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Chirping instabilities produced by a runaway electron beam at a spherical tokamak

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Plasma Science and Technology 2023年第7期25卷 19-24页

作者： I M BALACHEnKOv n n BAKHAREv v K GUSEv M v ILIASOvA E M KHILKEvICH P S KOREnEv A E KOnKOv v B MInAEv Yu v MITRIZHKIn M I PATROv Yu v PETROv n v sakharov A E SHEvELEv O M SKREKEL Ioffe Institute Saint-Petersburg 194021Russia Lomonosov Moscow State University Moscow 119991Russia

Two different types of MHD instabilities with rapidly chirping frequency were found to arise in the Globus-M2 spherical tokamak in substantially different frequency *** first type arises at frequencies of an order of 1 MHz in ohmic plasmas at relatively low density(n_(e))n a wide range of toroidal magnetic fields and plasma *** type of instability was identified as compressional Alfven waves,driven by electrons,accelerated during a sawtooth *** was found that the mode frequency is sweeping in time,according to the Berk-Breizman hole-clump nonlinear chirping *** second type of wave arises in a specific single-swing regime of the central solenoid current with a very narrow plasma column,when the plasma tends to decay at extremely low density(n_(e))nd,in fact,is an instability of the runaway electron *** exited modes cover the whole observed frequency range and are divided into several(two or three)frequency regions:approximately 0-30 MHz,60-120 MHz and sometimes 30-60 *** of the branches was also *** chirps are more rapid than for 1 MHz Alfven instability and follow an exponential *** paper,to our knowledge,is the first report of frequency chirping instabilities excited by accelerated electrons at a spherical tokamak.

关键词： Alfvén waves chirping instability spherical tokamak runaway electrons

Influence of the safety factor profile on the particle and heat transport in the Globus-M spherical tokamak

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Plasma Science and Technology 2019年第11期21卷 1-6页

作者： A YU TELnOvA G S KURSKIEv E O KISELEv n n BAKHAREv v K GUSEv n A KHROMOv S YU MEDvEDEv v B MIInAEv I v MIROSHnIKOv M I PATROv Yu v PETROv n v sakharov A D SLADKOMEDOvA P B SHCHEGOLEv v v SOLOKHA v A TOKAREv S YU TOLSTYAKOv E A TUKHMEnEvA Ioffe Institute Saint-Petersburg 194021Russia Keldysh Institute Russian Academy of SciencesMoscow 125047Russia nRC'Kurchatov Institute’ Moscow 123098Russia

The advanced tokamak scenario is a promising operation scenario for ITER and fusion neutron *** this scenario the minimum value of the safety factor in the center of the plasma exceeds *** the compact spherical tokamak Globus-M,the formation of such conditions is possible with neutral beam injection at the current ramp-up *** to the slower diffusion of current inside the plasma,a zone is formed with reduced heat and particle transport across the magnetic field,which affects the temperature and density profiles of the *** leads to the peaked density profile formation and improvement of the energy confinement *** achieve a high fraction of the bootstrap current,it is necessary to increase the plasma *** the same time,the maximum allowable pressure is limited to the normalized beta limit.

关键词： advanced tokamak mode transport analysis internal transport barriers

Dendritic spine degeneration:a primary mechanism in the aging process

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neural Regeneration Research 2025年第6期20卷 1696-1698页

作者： Gonzalo Flores Leonardo Aguilar-Hernández Fernado García-Dolores Humberto nicolini Andrea Judith vázquez-Hernández Hiram Tendilla-Beltrán Instituto de Fisiología Benemérita Universidad Autónoma de Puebla(BUAP)PueblaMexico Instituto de Ciencias Forenses(InCIFO) Tribunal Superior de Justicia de la Ciudad de México(TSJCDMX).Mexico CityMexico Instituto nacional de Medicina Genómica(InMEGEn) Mexico CityMexico

Recent reports suggest that aging is not solely a physiological process in living beings;instead, it should be considered a pathological process or disease(Amorim et al., 2022). Consequently, this process involves a wide range of factors, spanning from genetic to environmental factors, and even includes the gut microbiome(GM)(Mayer et al., 2022). All these processes coincide at some point in the inflammatory process, oxidative stress, and apoptosis, at different degrees in various organs and systems that constitute a living organism(Mayer et al., 2022;AguilarHernández et al., 2023).

关键词： aging process stress

SUPERSOnIC DUSTY-GAS FLOWS WITH KnUDSEn EFFECT In InTERPHASE MOMEnTUM EXCHAnGE

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Acta Mechanica Sinica 2004年第5期20卷 465-470页

作者：王柏懿 A.n.OSIPTSOv L.A.EGOROvA v.I.sakharov LnM Institute of MechanicsChinese Academy of SciencesBeijing 100080China Institute of Mechanics Moscow State UniversityMoscow 119899Russia

On the basis of the two-continuum model of dilute gas-solid suspensions,the dynamic behavior of inertial particles in supersonic dusty-gas flows past a blunt body is studied for moderate Reynolds numbers,when the Knudsen effect in the interphase momentum exchange is significant. The limits of the inertial particle deposition regime in the space of governing parameters are found numerically under the assumption of the slip and free-molecule flow regimes around *** a model problem,the flow structure is obtained for a supersonic dusty-gas point-source flow colliding with a hypersonic flow of pure *** calculations performed using the full Lagrangian approach for the near-symmetry-axis region and the free-molecular flow regime around the particles reveal a multi-layer structure of the dispersed-phase density with a sharp accumulation of the particles in some thin regions between the bow and termination shock waves.

关键词： gas-solid suspension supersonic flow Knudsen effect particle inertia

Impacts of PI3K/protein kinase B pathway activation in reactive astrocytes: from detrimental effects to protective functions

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neural Regeneration Research 2025年第4期20卷 1031-1041页

作者： Ramón Pérez-núñez María Fernanda González Ana María Avalos Lisette Leyton Cellular Communication Laboratory Programa de Biología Celular y MolecularCenter for Studies on ExerciseMetabolism and Cancer(CEMC)Instituto de Ciencias Biomédicas(ICBM)Facultad de MedicinaUniversidad de ChileSantiagoChile Advanced Center for Chronic Diseases(ACCDiS) Faculty of Chemical and Pharmaceutical Sciences&Faculty of MedicineUniversidad de ChileSantiagoChile Instituto de Ciencias Biomédicas Facultad de Ciencias de la SaludUniversidad Autónoma de ChileSantiagoChile

Astrocytes are the most abundant type of glial cell in the central nervous *** injury and inflammation,astrocytes become reactive and undergo morphological and functional *** on their phenotypic classification as A1 or A2,reactive astrocytes contribute to both neurotoxic and neuroprotective responses,***,this binary classification does not fully capture the diversity of astrocyte responses observed across different diseases and *** analysis has revealed that reactive astrocytes have a complex landscape of gene expression profiles,which emphasizes the heterogeneous nature of their *** actively participate in regulating central nervous system inflammation by interacting with microglia and other cell types,releasing cytokines,and influencing the immune *** phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)signaling pathway is a central player in astrocyte reactivity and impacts various aspects of astrocyte behavior,as evidenced by in silico,in vitro,and in vivo *** astrocytes,inflammatory cues trigger a cascade of molecular events,where nuclear factor-κB serves as a central mediator of the pro-inflammatory ***,we review the heterogeneity of reactive astrocytes and the molecular mechanisms underlying their *** highlight the involvement of various signaling pathways that regulate astrocyte reactivity,including the PI3K/AKT/mammalian target of rapamycin(mTOR),αvβ3 integrin/PI3K/AKT/connexin 43,and notch/PI3K/AKT *** targeting the inactivation of the PI3K/AKT cellular signaling pathway to control reactive astrocytes and prevent central nervous system damage,evidence suggests that activating this pathway could also yield beneficial *** dual function of the PI3K/AKT pathway underscores its complexity in astrocyte reactivity and brain function *** review emphasizes the importance of employing astrocyte-exclusive models to underst

关键词： inflammation integrins neuroprotective neurotoxic phosphatidylinositol 3-kinase reactive astrocytes signal transduction Thy-1(CD90)

Brain-derived neurotrophic factor signaling in the neuromuscular junction during developmental axonal competition and synapse elimination

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neural Regeneration Research 2025年第2期20卷 394-401页

作者： Josep Tomàs víctor Cilleros-Mañé Laia Just-Borràs Marta Balanyà-Segura Aleksandra Polishchuk Laura nadal Marta Tomàs Carolina Silvera-Simón Manel M.Santafé Maria A.Lanuza Unitat d’Histologia i neurobiologia(UHneurob) Facultat de Medicina i Ciències de la SalutUniversitat Rovira i VirgiliReusSpain

During the development of the nervous system,there is an overproduction of neurons and *** competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or *** have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse *** purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this *** particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental *** dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific *** describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75nTR pathways that can influence the timing and fate of the competitive interactions between the different axon *** downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary ***,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the n-type channel in developing nerve terminals)contributes to red

关键词： acetylcholine release adenosine receptors axonal competition brain-derived neurotrophic factor calcium channels motor end-plate muscarinic acetylcholine receptors postnatal synapse elimination serine kinases tropomyosin-related kinase receptorB

First results of turbulence investigation on Globus-M2 using radial correlation Doppler reflectometry

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Plasma Science and Technology 2024年第10期26卷 49-55页

作者： A.POnOMAREnKO A.YASHIn v.GUSEv E.KISELEv G.KURSKIEv v.MInAEv Y.PETROv n.sakharov P.SHCHEGOLEv E.TKACHEnKO n.ZHILTSOv Peter the Great St.Petersburg Polytechnic University St.Petersburg 195251Russia Ioffe Institute St.Petersburg 194064Russia

The first results of investigation of the turbulence structure using Doppler backscattering(DBS)on the Globus-M2 tokamak are presented.A one-channel DBS system with a variable probing frequency within the 18–26 GHz range was installed to investigate the edge plasma at normalized minor radiiρ=0.9–*** correlation Doppler reflectometry was used to study the changes in turbulence eddies after the LH *** analysis was applied to the phase derivative of complex in-phase and quadrature(IQ)signals of the DBS diagnostic as it contains information about the poloidal plasma rotation *** L-mode,the radial correlation length L_(r)is estimated to be 3 cm and after transition to H-mode reduces to approximately 2 *** modelling in a linear local approximation using code GEnE indicates that the instability with positive growth rate at the normalized minor radiusρ=0.75 in L-mode and H-mode on Globus-M2 was the ion temperature gradient(ITG)mode.

关键词： tokamak turbulence Doppler backscattering correlation reflectometry

Prolonged intermittent theta burst stimulation restores the balance between A_(2A)R-and A_(1)R-mediated adenosine signaling in the 6-hydroxidopamine model of Parkinson's disease

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neural Regeneration Research 2025年第7期20卷 2053-2067页

作者： Milica Zeljkovic Jovanovic Jelena Stanojevic Ivana Stevanovic Milica ninkovic Tihomir v.Ilic nadezda nedeljkovic Milorad Dragic Laboratory for neurobiology Department of General Physiology and BiophysicsFaculty of BiologyUniversity of BelgradeBelgradeSerbia Medical Faculty of Military Medical Academy University of DefenceBelgradeSerbia

An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's *** therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in *** transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's ***,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain *** purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydroxydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated *** with unilateral 6-hydroxydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod ***,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate *** intermittent theta burst stimulation improved motor symptoms in 6-hydroxydopamine-lesioned animals.A 6-hydroxydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate *** with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor *** treatment with prolonged intermittent theta burst stimulation,complete motor recovery was *** improvement was accompanied by downregulation of the e n/CD73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst *** results demonstrated that 6-hydroxydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)***

关键词： A_(1)R A_(2A)R adenosine receptors adenosine ecto-5′-nucleotidase intermittent theta burst stimulation non-invasive brain stimulation Parkinson's disease purinergic signalling

Ordered exponential and its features in Yang-Mills effective action

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Communications in Theoretical Physics 2023年第8期75卷 119-127页

作者： A v Ivanov n v Kharuk St.Petersburg Department of Steklov Mathematical Institute of Russian Academy of Sciences 27 FontankaSt.Petersburg 191023Russia Leonhard Euler International Mathematical Institute 10 Pesochnaya nab.St.Petersburg 197022Russia

In this paper,we discuss some non-trivial relations for ordered exponentials on smooth Riemannian *** an example of application,we study the dependence of the four-dimensional quantum Yang–Mills effective action on the special gauge transformation with respect to the background ***,we formulate some open questions about a structure of divergences for a special type of regularization in the presence of the background field formalism.

关键词： Yang-Mills effective action ordered exponential heat kernel Green's function short-distance asymptotics cutoff regularization Synge's world function