Плоское перемещение пятизвенного двуногого робота по поверхности с препятствиями в виде ступеней

Modeling the anthropomorphic robot movement is of great interest to researchers all over the world. At the same time, the movement control of a walking mechanism is always a high dimension challenge. The difficulty with the anthropomorphic robot control is also caused by the fact that such a mechanism has always a hybrid dynamics and represents a sequential change of two phases – the single support phase and the double support phase (phase of changing robot’s leg). At the single support phase and at another phase the behavior of the biped robot is described by a system of ordinary differential equations and by a system of linear algebraic equations, respectively.The task of biped robot movement control has been studied in detail for the case when the robot moves over the horizontal surface. Obstacles make the task significantly complicated. The paper considers the movement control of the biped robot over the surface that is a periodic alternation of horizontal sections and obstacles. The obstacles represent steps of the same height known. It is assumed that the lengths of horizontal sections and steps are known as well. The objective is to create a control that provides robot’s periodic movement over the specified surface according to inherent characteristics of a walking human.For the single support phase, the outputs are proposed, the equality of which to zero corresponds to the robot’s movement with a given set of characteristics. The paper presents the feedback controls that stabilize the proposed outputs for a finite amount of time. By choosing the feedback parameters, it is possible to adjust the stabilization time so that the outputs become equal to zero when reached the end of each step.It is shown that for the chosen control law, the problem of constructing the control of robot’s periodic movement is reduced to the solution of a nonlinear equation. In the paper, we discuss the approaches to solving this equation and present the results of numerical simulation.The results obtained can be used to solve the problem of providing control of the biped robot movement over the surfaces with obstacles of a more complicated shape.Modeling the anthropomorphic robot movement is of great interest to researchers all over the world. At the same time, the movement control of a walking mechanism is always a high dimension challenge. The difficulty with the anthropomorphic robot control is also caused by the fact that such a mechanism has always a hybrid dynamics and represents a sequential change of two phases – the single support phase and the double support phase (phase of changing robot’s leg). At the single support phase and at another phase the behavior of the biped robot is described by a system of ordinary differential equations and by a system of linear algebraic equations, respectively.The task of biped robot movement control has been studied in detail for the case when the robot moves over the horizontal surface. Obstacles make the task significantly complicated. The paper considers the movement control of the biped robot over the surface that is a periodic alternation of horizontal sections and obstacles. The obstacles represent steps of the same height known. It is assumed that the lengths of horizontal sections and steps are known as well. The objective is to create a control that provides robot’s periodic movement over the specified surface according to inherent characteristics of a walking human.For the single support phase, the outputs are proposed, the equality of which to zero corresponds to the robot’s movement with a given set of characteristics. The paper presents the feedback controls that stabilize the proposed outputs for a finite amount of time. By choosing the feedback parameters, it is possible to adjust the stabilization time so that the outputs become equal to zero when reached the end of each step.It is shown that for the chosen control law, the problem of constructing the control of robot’s periodic movement is reduced to the solution of a nonlinear equation. In the paper, we discuss the approaches to solving this equation and present the results of numerical simulation.The results obtained can be used to solve the problem of providing control of the biped robot movement over the surfaces with obstacles of a more complicated shape.Моделирование движений антропоморфных роботов представляет большой интерес для исследователей во всем мире. Вместе с тем, управление движением шагающего механизма – это всегда сложная задача большой размерности. Сложность управления антропоморфным роботом связана еще и с тем, что динамика такого механизма всегда гибридна и представляет собой последовательную смену двух фаз – фазы одноопорного движения и фазы перехода робота с одной ноги на другую. На фазе одноопорного движения поведение шагающего робота описывается системой обыкновенных дифференциальных уравнений, на фазе перехода – системой линейных алгебраических уравнений.Задача управления перемещением двуногого шагающего робота детально изучена для случая, когда робот совершает перемещение по горизонтальной поверхности. Наличие препятствий существенно усложняет задачу. В настоящей работе рассматривается проблема управления перемещением двуногого шагающего робота по поверхности, являющейся периодическим чередованием горизонтальных участков и препятствий. Препятствия представляют собой ступени одной и той же известной высоты. Длины горизонтальных участков и ступеней также предполагаются известными. Цель работы – построить управление, обеспечивающее периодическое движение робота по указанной поверхности в соответствии с характеристиками, присущими ходьбе человека.Для фазы одноопорного движения предложены выходы, равенство которых нулю отвечает движению робота с заданным набором характеристик. В работе построены управления в виде обратной связи, которые стабилизируют предложенные выходы за конечное время. За счет выбора параметров в обратной связи можно регулировать время стабилизации так, чтобы выходы становились равными нулю к концу каждого шага.Показано, что при выбранном законе управления задача построения периодического движения робота сводится к задаче решения нелинейного уравнения. В работе обсуждаются способы решения этого уравнения и приводятся результаты численного моделирования.Полученные в работе результаты могут быть использованы для решения задачи управления перемещением шагающих роботов по поверхностям с препятствиями более сложной формы

Fragmentation channels of relativistic 7^7Be nuclei in peripheral interactions

Nuclei of $^7$Li were accelerated at the JINR Nuclotron. After the charge-exchange reaction involving these nuclei at an external target a second $^7$Be beam of energy 1.23A GeV was formed. This beam was used to expose photo-emulsion chambers. The mean free path for inelastic $^7$Be interactions in emulsion $\lambda$=14.0$\pm$0.8 cm coincides within the errors with those for $^6$Li and $^7$Li nuclei. More than 10% of the $^7$Be events are associated with the peripheral interactions in which the total charge of the relativistic fragments is equal to the charge of the $^7$Be and in which charged mesons are not produced. An unusual ratio of the isotopes is revealed in the composition of the doubly charged $^7$Be fragments: the number of $^3$He fragments is twice as large as that of $^4$He fragments. In 50% of peripheral interactions, a $^7$Be nucleus decays to two doubly charged fragments. The present paper gives the channels of the $^7$Be fragmentation to charged fragments. In 50% of events, the $^7$Be fragmentation proceeds only to charged fragments involving no emission of neutrons. Of them, the $^3$He+$^4$He channel dominates, the $^4$He+d+p and $^6$Li+pchannels constitute 10% each. Two events involving no emission of neutrons are registered in the 3-body $^3$He+t+p and $^3$He+d+d channels. The mean free path for the coherent dissociation of relativistic $^7$Be nuclei to $^3$He+$^4$He is 7$\pm$1 m. The particular features of the relativistic $^7$Be fragmentation in such peripheral interactions are explained by the $^3$He+$^4$He 2-cluster structure of the $^7$Be nucleus.Comment: 10 pages, 3 figures, 3 tables, conference: Conference on Physics of Fundamental Interactions, Moscow, Russia, 5-9 Dec 200

Инвагинация червеобразного отростка

The pathology of the appendix remains one of the topical areas of abdominal surgery. Its rare diseases can be difficult to diagnose and treat, and are accompanied by the development of serious complications. One of them is  intussusception of the appendix to the cecum. Intussusception can be caused by previously undiagnosed primary lesions of the appendix. At the same time, it can simulate tumor and tumor-like formations of the cecum and lead to  diagnostic errors. The literature review provides modern data on the history of the study of the problem, the epidemiology of classification, the causes and mechanisms of the development of appendiceal intussusception, the methods of its diagnosis and treatment.  Патология червеобразного отростка остается одним из актуальных разделов абдоминальной хирургии. Его редкие заболевания могут представлять сложности для диагностики и лечения и сопровождаться развитием серьезных осложнений. Одно из них — инвагинация червеобразного отростка в слепую кишку. Инвагинация может быть вызвана ранее  недиагностированными первичными поражениями отростка. В  то же время инвагинат может симулировать опухолевые и опухолеподобные образования слепой кишки и приводить к  диагностическим ошибкам. В обзоре литературы приведены  современные данные об истории изучения проблемы,  эпидемиологии, классификации, причинам и механизмам развития инвагинации червеобразного отростка, методах ее диагностики и лечения.

Role of the Nuclear and Electromagnetic Interactions in the Coherent Dissociation of the Relativistic 7^7Li Nucleus into the 3^3H + 4^4He Channel

The differential cross section in the transverse momentum $Q$ and a total cross section of $(31\pm4)$ mb for the coherent dissociation of a 3-A-GeV/$c$ $^7$Li nucleus through the $^3$H$+^4$He channel have been measured on emulsion nuclei. The observed $Q$ dependence of the cross section is explained by the predominant supposition of the nuclear diffraction patterns on light (C, N, O) and heavy (Br, Ag) emulsion nuclei. The contributions to the cross section from nuclear diffraction ($Q\le400$ MeV/$c$) and Coulomb $(Q\le50$ MeV/$c$) dissociations are calculated to be 40.7 and 4 mb, respectively.Comment: ISSN 0021-3640, Pleiades Publishing, Ltd., 200

High-Temperature Behavior, Oxygen Transport Properties, and Electrochemical Performance of Cu-Substituted Nd1.6Ca0.4NiO4+δ Electrode Materials

In this study, Nd1.6Ca0.4Ni1−yCuyO4+δ-based electrode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs) are investigated. Materials of the series (y = 0–0.4) are obtained by pyrolysis of glycerol-nitrate compositions. The study of crystal structure and high-temperature stability in air and under low oxygen partial pressure atmospheres are performed using high-resolution neutron and in situ X-ray powder diffraction. All the samples under the study assume a structure with Bmab sp.gr. below 350◦C and with I4/mmm sp.gr. above 500◦C. A transition in the volume thermal expansion coefficient values from 7.8–9.3 to 9.1–12.0 × 10−6, K−1 is observed at approximately 400◦C in air and 500◦C in helium.The oxygen self-diffusion coefficient values, obtained using isotope exchange, monotonically decrease with the Cu content increasing, while concentration dependence of the charge carriers goes through the maximum at x = 0.2. The Nd1.6Ca0.4Ni0.8Cu0.2O4+δ electrode materialdemonstrates chemical compatibility and superior electrochemical performance in the symmetrical cells with Ce0.8Sm0.2O1.9, BaCe0.8Sm0.2O3−δ, BaCe0.8Gd0.19Cu0.1O3−δ and BaCe0.5Zr0.3Y0.1Yb0.1O3−δ solid electrolytes, potentially for application in IT-SOFCs. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.122013100200-2; Ministry of Education and Science of the Russian Federation, Minobrnauka: AAAA-A21-121011390009-1; Ural Branch, Russian Academy of Sciences, UB RAS: 122020100324-3Material synthesis, sample preparation, and electrochemical studies were performed in the framework of budget tasks for the Institute of High Temperature Electrochemistry, UB RAS, project № 122020100324-3. The standard characterization of powder and ceramic materials was carried out at the Shared Access Centre “Composition of Compounds” of the Institute of High Temperature Electrochemistry, UB RAS. The synchrotron XRD experiments were performed at the shared research center SSTRC on the basis of the Novosibirsk VEPP-3 complex at BINP SB RAS. The in situ XRD study was carried out using the facilities of the shared research center “National Center of Investigation of Catalysts” at the Boreskov Institute of Catalysis (BIC). The part of the reported study concerning the crystal structure of the samples was funded within the framework of budget project for Synchrotron radiation facility SKIF, Boreskov Institute of Catalysis.BIC support of the isotope exchange study by the Ministry of Science and Higher Education of the Russian Federation projects AAAA-A21-121011390009-1 and AAAA-A21-121011390007-7 is greatly acknowledged. XPS study of the electrode materials was partly performed in the framework of the budget task for the Institute of Metallurgy, UB RAS, project № 122013100200-2 using the equipment of the Shared Access Centre “Ural-M” of the Institute of Metallurgy, UB RAS.Acknowledgments: Material synthesis, sample preparation, and electrochemical studies were performed in the framework of budget tasks for the Institute of High Temperature Electrochemistry, UB RAS, project №122020100324-3. The standard characterization of powder and ceramic materials was carried out at the Shared Access Centre “Composition of Compounds” of the Institute of High Temperature Electrochemistry, UB RAS. The synchrotron XRD experiments were performed at the shared research center SSTRC on the basis of the Novosibirsk VEPP-3 complex at BINP SB RAS. The in situ XRD study was carried out using the facilities of the shared research center “National Center of Investigation of Catalysts” at the Boreskov Institute of Catalysis (BIC). The part of the reported study concerning the crystal structure of the samples was funded within the framework of budget project for Synchrotron radiation facility SKIF, Boreskov Institute of Catalysis.BIC support of the isotope exchange study by the Ministry of Science and Higher Education of the Russian Federation projects AAAA-A21-121011390009-1 and AAAA -A21-121011390007-7 is greatly acknowledged. XPS study of the electrode materials was partly performed in the framework of the budget task for the Institute of Metallurgy, UB RAS, project № 122013100200-2 using the equipment of the Shared Access Centre “Ural-M” of the Institute of Metallurgy, UB RAS

Острый аппендицит при инвагинации червеобразного отростка

Intussusception of the appendix is the introduction of the appendix into the lumen of the cecum may be accompanied by the development of acute appendicitis, or proceed without it. The combination of intussusception and acute inflammation of the appendix makes the diagnosis of appendicitis difficult due to the absence of classic clinical symptoms. The article presents the case of successful treatment of a patient with an untypical clinical presentation of acute appendicitis that developed in an invaginated vermiform appendix. Инвагинация червеобразного отростка — внедрение червеобразного отростка в просвет слепой кишки — может сопровождаться развитием острого аппендицита, либо протекать без него. Сочетание инвагинации и острого воспаления аппендикса создает сложности в диагностике аппендицита из-за отсутствия характерных клинических симптомов. В статье представлен случай успешного лечения больной с атипичной клинической картиной острого аппендицита, развившегося при инвагинации червеобразного отростка.

Influence of Gamma-Ray Emission on the Isotopic Composition of Clouds in the Interstellar Medium

We investigate one mechanism of the change in the isotopic composition of cosmologically distant clouds of interstellar gas whose matter was subjected only slightly to star formation processes. According to the standard cosmological model, the isotopic composition of the gas in such clouds was formed at the epoch of Big Bang nucleosynthesis and is determined only by the baryon density in the Universe. The dispersion in the available cloud composition observations exceeds the errors of individual measurements. This may indicate that there are mechanisms of the change in the composition of matter in the Universe after the completion of Big Bang nucleosynthesis. We have calculated the destruction and production rates of light isotopes (D, 3He, 4He) under the influence of photonuclear reactions triggered by the gamma-ray emission from active galactic nuclei (AGNs). We investigate the destruction and production of light elements depending on the spectral characteristics of the gamma-ray emission. We show that in comparison with previous works, taking into account the influence of spectral hardness on the photonuclear reaction rates can increase the characteristic radii of influence of the gamma-ray emission from AGNs by a factor of 2-8. The high gamma-ray luminosities of AGNs observed in recent years increase the previous estimates of the characteristic radii by two orders of magnitude. This may suggest that the influence of the emission from AGNs on the change in the composition of the medium in the immediate neighborhood (the host galaxy) has been underestimated.Comment: 13 pages, 13 figures, 3 table

Femtometer Toroidal Structures in Nuclei

The two-nucleon density distributions in states with isospin $T=0$, spin $S$=1 and projection $M_S$=0 and $\pm$1 are studied in $^2$H, $^{3,4}$He, $^{6,7}$Li and $^{16}$O. The equidensity surfaces for $M_S$=0 distributions are found to be toroidal in shape, while those of $M_S$=$\pm$1 have dumbbell shapes at large density. The dumbbell shapes are generated by rotating tori. The toroidal shapes indicate that the tensor correlations have near maximal strength at $r<2$ fm in all these nuclei. They provide new insights and simple explanations of the structure and electromagnetic form factors of the deuteron, the quasi-deuteron model, and the $dp$, $dd$ and $\alpha d$ $L$=2 ($D$-wave) components in $^3$He, $^4$He and $^6$Li. The toroidal distribution has a maximum-density diameter of $\sim$1 fm and a half-maximum density thickness of $\sim$0.9 fm. Many realistic models of nuclear forces predict these values, which are supported by the observed electromagnetic form factors of the deuteron, and also predicted by classical Skyrme effective Lagrangians, related to QCD in the limit of infinite colors. Due to the rather small size of this structure, it could have a revealing relation to certain aspects of QCD.Comment: 35 pages in REVTeX, 25 PostScript figure

Противоопухолевая активность кураксина CBL0137 на моделях острых лейкозов in vitro

Background. Curaxin CBL0137 is a novel non-genotoxic compound with anti-cancer activity based on CBL0137 ability of non-covalent interaction with DNA causing histone chaperone FACT relocation. Anti-cancer activity of this drug was demonstrated previously on the wide panel of solid cancer models in vitro and in vivo.Objectives. Estimation of anticancer effects of CBL0137 on the acute myeloblastic leukemia cells (THP-1) and acute lymphoblastic leukemia (CCRF-CEM).Materials and methods. CBL0137 cytotoxicity was analyzed using the MTT test, the effects on the cell cycle and the induction of apoptosis was assessed by flow cytometry, the activity of signaling pathways in cells treated with CBL0137 was determined by real-time polymerase chain reaction.Results. Cell treatment with CBL0137 led to cell cycle arrest and apoptosis induction. In the study of CBL0137 effect on target gene clusters of 10 signal transduction pathways involved in the pathogenesis of acute leukemia we have showed that CBL0137 inhibited the expression of down-stream genes of WNT and Hedgehog signaling in both cell lines. In THP-1 cells we also observed the inhibition of the expression of PPARγ target and hypoxia-activated genes. In CCRF-CEM cells CBL0137 also induced the expression of Notch signaling target genes.Conclusion. The antitumor activity of CBL0137 was demonstrated on acute leukemia cell cultures, the drug possesses cytotoxicity, causes cell cycle arrest and activation of apoptosis. Significant changes in the expression of efferent gene clusters of several signaling pathways were observed in the cells treated with CBL0137.Введение. Кураксин CBL0137 – новое негенотоксичное соединение, обладающее противоопухолевой активностью, в основе которой лежит способность препарата нековалентно взаимодействовать с ДНК, вызывая транслокацию гистонового шаперона FACT в хроматиновую фракцию. Ранее противоопухолевая активность этого агента была продемонстрирована относительно широкого спектра солидных опухолей in vitro и in vivo.Цель исследования – изучение противоопухолевой активности CBL0137 в отношении клеток острого миелобластного лейкоза (THP-1) и острого лимфобластного лейкоза (CCRF-CEM) in vitro.Материалы и методы. Для определения цитотоксичности CBL0137 использовали МТТ-тест, влияние на клеточный цикл и индукцию апоптоза оценивали с помощью проточной цитофлуориметрии, активность функционирования сигнальных путей при действии на клетки CBL0137 определяли с помощью полимеразной цепной реакции в реальном времени.Результаты. Обработка клеток CBL0137 приводит к аресту клеточного цикла и активации апоптоза. При исследовании влияния CBL0137 на кластеры таргетных генов 10 сигнальных путей, вовлеченных в онкогенез острых лейкозов, его ингибирующее действие было выявлено для сигнальных путей WNT и Hedgehog в обеих клеточных линиях. В клеточной линии THP-1 также наблюдалось ингибирование эфферентных генов PPARγ и генов, активирующихся при гипоксии. В клетках CCRF-CEM при действии CBL0137, кроме того, наблюдалось усиление экспрессии всех исследованных таргетных генов сигнального пути Notch.Заключение. На культурах клеток острых лейкозов продемонстрирована противоопухолевая активность CBL0137, препарат обладает цитотоксичностью, вызывает арест клеточного цикла и активацию апоптоза. При действии CBL0137 наблюдаются значительные изменения в экспрессии кластеров эфферентных генов сразу нескольких сигнальных путей