5,184 research outputs found

    182 Nuclear fragmentation in protontherapy

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    “Chaves” para análise facial em Ortodontia

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    Poster apresentado nas XXIII Jornadas Internacionais de Medicina Dentária ISCSEM, 20-21 Março 2015, Egas Moniz, Caparica, Portugal

    Monte Carlo Simulations Applied To Alx Gay In1-x-y X Quaternary Alloys (x=as,p,n): A Comparative Study

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    We develop a different Monte Carlo approach applied to the Ax By C1-x-y D quaternary alloys. Combined with first-principles total-energy calculations, the thermodynamic properties of the (Al,Ga,In) X (X=As, P, or N) systems are obtained and a comparative study is developed in order to understand the roles of As, P, and N atoms as the anion X in the system Alx Gay In1-x-y X. Also, we study the thermodynamics of specific compositions in which AlGaInN, AlGaInP, and AlGaInAs are lattice matched, respectively, to the GaN, GaAs, and InP substrates. We verify that the tendency for phase separation is always towards the formation of an In-rich phase. For arsenides and phosphides this occurs in general for lower temperatures than for their usual growth temperatures. This makes these alloys very stable against phase separation. However, for nitrides the In and/or Al concentrations have to be limited in order to avoid the formation of In-rich clusters and, even for low concentrations of In and/or Al, we observe a tendency of composition fluctuations towards the clustering of the ternary GaInN. We suggest that this latter behavior can explain the formation of the InGaN-like nanoclusters recently observed in the AlGaInN quaternary alloys. © 2005 The American Physical Society.7120Stringfellow, G.B., (1983) J. Appl. Phys., 54, p. 404. , JAPIAU 0021-8979 10.1063/1.331719Olego, D., Chang, T.Y., Silberg, E., Caridi, E.A., Pinczuk, A., (1982) Appl. Phys. Lett., 41, p. 476. , APPLAB 0003-6951 10.1063/1.93537Fujii, T., Nakata, Y., Sigiyama, Y., Hiyiamizu, S., (1986) Jpn. J. Appl. Phys., Part 1, 25, p. 254. , JAPNDE 0021-4922Mowbray, D.J., Kowalski, O.P., Hopkinson, M., Skolnick, M.S., David, J.P.R., (1994) Appl. Phys. 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    Methionine and Tryptophan Play Different Modulatory Roles in the European Seabass (Dicentrarchus labrax) Innate Immune Response and Apoptosis Signaling—An In Vitro Study

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    The range of metabolic pathways that are dependent on a proper supply of specific amino acids (AA) unveils their importance in the support of health. AA play central roles in key pathways vital for immune support and individual AA supplementation has shown to be able to modulate fish immunity. In vitro trials are important tools to evaluate the immunomodulatory role of AA, and the present study was conceived to evaluate methionine and tryptophan roles in immune-related mechanisms aiming to understand their effects in leucocyte functioning and AA pathways. For that purpose, head-kidney leucocytes were isolated and a primary cell culture established. The effect of methionine or tryptophan surplus on cell viability was assessed. Medium L-15 10% FBS without AA addition (0.5mM of L-methionine, 0.1 mM of L-tryptophan) was used as control. To that, L-methionine or L-tryptophan were supplemented at 1 and 2 times (M1x or M2x, and T1x or T2x). Nitric oxide, ATP, total antioxidant capacity, and immune-related genes were evaluated in response to lipopolysaccharides extracted from Photobacterium damselae subsp. piscicida or UV-inactivated bacteria). Moreover, caspase 3 activity and apoptosis-related genes were evaluated in response to the apoptosis-inducing protein, AIP56. Distinct roles in leucocytes’ immune response were observed, with contrasting outcomes in the modulation of individual pathways. Methionine surplus improved cell viability, polyamine production, and methionine-related genes expression in response to an inflammatory agent. Also, methionine supplementation lowered signals of apoptosis by AIP56, presenting lower caspase 3 activity and higher il1ß and nf-¿b expression. Cells cultured in tryptophan supplemented medium presented signals of an attenuated inflammatory response, with decreased ATP and enhanced expression of anti-inflammatory and catabolism-related genes in macrophages. In response to AIP56, leucocytes cultured in a tryptophan-rich medium presented lower resilience to the toxin, higher caspase 3 activity and expression of caspase 8, and lower expression of several genes, including nf-¿b and p65. This study showed the ability of methionine surplus to improve leucocytes’ response to an inflammatory agent and to lower signals of apoptosis by AIP56 induction, while tryptophan attenuated several cellular signals of the inflammatory response to UV-inactivated bacteria and lowered leucocyte resilience to AIP56.This work was partially supported by UIDB/04423/2020, UIDP/ 04423/2020 and INFLAMMAA (reference PTDC/CVT-CVT/ 32349/2017), financed by Portugal and the European Union through FEDER and COMPETE 2020, and national funds through Fundação para a Ciência e a Tecnologia (FCT, Portugal). MM and BC were supported by FCT, Portugal (SFRH/BD/108243/2015 and IF/00197/2015, respectively)
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