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Materials Sciences and Applications 2016年第3期7卷 150-158页

作者： Paulo Sérgio Rangel Cruz da Silva lívia rodrigues menezes Maria Inês Bruno Tavares Institute of Macromolecules Professor Eloisa Mano Federal University of Rio de Janeiro Rio de Janeiro Brazil

Spin-lattice and spin-spin relaxation times are one of the most attractive tools in the solid-state nuclear magnetic resonance spectroscopy to evaluate the level of clay dispersion in the nanocomposite matrices. The efficiency of the relaxation processes can be used to evaluate the nanoparticles intermolecular interactions and, consequently, the dispersion of them in the polymer matrix, the molecular dynamic of the hybrid compounds, as well as the molecular domains formation in an organic material. The determination of relaxation parameters was carried out to evaluate the organoclay exfoliation and intercalation process in the polymeric matrix, in addition to their dispersion and distribution in the matrix. The proton NMR relaxation data showed that the polymeric nanomaterials investigated presented good intermolecular interaction that promoted good nanoparticles dispersion and distribution in the hybrid materials. The proportion of 2% clay promoted a greater heterogeneity in the matrix compared to other ratios;1% clay influenced only to the higher molecular rigidity phase;and 3% clay had a decrease in heterogeneity compared to 2% though still influenced the matrix as a whole. These results prove the efficiency of NMR technique in the evaluation of nanofillers interaction with polymer matrices, as well as their dispersion and distribution.

关键词： Polymeric Nanocomposites Nanoparticles Relaxation Times NMR

Polymer Nanocomposites Used as Scaffolds for Bone Tissue Regeneration

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Materials Sciences and Applications 2018年第8期9卷 679-697页

作者： Raquel Couto de Azevedo Goncalves Mota Emerson Oliveira da Silva lívia rodrigues de menezes Instituto de Macromoléculas Professora Eloisa Mano Universidade Federal do Rio de JaneiroRio de JaneiroBrazil

Scaffolds are three-dimensional biocompatible structures that can mimic the properties of the extracellular matrix (ECM) of a given tissue, like mechanical support and bioactivity, which provides a platform for cellular adherence, proliferation and differentiation. Consequently, scaffolds are frequently used in tissue engineering with the intention of assisting the regeneration of a damaged tissue, and a major application in bone regeneration. An ideal scaffold needs to be biodegradable, biocompatible, and needs to match the biomechanical properties of bone. Polymers are widely used in this field because they fulfil the first two requirements. However, no polymeric material can achieve mechanical properties similar to the bone. For that reason, polymeric nanocomposites, which consist of ceramic/metallic nanoparticles dispersed in a polymer matrix, are being considered for bone scaffold fabrication in order to overcome this problem, since nanoparticles are known to improve composite mechanical strength, and enhance other properties.

关键词： Scaffolds Polymer Nanocomposites Nanoparticles Bone Tissue Engineering

3D Printed Scaffolds as a New Perspective for Bone Tissue Regeneration: literature Review

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Materials Sciences and Applications 2016年第8期7卷 430-452页

作者： Raquel Couto de Azevedo Gonçalves Mota Emerson Oliveira da Silva Felipe Fortes de lima lívia rodrigues de menezes Antonio Carlos Santos Thiele Instituto de Macromoléculas Professora Eloisa Mano Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil Universidade Federal do Rio de Janeiro Pólo Xerém Estr. de Xerém 27-Xerém Duque de Caxias-RJ Rio de Janeiro Brazil

Due to the high incidence of bone fractures in the population, it became necessary to produce scaffolds that are able to assist in tissue regeneration. It is necessary to find an appropriate balance between the mechanical and biological properties, in order to mimic the natural tissue, these properties are directly related to the architecture and their degree of porosity, as well as the size of their pores and their interconnectivity. In this perspective, the 3D printing stands out, where the structure is obtained layer by layer, according to a predetermined computational model which provides a greater control of architecture and scaffold geometry and overcomes, in this way, the limitations of traditional techniques of scaffolds manufacturing. In this way, the objective of this seminar is to present the state of the art of the polymer scaffolds produced by 3D printing and applied to bone tissue regeneration, highlighting the advantages and limitations of this process.

关键词： Scaffolds 3D Printing Tissue Engineering Bone Tissue

Small holes,big impact:Stomata in plant–pathogen–climate epic trifecta

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Molecular Plant 2024年第1期17卷 26-49页

作者： Shuguo Hou Olivier rodrigues Zunyong liu libo Shan Ping He Peking University Institute of Advanced Agricultural Sciences Shandong Laboratory of Advanced Agriculture Sciences in WeifangWeifangShandong 261325China School of Municipal&Environmental Engineering Shandong Jianzhu UniversityJinanShandong 250101China Unitéde Recherche Physiologie Pathologie et Génétique VégétalesUniversitéde Toulouse Midi-PyrénéesINP-PURPAN31076 ToulouseFrance Department of Molecular Cellularand Developmental BiologyUniversity of MichiganAnn ArborMI 48109USA

The regulation of stomatal aperture opening and closure represents an evolutionary battle between plants and pathogens,characterized by adaptive strategies that influence both plant resistance and pathogen *** ongoing climate change introduces further complexity,affecting pathogen invasion and host *** review delves into recent advances on our understanding of the mechanisms governing immunity-related stomatal movement and patterning with an emphasis on the regulation of stomatal opening and closure dynamics by pathogen patterns and host *** addition,the review explores how climate changes impact plant–pathogen interactions by modulating stomatal *** light of the pressing challenges associated with food security and the unpredictable nature of climate changes,future research in this field,which includes the investigation of spatiotemporal regulation and engineering of stomatal immunity,emerges as a promising avenue for enhancing crop resilience and contributing to climate control strategies.

关键词： stomatal movement stomatal patterning plant resistance pathogen virulence apoplastic immunity and climate change

Multi-point temperature measurements in packed beds using phosphor thermometry and ray tracing simulations

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Particuology 2024年第2期85卷 77-88页

作者： Guangtao Xuan Mirko Ebert Simson Julian rodrigues Nicole Vorhauer-Huget Christian lessig Benoit Fond Institute of Fluid Dynamics and Thermodynamics OVGU MagdeburgUniversitaetsplatz 2Magdeburg39106Saxony-AnhaltGermany Institute of Simulations and Graphics OVGU MagdeburgUniversitaetsplatz 2Magdeburg39106Saxony-AnhaltGermany Institute of Process Engineering OVGU MagdeburgUniversitaetsplatz 2Magdeburg39106Saxony-AnhaltGermany ONERA The French Aerospace LabDepartment of AerodynamicsAeroelasticity and Aeroacoustics(DAAA)Paris-Saclay University8rue des VertugadinsMeudon92190France

Packed bed reactors are commonly found in the process industry,for example in flame-assisted calci-nation for cement *** the heat transfer inside the bed is essential for process control,product quality and energy *** we propose a technique to determine the internal temperature distribution of packed beds based on a combination of lifetime-based phosphor ther-mometry,ray tracing simulations,and assimilation of temperature data using finite element heat transfer *** establish and validate the technique,we considered a reproducible regular packing of 6 mm diameter aluminum spheres,with one of the spheres in the top layer being electrically *** a sphere inside the packing is coated with thermographic phosphors and excitation light is directed to-wards the packing,luminescence from the coated sphere exits the packed bed after multiple reflection and the sphere's temperature can be *** measurements showed that the temper-ature obtained by phosphor thermometry is independent of the luminescent sphere *** imaging the luminescence on a camera,the luminescence distribution in recorded image depended,however,on the position of the ***,in setups with multiple phosphor-coated spheres,their signals can be separated using a least squares *** demonstrate the approach using a setup with three luminescent spheres and validated the temperature readings against thermocouple *** obtain the spatial signatures for individual sphere positions required for the least squares fit,ray tracing simulations were *** provide an efficient alternative to single sphere measurements that are only practical for regular spherical packed ***-point measurements were used as input to a finite element heat transfer simulations to determine parameters such as particle-to-particle air gap *** these,the full temperature distribution inside the bed could be assimilated from the meas

关键词： Packed beds Phosphor thermometry Ray tracing Heat transfer simulation Data assimilation

The impact of heterogeneity and pore network characteristics on single and multi-phase fluid propagation in complex porous media:An X-ray computed tomography study

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Petroleum Science 2024年第3期21卷 1719-1738页

作者： Shohreh Iraji Tales rodrigues De Almeida Eddy Ruidiaz Munoz Mateus Basso Alexandre Campane Vidal Department of Mechanical Engineering(FEM) State University of Campinas(UNICAMP)CampinasSP13083-860Brazil Department of Geology and Natural Resources Geosciences Institute(IG)State University of Campinas(UNICAMP)CampinasSP.13083-855.Brazil lRAP/COPPE/COPPETEC/UFRJ Rua Moniz Aragao 360Bloco 4 Cidade UniversitariaRio de Janeiro21941-594Brazil Center of Energy and Petroleum Studies(CEPETRO) State University of Campinas(UNICAMP)CampinasSP13083-896Brazil

This study investigates the impact of pore network characteristics on fluid flow through complex and heterogeneous porous media,providing insights into the factors affecting fluid propagation in such ***,high-resolution or micro X-ray computed tomography(CT)imaging techniques were utilized to examine outcrop stromatolite samples of the lagoa Salgada,considered flow analogous to the Brazilian Pre-salt carbonate *** petrophysical results comprised two distinct stromatolite depositional facies,the columnar and the fine-grained *** generating pore network model(PNM),the study quantified the relationship between key features of the porous system,including pore and throat radius,throat length,coordination number,shape factor,and pore *** study found that the less dense pore network of the columnar sample is typically characterized by larger pores and wider and longer throats but with a weaker connection of throats to *** facies exhibited less variability in the radius of the pores and throats in comparison to throat ***,a series of core flooding experiments coupled with medical CT scanning was designed and conducted in the plug samples to assess flow propagation and saturation *** study revealed that the heterogeneity and presence of disconnected or dead-end pores significantly impacted the flow patterns and ***-phase flow patterns and oil saturation distribution reveal a preferential and heterogeneous displacement that mainly swept displaced fluid in some regions of plugs and bypassed it in *** relation between saturation profiles,porosity profiles,and the number of fluid flow patterns for the samples was *** for the columnar plug sample was the enhancement in recovery factor after shifting to lower salinity water injection(SB)observed.

关键词： Pore network model Heterogeneous porous media Flow patterns Dead-end pores

Small-scale self-driving cars:A systematic literature review

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第2期11卷 271-292页

作者： Felipe Caleffi lauren da Silva rodrigues Joice da Silva Stamboroski Brenda Medeiros Pereira Autonomous Vehicles laboratory Federal University of Santa MariaCachoeira do Sul 96503-205Brazil Mobility and logistics laboratory Federal University of Santa MariaCachoeira do Sul 96503-205Brazil

The autonomous vehicle(AV)technology has the potential to significantly improve safety and efficiency of the transportation and logistics ***-scale AV testing is limited by time,space,and cost,while simulation-based testing often lacks the necessary accuracy of AV and environmental *** recent years,several initiatives have emerged to test autonomous software and hardware on scaled *** systematic literature review provides an overview of the literature surrounding small-scale self-driving cars,summarizing the current autonomous platforms deployed and focusing on the software and hardware developments in this *** studies published in English-language journals or conference papers that present small-scale testing of self-driving cars were *** of Science,Scopus,Springer link,Wiley,ACM Digital library,and TRID databases were used for the literature *** systematic literature search found 38 eligible *** gaps in the reviewed papers were identified to provide guidance for future *** key takeaway emerging from this manuscript are:(i)there is a need to improve the models and neural network architectures used in autonomous driving systems,as most papers present only preliminary results;(ii)increasing datasets and sharing databases can help in developing more reliable control policies and reducing bias and variance in the training process;(iii)small-scaled vehicles to ensure safety is a major benefit,and incorporating data about unsafe driving behaviors and infrastructure problems can improve the accuracy of predictive models.

关键词： Self-driving car Autonomous vehicle Small-scale vehicle Systematic literature review

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

The initial stages of li_(2)O_(2) formation during oxygen reduction reaction in li-O_(2) batteries:The significance of li_(2)O_(2) in charge-transfer reactions within devices

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Journal of Energy Chemistry 2024年第1期88卷 223-231,I0006页

作者： Daniela M.Josepetti Bianca P.Sousa Simone A.J.rodrigues Renato G.Freitas Gustavo Doubek Advanced Energy Storage Division LABCenter for Innovation on New EnergiesSchool of Chemical EngineeringUniversity of CampinasAv Albert Einstein 50013083-852CampinasSPBrazil Institute of Physics&Department of Chemistry Laboratory of Computational MaterialsFederal University of Mato Grosso78060-900CuiabáMTBrazil

lithium-oxygen batteries are a promising technology because they can greatly surpass the energy density of lithium-ion ***,this theoretical characteristic has not yet been converted into a real device with high *** with air contamination,metallic lithium reactivity,and complex discharge and charge reactions are the main issues for this technology.A fast and reversible oxygen reduction reaction(ORR)is crucial for good performance of secondary batteries',but the partial knowledge of its mechanisms,especially when devices are concerned,hinders further *** this perspective,the present work uses operando Raman experiments and electrochemical impedance spectroscopy(EIS)to assess the first stages of the discharge processes in porous carbon electrodes,following their changes cycle by cycle at initial operation.A growth kinetic formation of the discharge product signal(li_(2)O_(2))was observed with operando Raman,indicating a first-order reaction and enabling an analysis by a microkinetic *** solution mechanism in the evaluated system was ascribed for an equivalent circuit with three time *** the time constant for the anode interface reveals to remain relatively constant after the first discharge,its surface seemed to be more *** model indicated that the reaction occurs at the li_(2)O_(2) surface,decreasing the associated resistance during the initial discharge ***,the growth of li_(2)O_(2) forms a hetero-phase between li_(2)O_(2)/electrolyte,while creating a more compact and homogeneous on the li_(2)O_(2)/cathode *** methodology here described thus offers a way of directly probing changes in surface chemistry evolution during cycling from a device through EIS analysis.

关键词： li-O_(2)battery Operando Raman analysis Equivalent circuit modeling Time-constant distribution

Transarterial embolization is an acceptable bridging therapy to hepatocellular carcinoma prior to liver transplantation

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World Journal of Transplantation 2024年第2期14卷 126-134页

作者： Gabriel lazzarotto-da-Silva leandro A Scaffaro Mauricio Farenzena lucas Prediger Rafaela K Silva Flávia Heinz Feier Tomaz J M Grezzana-Filho Pablo D rodrigues Alexandre de Araujo Mario Reis Alvares-da-Silva Roberta C Marchiori Cleber Rosito Pinto Kruel Marcio Fernandes Chedid Department of liver Transplant and Hepatobiliary Surgery Unit Hospital de Clínicas de Porto AlegrePorto Alegre 90035-007Brazil Department of Interventional Radiology Unit Hospital de Clínicas de Porto AlegrePorto Alegre 90035-007Brazil Department of Gastroenterology and Hepatology Hospital de Clínicas de Porto AlegrePorto Alegre 90035-007Brazil

BACKGROUND Hepatocellular carcinoma(HCC)is an aggressive malignant neoplasm that requires liver transplantation(lT).Despite patients with HCC being prioritized by most organ allocation systems worldwide,they still have to wait for long *** therapies(lRTs)are employed as bridging therapies in patients with HCC awaiting *** largely used in the past,transarterial embolization(TAE)has been replaced by transarterial chemoembolization(TACE).However,the superiority of TACE over TAE has not been consistently shown in the *** To compare the outcomes of TACE and TAE in patients with HCC awaiting *** All consecutive patients with HCC awaiting lT between 2011 and 2020 at a single center were *** patients underwent lRT with either TACE or *** patients also underwent percutaneous ethanol injection(PEI),concom-itantly or in different treatment *** choice of lRT for each HCC nodule was determined by a multidisciplinary *** primary outcome was waitlist dropout due to tumor progression,and the secondary outcome was the occurrence of adverse *** the subset of patients who underwent lT,complete pathological response and post-transplant recurrence-free survival were also *** Twelve(18.5%)patients in the TACE group(only TACE and TACE+PEI;n=65)and 3(7.9%)patients in the TAE group(only TAE and TAE+PEI;n=38)dropped out of the waitlist due to tumor progression(P log-rank test=0.29).Adverse events occurred in 8(12.3%)and 2(5.3%)patients in the TACE and TAE groups,respectively(P=0.316).Forty-eight(73.8%)of the 65 patients in the TACE group and 29(76.3%)of the 38 patients in the TAE group underwent lT(P=0.818).Among these patients,complete pathological response was detected in 7(14.6%)and 9(31%)patients in the TACE and TAE groups,respectively(P=0.145).Post-lT,HCC recurred in 9(18.8%)and 4(13.8%)patients in the TACE and TAE groups,respectively(P=0.756).Posttransplant recurrence-free survival was simila

关键词： Hepatocellular carcinoma Transarterial embolization Transarterial chemoembolization liver transplantation locoregional therapy Bridging