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Improvements in tribological and anticorrosion performance of porous Ti–6Al–4V via PeO coating

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Friction 2021年第5期9卷 1303-1318页

作者： C.garcia-Cabezón M.L.Rodríguez-Méndez V.AmigóBorrás R.Bayón C.Salvo-Comino C.garcia-Hernandez F.Martin-Pedrosa Materials engineering E.I.I.Universidad de ValladolidValladolid 47011Spain BioecoUVA Research Institute Universidad de ValladolidValladolid 47011Spain Group UVASeNS Escuela de Ingenierías IndustrialesUniversidad de ValladolidValladolid 47011Spain Instituto de Tecnología de Materials Univesitat Politécnica de ValenciaValencia 46022Spain Tribology Unit Fundación IK4-TeknikerEibar 20600Spain

Medical implants manufactured using biomaterial Ti–6Al–4V exhibit some *** higher elastic modulus than that of natural bone can cause stress shielding *** can be avoided using Ti–6Al–4V with pores in the implant ***,poor corrosion and tribocorrosion behaviors are yielded because of the large area exposed to the *** mitigate both issues,coating technologies can be *** plasma electrolytic oxidation(PeO)process is a cost‐effective process that has been used successfully in nonporous Ti *** this study,two PeO coatings with different amounts of Ca/P are ***,reports regarding their application in porous materials are *** effects of PeO treatments on corrosion and tribocorrosion in Ti–6Al–4V powder metallurgy are analyzed *** porous materials provide an efficient surface for PeO coatings,as demonstrated via scanning electron microscopy(SeM)and atomic force microscopy(AFM),and the porosity of the substrates improved the adherence of the *** corrosion resistance measured via electrochemical impedance spectroscopy confirmed the beneficial effect of the coatings,particularly for long exposure *** lower roughness,small pore size,and more compact film observed in the PeO–Ca/P sample resulted in favorable tribological and corrosion properties.

关键词： Ti‐based alloys corrosion tribocorrosion surface modification

experimental evaluation and simulation of volumetric shrinkage and warpage on polymeric composite reinforced with short natural fibers

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Frontiers of Mechanical engineering 2015年第3期10卷 287-293页

作者： Jonnathan D. SANTOS Jorge I. FAJARDO Alvaro R. CUJI Jaime A. garcia Luis e. GARZON Luis M. LOPeZ Department of Mechanical engineering Universidad Polit6cnicaSalesiana Elia Liut Ecuador Department of Mechanical engineering Universidad PontificiaBolivariana Medellin Columbia

A polymeric natural fiber-reinforced composite is developed by extrusion and injection molding process. The shrinkage and warpage of high-density polyethylene reinforced with short natural fibers of Guadua angustifolia Kunth are analyzed by experimental measure- ments and computer simulations. Autodesk Moldflow and Solid Works are employed to simulate both volumetric shrinkage and warpage of injected parts at different configurations： 0wt.%, 20wt.%, 30wt.% and 40 wt.% reinforcing on shrinkage and warpage behavior of polymer composite. Become evident the restrictive effect of reinforcing on the volumetric shrinkage and warpage of injected parts. The results indicate that volumetric shrinkage of natural composite is reduced up to 58% with fiber increasing, whereas the warpage shows a reduction form 79% to 86% with major fiber content. These results suggest that it is a highly beneficial use of natural fibers to improve the assembly properties of polymeric natural fiber-reinforced composites.

关键词： biocomposite natural fiber shrinkage,simulation warpage

Preparation of Rod-like Aluminum Doped Zinc Oxide Powders by Sol-gel Technique Using Metal Chlorides and Acetylacetone Precursors

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Journal of Wuhan University of Technology(Materials Science) 2018年第6期33卷 1293-1297页

作者： KeSHTKAR Javad VARGAS garcia Jorge Roberto GALAVIZ PeReZ Jorge MARTINeZ TRINIDAD José escuela Superior de Ingenieria Mecánica y eléctrica Instituto Politécnico NacionalMéxico07738CDMXMéxico escuela Superior de Ingenieria Quimica e Industrias extractivas Instituto Politécnico NacionalMéxico07738CDMXMéxico Universidad Juárez Autònoma de Tabasco DivisiònAcadémica Multidisciplinaria de Jalpa de MéndezRibera AltaJalpa de MéndezTabasco86205México

Al-doped ZnO(AZO) powders were prepared by using metal chloride precursors and the sol-gel technique. IR peaks observed at 1590 cm-1 and 1620 cm-1indicated the formation of metal chelate as a consequence of the addition of acetylacetone to the metal chloride solution. TG-DSC analysis of the AZO gels confirmed the formation of metal chelate as evidenced by the development of several weight loss peaks accompanied by the introduction of new endothermic peaks. The resulting AZO gels were annealed at 500, 600, and 800 ℃ to study the effect of annealing temperature. XRD and SeM results showed that crystallization of AZO gels takes place around 600 ℃. Hexagonal wurtzite structure was identified as the main phase for all the samples. In addition, small shift of the XRD(002) peak coupled with XPS results from the AZO powders confirmed the successful doping of the ZnO powders. Micron sized rod-like AZO powders were uniform in dimension and morphology and remained stable even at 800 ℃.

关键词： aluminum doped ZnO rod-like metal chloride sol gel acetylacetone

The Battle to Sequence the Bread Wheat Genome:A Tale of the Three Kingdoms

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Genomics, Proteomics & Bioinformatics 2020年第3期18卷 221-229页

作者： Jiantao Guan Diego F.garcia Yun Zhou Rudi Appels Aili Li Long Mao National Key Facility for Crop Gene Resources and Genetic Improvement Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijing 100081China Collaborative Innovation Center of Crop Stress Biology&Institute of Plant Stress Biology School of Life ScienceHenan UniversityKaifeng 475004China AgriBio Centre for AgriBioscienceDepartment of Economic DevelopmentJobsTransportand ResourcesLa Trobe UniversityMelbourneVIC 3083Australia

In the year 2018,the world witnessed the finale of the race to sequence the genome of the world’s most widely grown crop,the common *** has been known to bear a notoriously large and complicated genome of a polyploidy nature.A decade competition to sequence the wheat genome initiated with a single consortium of multiple countries,taking a conventional strategy similar to that for sequencing Arabidopsis and rice,became ferocious over time as both sequencing technologies and genome assembling methodologies *** different stages,multiple versions of genome sequences of the same variety(e.g.,Chinese Spring)were produced by several groups with their special ***,16 years after the rice genome was finished and 9 years after that of maize,the wheat research community now possesses its own reference *** with these genomics tools,wheat will reestablish itself as a model for polyploid plants in studying the mechanisms of polyploidy evolution,domestication,genetic and epigenetic regulation of homoeolog expression,as well as defining its genetic diversity and breeding on the genome *** enhanced resolution of the wheat genome should also help accelerate development of wheat cultivars that are more tolerant to biotic and/or abiotic stresses with better quality and higher yield.

关键词： Common wheat Homoeologous genomes Polyploid Sequencing Triticum aestivum

Land-use Changes Alter energy and Water Balances on an African Brachiaria Pasture Replacing a Native Savanna in the Orinoco llanos

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Journal of Atmospheric Science Research 2019年第2期2卷 22-36页

作者： José San-José Rubén Montes Rafael Herrera jair M. Maia Nina Nikonova ecology Center Venezuelan Institute for Scientific ResearchAP 20632Caracas 1020-AVenezuela environment Studies Departament Simón Bolívar UniversityAP 89000Caracas 1080-AVenezuela escola Normal Superior Universidade do Estado do AmazonaManausBrazil

The seasonal changes in the energy balance after the substitution of a herbaceous savanna by a Brachiaria field located in the Orinoco lowlands were assessed over an entire year using the eddy covariance technique. Simultaneously, an herbaceous savanna was monitored as a control. This work provides evidence that the vegetation replacement lead to different patterns of energy and water balance. The seasonal trends of the latent heat flux (λe) to available energy (Ra) ratio tended to decrease as senescence increased due to seasonal influence of air humidity mole fraction deficit and soil water content on leaf area index (LAI) and surface conductance (gs). Therefore, the partitioning of the available energy depended on both climatological (i.e., solar radiation, volumetric soil water content and air humidity mole fraction deficit) and biological variables (i.e., conductance behavior and LAI) which were stress-induced. For the wet season, the seasonally averaged daily λe in the Brachiaria field (i.e., 0.8 ± 0.1 mm d^-1) was 1.3-fold higher than that in the herbaceous savanna (i.e., 0.6 ± 0.1 mm d-1)(Mann-Whitney U-test). For the dry season, the value was 2.7 ± 0.6 and 2.2 ± 0.4 mm d-1, respectively, these means values were not significantly different. In the Brachiaria and herbaceous savanna stands, the annual evapotranspiration was 731 and 594 mm year^-1, respectively, and the annual ratio of evapotranspiration to precipitation was 0.52 to 0.42 respectively. In Brachiaria field, the deep drainage was relatively lower (43% of total precipitation) than that in the herbaceous savanna stand (53%) leaving a similar amount of water to increase soil storage. The current shift in land cover decrease deep drainage and increased λe by water uptake from a pasture with high belowground phytomass and LAI.

关键词： energy balance Seasonal effect Orinoco lowlands

Unveiling the controversial mechanism of reversible Na storage in TiO2 nanotube arrays： Amorphous versus anatase TiO2

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Nano Research 2017年第8期10卷 2891-2903页

作者： Federico Bella Ana B. Munoz-garcia Giuseppina Meligrana Andrea Lamberti Matteo Destro Michele Pavone Claudio Gerbaldi GAMe Lab CHENERGY Group Department of Applied Science and Technology - DISAT Politecnico di Torino Corso Duca degli Abruzzi 24 10129 Torino Italy Department of Chemical Sciences University of Naples Fedefico II Via Cintia 21 University Campus of Monte Sant'Angelo 80126 Napoli Italy MPMNT Group Department of Applied Science and Technology - DISAT Politecnico di Torino Corso Duca degli Abruzzi 24 10129 Torino Italy LITHOPS S.r.l. Strada del Portone 61 10137 Torino Italy

Due to their inherent safety, low cost, and structural stability, TiO2 nanostructures represent a suitable choice as anode materials in sodiumion batteries. In the recent years, various hypotheses have been proposed regarding the actual mechanism of the reversible insertion of sodium ions in the TiO2 structure, and previous reports are often controversial in this respect. Interestingly, when tested as binder- and conducting additive-free electrodes in laboratory-scale sodium cells, amorphous and crystalline （anatase） TiO2 nanotubular arrays obtained by simple anodic oxidation exhibit peculiar and intrinsically different electrochemical responses. In particular, after the initial electrochemical activation, anatase TiO2 shows excellent rate capability and very stable long-term cycling performance with larger specific capacities, and thus a clearly superior response compared with the amorphous counterpart. To obtain deeper insight, the present materials are thoroughly characterized by scanning electron microscopy and ex situ X-ray diffraction, and the insertion of sodium ions in the TiO2 bulk phases is systematically modeled by density functional theory calculations. The present results may contribute to the development of more systematic screening approaches to identify suitable active materials for highly efficient sodium-based energy storage systems.

关键词： sodium battery TiO2 nanotube array anode modeling insertion mechanism

Thermoluminescence characterization of natural and synthetic irradiated Ce-monazites

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Journal of Rare earths 2024年第4期42卷 643-650页

作者： V.Correcher C.Boronat J.garcia-Guinea J.F.Benavente T.Rivera-Montalvo CIeMAT Av.Complutense 4028040MadridSpain MNCN-CSIC J.Gutierrez Abascal 228006MadridSpain Instituto Politécnico Nacional CICATA-IPNAv.Legaria 694Mexico City11500Mexico

The thermoluminescence(TL)emission of synthetic and natural Ce-monazites was characterized here to determine the potential application in the identification of microscopic defects from a qualitative point of view trying to link each TL peak to a chemical-physical *** kinetic parameters that lead the luminescence processes were calculated by means of variable heating rate and computing glow curve deconvolution methods and allow identifying three groups of components at~90,130 and 290℃(for the mineral sample)and~90,170,220,270 and 320℃(for the synthetic CePO_(4):Nd_(0.20),La_(0.25)).The main differences appreciated in these complex TL curves are mainly due to(i)the content of impurities(natural sample contains lanthanides as well as U 0.60%and Th 5.22%)and(ii)the degree of crystallinity of the samples which is directly related to the type of impurities(synthetic monazite relies only on Nd and La).The behavior of the dose response in the range of 1-8 Gy is similar for both samples;the TL intensity increases linearly as the dose increases without changes in the position of the maxima,denoting first-order kinetic luminescence *** peak could be mostly associated with structural defects(i.e.,phase transitions),chemical reactions(i.e.,Ce3+?Ce4+redox reaction,dehydration or dehydroxylation processes)or intrinsic defects(i.e.,Frenkel defects,ODCs or NBOHCs).

关键词： Thermoluminescence Kineticparameters Phosphate Ce-monazite Defects Rare earths

MORTl/FADD is involved in liver regeneration

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World Journal of Gastroenterology 2005年第46期11卷 7248-7253页

作者： Marcus Schuchmann Felix Rückert Jose F garcia-Lazaro Andrea Karg Jürgen Burg Natalia Knorr Jürgen Siebler eugene e Varfolomeev David Wallach Wolfgang Schreiber Ansgar W Lohse Peter R Galle Department of Medicine University of Mainz Langenbeckstr.1Mainz 55101 Germany Institute of RadiologyUniversity of Mainz Langenbeckstr.1Mainz 55101Germany Institute of PathologyUniversity of Mainz Langenbeckstr. 1 Mainz 55101 Germany Department of MedicineUniversity of Mainz Langenbeckstr.1Mainz 55101Germany GenentechSouth San Francisco CAUnited States The Weizmann Institute of ScienceRehovot Israel Institute of RadiologyUniversity of Mainz Langenbeckstr.1Mainz 55101 Germany Department of Medicine University of Mainz Langenbeckstr.1Mainz 55101 Germany

AIM: To explore the role of the adaptor molecule in liver regeneration after partial hepatectomy (PH). MeTHODS: We used transgenic mice expressing an N-terminal truncated form of MORT1/FADD under the control of the albumin promoter. As previously shown, this transgenic protein abrogated CD95- and CD120a-mediated apoptosis in the liver. Cyclin A expression was detected using Western blotting. eLISA and RT-PCR were used to detect IL-6 and IL-6 mRNA, respectively. DNA synthesis in liver tissue was measured by BrdU staining. ReSULTS: Resection of 70% of the liver was followed by a reduced early regenerative response in the transgenic group at 36 h. Accordingly, 36 h after hepatectomy, cyclin A expression was only detectable in wild-type animals. Consequently, the onset of liver mass restoration was retarded as measured by MRI volumetry and mortality was significantly higher in the transgenic group. CONCLUSION: Our data demonstrate for the first time an involvement of the death receptor molecule MORT1/ FADD in liver regeneration, beyond its well described role as part of the intracellular death signaling pathway.

关键词： MORT1/FADD CD95 TNF Apoptosis Liver regeneration

evaluation of activity of triclabendazole against Taenia solium metacestode in naturally infected pigs

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Asian Pacific Journal of Tropical Medicine 2016年第1期9卷 20-23页

作者： Ana Vargas-Calla Luis A.Gomez-Puerta Juan Calcina Omar Gonzales-Viera Cesar Gavidia Maria T.Lopez-Urbina Hector H.garcia Armando e.Gonzalez School of Veterinary Medicine Universidad Nacional Mayor de San Marcos Cysticercosis elimination Program and Center for Global Heath Tumbes Universidad Peruana Cayetano Heredia Department of Microbiology School of SciencesUniversidad Peruana Cayetano Heredia

Objective:To assess the efficacy of triclabendazole(TCBZ) in porcine ***:eighteen naturally infected cysticercotic pigs were divided into 3 groups of 6 individuals *** first group was treated orally with TCBZ at a single dose of 30 mg/kg of body weight,the second group was treated orally with oxfendazole at a single dose of 30 mg/kg of body weight and the third group received a placebo(control group).All animals were kept under the same management *** pigs were euthanized 17 wk post-treatment and the number of surviving cysts in muscles was assessed and compared between ***:All pigs treated with oxfendazole had only degenerated cysts in their *** contrast,TCBZ had very little effect against the parasitic *** from pigs in the TCBZ group looked apparently normal after ***,histological evaluation showed a mild to moderate degree of ***:TCBZ is not an efficacious drug against Taenia solium cysticercosis in swine using a single dose.

关键词： Taenia solium Cysticercosis Triclabendazole Oxfendazole Treatment