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Spherically Symmetric Problem of General Relativ.ty for a Fluid Sphere

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Journal of Modern Physics 2024年第4期15卷 401-415页

作者： v.lery v. v.siliev.leonid v. Fedorov Institute of Applied Mechanics of Russian Academy of Sciences Moscow Russia

The paper is dev.ted to a spherically symmetric problem of General Relativ.ty (GR) for a fluid sphere. The problem is solv.d within the framework of a special geometry of the Riemannian space induced by grav.tation. According to this geometry, the four-dimensional Riemannian space is assumed to be Euclidean with respect to the space coordinates and Riemannian with respect to the time coordinate. Such interpretation of the Riemannian space allows us to obtain complete set of GR equations for the external empty space and the internal spaces for incompressible and compressible perfect fluids. The obtained analytical solution for an incompressible fluid is compared with the Schwarzchild solution. For a sphere consisting of compressible fluid or gas, a numerical solution is presented and discussed.

关键词： General Relativ.ty Spherically Symmetric Problem Fluid Sphere

Essential Oils from Different Parts of the Sea Buckthorn Hippophae rhamnoides L.

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RANKL inhibition reduces lesional cellularity and Gαs v.riant expression and enables osteogenic maturation in fibrous dysplasia

Adv.nces in Bioscience and Biotechnology（生命科学与技术进展） 2019年第8期

作者： Nikolay M. Slynko leonid v. kuibida Ludmila E. Tatarov. George U. Galitsyn Tatiana N. Goryachkov.kaya Sergey E. Peltek

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Bone Research 2024年第1期12卷 165-179页

作者： Luis F.de Castro Jarred M.Whitlock Zachary Michel Kristen Pan Jocelyn Taylor v.v.an Szymczuk Brendan Boyce Daniel Martin v.rdit Kram Rebeca Galisteo Kamran Melikov.leonid v.Chernomordik Michael T.Collins Alison M.Boyce Skeletal Disorders and Mineral Homeostasis Section National Institute of Dental and Craniofacial ResearchNational Institutes of HealthBethesdaMDUSA Section on Membrane Biology Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA Metabolic Bone Disorders Unit National Institute of Dental and Craniofacial ResearchNational Institutes of HealthBethesdaMDUSA Department of Plastic and Reconstructiv. Surgery The Johns Hopkins Medical InstitutionsBaltimoreMDUSA Department of Pathology and Laboratory Medicine University of Rochester Medical CenterRochesterNYUSA NIDCR Genomics and Computational Biology Core National Institute of Dental and Craniofacial ResearchNational Institutes of HealthBethesdaMDUSA

Fibrous dysplasia(FD)is a rare,disabling skeletal disease for which there are no established *** ev.dence supports inhibiting the osteoclastogenic factor receptor activ.tor of nuclear kappa-B ligand(RANKL)as a potential treatment *** this study,we inv.stigated the mechanisms underlying RANKL inhibition in FD tissue and its likely indirect effects on osteoprogenitors by ev.luating human FD tissue pre-and post-treatment in a phase 2 clinical trial of denosumab(NCT03571191)and in murine in v.v. and ex v.v. preclinical *** analysis of human and mouse tissue demonstrated increased osteogenic maturation,reduced cellularity,and reduced expression of the pathogenic Gαs v.riant in FD lesions after RANKL *** sequencing of human and mouse tissue supported these *** interaction between osteoclasts and mutant osteoprogenitors was further assessed in an ex v.v. lesion model,which indicated that the proliferation of abnormal FD osteoprogenitors was dependent on *** results from this study demonstrated that,in addition to its expected antiosteoclastic effect,denosumab reduces FD lesion activ.ty by decreasing FD cell proliferation and increasing osteogenic maturation,leading to increased bone formation within *** findings highlight the unappreciated role of cellular crosstalk between osteoclasts and preosteoblasts/osteoblasts as a driv.r of FD pathology and demonstrate a nov.l mechanism of action of denosumab in the treatment of bone disease.

关键词： dysplasia treatment finding

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Pulsed THz radiation under ultrafast optical discharge of v.cuum photodiode

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Frontiers of Optoelectronics 2024年第2期 100-113页

作者： Aleksandr A.Ushakov.Kseniia A.Mamaev. leonid v.Seleznev.Georgy E.Rizaev.v.adimir Bukin Timophey v.Dolmatov.Pav.l A.Chizhov.v.adimir Bagdasarov.Sergey v.Garnov Prokhorov.General Physics Institute of the Russian Academy of Sciences Physical Institute Russian Academy of Sciences Moscow Institute of Physics and Technology Russian Institute for Scientific and Technical Information

In this paper, we first present an experimental demonstration of terahertz radiation pulse generation with energy up to 5 pJ under the electron emission during ultrafast optical discharge of a v.cuum photodiode. We use a femtosecond optical excitation of metallic copper photocathode for the generation of ultrashort electron bunch and up to 45 kv.cm external electric field for the photo-emitted electron acceleration. Measurements of terahertz pulses energy as a function of emitted charge density, incidence angle of optical radiation and applied electric field hav. been prov.ded. Spectral and polarization characteristics of generated terahertz pulses hav. also been studied. The proposed semi-analytical model and simulations in COMSOL Multiphysics prov. the experimental data and allow for the optimization of experimental conditions aimed at flexible control of radiation parameters.

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Basic formation mechanisms of Lake Doroninskoye soda water, East Siberia, Russia

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Acta Geochimica 2018年第4期37卷 546-558页

作者： Sv.tlana v. Borzenko leonid v. Zamana Larisa I. Usmanov. Institute of Natural Resources Ecology and Cryology of Siberian Branch of Russian Academy of Sciences ChitaRussia 672049 Tomsk Department of the Trofimuk Institute of Petroleum-Gas Geology and Geophysics of Siberian Branch of the Russian Academy of Sciences Tomsk Russia 634050

The primary scientific goal of studying salt lakes is to better understand the formation of small continental- type hydrogeochemical systems. Many scientists hav. attributed the metamorphism of the chemical composition of salt lakes to the ev.porativ. concentration of water. How- ev.r, the formation of soda water is inconsistent with this hypothesis. Thus, analyzing intrabasinal biochemical pro- cesses and water--rocks interactions during the ev.porativ. concentration of water allows us to understand the major mechanisms of the formation and ev.lution of water com- positions. Therefore, the aim of this paper is to identify the key processes inv.lv.d in the formation of the chemical composition of the water in Lake Doroninskoye. An analysis of the distribution of major components shows that Na＋, HCO3-, CO32-, and C1- are dominant in this water. High concentrations of these elements are the result of ev.porativ. water concentration. Calcium, magnesium, and potassium are not accumulated because the water is saturated in min- erals containing these elements. The main barrier to the growth of the sulfate content of water is sulfate reduction. This process also contributes to the additional reproduction of carbon dioxide, which reacts with the products of the hydrolysis of aluminosilicates OH- to form HCO3- and CO32-, thus further contributing to the natural processes of soda formation.

关键词： Saline lake Sulfate reduction Thermodynamic equilibrium

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小国的大气象亚美尼亚的地道风物

环球人文地理 2024年第1期 36-45页

作者：读书康梁庭俊宣砚 leonid Andronov.katiekk2 v.unsplash 摄图网

亚美尼亚人将水果杏奉为国宝，爱吃重油重盐的烤肉、大饼。在市中心的购物大街与教堂中，能一窥他们的生活与精神世界。说到葡萄酒，除了法国，亚美尼亚的葡萄酒也是历史悠久。除此以外，随处可见的修道院也是亚美尼亚的标志之一。左页...

亚美尼亚人将水果杏奉为国宝，爱吃重油重盐的烤肉、大饼。在市中心的购物大街与教堂中，能一窥他们的生活与精神世界。说到葡萄酒，除了法国，亚美尼亚的葡萄酒也是历史悠久。除此以外，随处可见的修道院也是亚美尼亚的标志之一。左页大图为当地的葡萄园。右页图为亚美尼亚的修道院。在杰尔穆克的日子，说得上是此行节奏最慢的时候。

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Computational study of laser fragmentation in liquid:Phase explosion,inv.rse Leidenfrost effect at the nanoscale,and ev.poration in a nanobubble

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Science China(Physics,Mechanics & Astronomy) 2022年第7期65卷 99-114页

作者： Hao Huang leonid v.Zhigilei School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China Department of Materials Science and Engineering University of VirginiaCharlottesville 22904-4745USA

Laser fragmentation in liquid is an effectiv. and env.ronment-friendly processing technique capable of yielding colloidal nanoparticles and atomic clusters with a narrow size distribution. The adv.ncement of this technique can be facilitated by an improv.d understanding of processes that control the sizes, shapes, and structures of the produced nanoparticles. In this work, the dependence of the fragmentation mechanisms on the energy density deposited by the laser pulse is inv.stigated in atomistic simulations performed for 20 nm Au nanoparticles irradiated in water by 10 ps laser pulses. The simulations rev.al that the decrease in the absorbed laser energy leads to sequential transitions from the regime of “strong” phase explosion, when all products of an explosiv. phase decomposition of the irradiated nanoparticle are promptly injected into the water surrounding a nanobubble formed around the nanoparticle, to two distinct regimes of nanoparticle fragmentation leading to the formation of a large central nanoparticle surrounded by smaller satellite fragments. First, in the regime of “mild” phase explosion, the central nanoparticle is produced by the reflection of some of the hot metal droplets generated by the explosiv. decomposition of the nanoparticle from the boundary of the nanobubble. This reflection is attributed to the inv.rse Leidenfrost effect acting at the nanoscale. The reflected droplets conv.rge in the center of the nanobubble and coalesce into a single droplet that solidifies shortly after the collapse of the nanobubble. Further decrease in the absorbed laser energy brings the irradiation conditions below the threshold for the phase explosion and results in the formation of a core-satellite structure of the fragmentation products through an interplay of the intense ev.poration from the surface of the irradiated nanoparticle, ev.lution of the nanobubble, and condensation of the metal v.por into clusters and small satellite nanoparticles. The computationa

关键词： laser fragmentation in liquid molecular dynamics simulations phase explosion inv.rse Leidenfrost effect nanobubble nanoparticles

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Nonlinear interference in crystal superlattices

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Light(Science & Applications) 2020年第1期9卷 1239-1245页

作者： Anna v.Paterov. leonid A.Kriv.tsky Institute of Materials Research and Engineering(IMRE) Agency for Science Technology and Research(A*STAR)138634 SingaporeSingapore

Nonlinear interferometers with correlated photons hold promise to adv.nce optical characterization and metrology techniques by improv.ng their performance and *** interferometers offer subshot noise phase sensitiv.ty and enable measurements in detection-challenging regions using inexpensiv. and efficient *** sensitiv.ty of nonlinear interferometers,defined by the ability to measure small shifts of interference fringes,can be significantly enhanced by using multiple nonlinear elements,or crystal ***,to date,experiments with more than two nonlinear elements hav. not been realized,thus hindering the potential of nonlinear ***,we build a nonlinear interferometer with up to fiv. nonlinear elements,referred to as superlattices,in a highly stable and v.rsatile *** study the modification of the interference pattern for different configurations of the superlattices and perform a proof-of-concept gas sensing experiment with enhanced *** approach offers a v.able path towards broader adoption of nonlinear interferometers with correlated photons for imaging,interferometry,and spectroscopy.

关键词： spectroscopy nonlinear Nonlinear

Autoimmunity in acute ischemic stroke and the role of bloodbrain barrier: the dark side or the light one?

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Frontiers of Medicine 2019年第4期13卷 420-426页

作者： Nikolay v. Tsygan Alexandr P. Trashkov.Igor v. Litv.nenko v.ktoriya A. Yakov.ev. Alexandr v. Ryabtsev.Andrey G. v.siliev.leonid P. Churilov Department of Molecular and Radiation Biophysics B.P. Konstantinov Petersburg Nuclear Physics Institute Gatchina Leningrad Region 188300 Russian Federation Department of Nerv.us Diseases S.M. Kirov Military Medical Academy Saint Petersburg 194044 Russian Federation Department of Experimental Pharmacology I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry Saint Petersburg 194223 Russian Federation Department of Pathological Physiology with the Course of Immunopathology Saint Petersburg State Pediatric Medical University Saint Petersburg Russian Federation Department of Pathology Laboratory of the Mosaic of Autoimmunity Saint Petersburg State University Saint Petersburg 199034 Russian Federation

This article presents a synopsis of the current data on the mechanisms of blood-brain barrier (BBB) alteration and autoimmune response in acute ischemic stroke. Most researchers confirm the relationship between the sev.rity of immunobiochemical changes and clinical outcome of acute ischemic stroke. Ischemic stroke is accompanied by aseptic inflammation, which alters the brain tissue and exposes the co-stimulatory molecules of the immune system and the neuronal antigens. To date, BBB is not considered the border between the immune system and central nerv.us system, and the local immune subsystems are found within and behind the BBB. BBB disruption contributes to the leakage of brain autoantigens and induction of secondary autoimmune response to neuronal antigens and long-term inflammation. Glymphatic system function is altered and jeopardized both in hemorrhagic and ischemic stroke types. The receptors of innate immunity (toll-like receptor-2 and toll-like receptor-4) are also inv.lv.d in acute ischemia-reperfusion injury. Immune response is related to the key processes of blood clotting and fibrinolysis. At the same time, the stroke-induced immune activ.tion may promote reparation phenomena in the brain. Subsequent research on the reduction of the acute ischemic brain injury through the target regulation of the immune response is promising.

关键词： stroke blood-brain barrier autoimmunity innate immunity inflammation cell death