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Bone Remodeling, Biomaterials And Technological Applications: Revisiting Basic concepts

Journal of Biomaterials and Nanobiotechnology 2011年第3期2卷 318-328页

作者： Patricia c.Salgado Plinio c.Sathler helena c.castro Gutemberg G.Alves Aline M.de Oliveira Rodrigo cde Oliveira Monica D.c.Maia carlos R.Rodrigues Paulo G.coelho Andre Fuly Lúcio M.cabral Jose M.Granjeiro Program of Post-Graduation in Medical Sciences Fluminense Federal UniversityNiteróiBrazil Post-Graduation in Biology of Interactions Institute of BiologyFluminense Federal UniversityNiteróiBrazil Program of Post-Graduation in Pathology Fluminense Federal UniversityNiteróiBrazil clinical Research Unit Antonio Pedro HospitalNucleus of Cell TherapyFluminense Federal UniversityNiteróiBrazil School of Odontology Fluminense Federal UniversityNiteróiBrazil Department of Biological Sciences Dental School of BauruSão Paulo UniversitySão PauloBrazil School of Pharmacy Federal University of Rio de JaneiroRio de JaneiroBrazil Department of Biomaterials and Biomimetics New York UniversityNew YorkUSA

Presently, several different graft materials are employed in regenerative or corrective bone surgery. However current misconceptions about these biomaterials, their use and risks may compromise their correct application and development. To unveil these misconceptions, this work briefly reviewed concepts about bone remodeling, grafts classification and manufacturing processes, with a special focus on calcium phosphate materials as an example of a current employed biomaterial. Thus a search on the last decade was performed in Medline, LILAcS, Scielo and other scientific electronic libraries using as keywords biomaterials, bone remodeling, regeneration, biocompatible materials, hydroxyapatite and therapeutic risks. Our search showed not only an accelerated biotechnological development that brought significant advances to biomaterials use on bone remodeling treatments but also several therapeutic risks that should not be ignored. The biomaterials specificity and limitations to clinical application point to the current need for developing safer products with better interactions with the biological microenvironments.

关键词： Biocompatible materials Bone remodeling Hydroxyapatite Therapeutic risks

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Development and assessment of a multifunctional chitosan-based coating applied on AZ31 magnesium alloy: corrosion resistance and antibacterial performance against Klebsiella Pneumoniae

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Journal of Magnesium and Alloys 2021年第6期9卷 2133-2144页

作者： Emmanuel Mena-Morcillo Lucien Veleva Mariana cerda-Zorrilla Montserrat Soria-castro Juan c.castro-Alcátara Rosa c.canul-Puc Applied Physics Department Center for Research and Advanced Study(CINVESTAV-IPN)Carr.Ant.a Progreso Km.697310MeridaYucatanMexico Marine Resources Department Center for Research and Advanced Study(CINVESTAV-IPN)Carr.Ant.a Progreso Km.697310MeridaYucatanMexico

This work presents a simple method to functionalise the surface of AZ31 magnesium alloy by applying a duplex MgF_(2)/chitosan coating,which improves its corrosion resistance and provides it with some antibacterial ***,the effect of three chitosan solutions with different concentrations on the growth of the bacteria Klebsiella pneumoniae in nutritive medium(TSB)was evaluated by absorbance kinetics experiments,where the chitosan solution at 2%(m/V)was selected for the coating *** coating application,the AZ31 substrate was pretreated with hydrofluoric acid for 48 hours in order to form a MgF_(2)conversion ***,the coating was applied to the pretreated substrate through the dry-casting *** of the alloy in each surface condition(bare,pretreated,and pretreated+coated with chitosan)were exposed to simulated body fluid(SBF)for 21 days at 37°c,with the solution renewed every 24 hours and the wastes *** surfaces were characterised by SEM-EDS,and XPS after the immersion tests,whereas the stored solutions were employed to measure the change in the Mg-ions *** impedance spectroscopy and potentiodynamic polarisation were performed in each surface condition to compare their corrosion resistance in *** antibacterial activity of the functionalised surfaces was evaluated by the plate counting method and compared with bare *** results were correlated and demonstrate that the modified surface of AZ31 achieved a higher corrosion resistance when it was exposed to SBF,as well as a reduction of the bacterial growth during in vitro tests.

关键词： AZ31 chitosan coating Simulated body fluid corrosion Antibacterial activity

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chinese Annals of Mathematics,Series B 2009年第5期30卷 505-512页

作者： Angel castro Diego cóRDOBA Instituto de ciencias Matemticas CSIC-UAM-UC3M-UCMConsejo Superior de Investigaciones Científicas

The authors construct self-similar solutions for an N-dimensional transport equation,where the velocity is given by the Riezs *** solutions imply nonuniqueness of weak *** addition,self-similar solution for a one-dime... 详细信息

关键词： Hilbert transform Riesz transform Transport equations Self-similar solutions

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The potential leaching and mobilization of trace elements from FGD-gypsum of a coal-fired power plant under water re-circulation conditions

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Journal of Environmental Sciences 2015年第6期27卷 72-80页

作者： Patricia córdoba Iria castro Mercedes Maroto-Valer Xavier Querol centre for Innovation on carbon capture and Storage Institute of Mechanical Process and Energy Engineering Heriot-Watt University Institute of Environmental Assessment and Water Research

Experimental and geochemical modelling studies were carried out to identify mineral and solid phases containing major, minor, and trace elements and the mechanism of the retention of these elements in Flue Gas Desulphurisation（FGD）-gypsum samples from a coal-fired power plant under filtered water recirculation to the scrubber and forced oxidation conditions. The role of the p H and related environmental factors on the mobility of Li, Ni, Zn, As, Se, Mo, and U from FGD-gypsums for a comprehensive assessment of element leaching behaviour were also carried out. Results show that the extraction rate of the studied elements generally increases with decreasing the p H value of the FGD-gypsum leachates. The increase of the mobility of elements such as U, Se, and As in the FGD-gypsum entails the modification of their aqueous speciation in the leachates; UO2SO4, H2 Se, and HAs O2 are the aqueous complexes with the highest activities under acidic *** speciation of Zn, Li, and Ni is not affected in spite of p H changes; these elements occur as free cations and associated to SO4 ^2 in the FGD-gypsum leachates. The mobility of cu and Mo decreases by decreasing the p H of the FGD-gypsum leachates, which might be associated to the precipitation of cu Se2 and Mo Se2, respectively. Time-of-Flight mass spectrometry of the solid phase combined with geochemical modelling of the aqueous phase has proved useful in understanding the mobility and geochemical behaviour of elements and their partitioning into FGD-gypsum samples.

关键词： Geochemical modelling studies Trace elements Leaching Landfills FGD-gypsum ToF mass spectrometry

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The inception of a Paleotethyan magmatic arc in Iberia

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Geoscience Frontiers 2015年第2期6卷 297-306页

作者： M.F.Pereira A.castro c.Fernández IDL Departamento de Geociências ECT Universidade de évora Departamento de Geología Universidad de Huelva Departamento de Geodinámica y Paleontología Universidad de Huelva

This paper presents a compilation of recent U-Pb （zircon） ages of late carboniferous-early Permian （Lc EP） calc-alkaline batholiths from lberia, together with a petrogenetic interpretation of magma generation based on comparisons with Mesozoic and Tertiary cordilleran batholiths and experimental melts. Zircon U-Pb ages distributed over the range ca. 315-280 Ma, indicate a linkage between calc-alkaline magmatism, Iberian orocline generation and Paleotethys subduction. It is also shown that Iberian Lc-EP calcalkaline batholiths present unequivocal subduction-related features comparable with typical cordilleran batholiths of the Pacific Americas active margin, although geochemical features were partially obscured by local modifications of magmas at the level of emplacement by country rock assimilation. When and how Lc-EP calc-alkaline batholiths formed in Iberia is then discussed, and a new and somewhat controversial interpretation for their sources and tectonic setting （plume-assisted relamination） is suggested. The batholiths are proposed to have formed during the subduction of the Paleotethys oceanic plate （Pangaea self-subduction） and, consequently, they are unrelated to Variscan collision. The origin of the Iberian batholiths is related to the Eurasian active margin and probably represents the inception of a Paleotethvan arc in the core of Pangaea.

关键词： Permo-carboniferous calc-alkaline arc-related batholiths Pangaea Paleotethys subduction Variscan and cimmerian cycles

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The off-crust origin of granite batholiths

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Geoscience Frontiers 2014年第1期5卷 63-75页

作者： Antonio castro Unidad Asociada de Petrología Experimental CSIC-Universidad de Huelva.Campus El Carmen21071 Huelva Spain

Granitod batholiths of I-type features （mostly granodiorites and tonalites）, and particularly those forming the large plutonic associations of active continental margins and intracontinental collisional belts, represent the most outstanding magmatic episodes occurred in the continental crust. The origin of magmas, however, remains controversial. The application of principles from phase equilibria is crucial to understand the problem of granitoid magma generation. An adequate comparison between rock com- positions and experimental liquids has been addressed by using a projected compositional space in the plane F（Fe ＋ Mg）-Anorthite-Orthoclase. Many calc-alkaline granitoid trends can be considered cotectic liquids. Assimilation of country rocks and other not-cotectic processes are identified in the projected diagram. The identification of cotectic patterns in batholith implies high temperatures of magma segregation and fractionation （or partial melting） from an intermediate （andesitic） source. The com- parison of batholiths with lower crust granulites, in terms of major-element geochemistry, yields that both represent liquids and solid residues respectively from a common andesitic system. This is compatible with magmas being formed by melting, and eventual reaction with the peridotite mantle, of subducted mOlanges that are finally relaminated as magmas to the lower crust. Thus, the off-crust generation of granitoids batholiths constitutes a new paradigm in which important geological implica- tions can be satisfactorily explained. Geochemical features of cordilleran-type batholiths are totally compatible with this new conception.

关键词： Batholith Granodiorite Andesite Relamination Granulite Lower crust

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A comparative study on emergent pollutants photo-assisted degradation using ruthenium modified titanate nanotubes and nanowires as catalysts

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Journal of Environmental Sciences 2020年第6期32卷 38-51页

作者： Beatriz Barrocas M.conceicao Oliveira helena I.S.Nogueira Sara Fateixa Olinda c.Monteiro centro de Química Estrutural Faculdade de CienciasUniversidade de LisboaLisboa 1749-016Portugal centro Química Estrutural Instituto Superior TécnicoUniversidade de LisboaLisboa 1049-001Portugal Department of chemistry CICECO-Aveiro Institute of MaterialsUniversity of AveiroAveiro 3810-193Portugal

Several methods have been used to tailor nanomaterials structure and ***,slight changes in the structure outcomes expressive improvements in the optical and photocatalytic properties of semiconductor *** this context,the influence of the metal doping and the morphology on a catalyst performance was studied in this ***,ruthenium doped titanate nanotubes(RuTNT)were synthesised for the first time using an amorphous Ru-containing ***,the photocatalytic performance of this sample was compared to the one obtained for ruthenium titanate nanowires(RuTNW),recently *** samples,RuTNW and RuTNT,were produced using the same Ru-containing precursor but distinct hydrothermal *** powders were structural,morphological and optical characterized by X-ray diffraction and fluorescence,transmission electron microscopy,Raman,X-ray photoelectron and photoluminescence *** variations on the structural and optical properties of the RuTNT and RuTNW nanoparticles,due to ruthenium incorporation were *** potential use as photocatalysts was evaluated on the hydroxyl radical photo-assisted *** samples were catalytic for this reaction,presenting better performances than the pristine counterparts,being RuTNT the best ***,the degradation of two emergent pollutants,caffeine and sulfamethazine,was *** demonstrated to be better photocatalyst than RuTNW for caffeine but identical performances were obtained for *** both catalysts,the degradation mechanism of the pollutants was explored through the identification and quantification of the intermediate compounds produced and several differences were *** indicates the importance of the structural and morphological aspects of a material on its catalytic performance.

关键词： Titanate nanotubes and nanowires Ruthenium doping Ru-Ti replacement Emergent pollutants Photocatalytic degradation

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Energy efficiency in a water supply system:Energy consumption and cO_2 emission

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Water Science and Engineering 2010年第3期3卷 331-340页

作者： helena M.RAMOS Filipe VIEIRA Dídia I.c.cOVAS Department of civil Engineering ISTTechnical University of Lisbon cEHIDRO IST-DECivilLisbon 1049-001Portugal

This paper presents important fundamentals associated with water and energy efficiency and highlights the importance of using renewable energy sources. A model of multi-criteria optimization for energy efficiency based on water and environmental management policies, including the preservation of water resources and the control of water pressure and energy consumption through a hybrid energy solution, was developed and applied to a water supply system. The methodology developed includes three solutions：（1） the use of a water turbine in pipe systems where pressures are higher than necessary and pressure-reducing valves are installed, （2） the optimization of pumping operation according to the electricity tariff and water demand, and （3） the use of other renewable energy sources, including a wind turbine, to supply energy to the pumping station, with the remaining energy being sold to the national electric grid. The use of an integrated solution （water and energy-） proves to be a valuable input for creating benefits from available hydro energy in the water supply system in order to produce clean power, and the use of a wind source allows for the reduction of energy consumption in pumping stations, as well as of the cO2 emission to the atmosphere.

关键词： multi-criteria optimization energy efficiency water supply renewable energy sources cO2 emission

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The ULT1 and ULT2 trxG Genes Play Overlapping Roles in Arabidopsis Development and Gene Regulation

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Molecular Plant 2013年第5期6卷 1564-1579页

作者： Mona M. Monfared cristel c. caries Pascale Rossignol helena R. Pires Jennifer c. Fletcher Plant Gene Expression center USDA-ARS/UC Berkeley 800 Buchanan Street. Albany CA 94710 USA Department of Plant and Microbial Biology University of California Berkeley 111 Koshland Hall Berkeley CA 94720 USA cNRS UMR5168 F-38054 Grenoble France Universite Grenoble Alpes UMR5168 F-38041 Grenoble France cEA iRTSV Laboratoire Physiologie Cellulaire et Vegetale F-38054 Grenoble France INRA F-38054 Grenoble France Department of Molecular Cellular and Developmental Biology Yale University New Haven CT 06520 USA Faculdade de ciencias da Universidade do Porto Porto Portugal

The epigenetic regulation of gene expression is critical for ensuring the proper deployment and stability of defined genome transcription programs at specific developmental stages. The cellular memory of stable gene expression states during animal and plant development is mediated by the opposing activities of Polycomb group （PcG） factors and trithorax group （trxG） factors. Yet, despite their importance, only a few trxG factors have been characterized in plants and their rotes in regulating plant development are poorly defined. In this work, we report that the closely related Arabidopsis trxG genes ULTRAPETALA1 （ULT1） and ULT2 have overlapping functions in regulating shoot and floral stem cell accumula- tion, with ULT1 playing a major role but ULT2 also making a minor contribution. The two genes also have a novel, redun- dant activity in establishing the apical-basal polarity axis of the gynoecium, indicating that they function in differentiating tissues. Like ULT1 proteins, ULT2 proteins have a dual nuclear and cytoplasmic localization, and the two proteins physically associate in planta. Finally, we demonstrate that ULT1 and ULT2 have very similar overexpression phenotypes and regulate a common set of key development target genes, including floral MADS-box genes and class I KNOX genes. Our results reveal that chromatin remodeling mediated by the ULT1 and ULT2 proteins is necessary to control the development of mer- istems and reproductive organs. They also suggest that, like their animal counterparts, plant trxG proteins may function in multi-protein complexes to up-regulate the expression of key stage- and tissue-specific developmental regulatory genes.

关键词： trxG factor epigenetics stem cells Arabidopsis polarity ULTRAPETALA.

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Global Warming and the Power-Laws of Ecology

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Atmospheric and climate Sciences 2012年第1期2卷 8-13页

作者： Joao D.T.Arruda-Neto Maria c.Bittencourt-Oliveira Alrenice c.castro Tulio E.Rodrigues Joseph Harari Joel Mesa Godofredo c.Genofre Physics Institute University of Sao PauloSao PauloBrazil cEPESq/UniItalo Italy-Brazilian University CenterSao PauloBrazil Laboratory of cyanobacteria ESALQUniversity of Sao PauloPiracicabaBrazil PROcAM Interdisciplinary Graduate Program on Environmental SciencesUniversity of Sao PauloSao PauloBrazil Institute of Oceanography University of Sao PauloSao PauloBrazil Institute of Biosciences Sao Paulo State UniversityBotucatuBrazil Institute of Biosciences University of Sao PauloSao PauloBrazil

A model based on Watson’s power law for the species-area relationship predicts that full global warming, projected up to the year 2050, could provoke the disappearance of roughly one-quarter of existing species. Here, an alternative approach is worked out, based on the combination of two ecology laws: Taylor and Watson’s power laws, where the former relates species variability with their mean abundance. Just how severely global warming would affect not only the number but the diversity of the surviving species is addressed by this approach, while at the same time giving indications for the post-disaster fate of the remaining species (extinction or recovery).

关键词： Global Warming Species Extinction Ecology Power-Laws Species Variability Model

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