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Optical Studies of Fluorescent Mesoporous Silica Nanoparticles

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Journal of Materials Science & Technology 2013年第8期29卷 742-746页

作者： Surbhi kumari p.D.Sahare Department of physics & Astrophysics University of DelhiNew Delhi 110007India

Spherically shaped mesoporous silica nanoparticles （MSNs） having honeycomb like porous structure were synthesized by sol-gel method. Transmission electron microscopy （TEM）, surface area measurement and X-ray diffractometry were used, revealing the hexagonal shaped pores in MSNs. MSNs with surface area of 1104.47 m^2/g and large porosity of 2.8 nm in pore diameter and 0.87 cm^3/g in pore volume were synthesized. TEM images showed spherical nanoparticles of - 200-300 nm having honeycomb like pores. Stilbene 420 laser dye was incorporated in MSNs and photoluminescence spectra of stilbene 420 in MSNs and in ethanol had been studied. Stilbene 420 laser dye showed high fluorescence intensity in the fluorescence spectra of MSNs than that of ethanol. The prolonged fluorescence lifetime decay of stilbene in MSNs and the increase in fluorescence intensity for stilbene 420 in MSNs would make these nanomaterials more useful for nanosensors and nanolasers application.

关键词： Mesoporous nano silica porosity Fluorescence Lifetime decay

Ab-initio studies of the structural,electronic,optical and magnetic properties of DyMg intermetallic compound

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Journal of Magnesium and Alloys 2017年第4期5卷 454-459页

作者： Meena kumari U.p.Verma School of Studies in physics Jiwaji UniversityGwalior 474001India

Structural,electronic,optical and magnetic properties of DyMg intermetallic compound are calculated by using the full potential linearized augmented plane wave(Fp-LApw)method employing density functional theory(DFT).The obtained optimized equilibrium lattice constant in stable structure of DyMg(B2 phase)with spin polarized calculations is 7.107 Bohr and that without spin polarized calculations is 7.115 *** electronic band structure and density of states plots show metallic character of *** energy-dependent components of dielectric function,refractive index,extinction coefficient,absorption spectra,optical conductivity,energy loss spectra and reflectivity are reported in the energy range 0–20 *** DyMg maximum absorption is observed in the range 4–11 *** highest optical conductivity peak is observed near 0.78 eV(1589.5409 nm)and maximum energy loss occurs at 11.90 eV which corresponds to~2.8 Hz in ultraviolet *** obtained total magnetic moment shows that its value decreases with the increase in lattice parameter.

关键词： Magnesium alloy Rare-earth elements Density functional theory Band structure Optical properties Magnetic properties

Heterogeneity of mature oligodendrocytes in the central nervous system

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Neural Regeneration Research 2025年第5期20卷 1336-1349页

作者： Chao weng Adam M.R.groh Moein Yaqubi Qiao-Ling Cui Jo Anne Stratton g.R.wayne Moore Jack p.Antel Neuroimmunology Unit Montreal Neurological Institute-HospitalDepartment of Neurology and NeurosurgeryMcGill UniversityMontrealQCCanada Department of Neurology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina

Mature oligodendrocytes form myelin sheaths that are crucial for the insulation of axons and efficient signal transmission in the central nervous *** evidence has challenged the classical view of the functionally static mature oligodendrocyte and revealed a gamut of dynamic functions such as the ability to modulate neuronal circuitry and provide metabolic support to *** the recognition of potential heterogeneity in mature oligodendrocyte function,a comprehensive summary of mature oligodendrocyte diversity is *** delve into early 20th-century studies by Robertson and Río-Hortega that laid the foundation for the modern identification of regional and morphological heterogeneity in mature ***,recent morphologic and functional studies call into question the long-assumed homogeneity of mature oligodendrocyte function through the identification of distinct subtypes with varying myelination ***,modern molecular investigations,employing techniques such as single cell/nucleus RNA sequencing,consistently unveil at least six mature oligodendrocyte subpopulations in the human central nervous system that are highly transcriptomically diverse and vary with central nervous system *** and disease related mature oligodendrocyte variation denotes the impact of pathological conditions such as multiple sclerosis,Alzheimer's disease,and psychiatric ***,caution is warranted when subclassifying mature oligodendrocytes because of the simplification needed to make conclusions about cell identity from temporally confined *** studies leveraging advanced techniques like spatial transcriptomics and single-cell proteomics promise a more nuanced understanding of mature oligodendrocyte *** research avenues that precisely evaluate mature oligodendrocyte heterogeneity with care to understand the mitigating influence of species,sex,central nervous system region,age,and disease,

关键词： aging central nervous system diseases electron microscopy heterogeneity immunohistochemistry myelin sheath natural history neuroglia oligodendroglia single-cell gene expression analysis

Full potential study of HoMg

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Journal of Magnesium and Alloys 2018年第2期6卷 189-196页

作者： Meena kumari U.p.Verma School of Studies in physics Jiwaji UniversityGwalior 474011India

In this paper,HoMg is studied in two different phases i.e.B1 and *** calculated lattice constants in B1 and B2 phases are 6.39°A and 3.78°A and corresponding energies are−25,648.49 Ry and−25,648.56 Ry,*** is more stable in B2 phase(pm-3m configuration with no.221).The analysis of the obtained band structure and density of states shows metallic character of *** information about the elastic properties is also presented in this *** calculated values of Cauchy pressure,g/B and poisson ratio are−10.72,0.58 and 0.26,respectively which indicates that HoMg have brittle *** for the optical spectra such as the components of dielectric function,refractive index and other parameters of the optical properties are performed in the energy range of 0-20 *** HoMg,the main peak of absorption spectra and energy loss function is located at 7.44 eV and 11.76 eV,*** parameters such as gruneisen parameter,Debye temperature,Specific heat *** been reported as a function of pressure and temperature.©2018 published by Elsevier *** behalf of Chongqing University.

关键词： Rare-earth magnesium alloy DFT Elastic properties Optical and thermal properties

Effect of various physical properties on the reflection coefficients of inhomogeneous waves at the stress-free surface of partially saturated soils induced by obliquely incident fast p-wave

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Journal of Ocean Engineering and Science 2022年第3期7卷 225-236页

作者： M.kumari M.S.Barak A.Singh M.Kumar Department of Mathematics M P College for WomenMandi Dabwali125104SirsaHaryanaIndia Department of Mathematics Indira Gandhi University MeerpurRewari122503HaryanaIndia Department of Mathematics Dr.B R Ambedkar Govt.CollegeDabwali125104SirsaHaryanaIndia

ghasemzadeh and Abounouri[1]developed a mathematical model of partially saturated soils that is solved using the potential method,which decomposes elastodynamics equations into two standard wave equations,a scalar wave equation for scalar potential and a vector wave equation for vector *** such a medium,four waves exist three longitudinal and one *** fluid phase tortuous path is taken into account in this *** inertial coupling between solid and fluid particles is ***,both open-pore and sealed-pore boundaries are explored to investigate the reflection phenomenon at the surface of partially saturated *** both boundaries,the reflection coefficients of inhomogeneous waves at a partially saturated soil surface are found as a non-singular set of linear *** waves(both reflected and incident)in partially saturated soils are pronounced as inhomogeneous due to viscosity in pore fluids(i.e.,distinct directions of attenuation and propagation).The energy shares of reflected waves are determined using an energy matrix.A numerical example is used to determine the reflection coefficients and the distribution of incident energy among the various reflected *** effect of different physical features on reflection coefficients and incident energy partitioning is illustrated *** conservation of incident energy at the surface of partially saturated soils is mathematically confirmed at all angles of incidence.

关键词： plane harmonic wave Inhomogeneous partially saturated soils Reflection coefficients Energy shares

Small molecule activators of the p53 response

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Journal of Molecular Cell Biology 2019年第3期11卷 245-254页

作者： Marcus J.g.w.Ladds Sonia Lain Department of Microbiology Tumor and Cell BiologyBiomedicumSolnavagen 9Karolinska Institutet17165StockholmSweden SciLifeLab Tomtebodavagen 23A171 65SoinaStockholmSweden

Drugging the p53 pathway has been a goal for both academics and pharmaceutical companies since the designation of p53 as the'guardian of the genome'.Through growing understanding of p53 biology,we can see multiple routes for activation of both wild-type p53 function and restoration of mutant p53?In this review,we focus on small molecules that activate wild-type p53 and that do so in a nongenotoxit *** particular,we will describe potential approaches to targeting proteins that alter p53 stability and function through posttranslational modification,affect p53's subcellular localization,or target RNA synthesis or the synthesis of *** plethora of pathways for exploitation of p53,as well as the wide-ranging response to p53 activation,makes it an attractive target for anti-cancer therapy.

关键词： cancer p53 small molecule cell biology cancer therapy

wave-induced flow of pore fluid in a cracked porous solid containing penny-shaped inclusions

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petroleum Science 2021年第5期18卷 1390-1408页

作者： Manjeet kumari Virender Manjeet Kumar Dept.of Mathematics M P College for WomenMandi Dabwali125104India Dept.of Mathematics Ramjas CollegeUniversity of DelhiDelhi110007India Dept.of Mathematics Dr.B R Ambedkar Govt.CollegeMandi Dabwali125104India

An aim of current study is to analyze the contribution of reflected longitudinal waves to wave-induced fluid flow(wIFF) in the cracked porous ***,we investigate the time harmonic plane waves in cracked porous solid by employing the mathematical model proposed by Zhang et al.(2019).The solution is obtained in form of the Christoffel *** solution of the Christoffel equations indicates that there exist four(three dilatational and one shear) *** waves are attenuated in nature due to their complex and frequency-dependent *** reflection coefficients are calculated at the sealed pore stress-free surface of cracked porous solid for the incidence of p1 and SV *** is found that three longitudinal waves contribute to wIFF and the contribution of these waves to the induced fluid in the cracked porous solid is analyzed using the reflection coefficients of these longitudinal *** analytically show that the fluid flow induced by these longitudinal waves is linked directly to their respective reflection ***,a specific numerical example is considered to discuss and to depict the impact of various parameters on the characteristics of propagation like phase velocity/attenuation,reflection coefficients and wIFF of longitudinal waves.

关键词： Cracked porous solid penny-shaped inclusions Longitudinal waves phase velocity Attenuation Reflection coefficients

A systematic review on the aboveground biomass and carbon stocks of Indian forest ecosystems

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Ecological processes 2018年第1期7卷 165-176页

作者： Onkar Salunkhe p.K.Khare Richa kumari M.L.Khan Laboratory of Ecology Department of BotanyDr.Hari Singh Gour UniversitySagarMadhya Pradesh 470003India

Background:Tropical forests play a crucial role as source and sink in global carbon *** and other anthropogenic activities have led to degradation of forest land,and ultimately,it results in loss of biodiversity and increases concentration of CO_(2) in ***,there is urgent need to estimate regional and national level carbon stock for making forest-based policies and strategies for mitigation of CO_(2).patchy and sporadic information is available on biomass and carbon stock of Indian *** paper presents a systematic review and comprehensive account of studies conducted in different forest types in ***:There are six major forest types found in India consisting of 15 groups and other subgroups with peculiar *** used by researchers for biomass/carbon stock estimation are destructive,nondestructive,tree inventories data,species-specific biomass estimation,and remote *** of estimates are based on nondestructive allometric equation *** showed positive correlation between tree species,diameter at breast height,and biomass/carbon ***-and medium-sized growing trees,invasive species,mixed forest,Agroforestry,and Agrosilviculture also play an important role in atmospheric carbon *** results of diverse forest carbon stock studies are broadly categorized in North,Central,and Southern *** review will be helpful for developing conservation policies and decision to increase carbon stock and also REDD+program for particular forest ***:The systematic literature review was carried out to gather and summarize information from different studies conducted on forest ecosystems and quantification methods used for biomass estimation and carbon stock in different forests types and states of *** general,great variability occurs in aboveground biomass and carbon stock on account of climatic and geographic *** obtain good and accurate

关键词： Tropical forests Aboveground biomass Carbon stock

Treating amyotrophic lateral sclerosis with allogeneic Schwann cell-derived exosomal vesicles: a case report

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Neural Regeneration Research 2025年第4期20卷 1207-1216页

作者： pascal J.goldschmidt-Clermont Aisha Khan george Jimsheleishvili patricia graham Adriana Brooks Risset Silvera Alexander J.p.goldschmidt Damien D.pearse w.Dalton Dietrich Allan D.Levi James D.guest Miller School of Medicine University of MiamiMiamiFLUSA Stem Cell Institute Miller School of MedicineUniversity of MiamiMiamiFLUSA The Miami project to Cure paralysis Miller School of MedicineUniversity of MiamiMiamiFLUSA Alzady International LLC MiamiFLUSA Neurological Surgery Miller School of MedicineUniversity of MiamiMiamiFLUSA

Schwann cells are essential for the maintenance and function of motor neurons,axonal networks,and the neuromuscular *** amyotrophic lateral sclerosis,where motor neuron function is progressively lost,Schwann cell function may also be ***,important signaling and potential trophic activities of Schwann cell-derived exosomal vesicles have been *** case report describes the treatment of a patient with advanced amyotrophic lateral sclerosis using serial intravenous infusions of allogeneic Schwann cell-derived exosomal vesicles,marking,to our knowledge,the first instance of such *** 81-year-old male patient presented with a 1.5-year history of rapidly progressive amyotrophic lateral *** initial diagnosis,the patient underwent a combination of generic riluzole,sodium phenylbutyrate for the treatment of amyotrophic lateral sclerosis,and *** patient volunteered to participate in an FDA-approved single-patient expanded access treatment and received weekly intravenous infusions of allogeneic Schwann cell-derived exosomal vesicles to potentially restore impaired Schwann cell and motor neuron *** confirmed that cultured Schwann cells obtained from the amyotrophic lateral sclerosis patient via sural nerve biopsy appeared impaired(senescent)and that exposure of the patient’s Schwann cells to allogeneic Schwann cell-derived exosomal vesicles,cultured expanded from a cadaver donor improved their growth capacity in *** a period of observation lasting 10 weeks,during which amyotrophic lateral sclerosis Functional Rating Scale-Revised and pulmonary function were regularly monitored,the patient received weekly consecutive infusions of 1.54×1012(×2),and then consecutive infusions of 7.5×1012(×6)allogeneic Schwann cell-derived exosomal vesicles diluted in 40 mL of Dulbecco’s phosphate-buffered *** of the infusions were associated with adverse events such as infusion reactions(allergic or otherwise)or

关键词： allogeneic amyotrophic lateral sclerosis exosomes infusion neuromuscular junction Schwann cell