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Interaction between Ni/Ti Nanomultilayers and Bulk Ti-6Al-4V during Heat Treatment
Cavaleiro, André João; Ramos, Ana Sofia; Fernandes, Francisco; Baehtz, Carsten; Vieira, Maria TeresaThe diffusion bonding of Ti-6Al-4V to NiTi alloys assisted by Ni/Ti reactive multilayer thin films indicates the diffusion of Ni from the filler material towards bulk Ti-6Al-4V. As a consequence, the fragile NiTi2 intermetallic phase is formed at the joint interface. In this context, the aim of this work is to investigate the occurrence of Ni diffusion from Ni/Ti nanomultilayers towards Ti-6Al-4V substrates. Fo...
MicroRNA-124-loaded nanoparticles increase survival and neuronal differentiatio...
Saraiva, Cláudia; Talhada, Daniela; Rai, Akhilesh; Ferreira, Raquel; Ferreira, Lino; Bernardino, Liliana; Ruscher, KarstenThere is a high quest for novel therapeutic strategies to enhance recovery after stroke. MicroRNA-124 (miR-124) has been described as neuroprotective and anti-inflammatory molecule. Moreover, miR-124 is a well described enhancer of adult neurogenesis that could offer potentially beneficial effects. Herein, we used miR-124-loaded nanoparticles (miR-124 NPs) to evaluate their therapeutic potential in an in vitro ...
Olfactory-cued navigation in shearwaters: linking movement patterns to mechanisms
Abolaffio, Milo; Reynolds, Andy M; Cecere, Jacopo G; Paiva, Vítor H.; Focardi, StefanoAfter foraging in the open ocean pelagic birds can pinpoint their breeding colonies, located on remote islands in visually featureless seascapes. This remarkable ability to navigate over vast distances has been attributed to the birds being able to learn an olfactory map on the basis of wind-borne odors. Odor-cued navigation has been linked mechanistically to displacements with exponentially-truncated power-law...
Statistical analysis of fatigue crack propagation data of materials from ancien...
Correia, J. A .F. O.; De Jesus, A. M. P.; Calcada, R.; Pedrosa, B.; Rebelo, C.; Silva, Luís Simões daFatigue crack growth (FCG) rates have traditionally been formulated from fracture mechanics, whereas fatigue crack initiation has been empirically described using stress-life or strain-life methods. More recently, there has been efforts towards the use of the local stress-strain and similitude concepts to formulate fatigue crack growth rates. A new model has been developed which derives stress-life, strain-life...
Anti-Inflammatory Strategy for M2 Microglial Polarization Using Retinoic Acid-L...
Machado-Pereira, Marta; Santos, Tiago; Ferreira, Lino; Bernardino, Liliana; Ferreira, RaquelInflammatory mechanisms triggered by microglial cells are involved in the pathophysiology of several brain disorders, hindering repair. Herein, we propose the use of retinoic acid-loaded polymeric nanoparticles (RA-NP) as a means to modulate microglia response towards an anti-inflammatory and neuroprotective phenotype (M2). RA-NP were first confirmed to be internalized by N9 microglial cells; nanoparticles did ...
Coating of Tungsten Wire with Ni/Al Multilayers for Self-Healing Applications
Ramos, Ana Sofia; Maj, Lukasz; Morgiel, Jerzy; Vieira, Maria TeresaSelf-healing materials are able to partially or completely reverse the damage inflicted on them. The possibility of self-healing mechanical and chemical failures that occur during service will improve the lifetime and reliability of structural materials. For this purpose, two main steps must be considered: (i) detection, and (ii) repairing (healing) of cracks. The exothermic character of reactive multilayers ha...
Environmentally driven sexual segregation in a marine top predator
Paiva, Vítor H.; Pereira, Justin da Silva; Ceia, Filipe R.; Ramos, Jaime A.Sexual segregation in foraging occurs in many animal species, resulting in the partitioning of resources and reduction of competition between males and females, yet the patterns and drivers of such segregation are still poorly understood. We studied the foraging movements (GPS-tracking), habitat use (habitat modelling) and trophic ecology (stable isotope analysis) of female and male Cory's shearwaters Calonectr...
Diosgenin: Recent Highlights on Pharmacology and Analytical Methodology
Jesus, Mafalda; Martins, Ana P. J.; Gallardo, Eugenia; Silvestre, SamuelDiosgenin, a steroidal sapogenin, occurs abundantly in plants such as Dioscorea alata, Smilax China, and Trigonella foenum graecum. This bioactive phytochemical not only is used as an important starting material for the preparation of several steroidal drugs in the pharmaceutical industry, but has revealed also high potential and interest in the treatment of various types of disorders such as cancer, hyperchole...
Can the CEIBA Cocktail Designed for Human Cytochrome P450 Enzymes be Used in th...
Magalhães, Paulo; De Andrés, Fernando; Falcão, Amílcar; LLerena, Adrián; Alves, GilbertoPurpose - The CEIBA cocktail consisting of caffeine (CAF), omeprazole (OZ), dextromethorphan (DM) and losartan (LOS) was previously proposed for the clinical phenotyping of five major human cytochrome P450 (CYP) isoenzymes. This work aimed to assess the usefulness of CEIBA cocktail to study non-clinical drug interactions in the rat. Methods - Wistar rats were divided into five groups to receive a single-oral do...
Joining of TiAl to Steel by Diffusion Bonding with Ni/Ti Reactive Multilayers
Simões, Sónia; Ramos, Ana S.; Viana, Filomena; Vieira, Maria Teresa; Vieira, ManuelDissimilar diffusion bonds of TiAl alloy to AISI 310 stainless steel using Ni/Ti reactive multilayers were studied in this investigation. The Ni and Ti alternating layers were deposited by d.c. magnetron sputtering onto the base materials, with a bilayer thickness of 30 and 60 nm. Joining experiments were performed at 700 and 800 C for 60 min under pressures of 50 and 10 MPa. The effectiveness of using Ni/Ti mu...