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提高难处理矿石的银回收率

国外金属矿选矿 1990年第11期27卷 29-32页

作者： c.nú ez 张立诚

难处理矿石银的回收率一般为30—50%。西班牙-韦尔瓦省的 Rio Tinto 及 Tharsis 的铁帽矿石和世界上的其他一些厂矿都是如此。本文介绍一种新的工艺,在碱性介质中用硫化钠处理矿石,用空气氧化过剩的硫化物,然后进行常规氰化,就可能使银... 详细信息

难处理矿石银的回收率一般为30—50%。西班牙-韦尔瓦省的 Rio Tinto 及 Tharsis 的铁帽矿石和世界上的其他一些厂矿都是如此。本文介绍一种新的工艺,在碱性介质中用硫化钠处理矿石,用空气氧化过剩的硫化物,然后进行常规氰化,就可能使银的回收率提高到76—80%。在这些物料中,大都分的银以银铁矾的形式存在,对生成不溶硫化银的硫化作用很敏感。这种硫化物可与氰化物反应。该工艺是在 Rio Tinto 铁帽矿石小型试验的基础上研究出来的。所得数据表明,在石灰碱性介质中得到的银回收率为60—66%。而在 naOH(至少1摩尔)碱性介质中,银回收率可升至71—76%。

关键词：银回收率矿石难处理氰化

Role of lipids in the control of autophagy and primary cilium signaling in neurons

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neural Regeneration Research 2024年第2期19卷 264-271页

作者： María Paz Hernández-cáceres Daniela Pinto-nuñez Patricia Rivera Paulina Burgos Francisco Díaz-castro Alfredo criollo Maria Jose Yañez Eugenia Morselli Instituto de Investigación en ciencias Odontológicas(IcOD) Facultad de OdontologíaUniversidad de ChileSantiagoChile Department of Basic Sciences Faculty of Medicine and ScienceUniversidad San SebastiánSantiagoChile Physiology Department Faculty of Biological SciencesPontificia Universidad Católica de ChileSantiagoChile Advanced center for chronic Diseases(AccDiS) Facultad de Ciencias Químicas y Farmacéuticas&Facultad de MedicinaUniversidad de ChileSantiagoChile Autophagy Research center SantiagoChile

The brain is,after the adipose tissue,the organ with the greatest amount of lipids and diversity in their composition in the human body.In neurons,lipids are involved in signaling pathways controlling autophagy,a lysosome-dependent catabolic process essential for the maintenance of neuronal homeostasis and the function of the primary cilium,a cellular antenna that acts as a communication hub that transfers extracellular signals into intracellular responses required for neurogenesis and brain development.A crosstalk between primary cilia and autophagy has been established;however,its role in the control of neuronal activity and homeostasis is barely known.In this review,we briefly discuss the current knowledge regarding the role of autophagy and the primary cilium in neurons.Then we review the recent literature about specific lipid subclasses in the regulation of autophagy,in the control of primary cilium structure and its dependent cellular signaling in physiological and pathological conditions,specifically focusing on neurons,an area of research that could have major implications in neurodevelopment,energy homeostasis,and neurodegeneration.

关键词： autophagic flux cholesterol fatty acids GPcR lysosomal storage diseases neurons nPc1 phosphoinositides primary cilium

Blockade of Rho-associated kinase prevents inhibition of axon regeneration of peripheral nerves induced by anti-ganglioside antibodies

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neural Regeneration Research 2024年第4期19卷 895-899页

作者： Andrés Berardo cristian R.Bacaglio Bárbara B.Báez Rubén Sambuelli Kazim A.Sheikh Pablo H.H.Lopez Laboratorio de neurobiología Instituto de Investigación Médica Mercedes y Martin Ferreyra(INIMEC)-Consejo Nacional de Investigaciones Cientificas y Técnicas(CONICET)Universidad Nacional de Córdoba Departamento de Química Biológica-centro de Investigaciones en Química Biológica de córdoba(cIQUIBIc)-consejo nacional de Investigaciones cientificas y Técnicas(cOnIcET) Facultad de Cs.QuímicasUniversidad Nacional de Córdoba Servicio de Anatomía Patológica Clínica Universitaria Reina FabiolaUniversidad Católica de Córdoba Department of neurology University of Texas Medical School at Houston

Anti-ganglioside antibodies are associated with delayed/poor clinical recovery in Guillain-Barrèsyndrome,mostly related to halted axon regeneration.cross-linking of cell surface gangliosides by anti-ganglioside antibodies triggers inhibition of nerve repair in in vitro and in vivo paradigms of axon regeneration.These effects involve the activation of the small GTPase Rho A/ROcK signaling pathways,which negatively modulate growth cone cytoskeleton,similarly to well stablished inhibitors of axon regeneration described so far.The aim of this work was to perform a proof of concept study to demonstrate the effectiveness of Y-27632,a selective pharmacological inhibitor of ROcK,in a mouse model of axon regeneration of peripheral nerves,where the passive immunization with a monoclonal antibody targeting gangliosides GD1a and GT1b was previously reported to exert a potent inhibitory effect on regeneration of both myelinated and unmyelinated fibers.Our results demonstrate a differential sensitivity of myelinated and unmyelinated axons to the pro-regenerative effect of Y-27632.Treatment with a total dosage of 9 mg/kg of Y-27632 resulted in a complete prevention of anti-GD1a/GT1b monoclonal antibody-mediated inhibition of axon regeneration of unmyelinated fibers to skin and the functional recovery of mechanical cutaneous sensitivity.In contrast,the same dose showed toxic effects on the regeneration of myelinated fibers.Interestingly,scale down of the dosage of Y-27632 to 5 mg/kg resulted in a significant although not complete recovery of regenerated myelinated axons exposed to anti-GD1a/GT1b monoclonal antibody in the absence of toxicity in animals exposed to only Y-27632.Overall,these findings confirm the in vivo participation of Rho A/ROcK signaling pathways in the molecular mechanisms associated with the inhibition of axon regeneration induced by anti-GD1a/GT1b monoclonal antibody.Our findings open the possibility of therapeutic pharmacological intervention targeting Rho A/Rock pathway in immune neuropathies associated wi

关键词： anti-ganglioside antibodies anti-glycan antibodies axon regeneration ganglioside Guillain-Barrésyndrome nerve repair ROcK Y-27632

Solar-assisted photocatalytic water splitting using defective UiO-66 solids from modulated synthesis

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nano Research 2024年第5期17卷 4134-4150页

作者： celia M.Rueda-navarro María cabrero-Antonino Paula Escamilla Valentín Díez-cabanes Dong Fan Pedro Atienzar Belén Ferrer Ignacio Vayá Guillaume Maurin Herme G.Baldoví Sergio navalón Departamento de Química Universitat Politècnica de ValènciaCamino de Vera s/nValencia 46022Spain Instituto de ciencia Molecular(IcMOL) Universitat de ValènciaPaterna 46980Spain IcGM Univ.MontpellierCNRSENSCMMontpellier34095France Instituto de Tecnología Química(UPV-cSIc) Universitat Politècnica de ValènciaAvenida de los Naranjos s/nValencia 46022Spain

Metal-organic frameworks(MOFs)are attracting increasing interests as photocatalysts for solar-driven hydrogen production from water.This paper reports on a comparative study of using either acetic acid(AA)or trifluoroacetic acid(TFA)as the representative UiO-66 organic modulators for synthesizing visible light responsive UiO-66(Zr)-X(X:nH_(2) or nO_(2))photocatalysts for water splitting.The results show that photocatalytic hydrogen generation from a water/methanol mixture can be improved by varying the nature and amount of the modulator employed to prepare the different UiO-66(Zr)-X(X:nH_(2) or nO_(2))solid derivatives.UiO-66(Zr)-nH_(2) was the most active photocatalyst,followed by UiO-66(Zr)-nO_(2),both prepared with 12 equivalents of AA with respect to the organic ligand.This UiO-66(Zr)-nH_(2) solid was more active than the parent MOF in photocatalytic overall water splitting(OWS)(H_(2) and O_(2) production of 450 and 160μmol·g^(-1),respectively,in 5 h;apparent quantum yield(AQY)at 400 nm of 0.06%)in the absence of methanol and compares favourably with analogous reports.Information on the photocatalytic activity of the most active solids of both series was obtained by means of a series of techniques,including ultraviolet-visible(UV-vis)diffuse reflectance,X-ray photoelectron spectroscopy(XPS),laser flash photolysis(LFP),electron spin resonance(ESR),photoluminescence and photoelectrochemical measurements together with density functional theory(DFT)calculations.The results showed that organic acid modulators can be used to enhance the photocatalytic activity of missing linker UiO-66 defective materials in solar-powered water splitting.

关键词： heterogeneous photocatalysis metal-organic frameworks(MOFs) UiO-66 materials carboxylic acid modulators water splitting solar light

Early Phases of Star Formation: Testing chemical Tools

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Research in Astronomy and Astrophysics 2024年第1期24卷 96-118页

作者： n.c.Martinez S.Paron cOnIcET-Universidad de Buenos Aires.Instituto de Astronomía y Física del Espacio Ciudad Universitaria(C1428EGA)Ciudad Autónoma de Buenos AiresArgentina

Star-forming processes strongly influence the ISM chemistry.nowadays,many high-quality databases are available at millimeter wavelengths.Using them,it is possible to carry out studies that review and deepen previous results.If these studies involve large samples of sources,it is preferred to use direct tools to study the molecular gas.With the aim of testing these tools such as the use of the Hcn/Hnc ratio as a thermometer,and the use of H^(13)cO^(+),Hc_(3)n,n_(2)H^(+) and c_(2)H as "chemical clocks," we present a molecular line study toward 55 sources representing massive young stellar objects at different evolutionary stages:infrared dark clouds(IRDcs),highmass protostellar objects(HMPOs),hot molecular cores(HMcs) and ultracompact H II regions.We found that the use of the Hcn/Hnc ratio as a universal thermometer in the ISM should be taken with care because the Hcn optical depth is a big issue that can affect the method.Hence,this tool should be utilized only after a careful analysis of the Hcn spectrum,checking that no line,neither the main nor the hyperfine ones,presents absorption features.We point out that the analysis of the emission of H^(13)cO^(+),Hc_(3)n,n_(2)H^(+) and c_(2)H could be useful to trace and distinguish regions among IRDcs,HMPOs and HMcs.The molecular line widths of these four species increase from the IRDc to the HMc stage,which can be a consequence of the gas dynamics related to the starforming processes taking place in the molecular clumps.Our results not only contribute with more statistics,acting as a probe of such chemical tools,useful to obtain information in large samples of sources,but also complement previous works through the analysis of other types of sources.

关键词： stars:formation ISM:molecules ISM:clouds

Photosynthetic Gas Exchange and nitrogen Assimilation in Green Bean Plants Supplied with Two Sources of Silicon

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Phyton-International Journal of Experimental Botany 2024年第5期93卷 963-980页

作者： Julio c.Anchondo-Páez Esteban Sánchez carlos A.Ramírez-Estrada Alondra Salcido-Martínez Erick H.Ochoa-chaparro Department of Plant Physiology Centro de Investigación en Alimentación y DesarrolloCiudad Delicias33089México

Beans contain a wide range of vitamins,proteins,calcium,and zinc which make them an important food source for many countries.To meet the demand for bean production worldwide,large amounts of fertilizers and pesticides are used.However,the cost of production and environmental impact increases.To produce food sustainably,the use of beneficial nutrients such as silicon as a biostimulant has been proposed.However,information about the effect of different sources of silicon on the metabolism of bean plants is scarce.Bean plants cv.Strike were grown in pots for 60 days and the effect of foliar application of silicon nanoparticles and the silicon-based biostimulant codasilat 4 concentrations(0,1,2,and 4 mM)on total biomass,yield,photosynthetic pigment concentration,photosynthetic activity,stomatal conductance,transpiration rate,chlorophyll fluorescence,and nitrogen assimilation were evaluated.The results obtained showed that the supply of silicon at a dose of 1 mM functioned as a biostimulant,favoring gas exchange and nitrogen assimilation within the plant,which stimulated growth and yield.The results of this research work allowed a better comprehension of the effects of silicon application through silicon nanoparticles and the biostimulant codasilon the physiology of green bean plants.

关键词： nanoparticles silicon Phaseolus vulgaris L.

Airway management of a patient with linear immunoglobulin A bullous dermatosis:A case report

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World Journal of clinical cases 2024年第13期12卷 2263-2268页

作者： Olga c nin Robert Hutnik neil n chheda David Hutchinson Department of Anesthesiology University of Florida College of MedicineGainesvilleFL 32610United States Department of Otolaryngology University of Florida College of MedicineGainesvilleFL 32610United States

BAcKGROUnD There is limited literature on managing the airway of patients with linear immunoglobulin A(IgA)bullous dermatosis,a rare mucocutaneous disorder that leads to the development of friable bullae.careful clinical decision making is necessary when there is a risk of bleeding into the airway,and a multidisciplinary team approach may lead to decreased patient morbidity during these high-risk scenarios,especially when confronted with an unusual cause for bleeding.cASE SUMMARY A 45-year-old African American female presented to our ambulatory surgical center for right corneal transplantation due to corneal perforation after blunt trauma in the setting of cicatricial conjunctivitis and diffuse corneal neovascularization from linear IgA bullous dermatosis.The diagnosis of IgA dermatosis was recent,and the patient had been lost to follow-up.The severity of the disease and extent of airway involvement was unknown at the time of the surgery.Significant airway bleeding was noticed upon intubation and the otorhinolaryngology team had to be called to the operating room.The patient required transfer to the intensive care unit where a multidisciplinary team was involved in her case.The patient was extubated on postoperative day 4.cOncLUSIOn A multidisciplinary approach to treating this disease is the best course of action before a surgical procedure.In our case,key communication between the surgery,anesthesia,and dermatology teams led to the quick and safe treatment of our patient’s disease.Ambulatory surgery should not be considered for these cases unless they are in full remission and there is no mucous membrane involvement.

关键词： Airway management Bleeding risk Linear immunoglobulin A bullous dermatosis Multidisciplinary approach Outpatient procedure case report

Empirical model for fusion cross sections of ca-induced reactions

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chinese Physics c 2024年第3期48卷 126-132页

作者： Reddi Rani.L n.Sowmya K.n Sridhar H c.Manjunatha M.M.Armstrong Arasu Department of Physics St.Joseph's College(Autonomous)Affiliated to Bharathidasan UniversityTiruchirappalli620002TNIndia Department of Physics Govt.First.Grade CollegeChikkaballapur-562101KarnatakaIndia Department of Physics Govt.First.Grade CollegeMalur-563160KarnatakaIndia Department of Physics Govt.First.Grade CollegeDevanahalli-562110KarnatakaIndia

A new empirical formula for the astrophysical S-factor has been suggested as a function of the coulomb interaction parameter,center of mass energy,and barrier height.About 22 fusion reactions with ^(40,48)ca as projectiles were considered for different targets,leading to compound nuclei with atomic and mass numbers varying between 40≤Z≤≤Z≤112 and 88≤A≤27888≤A≤278,respectively.The fusion cross-sections have been estimated using the geometric factor,the Gamow-Sommerfield factor,and the empirical formula for the S-factor.This study's findings showed better agreement with those of available experiments when compared to Wong's formula.The present work leads to a smaller standard deviation value than Wong's formula when used to correlate the experimental data of calcium-induced fusion reactions.Wong's formula provides a good approximation of fusion cross-sections when the center of mass energy is below the fusion barrier when compared to above the fusion barrier.

关键词： fusion cross-sections Wong formula Gamow-Sommerfield-factor Geometric-factor S-factor

Mathematical modeling and simulations of stress mitigation by coating polycrystalline particles in lithium-ion batteries

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： n.IQBAL J.cHOI S.F.SHAH c.LEE S.LEE Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline ni-rich LinixMnyco_(z)O_(2)(x>0.8)(nMc)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary nMc particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more homogeneously.Besides,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress mitigation.This paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of nMc active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation ni-rich LinixMnyco_(z)O_(2)(x>0.8)(nMc)