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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)

Combustion synthesis and luminescence characteristic of rare earth activated LiCaBO_3

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Journal of Rare Earths 2012年第10期30卷 1005-1008页

作者： n.s. Bajaj s.k. Omanwar Department of Physics SGB Amravati University Amravati-444602 (M.S.)

Lithium calcium borate （LiCaBO3） polycrystalline thermoluminescence （TL） phosphor doped with rare earth （Tb3＋ and Dy3＋） elements was synthesized by novel solution combustion synthesis. The reaction produced very stable crystalline LiCaBO3：D（D=Tb3＋ and Dy3＋） phosphors. These rare earth doped phosphors material showed maximum TL sensitivity with favorable glow curve shape. TL glow curve of X-ray irradiated that LiCaBO3：Tb3＋ and LiCaBO3：Dy3＋ samples showed two major well-separated glow peaks. The TL sensitivity of these phosphors to X-ray radiation was comparable with that of TLD-100（Harshaw）. Photoluminescence spectra of LiCaBO3：Tb3＋ and LiCaBO3：Dy3＋ showed the characteristic Tb3＋ and Dy3＋ peaks respectively. TL response to X-ray radiation dose was linear up to 25 Gy.

关键词： luminescence LiCaBO3 combustion synthesis rare earths kinetics

An optimized ion trap geometry to measure quadrupole shifts of ^(171)Yb~＋ clocks

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Chinese Physics B 2016年第11期25卷 230-237页

作者： n Batra B k sahoo s De Academy of scientific and Innovative Research CSIR-NPL Campus New Delhi India CsIR-national Physical Laboratory Dr. K. S. Krishnan Marg New Delhi 110012 India Theoretical Physics Division Physical Research Laboratory Navrangpura Ahmedabad 380009 India

We propose a new ion-trap geometry to carry out accurate measurements of the quadrupole shifts in the （171）Yb *** trap will minimize the quadrupole shift due to the harmonic component of the confining potential by an order of *** will be useful to reduce the uncertainties in the clock frequency measurements of the 6s 2s（1/2）→4f（13）6s2 2F（7/2）and 6s 2s（1/2）→5d2D（3/2） transitions,from which we can deduce the precise values of the quadrupole moments（0s） of the 4f（13）6s2 2F（7/2） and 5d2D（3/2） ***,it may be able to affirm the validity of the measured 0 value of the4f（13）6s22F（7/2） state,for which three independent theoretical studies defer almost by one order of magnitude from the *** also calculate 0s using the relativistic coupled-cluster（RCC） *** use these 0 values to estimate the quadrupole shift that can be measured in our proposed ion trap experiment.

关键词： validity minimize carry clock relativistic precise deduce magnitude expectation spatially

Investigation into machining performance of microstructurally engineered in-situ particle reinforced magnesium matrix composite

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Journal of Magnesium and Alloys 2023年第3期11卷 916-935页

作者： s.k.sahoo B.n.sahoo s.k.Panigrahi Department of Mechanical Engineering Indian Institute of Technology MadrasChennai 600036India Applied Magnesium Research Group Center of Excellence in Materials and Manufacturing for Futuristic MobilityIndian Institute of Technology MadrasChennai 600036India Department of Mechanical Engineering Sardar Vallabhbhai National Institute of TechnologySurat 395007India

Magnesium and magnesium in-situ composites have significant potential in the application of design and manufacturing for automotive and aerospace industries because of their high specific strength and reduced fuel *** there are many challenges for machining of Mg based alloys and composites because of the high tendency of fire and *** challenges can be minimized through microstructural *** this present study,the machining performances of AZ91 Mg alloy and in-situ hybrid TiC+TiB_(2)reinforced AZ91 metal matrix composite was *** effectβ-Mg_(17)Al_(12)phases and grain refinement with and without in-situ particles on machinability were studied through microstructural engineering via aging and friction stir *** end milling operation was carried out at different cutting speeds ranging from 25 mm/min to 90 mm/min under dry environment by using an AlTin-coated tungsten carbide *** optimum cutting speed for machining was found to be 75 mm/min based on the surface roughness values of all conditioned *** base material with dendritic microstructure was found to have poor machinability in terms of inadequate surface finish and edge-burrs *** combined effect of in-situ TiC+TiB_(2)particles addition and grain refinement enhanced the machining performance of the material with superior surface finish,negligible edge-burr formation and better tool wear *** influence of in-situ TiC+TiB_(2)particles,β-Mg_(17)Al_(12)phases and grain refinement on machining characteristics are explained based on the tool wear mechanisms,chip behavior and machining induced affected zone.

关键词： Magnesium In-situ composite End-milling Tool wear Chip morphology

Aldo-keto synthesis effect on Eu^(3+) fluorescence in YBO3 compared with solid state diffusion

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Journal of Rare Earths 2015年第5期33卷 486-490页

作者： k.A.koparkar n.s.Bajaj s.k.Omanwar Department of Physics Sant Gadge Baba Amravati University

The red-orange emitting phosphor YBO3：Eu3＋was prepared by aldo-keto method and solid state diffusion. Aldo-keto method implied to decrease the processing time and heating temperature. The red-orange emitting phosphor was characterized by X-ray diffraction （XRD）, scanning electron microscopy （sEM）, as well as emission and excitation photoluminescence spectra re-corded at room temperature. The result of aldo-keto method showed that the phosphor YBO3：Eu3＋could be obtained at 900 °C in less time^60%as compared to solid state diffusion （ssD）. The material showed that the strongest emission peak at 595 nm under excitation at 233 nm was only due to forced magnetic dipole 5D0→7F1 transition of Eu3＋ions. significantly, the emission inten-sity of YBO3：Eu3＋phosphor prepared by aldo-keto method was relatively higher as compared to that obtained by the solid state diffusion.

关键词： aldo-keto method yttria europium optical materials photoluminescence (PL) rare earths

non-spherical Gravitational Collapse of strange Quark Matter

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Chinese Physics Letters 2008年第5期25卷 1568-1570页

作者： Zade s s Patil k D Mulkalwar P n Department of Mathematics J. B. College of Science Wardha India Department of Mathematics B. D. College of Engineering Sewagram Wardha India Department of Computer science Amolakchand Mahavidyalaya Yavatmal India

We study the non-spherical gravitational collapse of the strange quark null fluid. The interesting feature which emerges is that the non-spherical collapse of charged strange quark matter leads to a naked singularity whereas the gravitational collapse of neutral quark matter proceeds to form a black hole. We extend the earlier work of Harko and Cheng [Phys. Lett. A 266 （2000） 249] to the non-spherical case.

关键词： nAkED sInGULARITIEs COsMIC CEnsORsHIP sPACETIMEs

Combustion synthesis of Ce^(3+), Eu^(3+) and Dy^(3+) activated naCaPO_4 phosphors

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Journal of Rare Earths 2011年第6期29卷 527-535页

作者： k n shinde s J Dhoble Animesh kumar Department of Physics RTM Nagpur University national Environmental Engineering Research Institute

The preparation of naCaPO4 doped with rare earth （RE） ions Ce3＋, Eu3＋ and Dy3＋ by combustion method was described. Under UV excitation （251 nm） of naCaPO4：Ce3＋ showsd emission （367 nm） in UV range. When naCaPO4：Dy3＋ phosphor was excited at 349 nm, the emission spectrum showed intense bands at 482 nm （blue） and 576 nm （yellow）. In Eu activated naCaPO4 phosphor, the emission spectrum showed a dominant peak at 594 nm （orange） while others were at 614 and 621 nm （red） when excited at 393 nm. The prepared phosphor was characterized by X-ray diffraction （XRD）, scanning electron microscope （sEM） and photoluminescence （PL） measurement. Thus, the photoluminescence behavior of naCaPO4：Ce3＋ was strongly suggested for scintillator. Likewise, Eu3＋ and Dy3＋ activated naCaPO4 phosphors were recommended for near-UV white light-emitting diodes （LEDs）.

关键词： combustion synthesis photoluminescence phosphor scintillator solid state lighting rare earths

study on mixing and segregation behaviors in particulate fluidized bed system for mineral processing

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International Journal of Mining science and Technology 2015年第3期25卷 459-464页

作者： sahu s.n. sahu A.k. Biswal s.k. Mineral Processing Department CSIR-Institute of Minerals and Materials Technology

In order to identify the mixing and segregation behaviors in a mineral processing operation, present study aimed on the hydrodynamics of solid–liquid fluidization. The study was carried out in a fluidization column with tapings at different height of the bed to collect the sample. The binary particles considered in this study are hematite(4800 kg/m3) and quartz(2600 kg/m3) at different size fractions in the range of average size 87×10^(-6)m to 400×10^(-6)m. It is observed that for various binary mixtures, both quartz and hematite particles share the equal composition by mass(50%) at a particular height of fluidized bed, referred as ‘‘locus point'' of mixing. study indicates that the mixing zone volume will increase for a continuous fluidized bed plant operation. It is observed that the number of locus points varies from 1 to 3 signifying their dependency on the size ratios of binary mixture. Whenever, the difference in terminal velocity between quartz and hematite particles approaches to zero, mixing is ***, the present study is extended to find the segregation index for the different size ratios of quartz and hematite particles. It is evident that depending on the size ratios, various regions such as complete segregation, partial mixing and complete mixing can be observed.

关键词： Liquid-solid fluidization Mixing segregation Locus point Mineral processing

Dispersion effect of nano-structure pyrolytic carbon on mechanical,electrical,and microstructural characteristics of cement mortar composite

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International Journal of smart and nano Materials 2024年第3期15卷 534-578页

作者： n.k.karthikeyan s.Elavenil school of Civil Engineering Vellore Institute of TechnologyChennaiIndia

In material science,converting waste into nanomaterials by green technologies highlights the interest in producing sus-tainable carbon nanomaterial(sCn).This study first-ever uti-lized tyre-char as a nano-structure Pyrolytic Carbon(nsPC)to develop electrically conductive *** other car-bon nanomaterials,the efficiency of nsPC particle as an sCn in developing electrically conductive composites was investi-gated in terms of dispersion,mechanical,water absorption,electrical resistivity,and *** results of sedi-mentation and zeta potential(-19 mV)showed the excellent dispersion of nsPC particle in water with the combined effect of superplasticizer and *** compressive(40.37%)and flexural strength(10.76%)than that of plain cement mortar composite(CMC)is achieved with 2 wt.%and 1.5 wt.%of nsPC particle,*** water absorption rate and volume of permeable voids were reduced,exhibiting less *** percolation zone of AC and DC resis-tivity of nsPC composite ranges between 1 and 2 wt.%,and the established percolation threshold is at 2 wt.%.XRD analysis showed C-s-H formation consistently increased with curing age,and HR-sEM with EDAX analysis exhibits the dense micro-structure and well-distributed nsPC particle at the *** experimental outcomes significantly enhanced the relia-bility and provided a framework for tailoring nsPC particle as sCn for developing electrically conductive composite.

关键词： sustainable nanomaterial dispersion mechanical properties electrical resistivity microstructure analysis