Multibit structure for the formation of combined or alternating electron-ion beams

Currently, sources of ion and electron beams make it possible to implement a wide range of effective technologies for processing materials and surface modifications. In some cases, a significant increase in the effectiveness of such technologies is achieved with simultaneous exposure to electron and ion beams through the use of two types of separate (electron and ion) sources. At the same time, experience in the development and use of plasma sources of charged particles shows the possibility of creating a combined electron-ion flow in one direction and in a single discharge system. In this work, we propose an experimental electrode structure of a plasma electron-ion source for the formation of a combined electron-ion or separate electron and ion beams. A number of its characteristics and the prospects for further development of an electron-ion source for industrial use on its basis are shown

Molecular packing, piezo- and pyroelectric properties of tert-butyl N-(tert-butoxycarbonyl)-(S)-prolinamide

The work was financially supported by the Russian Foundation for Basic Research (grant no. 16-33-60122). The equipment of the Ural Centre for Shared Use “Modern Nanotechnologies” UrFU and Centre for Joint Use “Spectroscopy and Analysis of Organic Compounds” was used

Fragment-based approach to novel bioactive purine derivatives

Using purine as a scaffold, the methods for preparation of novel 2-aminopurine and purine derivatives substituted at position C6 by the fragments of natural amino acids, short peptides, andN-heterocycles, including enantiopure ones, have been proposed. The methods for determination of the enantiomeric purity of the obtained chiral compounds have been developed. Conjugates exhibiting high antimycobacterial or antiherpesvirus activity against both laboratory and multidrug-resistant strains were revealed among the obtained compounds. © 2020 De Gruyter. All rights reserved.Russian Science Foundation, RSF: 19-13-00231Funding : The reviewed studies were financially supported by the Russian Science Foundation (project no. 19-13-00231)

Synthesis of a novel planar-chiral nido-carborane amino acid

The deboronation of enantiomers of planar-chiral benzyl (3-formamido-1,2-dicarba-closo-dodecaboran-1-yl)acetate gave the individual (RP)- and (SP)-enantiomers (ee > 98%) of a new amino acid containing a nido-carborane fragment, (3-ammonio-7,8-dicarba-nido-undecaboran-7-yl)acetic acid. Chiral HPLC methods for the analysis of enantiomeric purity of this compound was developed. © 2021, Springer Science+Business Media LLC.Ministry of Education and Science of the Russian Federation, Minobrnauka, (AAAA-A19-119012490007-8)This work was financially supported by the Ministry of Science and Higher Education of the Russian Federation (Project No. AAAA-A19-119012490007-8). Equipment of the Centre for Joint Use “Spectroscopy and Analysis of Organic Compounds” (CJU “SAOC”) at the Postovsky Institute of Organic Synthesis of the Russian Academy of Sciences (Ural Branch) was used

High-precision calculations of In I and Sn II atomic properties

We use all-order relativistic many-body perturbation theory to study 5s^2 nl configurations of In I and Sn II. Energies, E1-amplitudes, and hyperfine constants are calculated using all-order method, which accounts for single and double excitations of the Dirac-Fock wave functions.Comment: 10 pages, accepted to PRA; v2: Introduction changed, references adde

Piezoelectric properties of the crystals of ortho-carboranyl (S)-phenylalanine and (S)-valine derivatives

Piezoelectric response of the crystals of carborane-containing pseudo-dipeptides was measured using the piezoresponse force microscopy. Observable piezocoefficients of the crystals reached 76.2 pC/N. Structure and stereo configuration of compounds affected the piezoelectric response of the crystals.The equipment of Ural Center for Shared Use "Modern Nanotechnology" UrFU has been used. The work was financially supported by Russian Foundation for Basic Research (grant no. 16-33-60122)

Synthesis of Pyrimidine Conjugates with 4-(6-Amino-hexanoyl)-7,8-difluoro-3,4-dihydro-3-methyl-2H-[1,4] benzoxazine and Evaluation of Their Antiviral Activity

A series of pyrimidine conjugates containing a fragment of racemic 7,8-difluoro-3,4-dihydro-3-methyl-2H-[1,4]benzoxazine and its (S)-enantiomer attached via a 6-aminohexanoyl fragment were synthesized by the reaction of nucleophilic substitution of chlorine in various chloropyrimidines. The structures of the synthesized compounds were confirmed by1H,19F, and 13 C NMR spectral data. Enantiomeric purity of optically active derivatives was confirmed by chiral HPLC. Antiviral evaluation of the synthesized compounds has shown that the replacement of purine with a pyrimidine fragment leads to a decrease in the anti-herpesvirus activity compared to the lead compound, purine conjugate. The studied compounds did not exhibit significant activity against influenza A (H1N1) virus. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Russian Science Foundation, RSF: 19-13-00231-PFunding: This research was funded by the Russian Science Foundation, grant number 19-13-00231-P

Плазменный источник заряженных частиц для формирования совмещенных ионно-электронных пучков

One of the ways to increase the efficiency of the implementation of ion-plasma technologies of exposure to the surfaces of various materials is partial or full compensation of the positive charge of ions in the stream or on the treated surface, for which additional emitting systems are used that create compensating electron flows in the discharge space, accelerating gap or on the processed surface. It was previously shown that for the implementation of such a compensating effect, it is possible to use plasma sources of charged particles, capable of forming beams of both signs when the polarity of the accelerating voltage is changed. The main problem in this case is the difficulty in achieving simultaneously high emission efficiency of ions and electrons, since the conditions for their emission from plasma are significantly different. This article proposes a concept and a design developed on its basis for a prototype of a multi-discharge plasma electron-ion source for the joint or alternating formation of electron and ion beams. It is shown that the proposed design realizes the possibility of increasing the perveance by compensating for the space charge by particles of the opposite sign. A number of characteristics of the developed model of a plasma electron-ion source (current-voltage characteristics of the extraction of electrons and ions) are presented and its prospects for further development of an electron-ion source for industrial use on its basis are shown. Combined or alternating ion-electron beams formed in the presented source can be used to implement the technology of applying thin-film layers of metals, semiconductors, and dielectrics to maintain ionization processes and ensure stable discharge burning, compensation of both the space charge in the beam and the surface charge on the formed film.Одним из способов повышения эффективности реализации ионно-плазменных технологий воздействия на поверхности различных материалов является частичная или полная компенсация положительного заряда ионов в потоке или на обрабатываемой поверхности, для чего используются дополнительные эмитирующие системы, которые создают компенсирующие электронные потоки в разрядное пространство, ускоряющий промежуток или на обрабатываемую поверхность. Для реализации такого компенсирующего воздействия возможно применение плазменных источников заряженных частиц, способных при изменении полярности ускоряющего напряжения формировать пучки обоих знаков. Основная проблема при этом заключается в сложности достижения одновременно высокой эффективности эмиссии ионов и электронов, поскольку условия их эмиссии из плазмы существенно различаются. В данной статье предложена концепция и разработанная на ее основе конструкция макета мультиразрядного плазменного электронно-ионного источника для совместного или попеременного формирования электронных и ионных пучков. Показано, что в предложенной конструкции реализуется возможность повышения первеанса за счет компенсации объемного заряда частицами противоположного знака. Приведен ряд характеристик разработанного макета плазменного электронно-ионного источника (вольтамперные характеристики извлечения электронов и ионов) и показана его перспективность для дальнейшей разработки на его основе электронно-ионного источника для промышленного применения. Совмещенные или попеременные ионно-электронные пучки, формируемые в представленном источнике, могут быть использованы при реализации технологий нанесения тонкопленочных слоев металлов, полупроводников и диэлектриков для поддержания процессов ионизации и обеспечения устойчивого горения разряда, компенсации как объемного заряда в пучке, так и поверхностного на формируемой пленке

Crystal structure and growth kinetics of self-assembled microtubes with different chirality

The measurements of microtubes growth kinetics and morphology analysis were done in Ural Federal University (UrFU) and made possible by Russian Science Foundation (Grant No. 18-72-00052). The equipment of the Ural Center for Shared Use “Modern nanotechnology” UrFU was used. Computer simulation was performed under the support of Russian Foundation for Basic Research (Grant No. 19-01-00519 А). X-ray diffraction data were collected under the experiment SC-4587 at the European Synchrotron Radiation Source (ESRF, Grenoble, France). S.K., P.Z., L.M. and A.K. are grateful to FCT project PTDC/CTM-CTM/31679/2017. P.Z. and L.M. are grateful to FCT project PTDC/QEQ-QAN/6373/2014. S.K and A.K were also supported by the joint Portugal-Turkey project (TUBITAK/0006/2014). Part of this work was developed within the scope of the project CICECO-Aveiro Institute of Materials, FCT Ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES

КОМПЬЮТЕРНАЯ ТОМОГРАФИЯ С ИСПОЛЬЗОВАНИЕМ МОДЕЛЬ-БАЗИРОВАННЫХ ИТЕРАТИВНЫХ РЕКОНСТРУКЦИЙ В КЛИНИЧЕСКОЙ ПРАКТИКЕ

Due to the widespread introduction of CT in clinical practice, the issue of reducing the radiation dose remains one of the most urgent. One of the ways to reduce radiation exposure is to improve the reconstruction algorithms of CT images. When using model interactive reconstruction, images are repeatedly processed to maximize the elimination of digital noise, which allows lowdose studies to be performed without compromising visual quality. The literature review presents the possibilities of applying model iterative reconstruction in CT studies of various organs and systems, including low-dose studies with a radiation exposure of less than 1 mSv, assessment the quality of studies and visualization of the pathology of various organs and systems. The most popular new technique is for screening studies, for example, for LDCT screening of lung cancer, and studies that require high resolution, for example, for CT-coronarography.В связи с широким внедрением КТ в клиническую практику вопрос о снижении дозы облучения остается одним из самых насущных. Одним из направлений снижения лучевой нагрузки является совершенствование алгоритмов реконструкции КТ-изображений. При использовании модельной интерактивной реконструкции изображения многократно  обрабатываются для максимального устранения цифрового шума, что позволяет выполнять низкодозовые исследования без снижения качества визуализации. В обзоре литературы представлены возможности применения модельной итеративной реконструкции при КТ-исследовании различных органов и систем, в том числе при низкодозовых исследованиях с дозой облучения менее 1 мЗв, оценка качества выполненных исследований и визуализации патологии различных органов и систем. Наиболее востребованной новая методика является для скрининговых исследований, например, для НДКТ-скрининга рака легкого, и исследований, в которых требуется высокое разрешение, например, для КТ- коронарографии