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Effect of radiative loss mechanisms on FIR thermometric parameters of Nd^(3+)-doped lithium tellurite glasses

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Journal of Rare Earths 2024年第7期42卷 1250-1257,I0002页

作者： C.Y.Morassuti A.P.l silva l.A.o.Nunes s.M.lima l.H.C.Andrade optical and Photothermal spectroscopy Group(GEoF) Center for Studies in Natural Resources(CERNA)State University of Mato Grosso do Sul(UEMS)C.P.351DouradosMSBrazil Renato Archer Information Technology Center Dom Pedro I Highway(SP-65)Km 1436-Chácaras Campos dos AmaraisCampinasSPBrazil Institute of Physics of são Carlos University of São PauloSão CarlosSPBrazil

Nd^(3+)-doped tellurite glasses are promising materials for thermometers based on the fluorescence intensity ratio(FIR)***,at high Nd^(3+)concentrations,energy transfer(ET)processes such as optical reabsorption and cross-relaxation can affect the Nd^(3+)emission,which has been little explored in the ***,the present work investigated the use of Nd^(3+)-doped tellurite glass(samples doped with Nd^(3+)at 0.2 mol%,0.5 mol%,2.0 mol%,and 4.0 mol%)in fluorescence thermometers,in the temperature range from 299 to 371 *** results indicate a strong dependence of the FIR parameters on the Nd^(3+)concentration,due to changes in the emission band profiles caused by optical reabsorption of the Nd^(3+)emissions and cross-relaxation processes.A decrease of the relative sensitivity of the ratio^(4)F_(5/2)→^(4)I_(9/2)/^(4)F_(3/2)→^(4)I_(9/2)is observed for samples doped with higher amounts of Nd^(3+).The maximum relative sensitivity at 299 K is 3.00%/K,which is the highest value among the reported Nd^(3+)ions.

关键词： Nd^(3+)-doped tellurite glass Fluorescence intensity ratio optical thermometry Judd-ofelt Rare earths

Highly defective dark Tio_(2) Modified with Pt: Effects of Precursor Nature and Preparation Method on Photocatalytic Properties

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Transactions of Tianjin University 2024年第2期30卷 198-209页

作者： E.d.Fakhrutdinova o.A.Reutova T.A.Bugrova I.Yu.ovsyuk l.s.Kibis o.A.stonkus d.B.Vasilchenko o.V.Vodyankina V.A.svetlychnyi National Research Tomsk state University TomskRussia 634050 Novosibirsk state University NovosibirskRussia 630090 Boreskov Institute of Catalysis NovosibirskRussia 630090 Nikolaev Institute of Inorganic Chemistry NovosibirskRussia 630090

The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibited similar phase compositions, specific surface areas, and Pt contents. High-resolution transmission electron microscopy coupled with pulsed Co adsorption revealed increased dispersity when photoreduction and the hydroxonitrate complex (Me _(4) N) _(2) [Pt _(2) (oH) _(2) (No _(3) ) _(8) ] were used. The sample featured a high content of single-atom species and subnano-sized Pt clusters. The X-ray photoelectron spectroscopy results showed that the photoreduction method facilitated the appearance of a larger number of Pt ^(2+) states, which appeared owing to the strong metal-support interaction (sMsI) eff ect of the transfer of electron density from the electron-saturated defects on the Tio _(2) surface to Pt ^(4+) . In the hydrogen evolution reaction, samples with a significant fraction of the Pt ^(2+) ionic component, capable of generating short-lived Pt^(0) single-atom sites under irradiation due to the sMsI eff ect, exhibited the highest photocatalytic activity. The 0.5Pt(C)/Tio_(2) -Ph sample exhibited the highest hydrogen yield with a quantum efficiency of 0.53, retaining its activity even after 8 h of operation.

关键词： dark(black)Tio_(2) Pulsed laser ablation Platinum reduction method Precursor type Photocatalysis Hydrogen evolution reaction

sex differences in Alzheimer's disease:an urgent research venue to follow

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Neural Regeneration Research 2024年第12期19卷 2569-2570页

作者： Raquel Jiménez-Herrera Ana Contreras Juan d.Navarro-lópez lydia Jiménez-díaz Neurophysiology&Behavior lab University of Castilla-La ManchaSchool of Medicine of Ciudad RealCiudad RealSpain

due to increasing life expectancy,the amount of people with dementia worldwide is expected to experience a substantial rise,with estimates indicating a growth from 55 million in 2019 to a staggering 139 million by the... 详细信息

关键词： Alzheimer predominant estimates

Adsorption of yttrium(Y^(3+)) and concentration of rare earth elements from phosphogypsum using chitin and chitin aerogel

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Journal of Rare Earths 2024年第4期42卷 775-782页

作者： Glaydson s.dos Reis diana Pinto sabrina F.lütke Eder C.lima luis F.o.silva Irineu A.s.de Brum Guilherme l.dotto department of Forest Biomaterials and Technology Biomass Technology Centre Swedish University of Agricultural SciencesUmeaE13Swedn Universidad de la Costa Calle 58#55-66080002BarranquillaAtlanticoColombia Research Group on Adsorptive and Catalytic Process Engineering(ENGEPAC) Federal University of Santa MariaAv.Roraima100079705900Santa MariaRSBrazil Institute of Chemistry Federal University of Rio Grande do Sul90040060Porto AlegreBrazil

Chitin powder and chitin-aerogel were prepared from shrimp wastes and used to uptake Y^(3+)from aqueous solutions and concentrate this rare earth element from phosphogypsum(PG).Chitin aerogel displays a specific surface area of 945 m^(2)/g,while chitin powder is 3.6 m^(2)/g,which largely influences its adsorption *** the adsorption in synthetic solutions,the effect of pH on Y^(3+)removal is strong for chitin powder *** contrast,no big pH influence was detected for chitin *** interactions and chelation can highlight the proposed mechanism of Y^(3+)on chitin adsorbents for the powder and ***,in addition to these interactions,pore filling/pore diffusion is the main mechanism of Y^(3+)removal in the chitin *** aerogel is efficient in concentrating 8 times the Y^(3+)from PG,a very complex *** complex chitin aerogel-Y^(3+)can be a secondary source of rare earth elements for other applications.

关键词： Rare earths sustainable material Chitin powder Chitin porous aerogel Yttrium adsorption and recovery

localized-states quantum confinement induced by roughness in CdMnTe/CdTe heterostructures grown on si(111) substrates

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Journal of semiconductors 2024年第9期45卷 28-35页

作者： leonarde N.Rodrigues Wesley F.Inoch Marcos l.F.Gomes odilon d.d.Couto Jr. Bráulio s.Archanjo sukarno o.Ferreira Physics department Federal University of ViçosaViçosa36570-900Minas GeraisBrazil Instituto de Física Gleb Wataghin Universidade Estadual de CampinasCampinas13083-859São PauloBrazil National Institute of Metrology Quality and Technology(Inmetro) Materials Metrology Division(DIMAT)Xerém2525-020Rio de JaneiroBrazil

This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro-and micro-photoluminescence. low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have different confinement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 eV)is associated to defects and bound exciton states, while the main emission at 1.61 eV has a weak 2d character and the higher energy one at 1.71 eV has a well-defined (zero-dimensional, 0d) 0d nature. Micro-photoluminescence measurements show the existence of sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of Mn in the heterostructure. This result opens the possibility of producing photon sources with the typical spin control of the diluted magnetic semiconductors using the low-cost silicon technology.

关键词： CdMnTe/CdTe/CdMnTe heterostructure CdTe/CdMnTe quantum emitters quantum dot-like emission silicon(111)substrate

Perturbations in the earthworm metabolite profile during a two-week exposure to metformin

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Emerging Contaminants 2024年第3期10卷 221-229页

作者： J.d.Gillis G.W.Price s.o.Prasher department of Bioresource Engineering McGill UniversityFaculty of Agricultural and Environmental SciencesMacdonald-Stewart Building MS1-02721111 Lakeshore RoadSainte-Anne-de-BellevueQuebecH9X 3V9Canada department of Engineering Dalhousie UniversityFaculty of Agriculture39 Cox RoadPO Box 550TruroNova ScotiaB2N 5E3Canada

Metformin is among the most prescribed pharmaceuticals in many countries,and as a result has shown up in biosolids derived from municipal wastewater treatment that are destined for land *** humans taking metformin,the effects include reduced glucose uptake in the intestine,a reduction in gluconeogenesis,increased oxidation of fatty acids,and reduced fatty acid *** effects of metformin on soil-dwelling organisms are not well *** study tested the effects of metformin exposure(0,10,40,160,640μg g^(-1))on the earthworm(***)at four time points(6 h,2 d,7 d,and 14 d)using GC-Ms to reveal sub-lethal effects and elucidate potential modes of action for *** were no mortalities observed,and earthworms exposed to the highest concentrations(160 and 640μg g^(-1))gained weight relative to the control on days 7 and *** reductions on day 7 were observed for glucose and malic acid(consistent with a reduction in gluconeogenesis),and for palmitic and margaric acid(consistent with increased oxidation and reduced synthesis of fatty acids).lactic acid ranked first and second among canonicals 1 and 2 respectively and led to significant differences in discriminant scores across concentration and *** levels increased to equal or greater than the control on day 14,likely caused by reduced exposure as metformin is reported to be readily transformed by microorganisms under aerobic *** observations were consistent with the known effects of metformin in humans,and suggests that a similar mode of action exists in earthworms.

关键词： Metabolites Toxicity Earthworms Metformin GC-Ms

Rotating effects on the photoionization cross-section of a 2d quantum ring

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Communications in Theoretical Physics 2024年第10期76卷 153-159页

作者： Carlos Magno o Pereira Frankbelson dos s Azevedo luís Fernando C Pereira Edilberto o silva departamento de Física Universidade Federal do Maranh?o

In this article, we investigate the nonrelativistic quantum motion of a charged particle within a rotating frame, taking into account the Aharonov–Bohm(AB) effect and a uniform magnetic field. our analysis entails the derivation of the equation of motion and the corresponding radial equation to describe the system. solving the resulting radial equation enables us to determine the eigenvalues and eigenfunctions, providing a clear expression for the energy levels. Furthermore,our numerical analysis highlights the substantial influence of rotation on both energy levels and optical properties. specifically, we evaluate the photoionization cross-section with and without the effects of rotation. To elucidate the impact of rotation on the photoionization process of the system, we present graphics that offer an appealing visualization of the intrinsic nature of the physics involved.

关键词： Aharonov-Bohm effect photoionization cross-section quantum ring rotating effect

Vanillylacetone attenuates cadmium chloride-induced hippocampal damage and memory loss through upregulation of nuclear factor erythroid 2-related factor 2 gene and protein expression

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Neural Regeneration Research 2024年第12期19卷 2750-2759页

作者： Fahaid H.A.l-Hashem salah o.Bashir Amal F.dawood Moutasem s.Aboonq Ismaeel Bin-Jaliah Abdulaiziz M.Al-Garni Mohamed d.Morsy department of Physiology College of MedicineKing Khalid UniversityAbhaSaudi Arabia department of Basic Medical sciences College of MedicinePrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh 11671Saudi Arabia department of Physiology College of MedicineTaibah UniversityAl-Madinah Al-MunawwarahSaudi Arabia department of Medicine College of MedicineKing Khalid UniversityAbhaSaudi Arabia

Memory loss and dementia are major public health concerns with a substantial economic *** stress has been shown to play a crucial role in the pathophysiology of hippocampal damage-induced memory *** investigate whether the antioxidant and anti-inflammatory compound vanillyla cetone(zingerone) can protect against hippocampal damage and memory loss induced by cadmium chloride(CdCl_(2)) administration in rats,we explo red the potential involvement of the nuclear factor erythroid 2-related factor 2(Nrf2) signaling pathway,which is known to modulate oxidative stress and *** healt hy male Wistar rats were divided into five groups:vehicle-treated(control),vanillylacetone,CdCl_(2),vanillylacetone+ CdCl_(2),vanillylacetone+ CdCl_(2)+ brusatol(a selective pharmacological N rf2inhibitor) *** effectively attenuated CdCl_(2)-induced damage in the dental gyrus of the hippocampus and improved the memory function assessed by the Morris Water Maze ***,vanillylacetone markedly decreased the hippocampal tissue levels of inflammatory biomarkers(interleukin-6,tumor necrosis factor-α,intracellular cell adhesive molecules) and apoptosis biomarkers(Bax and cleaved caspase-3).The control and CdCl_(2)-treated groups treated with va nillylacetone showed reduced generation of reactive oxygen species,decreased malondialdehyde levels,and increased superoxide dismutase and glutathione activities,along with significant elevation of nuclear Nrf2 mRNA and protein expression in hippocampal *** the protective effects of vanillylacetone we re substantially blocked by the co-administration of brusatol(a selective N rf2 inhibitor).Va nillylacetone mitigated hippocampal damage and memory loss induced by CdCl_(2),at least in part, by activating the nuclear transcription factor ***,vanillylacetone exerted its potent antioxidant and antiinflammatory actions.

关键词： hippocampus neuroprotective Nrf2 gene oxidative stress vanillylacetone

High-precision inverse potentials for neutron-proton scattering using piece-wise smooth Morse functions

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Chinese Physics C 2024年第10期48卷 201-213页

作者： Ayushi Awasthi Arushi sharma Ishwar Kant o.s.K.s.sastri department of Physics and Astronomical science Central University of Himachal PradeshDharmshala176215India

The aim of this study is to construct inverse potentials for various ℓ-channels of neutron-proton scattering using a piece-wise smooth Morse function as a *** phase equations for single-channel states and the coupled equations of multi-channel scattering are solved numerically using the 5^(th) order Runge-kutta *** employ a piece-wise smooth reference potential comprising three Morse functions as the initial *** a machine learning-based genetic algorithm,we optimize the model parameters to minimize the mean-squared error between simulated and anticipated phase *** approach yields inverse potentials for both single and multichannel scattering,achieving convergence to a mean-squared error≤10^(-3).The resulting scattering lengths"a_(0)"and effective ranges"r"for ^(3)s_(1) and ^(1)s_(0) states,expressed as[a_(0),r],are found to be[5.445(5.424),1.770(1.760)]and[–23.741(–23.749),2.63(2.81)],respectively;these values are in excellent agreement with experimental ***,the calculated total scattering cross-sections are highly consistent with their experimental counterparts,having a percentage error of less than 1%.This computational approach can be easily extended to obtain interaction potentials for charged particle scattering.

关键词： inverse potentials neutron-proton scattering piece-wise smooth Morse function phase function method reference potential approach genetic algorithm