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Environmental factors Affecting Chromium-Manganese oxidation-Reduction Reactions in Soil

Pedosphere 2011年第1期21卷 84-89页

作者： D.o.P.TREBIEN L.BoRToLoN M.J.TEDESCo C.A.BISSANI f.a.o.camargo Department of Agricultural Engineering Federal University of Santa Catarina Department of Soil Science Federal University of Rio Grande do Sul

Disposal of chromium （Cr） hexavalent form, Cr（Ⅵ）, in soils as additions in organic fertilizers, liming materials or plant nutrient sources can be dangerous since Cr（Ⅵ） can be highly toxic to plants, animals, and humans. In order to explore soil conditions that lead to Cr（Ⅵ） generation, this study were performed using a Paleudult （Dystic Nitosol） from a region that has a high concentration of tannery operations in the Rio Crande do Sul State, southern Brazil. Three laboratory incubation experiments were carried out to examine the influences of soil moisture content and concentration of cobalt and organic matter additions on soil Cr（Ⅵ） formation and release and manganese （Mn） oxide reduction with a salt of chromium chloride （CrCl3） and tannery sludge as inorganic and organic sources of Cr（Ⅲ）, respectively. The amount of Cr（Ⅲ） oxidation depended on the concentration of easily reducible Mn oxides and the oxidation was more intense at the soil water contents in which Mn（Ⅲ/Ⅳ） oxides were more stable. Soluble organic compounds in soil decreased Cr（Ⅵ） formation due to Cr（Ⅲ） complexation. This mechanism also resulted in the decrease in the oxidation of Cr（Ⅲ） due to the tannery sludge additions. Chromium（Ⅲ） oxidation to Cr（Ⅵ） at the solid/solution interface involved the following mechanisms： the formation of a precursor complex on manganese （Mn） oxide surfaces, followed by electron transfer from Cr（Ⅲ） to Mn（Ⅲ or Ⅳ）, the formation of a successor complex with Mn（Ⅱ） and Cr（Ⅵ）, and the breakdown of the successor complex and release of Mn（Ⅱ） and Cr（Ⅵ） into the soil solution.

关键词： cobalt Cr(VI) oxidation Mn oxides soil moisture tannery sludge

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Morphological traits explain the individual position within resource-consumer networks of a Neotropical marsupial

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Current Zoology 2024年第4期70卷 453-464页

作者： Nicholas f.de camargo Hernani f.M.de oliveira Juliana f.Ribeiro Amabilio J.A.de camargo Emerson M.Vieira Laboratorio de Ecologia de Vertebrados Departamento de EcologiaInstituto de Ciencias BiologicasUniversidade de BrasiliaCP 04457BrasiliaDF70910-900Brazil Departamento de Zoologia Setor de Ciencias BiologicasUniversidade Federal do ParanaAvenida Coronel Francisco Heraclito dos Santos100CuritibaPR81531980Brazil Embrapa Cerrados Rodovia BR020km 18CP 08223PlanaltinaDE73310-970Brazil

Knowledge regarding the influence of individual traits on interaction patterns in nature can help understand the topological role of individuals within a network of intrapopulation *** tested hypotheses on the relationships between individuals'positions within networks(specialization and centrality)of 4 populations of the mouse opossum Gracilinanus agilis and their traits(i.e.,body length,body condition,tail length relative to body length,sex,reproductive condition,and botfly parasitism)and also seasonal effects in the Brazilian *** with lower body length,better body condition,and relatively shorter tail were more specialized(i.e.,less connected within the network).Individuals were also more specialized and less connected during the warm-wet *** relationship between individuals'position in the network and body traits,however,was independent of *** propose that specialization may arise not only as a result of preferred feed-ing strategies by more capable individuals(i.e.,those with better body condition and potentially prone to defend and access high-quality food resources)but alsobecause of morphological ***/younger individuals(consequently with less experience in foraging)and short-tailed individuals(less skilled to explore the vertical strata of the vegetation)would feed only on a subset of the available food resources and consequently become more ***,individuals are more specialized during the warm-wet season because of high competition(population-dense period)and higher ecological opportunities(resource-rich period).Therefore,our study reveals the relevance of individual traits inshaping interactionpatternsandspecialization inpopulations.

关键词： bodytraits centrality Cerrado Gracilinanus agilis seasonality specialization.

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Glyphosate as a direct or indirect activator of pro-inflammatory signaling and cognitive impairment

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Neural Regeneration Research 2024年第10期19卷 2212-2218页

作者： Yukitoshi Izumi Kazuko A.o'Dell Charles f.Zorumski Department of Psychiatry Washington University School of MedicineSt.LouisMOUSA Taylor family Institute for Innovative Psychiatric Research Washington University School of MedicineSt.LouisMOUSA

Glyphosate-based herbicides are widely used around the world, making it likely that most humans have significant exposure. Because of habitual exposure, there are concerns about toxicity including neurotoxicity that could result in neurological, psychiatric, or cognitive impairment. We recently found that a single injection of glyphosate inhibits long-term potentiation, a cellular model of learning and memory, in rat hippocampal slices dissected 1 day after injection, indicating that glyphosate-based herbicides can alter cognitive function. Glyphosate-based herbicides could adversely affect cognitive function either indirectly and/or directly. Indirectly, glyphosate could affect gut microbiota, and if dysbiosis results in endotoxemia(leaky gut), infiltrated bacterial by-products such as lipopolysaccharides could activate pro-inflammatory cascades. Glyphosate can also directly trigger pro-inflammatory cascades. Indeed, we observed that acute glyphosate exposure inhibits long-term potentiation in rat hippocampal slices. Interestingly, direct inhibition of long-term potentiation by glyphosate appears to be similar to that of lipopolysaccharides. There are several possible measures to control dysbiosis and neuroinflammation caused by glyphosate. Dietary intake of polyphenols, such as quercetin, which overcome the inhibitory effect of glyphosate on long-term potentiation, could be one effective strategy. The aim of this narrative review is to discuss possible mechanisms underlying neurotoxicity following glyphosate exposure as a means to identify potential treatments.

关键词： cognitive impairment glyphosate microglia neuroinflammation roundup toll-like receptor 4 zinc chelation

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on the analytical solution of transient friction in channel flows

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1447-1466页

作者： f.J.GARCíA-GARCíA P.fARINAS-ALVARINo Department of Naval&Industrial Engineering Polytechnic School of EngineeringUniversity of A CorunaCampus Industrial de FerrolFerrol 15403A CorunaSpain Integraciones Técnicas de Seguridad S.A.Pol.Ind.Espiritu SantoC/Nobel15Cambre 15650A CorunaSpain

The transient friction in channel mean flows is the sum of two contributions,i.e.,the underlying laminar flow(ULf)and the purely turbulent component(PTC),and the contributions are analyzed separately by theoretical *** is found that,the transient friction may be higher or remarkably lower than that in equal-Reynolds number steady-state *** universal time constant for plane-parallel laminar flows is reported,and the role of the time constant in a turbulent mean flow is *** is shown that the time constant is related to the turbulence's frozen ***,a study of the logarithmic layer during the transient flow is accomplished,which shows that the logarithmic layer is destroyed.

关键词： transient friction transient flow unsteady channel flow

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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

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Phase composition,conductivity,and sensor properties of cerium-doped indium oxide

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Nano Materials Science 2024年第2期6卷 193-200页

作者： M.I.Ikim G.N.Gerasimov V.f.Gromov o.J.Ilegbusi L.I.Trakhtenberg N.N.Semenov federal Research Center for Chemical Physics of RAS MoscowRussia University of Central florida OrlandoFLUSA Moscow Institute of Physics and Technology(State University) DolgoprudnyMoscow RegionRussia Lomonosov Moscow State University MoscowRussia

The hydrothermal synthesis of In_(2)o_(3)and Ceo_(2)–In_(2)o_(3)is investigated as well as the properties of sensor layers based on these *** the synthesis of In_(2)o_(3),intermediate products In(oH)_(3)and InooH are formed,which are the precursors of stable cubic(c-In_(2)o_(3))and metastable rhombohedral(rh-In_(2)o_(3))phases,respectively.A transition from c-In_(2)o_(3)to rh-In_(2)o_(3)is observed with the addition of Ceo_(2).The introduction of cerium into rh-In_(2)o_(3)results in a decrease in the sensor response to hydrogen,while it increases in composites based on c-In_(2)o_(3).The data on the sensor activity of the composites correlate with XPS results in which Ceo_(2)causes a decrease in the concentrations of chemisorbed oxygen and oxygen vacancies in rh-In_(2)o_(3).The reverse situation is observed in composites based on c-In_(2)o_(3).Compared to In_(2)o_(3)and Ceo_(2)–In_(2)o_(3)obtained by other methods,the synthesized composites demonstrate maximum response to H_(2)at low temperatures by 70–100℃,and have short response time(0.2–0.5 s),short recovery time(6–7 s),and long-term stability.A model is proposed for the dependence of sensitivity on the direction of electron transfer between In_(2)o_(3)and Ceo_(2).

关键词： Cerium oxide Indium oxide Nanocomposite Hydrothermal method Cubic phase Rhombohedral phase Sensor response Conductivity Hydrogen Response/recovery time

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Stability analysis of a time-delayed Van der Pol–Helmholtz–Duffing oscillator in fractal space with a non-perturbative approach

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Communications in Theoretical Physics 2024年第4期76卷 22-31页

作者： Yusry o El-Dib Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

The time-delayed fractal Van der Pol–Helmholtz–Duffing(VPHD)oscillator is the subject of this paper,which explores its mechanisms and highlights its stability *** time-delayed technologies are currently garnering significant attention,the focus of this research remains crucially relevant.A non-perturbative approach is employed to refine and set the stage for the system under *** innovative methodologies introduced yield an equivalent linear differential equation,mirroring the inherent nonlinearities of the ***,the incorporation of quadratic nonlinearity into the frequency formula represents a cutting-edge *** analytical solution's validity is corroborated using a numerical *** conditions are ascertained through the residual Galerkin ***,it is observed that the delay parameter,in the context of the fractal system,reverses its stabilizing influence,impacting both the amplitude of delayed velocity and the *** analytical solution's precision is underscored by its close alignment with numerical ***,the study reveals that fractal characteristics emulate damping *** its applicability across diverse nonlinear dynamical systems,this non-perturbative approach emerges as a promising avenue for future research.

关键词： Van der Pol-Helmholtz-Duffing oscillator fractal space time-delay non-perturbative approach stability analysis El-Dib's frequency formula

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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

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Possible Uses for Silymarin in Human Health: Systematic Review

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American Journal of Plant Sciences 2024年第2期15卷 95-109页

作者： Gisele Mara Silva Gonçalves Andre Bernardo de camargo Eisingher Postgraduate Program in Health Sciences Pontifical Catholic University of Campinas (PUC-Campinas) Campinas Brazil

Silymarin, from the fruit of Silybum marianum, is known for its hepatoprotective action. The aim of this study was to review the mechanisms of action of the silymarin phytocomplex to expand the possibilities for its application in human health. The search for published articles was carried out on the CAPES Journals Portal platform, which covers worldwide scientific databases. Publications from 2010 to 2022 were included. of the 311 articles retrieved, 21 were included. The articles discuss the diversity of silymarin’s applications and the possibility of optimizing its bioavailability using drug delivery systems. Silymarin shows promise in numerous diseases, such as liver, kidney, cardiovascular, respiratory and others. Its antiviral action has been demonstrated in studies and silymarin has the potential to be used as a complementary therapy in the treatment of many diseases, with the expectation that, in the future, it will be used in therapeutic protocols for exclusive use.

关键词： Silymarin flavonoids Phytotherapeutic Drugs

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Transformer for the Design of Automatic Control Systems with Prefilters

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World Journal of Engineering and Technology 2024年第3期12卷 575-586页

作者： Isaac Hughes John f. o’Brien Department of Electrical Engineering and Computer Science University of Wyoming Laramie USA

A machine learning model, using the transformer architecture, is used to design a feedback compensator and prefilter for various simulated plants. The output of the transformer is a sequence of compensator and prefilter parameters. The compensator and prefilter are linear models, preserving the ability to analyze the system with linear control theory. The input to the network is a window of recent reference and output samples. The goal of the transformer is to minimize tracking error at each time step. The plants under consideration range from simple to challenging. The more difficult plants contain closely spaced, lightly damped, complex conjugate pairs of poles and zeros. Results are compared to PID controllers tuned for a similar crossover frequency and optimal phase margin. for simple plants, the transformer converges to solutions which overly rely on the prefilter, neglecting the maximization of negative feedback. for more complex plants, the transformer designs a compensator and prefilter with more desirable qualities. In all cases, the transformer can start with random model parameters and modify them to minimize tracking error on the step reference.

关键词： feedback Machine Learning Compensator Design

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