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Non-destructive microstructural analysis by electrical conductivity:Comparison with hardness measurements in different materials

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Journal of materials Science & Technology 2019年第3期35卷 360-368页

作者： Gon?alo L.Sorger J.P.Oliveira Patrick L.Inácio Norbert Enzinger Pedro Vila? R.m.miranda Telmo G.santos Department of Engineering Design and Production School of Engineering Aalto University Department of materials Science and Engineering The Ohio State University UNIDEmI Departamento de Engenharia Mecanica e Industrial Faculdade de Ciências e Tecnologia Universidade Nova de Lisboa ImAT-Institute of materials Science Joining and FormingTU Graz

The use of non-destructive evaluation(NDE) techniques for assessing microstructural changes in processed materials is of particular importance as it can be used to assess, qualitatively, the integrity of any material/structure. Among the several NDE techniques available, electrical conductivity measurements using eddy currents attract great attention owing to its simplicity and reliability. In this work, the electrical conductivity profiles of friction stir processed Ti6Al4 V, Cu, Pb, S355 steel and gas tungsten arc welded AISI 304 stainless steel were determined through eddy currents and four-point probe. In parallel, hardness measurements were also performed. The profiles matched well with the optical macrographs of the materials: while entering in the processed region a variation in both profiles was always observed. One particular advantage of electrical conductivity profiles over hardness was evident: it provides a better resolution of the microstructural alterations in the processed materials. moreover, when thermomechanical processing induces microstructural changes that modify the magnetic properties of a material,eddy currents testing can be used to qualitatively determine the phase fraction in a given region of the material. A qualitative relation between electrical conductivity measurements and hardness is observed.

关键词： Non-destructive evaluation techniques Electrical conductivity Hardness Friction stir processing Gas tungsten arc welding

Coating independent cytotoxicity of citrate-and PEG-coated silver nanoparticles on a human hepatoma cell line

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Journal of Environmental Sciences 2017年第1期29卷 191-201页

作者： Veronica Bastos Jose m.P.Ferreira-de-Oliveira Joana Carrola Ana L.Daniel-da-Silva Iola F.Duarte Conceicao santos Helena Oliveira CESAm&Laboratory of Biotechnology and Cytomics Department of BiologyUniversity of Aveiro3810-193 AveiroPortugal CICECO-Aveiro Institute of materials Department of ChemistryUniversity of Aveiro3810-193 AveiroPortugal Department of Biology Faculty of SciencesUniversity of Porto4169-007 PortoPortugal

The antibacterial potential of silver nanoparticles（AgNPs） resulted in their increasing incorporation into consumer,industrial and biomedical ***,human and environmental exposure to AgNPs（either as an engineered product or a contaminant）supports the emergent research on the features conferring them different toxicity *** this study,30 ran AgNPs coated with citrate or poly（ethylene glycol）（PEG） were used to assess the influence of coating on the effects produced on a human hepatoma cell line（HepG2）,namely in terms of viability,apoptosis,apoptotic related genes,cell cycle and cyclins gene *** types of coated AgNPs decreased cell proliferation and viability with a similar toxicity *** the concentrations used（11 and 5 μg/mL corresponding to IC50 and-IC10 levels,respectively） the amount of cells undergoing apoptosis was not significant and the apoptotic related genes BCL2（anti-apoptotic gene）and BAX（pro-apoptotic gene） were both ***,both AgNPs affected HepG2 cell cycle progression at the higher concentration（11 μg/mL） by increasing the percentage of cells in S（synthesis phase） and G2（Gap 2 phase） *** the cell-cycle related genes,the expression of cyclin B1 and cyclin E1 genes were ***,this work has shown that citrate- and PEG-coated AgNPs impact on HepG2 apoptotic gene expression,cell cycle dynamics and cyclin regulation in a similar *** research is needed to determine the properties that confer AgNPs at lower toxicity,since their use has proved helpful in several industrial and biomedical contexts.

关键词： Silver nanoparticles(AgNPs) Citrate Polyethylene glycol)(PEG) HepG2 cells Cytotoxicity Nanotoxicology

Renal sympathetic denervation in resistant hypertension

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World Journal of Cardiology 2013年第4期5卷 94-101页

作者： mário santos Henrique Carvalho Cardiology Department Hospital Santo AntónioLargo Professor Abel Salazar4099-001 PortoPortugal

Resistant hypertension remains a major clinical problem despite the available multidrug *** the next decades,its incidence will likely increase given that it is strongly associated with older age and *** hypertension patients have an increased cardiovascular risk,thus effective antihypertensive treatment will provide substantial health *** crosstalk between sympathetic nervous system and kidneys plays a crucial role in *** influences several pathophysiological mechanisms such as the central sympathetic tone,the sodium balance and the systemic neurohumoral *** fact,studies using several animal models demonstrated that the renal denervation prevented and attenuated hypertension in multiple *** reductions in blood pressure were also observed in malignant hypertension patients submitted to sympathectomy ***,these approaches had an unacceptably high rates of periprocedural complications and disabling adverse ***,an innovative non-pharmacological therapy that modulates sympathetic activation has been successfully *** sympathetic percutaneous denervation is an endovascular procedure that uses radiofrequency energy to destroy the autonomic renal nerves running inside the adventitia of renal *** method represents a promising new approach to the strategy of inhibiting the sympathetic nervous *** aim of this review is to examine the background knowledge that resulted in the development of this hypertension treatment and to critically appraise the available clinical evidence.

关键词： Arterial hypertension Sympathetic activity Renal denervation Percutaneous ablation Resistant hypertension

Fluorine-containing drugs approved by the FDA in 2019

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Chinese Chemical Letters 2020年第9期31卷 2401-2413页

作者： Haibo mei Attila mario Remete Yupiao Zou Hiroki moriwaki santos Fustero Lorand Kiss Vadim ASoloshonok Jianlin Han Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources College of Chemical EngineeringNanjing Forestry UniversityNanjing 210037China University of Szeged Institute of Pharmaceutical Chemistry6720 SzegedEotvos u.6Hungary Hamari Chemicals Ltd. 1-4-29 KunijimaHigashi-Yodogawa-kuOsaka 533-0024Japan Departamento de Quimica Organica Universidad de Valencia46100 BurjassotValenciaSpain Department of Organic Chemistry 1 Faculty of ChemistryUniversity of the Basque Country UPV/EHUPaseo Manuel Lardizabal 320018 San SebastianSpain IKERBASQUE Basque Foundation for Science.Maria Diaz de Haro 3Plaza Bizkaia48013 BilbaoSpain

Eleven new fluorine-containing FDA-approved drugs have been profiled and details of their discovery and preparation are *** areas include schizophrenia,migraine,multiple sclerosis,insomnia,rheumatoid arthritis,anti-tuberculosis,breast cancer,lymphoma kinase inhibitor,serotonin receptor *** pharmaceuticals feature four examples of aromatic fluorine,three aromatic CF3 group,three aliphatic CF3 and one compound with aromatic CF3O ***,among the new compounds,six are chiral and seven are derived from tailor-made amino acids.

关键词： Fluorine Pharmaceuticals Synthesis medicinal chemistry marketed medicinal drugs

Tree succession across a seasonally dry tropical forest and forest-savanna ecotone in northern minas Gerais,Brazil

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Journal of Plant Ecology 2017年第5期10卷 859-868页

作者： Polyanne A.Coelho Paola Ferreira santos Eduardo de Paiva Paula Deborah m.G.Apgaua Bruno Gini madeira Gisele Cristina de Oliveira menino Yule Roberta Ferreira Nunes Rubens m.santos David Y.P.Tng Department of Forest Sciences Federal University of LavrasC.P.3037CEP 37200-000LavrasMinas GeraisBrazil Department of General Biology State University of Montes ClarosC.P.126CEP 39401-089Montes ClarosMinas GeraisBrazil Instituto Federal Goiano C.P.66CEP 75901-970Rio VerdeGoiâniaBrazil Centre for Tropical Environmental and Sustainability Sciences College of Marine and Environmental SciencesJames Cook University14-88 McGregor RdSmithfield QLD 4878CairnsQueenslandAustralia

Aims Understanding succession in tropical forest is an important aspect of vegetation science,but to date,successional processes in sea-sonally dry tropical forests(SDtFs)have received much less atten-tion than evergreen humid tropical *** aim to fill this knowledge *** We investigated vegetation succession in SDtF areas consisting of three different successional stages(early,intermediate,late),and a SDtF-savanna ecotone in the municipal district of Juramento,north of minas Gerais State,*** twelve 400 m2 plots in each area,we compared vegetation parameters and structural variables(absolute density and basal area)and examined the floristic composition of the tree component to find gradients of *** Findings We found evidence of species turnover along a successional gradi-ent,with the intermediate stage showing the highest species rich-ness and *** was accompanied with a significant increase in the number of tree individuals and basal area from the early to intermediate successional ***,the intermediate and late SDtF successional stages were more similar in structure and *** ecotone was the most species rich and was similar to the intermediate SDtF and early successional stage in species richness and floristic composition *** results will have implications for guiding SDtF management and recovery programs.

关键词： caatinga floristic Similarity ecotone forest succession resilience.

Sticky-mARTINI as a reactive coarse-grained model for molecular dynamics simulations of silica polymerization

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npj Computational materials 2022年第1期8卷 467-479页

作者： AndréP.Carvalho Sérgio m.santos Germán Pérez-Sánchez JoséD.Gouveia JoséR.B.Gomes miguel Jorge CICECO-Aveiro Institute of materials Department of ChemistryUniversity of AveiroCampus Universitário de Santiago3810-193AveiroPortugal Department of Chemical and Process Engineering University of Strathclyde75 Montrose StreetGlasgowG11XJUK

We report a molecular modeling paradigm to describe silica polymerization reactions in aqueous solutions at conditions that are representative of realistic experimental processes like biosilicification or porous silica synthesis–*** close to ambient temperatures and over a wide range of *** key point is to describe the Si-O-Si chemical bond formation and breakage processes through a continuous potential with a balance between attractive and repulsive interactions between suitably placed virtual sites and sticky *** simplicity of the model,its applicability in standard parallelized molecular dynamics codes,and its compatibility with the widely used mARTINI coarse-grained force-field allows for the study of systems containing millions of atoms over microsecond time *** model is calibrated to match experimental results for the temporal evolution of silica polymerization in aqueous solution close to the isoelectric point,and can describe silica polymerization and self-assembly processes during encapsulation of a surfactant micelle.

关键词： silica polymerization dynamics

Isotopic and geochemical constraints for a Paleoproterozoic accretionary orogen in the Borborema Province,NE Brazil:Implications for reconstructing Nuna/Columbia

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Geoscience Frontiers 2022年第5期13卷 267-285页

作者： Lauro Cézar m.de Lira santos Geysson A.Lages Fabrício A.Caxito Elton L.Dantas Peter A.Cawood Haroldo m.Lima Felipe Jda Cruz Lima Departamento de Geologia Universidade Federal de PernambucoAv.da ArquiteturaCidade UniversitáriaRecifePEBrazil Serviço Geológico do Brasil-CPRm Av.SulAfogadosRecifePEBrazil CPmTC Instituto de GeociênciasUniversidade Federal de Minas GeraisAv.Pres.Antônio CarlosPampulhaBelo HorizonteMGBrazil Instituto de Geociências Universidade de BrasíliaCampus Universitário Darcy RibeiroAsa NorteBrasíliaDFBrazil School of Earth Atmosphere and EnvironmentMonash UniversityWellington RdClaytonVIC 3800Australia Departamento de Geologia Universidade Federal do CearáCampus do PiciParquelândiaFortalezaCEBrazil

The Alto moxotóTerrane of the Borborema Province presents a wide exposure of Paleoproterozoic crust,but unlike other continental blocks of South America,its orogenic history is strongly obliterated by late Neoproterozoic *** isotopic and geochemical studies were conducted in mafic-ultramafic(Fazenda Carmo Suite)and granitic-gneissic rocks(Riacho do Navio Suite)within the *** former present zircon U-Pb crystallization ages at ca.2.13 Ga,whereas Sm-Nd data suggests a juvenile origin via melting of early Paleoproterozoic to Archean peridotitic *** data for these rocks are compatible with tholeiitic magmas with some degree of crustal contamination and trace element distribution points to a continental-arc related setting interpreted as remnants of the early stages of *** contrast,the Riacho do Navio Suite was emplaced at ca.2.08 Ga and has highly negativeεNd(t)values indicating crustal *** suite displays calc-alkali to alkali-calcic and ferroan geochemical signatures compatible with Cordilleran *** addition,trace-element distribution as well as discriminant diagrams suggest that the precursor magmas were generated during the later stages of a continental arc or in a syn-collisional *** on our results,we suggest that the studied units might represent missing pieces of a Paleoproterozoic accretionary orogen that formed the crustal framework of the Alto moxotóTerrane,and that this represents a block associated with assembly of the Nuna/Columbia supercontinent,which is now largely hidden within the Neoproterozoic orogenic belts of West Gondwana.

关键词： Paleoproterozoic accretionary-collisional event Early orogenic and syn-collisional magmatism Paleoproterozoic inlier within West Gondwana Nuna/Columbia Supercontinent

Ion dynamics into different pore size distributions in supercapacitors under compression

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Journal of Energy Chemistry 2023年第5期80卷 110-119,I0004页

作者： João Pedro Aguiar dos santos Cesar J.B.Pagan Rafael Vicentini Reinaldo F.Teófilo Renato Beraldo Leonardo m.Da Silva Hudson Zanin Brazilian Renewable Energies Center for Innovation on New EnergiesSchool of Electrical and Computer EngineeringUniversity of CampinasAv.Albert Einstein 40CampinasSP13083-852Brazil School of Electrical and Computer Engineering University of CampinasSP 13083-852Brazil multivariate Chemical Data Analysis Laboratory Department of ChemistryUniversidade Federal de Viçosa36570-900 ViçosaMGBrazil Department of Chemistry Laboratory of Fundamental and Applied ElectrochemistryFederal University of Jequitinhonha and Mucuri's ValleyRodovia MGT 367km 5835000 Alto da Jacuba39100-000DiamantinaMGBrazil

Compressing supercapacitor(SCs)electrode is essential for improving the energy storage characteristics and minimizing ions’distance travel,faradaic reactions,and overall ohmic *** comprising the ion dynamics in SC electrodes under compression are still ***,the ionic dynamics of five aqueous electrolytes in electrodes under compression were studied in this work for tracking electrochemical and structural changes under mechanical stress.A superionic state is formed when the electrode is compressed until the micropores match the dimensions with the electrolyte’s hydrated ion sizes,which increases the *** excessive compression is applied,the accessible pore regions decrease,and the capacitance ***,as the studied hydrated ions have different dimensions,the match between ion/pore sizes *** the LiOH and NaClO4electrolytes,increasing the pressure from 60 to 120 and 100 PSI raised the capacitance from 13.5 to 35.2 F g^(-1)and 30.9 to 39.0 F g^(-1),***,the KOH electrolyte with the lowest and LiCl with the biggest combination of hydrated ion size have their point of maximum capacitance(39.5 and 36.7F g^(-1))achieved at 140 and 80 PSI,*** LiCl and KCl electrolytes,overcompression causes a drop in capacitance higher than 23%.

关键词： mechanic compression Pore size distribution lon dynamics Activated carbon Supercapacitors

Development and characterization of 3CaO·P_(2)O_(5)-SiO_(2)-mgO glass-ceramics with different crystallization degree

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Journal of Advanced Ceramics 2013年第4期2卷 378-388页

作者： Juliana Kelmy m.F.DAGUANO Paulo A.SUZUKI Kurt STRECKER Josémartinho marques de OLIVEIRA maria Helena Figueira Vaz FERNANDES Claudinei santos Universidade de São Paulo-Escola de Engenharia de Lorena USP-EEL-Pólo Urbo-Industrials/nGleba AI-6Lorena-SPCEP 12600-000Brazil Universidade Federal de São João del-Rei -UFSJ-CENENCampus S^(to)Antônio-Praça Frei Orlando 170-CentroS.J.del-Rei-MG.CEP 36307-352Brazil Escola Superior Aveiro Norte Edifício Rainha3720-232 O.AzeméisPortugal Universidade de Aveiro Campus Universitário de Santiago 3810-193 AveiroPortugal Universidade do Estado do Rio de Janeiro-Faculdade de Tecnologia de Resende-UERJ-FAT-Rod.Presidente Dutra km298Resende-RJCEP 27537-000Brazil

The CaO-P_(2)O_(5)-SiO_(2)-mgO system presents several compounds used as biomaterials such as hydroxyapatite(HA),tricalcium phosphate(TCP)and TCP with magnesium substituting partial calcium(TCmP).Theβ-TCmP phase with whitlockite structure has interesting biological features and mechanical properties,meeting the requirements of a bioactive material for bone *** this work,the production of mg-doped TCP,β-TCmP,has been investigated by crystallization from a glass composed of 52.75 wt%3CaO·P_(2)O_(5),30 wt%SiO_(2)and 17.25 wt%mgO(i.e.,31.7 mol%CaO,10.6 mol%P_(2)O_(5),26.6 mol%mgO and 31.1 mol%SiO_(2))using heat treatments between 775℃and 1100℃for up to 8 *** devitrification process of the glass has been accompanied by differential scanning calorimetry(DSC),high-resolution X-ray diffraction(HRXRD),relative density and bending strength *** characterization by HRXRD and DSC revealed the occurrence of whitlockite soon after the bulk glass preparation,a transient non-cataloged silicate between 800℃and 1100℃,and the formation of diopside in samples treated at 1100℃as crystalline *** overall crystalline fraction varied from 26%to 70%depending on the heat ***,contraction of the a-axis lattice parameter and expansion of the c-axis lattice parameter of the whitlockite structure have been observed during the heat treatments,which were attributed to theβ-TCmP formation with the partial substitution of Ca^(2+)by mg^(2+).Relative densities near 99%and 97%for the glass and glass-ceramics respectively indicated a discrete reduction as a function of the devitrification *** strengths of 70 mPa and 120 mPa were determined for the glass and glass-ceramic material crystallized at 975℃for 4 h,respectively.

关键词： glass-ceramics heat treatment high-resolution X-ray diffraction(HRXRD) bending strength