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NiTi laser textured implants with improved in vivo osseointegration:An experimental study in rats

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Journal of Materials Science & Technology 2022年第19期114卷 120-130页

作者： M.M.Costa A.miranda F.Bartolomeu O.Carvalho S.Matos g.miranda F.S.Silva Center for MicroElectroMechanical Systems(CMEMS-UMinho) University of MinhoCampus de AzurémGuimarães 4800-058Portugal Life and Health Sciences Research Institute(ICVS) School of MedicineUniversity of MinhoCampus de GualtarBraga 4710-057Portugal ICVS/3B’s-PT government Associate Laboratory Braga/GuimarãesPortugal Center for Innovation and Research in Oral Sciences(CIROS) Faculty of MedicineUniversity of CoimbraFMUCPortugal CICECO Aveiro Institute of MaterialsDepartment of Materials and Ceramic EngineeringUniversity of AveiroAveiro 3810-193Portugal

Laser surface texturing is a versatile approach for manufacturing implants with suitable surfaces for *** work explores the use of laser to fabricate NiTi textured implants,testing two dif-ferent groove-based *** performance was evaluated in vivo through implantation in Sprague Dawley rats’femur,being then analyzed after 4 and 12 weeks of ***-out experiments and histological characterization allowed to assess bone-implant bond and osseointegration and to compare the laser textured solutions with non-textured *** showed that,at 4 weeks of implantation,mainly immature woven bone was present whilst at 12 weeks a more mature bone had ***-sidering the largest implantation time(12 weeks),results showed extraction forces considerably higher for textured implants(g2 and g3).Moreover,when comparing g2 and g3,it was found that g2(having the highest textured surface area)displayed the maximum extraction force among all groups,with an increase of 212%when compared to non-textured implants(g1).These results prove that the design and manufacturing technology are effective to promote an im-proved bone-implant bond,aiming the development of orthopedic implants.

关键词： NiTi Laser surface texturing In vivo studies Osseointegration Implants

Wear behavior of Ti6Al4V biomedical alloys processed by selective laser melting, hot pressing and conventional casting

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Transactions of Nonferrous Metals Society of China 2017年第4期27卷 829-838页

作者： F.BARTOLOMEU M.BUCIUMEANU E.PINTO N.ALVES F.S.SILVA O.CARVALHO g.miranda Center for Micro-Electro Mechanical Systems (CMEMS-UMinho) University of Minho Azurem 4800-058 Guimaraes Portugal Cross-Border Faculty of Humanities Economics and Engineering"Dunarea de Jos" University of Galati Domneasca 47 800008 Galati Romania Centre for Rapid and Sustainable Product Development Polytechnic Institute of Leiria Rua General Norton de Matos Apartado 4133 2411-901 Leiria Portugal

The aim of this work was to study the influence of the processing route on the microstructural constituents,hardness andtribological(wear and friction)behavior of Ti6Al4V biomedical *** this sense,three different processing routes were studied:conventional casting,hot pressing and selective laser melting.A comprehensive metallurgical,mechanical and tribologicalcharacterization was performed by X-ray diffraction analysis,Vickers hardness tests and reciprocating ball-on-plate wear tests ofTi6Al4V/Al2O3sliding *** results showed a great influence of the processing route on the microstructural constituents andconsequent differences on hardness and wear *** highest hardness and wear resistance were obtained for Ti6Al4Valloy produced by selective laser melting,due to a markedly different cooling rate that leads to significantly different microstructurewhen compared to hot pressing and *** study assesses and confirms that selective laser melting is potential to producecustomized Ti6Al4V implants with improved wear performance.

关键词： biomedical alloy Ti6Al4V alloy wear behavior microstructure selective laser melting hot pressing casting

Corrosion behaviour of PEEK or β-TCP-impregnated Ti6Al4V SLM structures targeting biomedical applications

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Transactions of Nonferrous Metals Society of China 2019年第12期29卷 2523-2533页

作者： M.M.COSTA T.A.DANTAS F.BARTOLOMEU N.ALVES F.S.SILVA g.miranda F.TOPTAN Center for Micro Electro Mechanical Systems(CMEMS) University of Minho(UMinho)4800-058 GuimarãesPortugal MIT Portugal Program School of EngineeringUniversity of MinhoGuimarãesPortugal Centre for Rapid and Sustainable Product Development Polytechnic Institute of Leiria Rua General Norton de MatosApartado 4133LeiriaPortugal IBTN/Br–Brazilian Branch of the Institute of Biomaterials Tribocorrosion and NanomedicineUNESPCampus de BauruAv.Eng.Luiz Edmundo Carrijo Coube14-0117033-360BauruSPBrazil

Ti6Al4V cellular structures were produced by selective laser melting(SLM)and then filled either with beta-tricalcium phosphate(β-TCP)or PEEK(poly-ether-ether-ketone)through powder metallurgy techniques,to improve osteoconductivity and wear *** corrosion behavior of these structures was explored considering its importance for the long-term performance of *** revealed that the incorporation of open cellular pores induced higher electrochemical kinetics when being compared with dense *** impregnation ofβ-TCP and PEEK led to the creation of voids or gaps between the metallic matrix and the impregnated material which also influenced the corrosion behavior of the cellular structures.

关键词： Ti6Al4V cellular structures corrosion multimaterial design poly-ether-ether-ketone(PEEK) beta-tricalcium phosphate(β-TCP)

Preventing brain aging by the artificial enforcement of the unfolded protein response:future directions

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Neural Regeneration Research 2024年第2期19卷 393-394页

作者： Felipe Cabral-miranda Claudio Hetz Instituto de Ciências Biomédicas Universidade Federal do Rio de JaneiroRio de JaneiroBrazil Center for geroscience Brain Health and MetabolismSantiagoChile、Biomedical Neuroscience InstituteFaculty of MedicineUniversity of ChileSantiagoChile、Program of Cellular and Molecular BiologyInstitute of Biomedical SciencesFaculty of MedicineUniversity of ChileSantiagoChile、Buck Institute for Research on AgingNovatoCAUSA

As the life expectancy of the world’s population increases,age-related diseases are emerging as one of the greatest problems facing modern *** onset of dementia and neurodegenerative diseases is strictly dependent on aging as a major risk factor and has a profound impact on various aspects of the lives of individuals and their families.

关键词： diseases aging directions

Assessment of CO_(2)storage prospect based on physical properties of Rio Bonito Formation rock units

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Energy geoscience 2024年第1期5卷 321-330页

作者： Richardson M.Abraham-A Stephanie San Martín Cañas Isabella F.S.miranda Colombo C.g.Tassinari Institute of Energy and Environment(IEE) University of São Paulo(USP)Brazil Research Centre for greenhouse gas Innovation(RCgI) University of Sãao Paulo(USP)Brazil

The physical properties of the rock units associated with the Rio Bonito Formation are presented in this study with the focus on modelling reservoir quality based on petrophysics-derived parameters to evaluate CO_(2)storage *** involves the modelling of the reservoir depths,thicknesses,flow zone indicators(FZI),and effective permeability(Keff)and presenting the CO_(2)storage efficiency factors peculiar to the rock units of the study *** results presented by this study for the stated objectives are not quite common in the *** values range from 200 mD to higher than 2000 mD,and FZI values are generally above 1.0 mm and up to 13.0 mm within the portions covered by the drilled *** sandstone units recorded are up to 20 m thick in some *** Keff and FZI models indicate the sandstone reservoirs as permeable units to support the injection and circulation of CO_(2)within the potential reservoir units of the Rio Bonio Formation across São Paulo *** from some points in the southeastern part of the study location,where the Rio Bonito are delineated at depths less than 800 m(minimum CO_(2)storage depth based on best practices),other portions are deeper,ranging from 950 m to 3500 ***-bedded layers will affect the integrity of the rocks as CO_(2)storage tanks or reservoir seals/traps/overburden within the *** bed thicknesses are up to 20 m in some ***,hybrid CO_(2)reservoir units are feasible,especially in portions where thin siltstone layers are sandwiched between sandstone units to provide considerable thicknesses based on CO_(2)storage *** current study shows that useable areas considering reservoir thickness,depth,and other physical qualities will significantly control the CO_(2)storage efficiency of the study *** studies featuring a detailed geophysical exploration of the site to confirm the availability and saturations of preexisting fluid(hydrocarbon and water)are encouraged

关键词： Rio Bonito Effective permeability Fluid transmissibility CO_(2)storage prospect Reservoir quality Overburden integrity Flow zones

High-resolution multi-scale air pollution system:Evaluation of modelling performance and emission control strategies

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Journal of Environmental Sciences 2024年第3期137卷 65-81页

作者： Diogo Lopes Joana Ferreira Sandra Rafael Ka In Hoi Xin Li Yuan Liu Ka-Veng Yuen Kai Meng Mok Ana Isabel miranda Department of Environment and Planning&CESAM University of AveiroAveiroPortugal Department of Civil&Environmental Engineering Faculty of Science and TechnologyUniversity of MacaoMacao SARChina

A high percentage of the world's population lives in areas where air pollutant concentrations exceed the World Health Organization *** work aims to develop and test,a high-resolution multi-scale air pollution modelling system by integrating a set of adequate *** system is able to provide detailed air pollutant concentrations in urban areas and support air quality management strategies through a better identification of different atmospheric *** also allows furthering the design and assessment of air pollution control measures for a specific *** evaluate its performance and suitability,the system was applied to the Macao Special Administrative Region(SAR),China,one of the most densely populated areas on earth,during a winter period when this area is affected by high levels of Particulate Matter(PM).Although the developed system tends to underestimate the PM concentrations,it revealed a good performance in reproducing the temporal and spatial air pollution *** exceedances of the Chinese air quality standards were calculated and high population exposure to PM pollution was *** tested urban atmospheric emission reduction scenarios have shown air quality improvements,indicating that emission reduction measures at urban level should focus on the domestic ***,it is crucial to implement joint pollution prevention strategies with neighbouring regions to improve the air quality in Macao *** approach developed in this work can support policymakers in defining new strategies to reduce atmospheric pollution in urban areas.

关键词： Urban areas High-resolution emission inventory Particulate matter Population exposure

Association of Congenital Heart Defects (CHD) with Factors Related to Maternal Health and Pregnancy in Newborns in Puerto Rico

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Congenital Heart Disease 2024年第1期19卷 19-31页

作者： Yamixa Delgado Caliani gaytan Naydi Perez Eric miranda Bryan Colón Morales Mónica Santos Biochemistry&Pharmacology Department San Juan Bautista School of MedicineCaguas00726Puerto Rico Hispanic Alliance for Clinical and Translational Research University of Puerto Rico Medical Sciences CampusSan Juan00936Puerto Rico Department of Internal Medicine University of Puerto Rico Medical Sciences CampusSan Juan00936Puerto Rico

Background:given the pervasive issues of obesity and diabetes both in Puerto Rico and the broader United States,there is a compelling need to investigate the intricate interplay among body mass index(BMI),pregesta-tional,and gestational maternal diabetes,and their potential impact on the occurrence of congenital heart defects(CHD)during neonatal ***:Using the comprehensive System of Vigilance and Surveillance of Congenital Defects in Puerto Rico,we conducted a focused analysis on neonates diagnosed with CHD between 2016 and *** assessment encompassed a range of variables,including maternal age,gestational age,BMI,pregestational diabetes,gestational diabetes,hypertension,history of abortion,and presence of ***:A cohort of 673 patients was included in our *** average maternal age was 26 years,within a range of 22 to 32 *** mean gestational age measured 39 weeks,with a median span of 38 to 39 *** the 673 patients,274(41%)mothers gave birth to neonates diagnosed with *** this group,22 cases were linked to pre-gestational diabetes,while 202 were not;20 instances were associated with gestational diabetes,compared to 200 without;and 148 cases exhibited an overweight or obese BMI,whereas 126 displayed a normal ***:We identiﬁed a statistically signiﬁcant correlation between pre-gestational diabetes mellitus and the occurrence of ***,our analysis did not show a statistically signiﬁcant association between maternal BMI and the likelihood of *** results may aid in developing effective strategies to prevent and manage CHD in neonates.

关键词： Congenital heart defects(CHD) obesisty maternal health diabetes body mass index(BMI)

Temperature Drop of Molten Metals in Open Channels

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World Journal of Engineering and Technology 2024年第3期12卷 493-500页

作者： Miguel A. Barron-Meza Joan Reyes-miranda Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Ciudad de Mexico Mexico

The temperature drop of molten metal flowing in open channels is numerically determined. Rectangular, trapezoidal and triangular geometries are considered. The overall heat transfer coefficients for the bottom, side walls and free surface of the channel have been taken from the literature. For each geometry, the volumetric flow rate, mean residence time and temperature drop as a function of the channel inclination angle were determined. The rectangular and trapezoidal geometries present the smallest temperature drops, while the triangular geometry presents the greatest temperature drop. The factors that most affect this drop are the value of the free surface area of the channel, and the average residence time of the molten metal in the channel.

关键词： Free Surface Heat Transfer Molten Metal Open Channel geometry Residence Time Temperature Drop

Non-Darcy Flow in Molding Sands

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Open Journal of Applied Sciences 2024年第4期14卷 976-982页

作者： Miguel A. Barron-Meza Joan Reyes-miranda Daniel Flores-Sanchez Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Ciudad de Mexico Mexico

Darcy’s law is widely used to describe the flow in porous media in which there is a linear relationship between fluid velocity and pressure gradient. However, it has been found that for high numbers of Reynolds this law ceases to be valid. In this work, the Ergun equation is employed to consider the non-linearity of air velocity with the pressure gradient in casting sands. The contribution of non-linearity to the total flow in terms of a variable defined as a non-Darcy flow fraction is numerically quantified. In addition, the influence of the shape factor of the sand grains on the non-linear flow fraction is analyzed. It is found that for values of the Reynolds number less or equal than 1, the contribution of non-linearity for spherical particles is around 1.15%.

关键词： Darcy’s Law Molding Sands Non-Darcy Flow Reynolds Number Shape Factor