The Concept of a Research Reactor of Small Power for Isotope Processing

The concept of a low-power research reactor for the production of radioisotopes is proposed, the results of calculations of the neutron-physical parameters of the core are presented, which can be used to substantiate the claimed reactor characteristics. In this article, the characteristics of the core of a research reactor of low power is substantiated, the main purpose of which is the production of radioisotope products for medical purposes. Nuclear medicine is one of the most advanced and demanded in the world of modern high-tech medicine, based on the using of atomic nucleus properties. As a rule, atoms with unstable nuclei are radionuclides. The reactor method of radionuclide production allows obtaining large quantities of radioisotope products at a relatively low price, but the reactor base is currently rather limited.     Keywords: radioisotope products, research reactors, neutron-physical characteristic

The Analysis of Conceptual Theoretical Approaches to the Problem of Technology Transfer in Foreign Universities

В статье представлен обзор существующих моделей трансфера технологий, в том числе в зарубежных университетах, освещены наиболее релевантные модели, которые могут быть использованы российскими вузами, в том числе в условиях постпандемии COVID-19. Проведенное исследование позволит формирующимся на базе университетов центрам трансфера выбрать наиболее подходящую для их ситуации модель и включить в нее элементы, которые будут способствовать максимизации эффективности их деятельности. Существующие же центры смогут внести изменения в свою деятельность с целью ее актуализации и/или трансформации в соответствии с изменившимися условиями. Также в статье приводятся практические рекомендации для управленческих кадров университета по руководству центрами трансфера технологий. Авторы раскрывают ключевые элементы функционирования различных моделей трансфера технологий, которые могут применяться управленческими кадрами для проектирования центров трансфера технологий на базе российских университетов. Возможно, результатом ознакомления заинтересованных сторон с данным исследованием станет создание и внедрение нормативно-правовых актов, регламентирующих деятельность центров трансфера технологий; формирование кадрового резерва, а также повышение квалификации имеющихся кадров и создание мультикомпетентностных команд; формирование гибкой бюджетной политики, а также политики ценностей, в рамках которой будет функционировать центр трансфера технологий.The article overviews the existing models of technology transfer, including those within foreign universities, and highlights the most relevant ones that can be used by Russian universities in the post-COVID-19 conditions. The study should allow the university-based transfer centers to choose the model which is mostly suitable for their situation, and to include elements that will help them to maximize the efficiency of their activities. The existing centers will be able to make changes in their activity in order to update and/or to transform it in accordance with the changed conditions. For the management personnel of the university, the article also provides practical recommendations on managing technology transfer centers. The authors reveal the key functioning elements of various technology transfer models, which can be used by management personnel to design technology transfer centers based on Russian universities. The possible result of the stakeholders’ getting to know this study might be their creating and implementing regulations to govern the technology transfer centers’ activities; forming a personnel reserve; advanced existing personnel training and multi-competence teams’ creating; forming a flexible budgetary policy, as well as a policy of values, for the technology transfer center to function within.Статья подготовлена в рамках реализации государственного задания № 074-00508-18-03, реестровый номер 730000Ф.99.1.БВ16АА02001 «Научно-методическое и информационное обеспечение создания центра трансфера технологий как элемента международной инновационной сети трансфера технологий, ориентированной на коммерциализацию технологий»

Molecular modeling of a tandem two pore domain potassium channel reveals a putative binding Site for general anesthetics

[Image: see text] Anesthetics are thought to mediate a portion of their activity via binding to and modulation of potassium channels. In particular, tandem pore potassium channels (K2P) are transmembrane ion channels whose current is modulated by the presence of general anesthetics and whose genetic absence has been shown to confer a level of anesthetic resistance. While the exact molecular structure of all K2P forms remains unknown, significant progress has been made toward understanding their structure and interactions with anesthetics via the methods of molecular modeling, coupled with the recently released higher resolution structures of homologous potassium channels to act as templates. Such models reveal the convergence of amino acid regions that are known to modulate anesthetic activity onto a common three- dimensional cavity that forms a putative anesthetic binding site. The model successfully predicts additional important residues that are also involved in the putative binding site as validated by the results of suggested experimental mutations. Such a model can now be used to further predict other amino acid residues that may be intimately involved in the target-based structure–activity relationships that are necessary for anesthetic binding

Recognition of Anesthetic Barbiturates by a Protein Binding Site: A High Resolution Structural Analysis

Barbiturates potentiate GABA actions at the GABAA receptor and act as central nervous system depressants that can induce effects ranging from sedation to general anesthesia. No structural information has been available about how barbiturates are recognized by their protein targets. For this reason, we tested whether these drugs were able to bind specifically to horse spleen apoferritin, a model protein that has previously been shown to bind many anesthetic agents with affinities that are closely correlated with anesthetic potency. Thiopental, pentobarbital, and phenobarbital were all found to bind to apoferritin with affinities ranging from 10–500 µM, approximately matching the concentrations required to produce anesthetic and GABAergic responses. X-ray crystal structures were determined for the complexes of apoferritin with thiopental and pentobarbital at resolutions of 1.9 and 2.0 Å, respectively. These structures reveal that the barbiturates bind to a cavity in the apoferritin shell that also binds haloalkanes, halogenated ethers, and propofol. Unlike these other general anesthetics, however, which rely entirely upon van der Waals interactions and the hydrophobic effect for recognition, the barbiturates are recognized in the apoferritin site using a mixture of both polar and nonpolar interactions. These results suggest that any protein binding site that is able to recognize and respond to the chemically and structurally diverse set of compounds used as general anesthetics is likely to include a versatile mixture of both polar and hydrophobic elements

The peroxisome proliferator-activated receptor (PPAR) alpha agonist fenofibrate maintains bone mass, while the PPAR gamma agonist pioglitazone exaggerates bone loss, in ovariectomized rats

<p>Abstract</p> <p>Background</p> <p>Activation of peroxisome proliferator-activated receptor (PPAR)gamma is associated with bone loss and increased fracture risk, while PPARalpha activation seems to have positive skeletal effects. To further explore these effects we have examined the effect of the PPARalpha agonists fenofibrate and Wyeth 14643, and the PPARgamma agonist pioglitazone, on bone mineral density (BMD), bone architecture and biomechanical strength in ovariectomized rats.</p> <p>Methods</p> <p>Fifty-five female Sprague-Dawley rats were assigned to five groups. One group was sham-operated and given vehicle (methylcellulose), the other groups were ovariectomized and given vehicle, fenofibrate, Wyeth 14643 and pioglitazone, respectively, daily for four months. Whole body and femoral BMD were measured by dual X-ray absorptiometry (DXA), and biomechanical testing of femurs, and micro-computed tomography (microCT) of the femoral shaft and head, were performed.</p> <p>Results</p> <p>Whole body and femoral BMD were significantly higher in sham controls and ovariectomized animals given fenofibrate, compared to ovariectomized controls. Ovariectomized rats given Wyeth 14643, maintained whole body BMD at sham levels, while rats on pioglitazone had lower whole body and femoral BMD, impaired bone quality and less mechanical strength compared to sham and ovariectomized controls. In contrast, cortical volume, trabecular bone volume and thickness, and endocortical volume were maintained at sham levels in rats given fenofibrate.</p> <p>Conclusions</p> <p>The PPARalpha agonist fenofibrate, and to a lesser extent the PPARaplha agonist Wyeth 14643, maintained BMD and bone architecture at sham levels, while the PPARgamma agonist pioglitazone exaggerated bone loss and negatively affected bone architecture, in ovariectomized rats.</p

The Concept of A Research Reactor of Small Power for Isotope Processing

The concept of a low-power research reactor for the production of radioisotopes is proposed, the results of calculations of the neutron-physical parameters of the core are presented, which can be used to substantiate the claimed reactor characteristics. In this article, the characteristics of the core of a research reactor of low power is substantiated, the main purpose of which is the production of radioisotope products for medical purposes. Nuclear medicine is one of the most advanced and demanded in the world of modern high-tech medicine, based on the using of atomic nucleus properties. As a rule, atoms with unstable nuclei are radionuclides. The reactor method of radionuclide production allows obtaining large quantities of radioisotope products at a relatively low price, but the reactor base is currently rather limited. &nbsp; &nbsp; Keywords: radioisotope products, research reactors, neutron-physical characteristic

On deformation of thin-walled parts while turning on the lathes

In a number of industries such as aviation engineering, instrumentation engineering, etc. the nonrigid thin-walled parts are a widespread sort of products. For their turning on the lathes the specially designed arrangements are necessary to prevent parts from deformation caused by the action of cutting force and retaining pressure. To create and use the arrangements extra costs are needed, and it, as a consequence, leads to the growth of production price. Potentially, there is another approach. It is to machine using the standard arrangements under special "soft" cutting operation conditions, which are characterized by reduced forces to act on the part, thus decreasing process deformations to the appropriate level. It may be a priori expected that such approach is economically more preferable. Unfortunately, it is difficult to conduct a comparative assessment of these two alternatives to choose a preferable version because of limited data on studies and implementation of the second alternative. Thereupon, to learn the thin-walled deformations versus their treatment conditions is of interest.The aim of the paper is to have general information on topology and elastic deformation value of thin-walled parts, machined on the lathes. The objective is to assess a perspective for further potentially possible activities to develop a concept of machining the thin-walled parts with controlled deformation due to selecting the "soft" cutting operation conditions.The paper studies the thin-walled steel parts of class "Tube" and "Disk" in the role of force action with their dimensions within the range of 5-200 mm for the length, 60-250 mm for diameter, and 4-25 mm for the wall thickness. It considers a chucked work-holding scheme and two machining types, namely external turning cut (for parts of class "Tube") and cross butt turning (for parts of class "Disk"). Three stages of machining have been simulated for each type of machining, namely rough (Ra 12.5; IT10), finishing (Ra 6.3; IT8), and fine finishing (Ra 1.25; IT6). Normative cutting operating conditions are as follows: rough processing – cutting depth of 1.25 mm, feed of 0,9 mm/rev; finish processing – cutting depth of 1.0mm, feed of 0.35mm/rev; fine processing – cutting depth of 0.85 mm, feed of 0.1 mm/rev. There are calculated cutting forces within the following ranges: Px – from 2900 tо 210 Н; Pу – from 3740 tо 270 Н; Pz – from 5100 tо 280 Н, which correspond to these stages. It is assumed that the part is held in the chuck by the friction forces arising in the points of jaws holder. In this case the calculated workholding forces had values from 5100 tо 380 Н provided that the part is non- displaceable.The elastic deformation characteristics of the thin-walled parts of class "Tube" and "Disk" have been achieved by using a numeric simulation of conditions for technological strength loading of these parts. The simulation has been accomplished using an ANSYS software complex. As a result 3-D diagrams have been obtained to show a distribution of elastic deformation fields of the parts "Tube" and "Disk" for machining versions under consideration. The maximum values of elastic displacements on the working surfaces of parts are given in tables to illustrate, in general, a dependence of parts deformation on the varying parameters for considered cases of turning on lathes.Data obtained shows that machining the thin-walled parts under the normative cutting operation conditions is accompanied by their deformation, which changes in a wide range (in the conducted experiment from 0.1 to 3 values of tolerance field for dimensions of machined surfaces). This allows us to make the following conclusions. 1) Deformation control of processing parts is an important factor to provide its accuracy and minimization 2) Modern computer-aided simulation software (in our case complex ANSYS) is an efficient tool to assess an expected deformation of the parts to be machined. 3) Computer-based simulation software enables new capabilities for prompt and low cost solution of two challenges of process design; а) search for the rational scheme to hold the parts on the lathe and a reasonable choice of arrangement standard or special one; б) finding the «soft» cutting operation conditions to restrict the process deformation by permissible values.At the contemporary level to develop the issue under discussion the second challenge can be solved by the method of iterations. For direct optimized solution of the second challenge it is necessary to design a target formalized tool. This tool contributes to increasing promptness and visibility to find the rational solutions, as well as to creating new prerequisites to diversify a sphere of computer-aided design and manufacturing processes control.</p