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Influence of Zr and Mn additions on microstructure and properties of Mg-2.5wt%Cu-Xwt%Zn(X=2.5,5 and 6.5)alloys

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International Journal of Minerals,Metallurgy and Materials 2022年第9期29卷 1733-1745页

作者： A.V.Koltygin V.E.Bazhenov I.V.Plisetskaya V.A.Bautin A.I.Bazlov n.y.tabachkova O.O.Voropaeva A.A.Komissarov V.D.Belov Foundry Department National University of Science and Technology(MISiS)Moscow 119049Russia Department of Metallurgy Steel New Production Technologies and Protection of MetalsNational University of Science and Technology(MISiS)Moscow 119049Russia Laboratory of Advanced Green Materials National University of Science and Technology(MISiS)Moscow 119049Russia Department of Materials Science of Semiconductors and Dielectrics National University of Science and Technology(MISiS)Moscow 119049Russia Fianit Laboratory(Laser Materials and Technology Research Center at GPI) Prokhorov General Physics Institute RASMoscow 119991Russia Laboratory of Hybrid nanostructured Materials National University of Science and Technology(MISiS)Moscow 119049Russia Laboratory of Medical Bioresorption and Bioresistance Moscow State University of Medicine and DentistryMoscow 127473Russia

This work studied the effects of adding Zr and Mn in amounts less than 1wt%on the microstructure,mechanical properties,casting properties,and corrosion resistance of Mg-Zn-Cu alloys containing 2.5wt%Cu and 2.5wt%-6.5wt%*** hardness and electrical conductivity measurements were used to find an optimal heat treatment schedule with the best mechanical *** has been established that Zr significantly increases the yield strength of the alloys due to a strong grain refinement ***,the presence of Mn and Zr has a detrimental effect on alloy’s elongation at *** was shown that the precipitation of the Mg_(2)Cu cathodic phase in the alloy structure negatively affects the corrosion ***,the addition of Mn decreases the corrosion rate of the investigated *** best combination of the mechanical,casting,and corrosion properties were achieved in the alloys containing 2.5wt%Cu and 5wt%***,the Mn or Zr addition can improve the properties of the alloys;for example,the addition of Mn or Zr increases the fluidity of the alloys.

关键词： magnesium alloy Mg-Zn-Cu casting alloy Mn addition Zr addition

Joint effect of quasicrystalline icosahedral and L1_(2)-strucutred phases precipitation on the grain structure and mechanical properties of aluminum-based alloys

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Journal of Materials Science & Technology 2021年第28期87卷 196-206页

作者： A.G.Mochugovskiy n.yu.tabachkova M.Esmaeili Ghayoumabadi V.V.Cheverikin A.V.Mikhaylovskaya national University of Sciences and Technology“MISIS” 119049Leninskiy Ave.4MoscowRussia Prokhorov General Physics Institute of the Russian Academy of Sciences MoscowRussia

Dispersoid hardening is a key factor in increasing the recrystallization resistance and mechanical strength of non-heat treatable aluminum-based *** and Zr are the main elements that form dispersoids in commercial Al-based *** this work,the annealing-induced precipitation behavior,the grain structure,and the mechanical properties of Al-3.0 Mg-1.1 Mn and Al-3.0 Mg-1.1 Mn-0.25 Zr alloys were *** microstructure and the mechanical properties were significantly affected by annealing regimes after casting for both *** research demonstrated a possibility to form high-density distributed quasicrystalline-structured I-phase precipitates with a mean size of 29 nm during low-temperature annealing of as-cast *** manganese-bearing precipitates of I-phase increased recrystallization resistance and significantly enhanced the mechanical strength of the alloys *** estimated strengthening effect owing to I-phase precipitation was 150 *** to the formation of L1_(2)-structured Al3Zr dispersoids with a mean size of 5.7 nm,additional alloying with Zr increased yield strength by about 90 *** L1_(2)-phase strengthening effect was estimated through the dislocation bypass looping and shearing mechanisms.

关键词： Aluminum alloy Quasicrystals Dispersoid hardening Recrystallization Mechanical properties

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)

Melt-spun thin ribbons of shape memory TiniCu alloy for micromechanical applications

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International Journal of Smart and nano Materials 2011年第2期2卷 68-77页

作者： A.V.Shelyakov n.n.Sitnikov V.V.Koledov D.S.Kuchin A.I.Irzhak n.yu.tabachkova Department of Solid State Physics and nanosystems National Research Nuclear University“MEPhI”Kashirskoe shosse 31115409 MoscowRussian Federation Department of Physics of Magnetic Phenomena Kotelnikov Institute of Radio-Engineering and Electronics of Russian Academy of SciencesMohovaya st.11/7125009 MoscowRussian Federation Department of Material Science of Semiconductors and Dielectrics National University of Science and Technology“MISiS”Leninsky prospect 4119049 MoscowRussian Federation

The development of micromechanical devices(MEMS and nEMS)on the basis of nanostructured shape memory alloys is reported.A Ti_(50)ni_(25)Cu_(25)(at.%)alloy fabricated by the melt spinning technique in the form of a ribbon with a thickness around 40µm and a width about 1.5 mm was chosen as a starting *** parameters were optimized to produce the alloy in an amorphous *** thickness of the ribbon was reduced to 5–14µm by means of electrochemical polishing.A nanostructural state of the thin ribbons was obtained via the dynamic crystallization of the amorphous alloy by application of a single electric pulse with duration in the range of 300–900µs.A microtweezers prototype with a composite cantilever of 0.8µm thick and 8µm long was developed and produced on the basis of the obtained nanostructured thin ribbons by means of the focused ion beam *** deformation of the micromanipulator was achieved by heating using semiconductor laser radiation in a vacuum chamber of scanning ion-probe microscope.

关键词： melt-spun ribbon shape memory alloy composite micromanipulator microtweezers

Quaternion methods and models of regular celestial mechanics and astrodynamics

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Applied Mathematics and Mechanics(English Edition) 2022年第1期43卷 21-80页

作者： y.n.CHELnOKOV Institute of Precision Mechanics and Control Russian Academy of SciencesSaratov410031Russia

This paper is a review,which focuses on our work,while including an analysis of many works of other researchers in the field of quaternionic *** regular quaternion models of celestial mechanics and astrodynamics in the Kustaanheimo-Stiefel(KS)variables and Euler(Rodrigues-Hamilton)parameters are *** models are derived by the quaternion methods of mechanics and are based on the differential equations of the perturbed spatial two-body problem and the perturbed spatial central motion of a point *** paper also covers some applications of these *** and Scheifele are known to have doubted that quaternions and quaternion matrices can be used efficiently to regularize the equations of celestial ***,the author of this paper and other researchers refuted this point of view and showed that the quaternion approach actually leads to efficient solutions for regularizing the equations of celestial mechanics and *** paper presents convenient geometric and kinematic interpretations of the KS transformation and the KS bilinear relation proposed by the present *** general(compared with the KS equations)quaternion regular equations of the perturbed spatial two-body problem in the KS variables are *** equations are derived with the assumption that the KS bilinear relation was not *** main stages of the quaternion theory of regularizing the vector differential equation of the perturbed central motion of a point particle are presented,together with regular equations in the KS variables and Euler parameters,derived by the aforementioned *** also present the derivation of regular quaternion equations of the perturbed spatial two-body problem in the Levi-Civita variables and the Euler parameters,developed by the ideal rectangular Hansen coordinates and the orientation quaternion of the ideal coordinate *** paper also gives new results using quaternionic methods in the pertur

关键词： celestial mechanics astrodynamics perturbed spatial two-body problem central motion regularization Levi-Civita and Kustaanheimo-Stiefel(KS)variables Euler parameter quaternion

Absorption of laser radiation in ultracold plasma

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Chinese Physics B 2016年第10期25卷 128-131页

作者： n y Shaparev Institute of Computational Modeling Russian Academy of Sciences national Research Tomsk State University

In this paper, we analyze the spectral behavior(optical thickness, shape and linewidth) of laser radiation absorption under the correlation heating of ions in an ultracold plasma. The Voigt formula is used to find the absorption *** spectral line width is shown to grow with time while the optical thickness reduces. Our modeling results are in good agreement with the experimental findings reported in the literature.

关键词： absorption laser radiation ultracold plasma

Thermoluminescence glow curve analysis and kinetic parameters of Dy-doped BaSi_(2)O_(5)phosphor

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Journal of Rare Earths 2022年第2期40卷 234-242,I0002页

作者： y.Alajlani n.Can Physics Department Jazan UniversityP.O.Box 114Jazan45142Saudi Arabia Department of Physics Faculty of Arts and SciencesManisa Celal Bayar UniversityMuradiye-Manisa45010Turkey

In this paper,Dy^(3+)incorporated BaSi_(2)O_(5)phosphors were synthesized by gel co mbustion method and characterized by X-ray diffraction(XRD).The effects of various heating rate s on thermoluminescence(TL)kinetics and glow peak temperatures of Dy^(3+)incorporated BaSi_(2)O_(5)phosphors exposed toβirradiation at room temperature were *** glow curves of the phosphor exposed toβ-irradiation(0.1-100 Gy)consist of four main peaks located at 87,130,271,and 327℃and exhibit a good linearity between 0.1 and100 *** experimental techniques including variable heating rate(VHR),repeated initial rise(RIR),peak shape(PS)and computerized glow curve deconvolution(CGCD)were employed to determine TL kinetic *** findings indicate that the TL glow peaks of the phosphor obey first-order *** of the main dosimetric peaks through the techniques mentio ned above indicates that activation energies(E)and pre-exponential factor(s)are in the range of 0.80-1.50 eV and 1.15×10^(8)-3.28×10^(13)s^(-1).Additionally,it is found that the temperature of the glow peaks shifts toward the higher temperatures and the TL intensity smoothly decreases as the heating rate *** effect on the TL intensities and glow peak temperatu res of the heating rate is discussed in terms of thermal quenching.

关键词： BaSi_(2)O_(5) Dy^(3+) Gel combustion XRD Thermoluminescence Kinetic parameters

Creeping fat and gut microbiota in Crohn’s disease

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World Journal of Gastroenterology 2025年第1期31卷 16-23页

作者： Ana EV Quaglio Daniéla O Magro Marcello Imbrizi Ellen CS De Oliveira Luiz C Di Stasi Ligia y Sassaki Verum Ingredients Botucatu Technology ParkBotucatu 18605-525São PauloBrazil Department of Surgery Faculty of Medical SciencesState University of CampinasCampinas 13083-970São PauloBrazil Department of Gastroenterology Faculty of Medical SciencesUniversity of CampinasCampinas 13083-970São PauloBrazil Department of Internal Medicine Medical SchoolSão Paulo State UniversityBotucatu 18618-686São PauloBrazil Department of Biophysics and Pharmacology Institute of BiosciencesSão Paulo State UniversityBotucatu 18618-689São PauloBrazil

In this article,we explored the role of adipose tissue,especially mesenteric adipose tissue and creeping fat,and its association with the gut microbiota in the pathophysiology and progression of Crohn’s disease(CD).CD is a form of inflammatory bowel disease characterized by chronic inflammation of the gastrointestinal tract,influenced by genetic predisposition,gut microbiota dysbiosis,and environmental *** microbiota plays a crucial role in modulating immune response and intestinal inflammation and is associated with the onset and progression of ***,visceral adipose tissue,particularly creeping fat,a mesenteric adipose tissue characterized by hypertrophy and fibrosis,has been implicated in CD pathogenesis,inflammation,and *** bacteria from the gut microbiota may translocate into mesenteric adipose tissue,contributing to the formation of creeping fat and influencing CD *** creeping fat may be a protective barrier against bacterial invasion,its expansion can damage adjacent tissues,leading to *** gut microbiota through interventions such as fecal microbiota transplantation,probiotics,and prebiotics has shown potential in managing ***,more research is needed to clarify the mechanisms linking gut dysbiosis,creeping fat,and CD progression and develop targeted therapies for microbiota modulation and fat-related complications in patients with CD.

关键词： Creeping fat Mesenteric adipose tissue Gut microbiota Crohn’s disease Inflammatory bowel disease

Torsion problem for elastic multilayered finite cylinder with circular crack

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Applied Mathematics and Mechanics(English Edition) 2017年第3期38卷 423-438页

作者： y.PROTSEROV n.VAySFELD Institute of Mathematics Economics and Mechanics Odessa Mechnikov University Dvoryanskaya str. 2 Odessa 65082 Ukraine

An axisymmetric tangent stress is applied to a lateral surface of a multilayered elastic finite cylinder with a fixed bottom face. The problem is solved for an arbitrary number of layers. The layers are coaxial, and the conditions of an ideal mechanical contact are fulfilled between them. A circular crack is situated parallel to the cylinder’s faces in the internal layer with branches free from stress. The upper face of the cylinder is also free from stress. Concretization of the problem is done on examples of two-and three-layered cylinders. An analysis of cylinders’ stress state is conducted and the stress intensity factor is evaluated depending on the crack’s geometry, its location and ratio of the shear modulus. Advantages of the proposed method include reduction of the solution constants’ number regardless of the number of layers, and presentation of the mechanical characteristics in a form of uniformly convergent series.

关键词： multilayered cylinder circular crack integral transformation singular integral equation