Analysis of historical and modern approaches to teaching neurosurgery by professional communities and public authorities in the United States, the European Union and the Russian Federation makes it ...possible to develop a modern training program regarding content and duration. High-tech and dynamically developing specialty has acquired several large sub-specializations over the past decades. Each direction requires a long-term training and a special program. Training in neurosurgery in the modern world takes 5-7 years and involves acquisition of clinical and scientific knowledge. Some issues are brought up for discussion by professional community. Solution of these problems will provide an opportunity for international integration of the Russian training program for neurosurgeons. High level of neurosurgery in our country and a single educational space with the European community will allow exchanging students, adopting foreign experience and sharing our own experience.
Surface‐selective laser sintering (SSLS) has been developed for fabrication of three‐dimensional polymer composite scaffolds with precise dimensions and intricate structure (see Figure), which are ...bioactive and biodegradable. SSLS allows sintering of polymer powders by melting only the surface layers of particles, which prevents overheating of internal domains, allowing incorporation of bioactive molecules into the structures.
•The sharp increase in the ionization degree and temperature is observed at the ionization front simultaneously with decrease in density and magnetic field.•The sharp acceleration of plasma takes ...place behind the ionization front due to the Ampere force.•The transonic flow is formed in the accelerator channel.•The radiation coming from the ionization front for the recombination part of spectrum can penetrate deeply in the incoming flow of weakly ionized gas.•The Lyman alpha line brings an essential contribution to the density of the radiation energy and the radiation energy flux in hydrogen plasma.
The study of the axisymmetric ionizing gas flows in a channel of the quasi-steady plasma accelerator is presented. Model is based on the MHD and radiation transport equations. The MHD model for a three-component medium consisting of atoms, ions and electrons takes into account the basic mechanisms of the electrical conductivity and heat transport. The model of the radiation transport includes the basic mechanisms of emission and absorption for the different parts of the spectrum. Results of the numerical studies of ionization process and radiation transport are obtained in the approximation of the local thermodynamic equilibrium.
Individual polymer implants are widespread for bone reconstruction after decompressive craniectomy. Despite the availability of customized titanium products, various specialists and hospitals prefer ...polymer implants.
To compare the methods of modeling and manufacturing the polymethylmethacrylate implants and identify the features affecting the quality of reconstruction.
We analyzed 14 patients with extensive skull defects after installation of polymethyl methacrylate implants. Software used for modeling of individual implants by different specialists was compared.
Satisfactory reconstruction result was obtained in all cases. There were no infectious complications. The authors outlined certain important aspects for modeling of individual polymer products: local use of anatomical thickness of the implant, leaving safe spaces, prevention of temporal retraction, template-based resection before reconstruction.
To date, skull defect closure with polymeric materials remains relevant, and even has certain advantages over customized titanium products.
Experimentally, as well as using numerical simulation methods, the features of the processes of heat and mass transfer and explosive boiling of water, initiated by continuous laser radiation with ...λ = 1.94 μm, emerging from the tip of the laser fiber, are studied. The trajectories of the microvolume with the maximum temperature of the superheated liquid under laser heating, in which the probability of explosive boiling up is maximum, are determined. The calculations took into account changes in the density of superheated water and the dependence of the absorption coefficient of laser radiation on temperature. Using acoustic methods and high-speed video recording, it is shown that during explosive boiling up, the duration of the leading front of the acoustic signal is ∼300 ns. Such a long duration of pressure rise at the receiving point is explained by the fact that explosive boiling occurs in a wide area of superheated liquid near fiber tip, when the nuclei located in it are stimulated by an initially arising pressure pulse.
The Globus-M spherical tokamak has demonstrated practically all of the project objectives during the 15-year period of operation. The main factor limiting further progress in plasma performance is a ...relatively low toroidal magnetic field. The maximum toroidal magnetic field achieved on Globus-M was 0.4 T with the exception of a limited number of shots with 0.55 T, which led to damage of the toroidal field coil in 2002. The increase of the magnetic field up to 1.0 T together with the plasma current up to 0.5 MA will result in the significant enhancement of the operating parameters in the upgraded Globus-M2 machine. The experimental program will be focused on plasma heating and non-inductive current drive and will contribute to the creation of a physical and technological base for the compact fusion neutron source development. In the article a brief overview of the physical background for the machine upgrade is outlined. The current status of the project implementation is described. First experimental results on moderate magnetic field increase from 0.4 T up to 0.5 T in the existing Globus-M machine are discussed. The improvement of plasma confinement as well as enhancement of efficiency of the beam driven current is observed.
Stationary and unstable pulsating flows of ionizing hydrogen in the channel of a quasi-stationary plasma accelerator are considered. Numerical studies of two-dimensional axisymmetric flows are ...carried out based on the modified magnetogasdynamic (MGD) equations in the approximation of local thermodynamic equilibrium, taking into account electrical conductivity, thermal conductivity, and radiation transport. The generalization of the calculation results led to the formulation of the empirical condition for the stationarity of two-dimensional flows of an ionizing gas.
Intramedullary hemangioblastomas (HAB) refer to very rare highly vascularized vascular spinal cord tumors associated with various neurological disorders. Effective HAB therapy to a greater extent ...depends on diagnostic accuracy and the absence of intra- and postoperative complications. The present study is a review of publications concerned with modern diagnostic and therapeutic techniques to control spinal HAB. The authors showed that perfusion computed tomography, computed tomographic angiography, and magnetic resonance angiography can be reasonably used for diagnosis and differentiation in a number of HAB due to their high vascularization. Preoperative embolization significantly reducing intraoperative bleeding risks is highly efficient. Some authors recommend this procedure in case of large lesions and high risks of intraoperative bleeding. The review also considered intraoperative imaging of a tumor and its feeding vessels using indocyanine green providing inspectability over the total tumor resection and clear imaging of tumor vascular architecture. The advantages and restrictions of the mentioned procedures were described.
The diagnostic complex of the Globus-M2 spherical tokamak (
R
= 36 cm,
a
= 24 cm), the only operating tokamak in Russia with a divertor plasma configuration, which operates in the range of ...subthermonuclear temperatures (
T
e
to 1.6 keV,
T
i
to 4.5 keV) and densities (
n
e
to 2 × 10
20
m
–3
), is described. The Globus‑M2 tokamak is the unique scientific facility, which is a part of the Federal Center for Collective Use of the Ioffe Institute, Russian Academy of Sciences “Materials Science and Diagnostics in Advanced Technologies.” This allows third parties to perform their research using it. The work contains a list of all diagnostics currently available on the tokamak. The description of the diagnostics is structured in such a way that the reader gets an idea of their capabilities for measuring plasma parameters with an emphasis on the limits and accuracy of the measured values, and also spatial and time resolution. At the same time, many technical details are omitted in order to save space; references are given to papers with a more detailed description of individual diagnostics.
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