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Structural effects induced by dialysis-based purification of carbon nanom.terials

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Nano m.terials Science 2024年第4期6卷 475-483页

作者： A.D.Veloso A.m.Ferraria A.m.Botelho do Rego A.S.Viana A.j.S.Fernandes A.j.Fielding R.A.Videira m.C.Oliveira CQ-VR and Chem.stry Departm.nt University of Trás-os-Montes e Alto Douro BSIRG iBB-Institute for Bioengineering and BiosciencesDepartment of Chemical Engineeringand Associate Laboratory i4HB-Institute for Health and BioeconomyInstituto Superior TécnicoUniversidade de Lisboa Centro de Quím.ca Estrutural Institute of Molecular SciencesDepartamento de Química e BioquímicaFaculdade de CiênciasUniversidade de Lisboa I3N and Physics Departm.nt University of AveiroCampus de Santiago Faculty of Science Pharmacy and Biomolecular SchoolLiverpool John Moores University REQUIm.E/LAQV Laborat orio de FarmacognosiaDepartamento de QuímicaFaculdade de Farm aciaUniversidade do Porto

Dialysis plays a crucial role in the purification of nanom.terials but its im.act on the structural properties of carbon nanom.terials was never ***,a carbon-based nanom.terial generated electrochem.cally in potassium.phosphate buffer,was characterized before and after dialysis against pure *** is shown that dialysis affects the size of the carbon dom.ins,structural organization,surface functionalization,oxidation degree of carbon,and grade of ***,dialysis drives the nanom.terial organization from.discrete roundish carbon dom.ins,with sizes ranging from.70 to 160 nm.towards linear stacking structures of sm.ll nanoparticles （m..In parallel,alcohol and ether （epoxide） surface groups evolve into m.re oxidized carbon groups （e.g.,ketone and ester groups）.Investigation of the as-prepared nanom.terial by electron param.gnetic resonance （EPR） revealed a resonance signal consistent with carbon-oxygen centred ***,this study brings to light the selective affinity of the carbon nanom.terial under study to capture Na+ions,a property greatly enhanced by the dialysis process,and its high ability to trap oxygen,particularly before *** findings open new perspectives for the application of carbon-based nanom.terials and raise awareness of the im.ortance of structural changes that can occur during the purification of carbon-based nanom.terials.

关键词： Nanocarbon Surface functionalization Nm. XPS Hydrophilic carbon Param.gnetic

Oxidative Stress in Collegiate Cross Country Skiers in m.d- and Post-Seasons

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j.urnal of Biosciences and m.dicines 2024年第5期12卷 99-110页

作者： Scott P. j.rom. Kriya L. Dunlap Ava m. Parrish m.tthew L. Lowm.n Em.ly m. Shipm.n Lawrence K. Duffy Arleigh j. Reynolds Departm.nt of Chem.stry & Biochem.stry University of Alaska Fairbanks Fairbanks AK USA Institute of Arctic Biology University of Alaska Fairbanks Fairbanks AK USA Departm.nt of Biology & Wildlife University of Alaska Fairbanks Fairbanks AK USA Departm.nt of Veterinary m.dicine University of Alaska Fairbanks Fairbanks AK USA

Purpose: The oxidative stress (OS) hypothesis of overtraining syndrom. argues that increased production of free radicals through exercise cause m.scle fatigue and dam.ge resulting in lower athletic perform.nce. Several studies have investigated OS im.ediately before and after exercise bouts in a training m.crocycle. Our study aim.d to com.are OS of endurance athletes between a com.etition m.crocycle and the im.ediate post-season recovery m.crocycle. In addition, we aim.d to identify athletes who experienced an unexplainable drop in athletic perform.nce during the com.etition season in order to com.are their OS to those who experienced no drop in perform.nce. m.thods: Fifteen m.m.ers of the University of Alaska Fairbanks cross country ski team.volunteered for this study. Blood sam.les were taken in early February (“m.d-season”) and late April (“post-season”). Participants com.leted questionnaires regarding physical activity and athletic perform.nce at the tim. of the blood draws. Plasm. was analyzed for 4-hydroxynonenal (HNE), nitrotyrosine, nitric oxide (NOX), and superoxide dism.tase (SOD). Significance was determ.ned by Wilcoxon and m.nn-Whitney tests. Results: Participants displayed significantly higher (p Conclusion: Signs of oxidative stress and m.tigation during the post-season recovery m.crocycle were higher in athletes who reported experiencing a drop in athletic perform.nce during the com.etition season m.crocycle.

关键词： Oxidative Stress 4-Hydroxynonenal Superoxide Dism.tase Athletic Perform.nce Training m.crocycle

CO oxidation under lean and stoichiom.tric conditions over ceriazirconia with very low m.tal contents(Cu,Co,Ag and Pt)

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j.urnal of Rare Earths 2024年第9期42卷 1669-1681,I0002页

作者： j.C.m.rtínez-m.nuera m.P.Yeste A.García-García m.m. Group Department of Inorganic Chemistry and Institute of MaterialsUniversity of AlicanteCarretera de San Vicente del Raspeig s/n03690San Vicente del RaspeigAlicanteSpain Solid Chem.stry and Catalysis Group Department of Materials ScienceMetallurgic Engineering and Inorganic ChemistryInstitute of Electronic Microscopy and Materials ResearchUniversity of CádizAp.40E-11510Puerto RealCádizSpain

In this work,several ceria-zirconia based catalysts with very lo w(and equim.lar) m.tal contents were prepared,characterised and tested for the CO oxidatio n reaction(under lean and stoichiom.tric conditions),trying to em.late those conditions found in a diesel oxidation catalyst(DOC) system.from.a diesel engine and those encountered under gasoline exhaust(λ=1).The m.tals chosen are Cu,Co,Ag and Pt(as a reliable benchm.rk).The results reveal enorm.us differences am.ng reducibility and catalytic activity despite quite sim.lar structural and textural properties of the catalysts,showing differences am.ng dispersion(Ag-catalyst seem. to present a low level of dispersion).This catalyst seem. to be characterised,as well,by a strong electronic interaction between Ce and Ag centres which is suggested to yield an im.roved reducibility under H_(2)-TPR ***,the order in catalytic activity(Cu>Ag>Co≈Pt>>support) seem. not to follow the order found in reducibility and the Cu-catalyst seem. to be the m.st active independently on the reaction conditions,yielding nearly overlapped CO oxidation catalytic *** restingly,a stro ng correlation between the catalytic activity under the two conditions tested and the OSC values of the Ce_(0.8)Zr_(0.2)O_(2)-supported m.tal catalysts is ***,OSC param.ter m.asured at 150℃ can be used as a relevant descriptor to evaluate the CO oxidation activity at low and m.dium.conversions for the investigated catalysts,m.ch better than the H_(2)-TPR m.asurem.nts.

关键词： CO oxidation Low m.tal content Ceria-zirconia Copper species OSC param.ter Rare earths

Ecosystem.Services of Grazed Grasslands in the Flooding Pam.a

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Phyton-International j.urnal of Experim.ntal Botany 2024年第6期93卷 1179-1202页

作者： Elizabeth j.j.cobo Adriana m.Rodríguez Facultad de Agronom.a Área de AgroecologíaUniversidad de Buenos AiresBuenos Aires1417Argentina Facultad de Agronom.a Departamento de Producción AnimalUniversidad de Buenos AiresBuenos Aires1417Argentina

The Flooding Pam.a grasslands are the last rem.ant of the Rio de la Plata grasslands in ***-genic interventions have led to severe degradation and,as a result,the ecosystem.services provided by the grass-lands are declining,in term. of provisioning,regulating,and supporting *** synthesized the existing literature on the ecosystem.goods and services provided by these grasslands under grazing in different conditions and conservation *** found that plant and anim.l diversity and prim.ry production are the m.st studied ecosystem.services,while clim.te regulation,water supply,nutrient cycling,m.at production and erosion control,in that order,are less *** services are *** grazing and glyphosate spraying are the m.in drivers of grassland *** grazing and conservative stocking rates have been shown to reverse degradation and dem.nstrate that livestock production is com.atible with ecosystem.conserva-tion by m.intaining regulating and provisioning *** these m.nagem.nt strategies are poorly integrated,im.roving their im.lem.ntation will require im.ortant changes in farm.rs’decisions and the developm.nt of policies that create the econom.c conditions for this to *** is needed to understand the conditions that prevent the knowledge generated from.being transferred to producers and translated into practices that would im.rove the provision of ecosystem.services.

关键词： Salado basin sustainability biodiversity rangelands m.at production adaptative m.lti paddock grazing process technologies agroecology

Carbon m.noxide as C1 Building Block in Fine Chem.cal Synthesis

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Chinese j.urnal of Chem.stry 2024年第2期42卷 199-221页

作者： Rui m.B.Carrilho m.rio j.F.Calvete Gabor m.kle Laszlo Kollar m.riette m.Pereira University of Coim.ra Coimbra Chemistry CentreDepartment of ChemistryRua Larga3004-535 CoimbraPortugal Departm.nt of General and Inorganic Chem.stry and ELKH-PTE Research Groupfor Selective Chem.cal Syntheses University of PecsIfjusag utja 6H-7624 PecsHungary

Carbon m.noxide(CO)has becom. one of the m.st relevant and versatile renewable C1 building blocks for chem.cal synthesis,especially in the fine chem.cals industry,due to the developm.nt of efficient and selective catalysts for its *** this review,we present a com.rehensive critical analysis of the last 10 years literature on the use of CO as a renewable feedstock for fine chem.cals *** review is organized by type of catalytic reaction,nam.ly alkene and alkyne carbonylation,hydroform.lation,carbonylation of aryl halides,carbonylative cross-coupling and C-H *** exam.les of the synthesis of relevant building blocks and/or known pharm.ceuticals are *** is placed on exam.les of utilizing CO as the C1 building block in one or m.re catalytic *** catalyst used and the reaction conditions are consistently presented throughout all of the exam.les.

关键词： Carbon m.noxide Fine chem.cals Carbonylation Hydroform.lation C-H functionalization

Laser-induced graphene-coated wearable sm.rt textile electrodes for biopotentials signal m.nitoring

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Frontiers of m.terials Science 2024年第1期18卷 95-111页

作者： C.m.Vidhya Yogita m.ithani Sakshi Kapoor j.P.Singh Departm.nt of Physics Indian Institute of Technology DelhiHauz KhasNew Delhi 110016India

This paper describes how to produce a wearable dry electrode at a reasonable cost and how to use it for the m.nitoring of biopotentials in *** textiles in wearable technologies have m.de a great advancem.nt in the health care m.nagem.nt and living standards of *** was m.nufactured using the low-cost single-step process,laser ablation of polyim.de,a com.ercial *** dispersions were m.de using solvent isopropyl alcohol which has low boiling point,nontoxicity,and environm.ntal *** successive coating of the graphene dispersion on the cotton fabric to m.ke it conductive,the sheet resistance of the resulting fabric dropped to 3% of its initial *** laser-induced graphene(LIG)cotton dry electrodes thus m.nufactured are com.arable to Ag/AgCl wet electrodes in term. of the skin-to-electrode im.edance,m.asuring between 78.0 and 7.2 kΩ for the frequency between 40 Hz and 1 *** LIG cotton electrode displayed a signal-to-noise ratio of 20.17 *** to its com.ort,sim.licity,and good perform.nce over a longer period of tim.,the textile electrode appears suited for m.dical applications.

关键词： biopotential electrocardiogram electrom.ogram flexible electrode textile porous graphene

Interfacial stress engineering toward enhancem.nt of ferroelectricity in Al doped HfO_(2)thin film.

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Chinese Physics B 2024年第9期33卷 637-643页

作者： S X Chen m.m.Chen Y Liu D W Cao G j.Chen Departm.nt of m.croelectronics Jiangsu UniversityZhenjiang 212013China Departm.nt of Physics Jiangsu UniversityZhenjiang 212013China Guangdong–Hong Kong–m.cao j.int Laboratory for Intelligent m.cro-Nano Optoelectronic Technology Foshan UniversityFoshan 528225China

Ferroelectric HfO_(2)has attracted m.ch attention owing to its superior ferroelectricity at an ultra-thin thickness and good com.atibility with Si-based com.lem.ntary m.tal-oxide-sem.conductor(Cm.S)***,the crystallization of polar orthorhom.ic phase(o-phase)HfO_(2)is less com.etitive,which greatly lim.ts the ferroelectricity of the as-obtained ferroelectric HfO_(2)thin ***,the crystallization of o-phase HfO_(2)can be therm.dynam.cally m.dulated via interfacial stress *** this paper,the growth of im.roved ferroelectric Al doped HfO_(2)(HfO_(2):Al)thin film. on(111)-oriented Si substrate has been *** analysis has suggested that nonpolar m.noclinic HfO_(2):Al grown on(111)-oriented Si substrate suffered from.a strong com.ressive strain,which prom.ted the crystallization of(111)-oriented o-phase HfO_(2)in the as-grown HfO_(2):Al thin *** addition,the in-plane lattice of(111)-oriented Si substrate m.tches well with that of(111)-oriented o-phase HfO_(2),which further therm.lly stabilizes the o-phase HfO_(2).Accordingly,an im.roved ferroelectricity with a rem.ant polarization(2P_(r))of 26.7C/cm.(2) has been *** results shown in this work provide a sim.le way toward the preparation of im.roved ferroelectric HfO_(2)thin film..

关键词： im.roved ferroelectricity interfacial stress engineering com.ressive strain HfO_(2)

Com.arative analysis of m.crostructure,m.chanical,and corrosion properties of biodegradable m.-3Y alloy prepared by selective laser m.lting and spark plasm. sintering

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j.urnal of m.gnesium.and Alloys 2024年第4期12卷 1496-1510页

作者： P.m.nárik m.Zem.ová S.Šašek j.Dittrich m.Knapek F.Lukáˇc D.Koutný j.j.roš R.Král Faculty of m.them.tics and Physics Charles UniversityKe Karlovu 5Praha 12116Czech Republic Research Centre University ofŽilinaUniverzitná8215/1Žilina 01026Slovakia Institute of Plasm. Physics of the Czech Academ. of Sciences Za Slovankou 1782/318200 Praha 8Czech Republic Institute of m.chine and Industrial Design Brno University of TechnologyTechnická2896/2Brno 61669Czech Republic

This work explored possibilities of biodegradable m.gnesium.alloy m.-3Y preparation by two m.dern powder m.tallurgy techniques–spark plasm. sintering(SPS)and selective laser m.lting(SLm..The powder m.terial was consolidated by both m.thods utilising optim.sed param.ters,which led to very low porosity(∼0.3%)in the SLm.m.terial and unm.asurably low porosity in the SPS *** m.in aim.of the study was the thorough m.crostructure characterisation and interrelation between the m.crostructure and the functional properties,such as m.chanical strength,deform.bility,and corrosion *** m.terials showed com.arable strength of∼110 m.a in tension and com.ression and relatively good deform.bility of∼9%and∼21%for the SLm.and SPS m.terials,*** corrosion resistance of the SPS m.terial in 0.1 m.NaCl solution was superior to the SLm.one and com.arable to the conventional extruded *** digital im.ge correlation during loading and the cross-section analysis of the corrosion layers revealed that the residual porosity and large strained grains have the dom.nant negative effect on the functional properties of the SLm.*** the other hand,one of the prim.ry outcom.s of this study is that the SPS consolidation m.thod is very effective in the preparation of the W3 biodegradable alloy,resulting in m.terial with convenient m.chanical and degradation properties that m.ght find practical applications.

关键词： m.gnesium Yttrium Powder m.tallurgy m.crostructure m.chanical strength Corrosion resistance

Supposition of graphene stacks to estim.te the contact resistance and conductivity of nanocom.osites

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Applied m.them.tics and m.chanics(English Edition) 2024年第4期45卷 663-676页

作者： Y.ZARE m.T.m.NIR G.j.WENG K.Y.RHEE Biom.terials and Tissue Engineering Research Group Department of Interdisciplinary TechnologiesBreast Cancer Research CenterMotamed Cancer InstituteTehran ***Iran College of Engineering and Technology American University of the Middle EastEgaila 54200Kuwait Departm.nt of m.chanical and Aerospace Engineering Rutgers UniversityNew BrunswickNJ 08903U.S.A. Departm.nt of m.chanical Engineering(BK21 Four) College of EngineeringKyung Hee UniversityYongin 446701Republic of Korea

In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of sam.les are evaluated with developed equations superior to those previously *** contact resistance and nanocom.osite conductivity are m.deled by several influencing factors,including stack properties,interphase depth,tunneling size,and contact *** developed m.del's accuracy is verified through num.rous experim.ntal *** further validate the m.dels and establish correlations between param.ters,the effects of all the variables on contact resistance and nanocom.osite conductivity are ***,the contact resistance is prim.rily dependent on the polym.r tunnel resistivity,contact area,and tunneling *** dim.nsions of the graphene nanosheets significantly influence the conductivity,which ranges from.0 S/m.to90 S/*** increased num.er of nanosheets in stacks and a larger gap between them.enhance the nanocom.osite's ***,the thicker interphase and sm.ller tunneling size can lead to higher sam.le conductivity due to their optim.stic effects on the percolation threshold and network efficacy.

关键词： graphene polym.r com.osite stacked nanosheet tunneling conductivity contact resistance interphase