status of cardiovascular, excretory systems, kidneys and gastrointestinal tract functions.

DESIGN OF A SINGLE-PHASE POWER AUTOTRANSFORMER TANK OF ELECTRIC POWER SYSTEMS AND CALCULATION OF ITS SURFACES TEMPERATURE

A mathematical model has been developed that adequately describes the complex profi le of a high-power single-phase autotransformer tank over 100 MVA. The tangential components of the magnetic fi eld of dispersion on the surfaces of the tank and additional losses of active power from eddy currents in the walls of the tank are determined when the magnetic system of the autotransformer is saturated with direct current fl owing through grounded windings. Many of the hott est points of the tank autotransformer are found. The dependence of the maximum values of the rate of change in the temperature of the most heated points on the surface of the tank of the autotransformer AODTSTN-267000/500/220 on the magnitude of the direct current was established.

Static or dynamic low-frequency magnetic field? A review of literature

The therapeutic application of magnetic fi elds has experienced signifi cant growth in recent years. A small number of contraindications, as well as the lack of side effects makes both permanent magnets and alternating magnetic fi elds frequently used in physical therapy practice. In a signifi cant number of clinical studies the effi cacy of this physical factor as both an independent method, as well as supporting treatment programs has been confi rmed. In the last few years, a lot of emphasis is put on the fact that all therapeutic methods should have a scientifi c basis and their usage should meet the evidence based medicine criteria (EBM). Therefore, this work will focus on comparison of the use of permanent magnets and alternating low-frequency magnetic fi eld on the basis of the available literature, including mainly, a randomized double-blind trial. Analysis of the available literature on permanent magnet usage has shown clinical effi cacy in many diseases, however, placebo-controlled studies confi rm mainly the analgesic effect in patients after liposuction surgery, with diabetic neuropathy and with chronic pelvic pain. The use of the alternating low-frequency magnetic fi eld also leaves many questions to which scientists have still not found the answer. Randomized double-blind trial proved its therapeutic effi cacy in patients after knee arthroscopy, fractures and delayed bone unions, knee and cervical spine osteoarthritis as well as in case of leg ulceration. Alternating magnetic fi eld application has a wider therapeutic range in comparison to permanent magnets and its effectiveness is much better documented, both in clinical studies as well as randomized double-blind trials. Cite this article as: Głąb G., Dudek J., Klimek K., Skalska-Dulińska B., Chrabota U., Chojak-Fijałka K., Ridan T., Glodzik J. Static or dynamic low-frequency magnetic field? A review of literature. Med Rehabil 2016; 20(2): 31-35.