17 research outputs found
Diffusion study of 15N implanted into α-Ti using the nuclear resonance technique
No full textThe diffusion of 15 N in a-Ti was studied in the 673-1023 K temperature range by using ion implantation and nuclear resonance techniques. The measurements show that the diffusion coefficients follow an Arrhenius behaviour D(T) = D0 exp (-Q/RT) where D0 = (1.1 ± 0.8) x 10-7 m2 s-1 and Q = (183 ± 2) kJ/mol. A comparison with previous results is also given.Fil: Bregolin, F. L.. Universidade Federal do Rio Grande do Sul; BrasilFil: Behar, M.. Universidade Federal do Rio Grande do Sul; BrasilFil: Dyment, Fanny. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
External RBS analysis setup at University of Göttingen: RBS analysis for liquid samples
No full textIn this work, we describe new developments in the external analysis setup at University of Göttingen. The aim of this work is to expand the ability of the setup for performing Rutherford backscattering spectrometry (RBS) in atmospheric condition. This work presents the detail of the developed device for external RBS, as well as the initial result of RBS analysis for a volatile liquid sample. We also made an electrochemical cell with a Si 3 N 4 window designed for external RBS analysis. By using this setup, we have successfully acquired the change of composition around an electrode/liquid electrolyte interface. Since RBS can give us quantitative depth information, the external RBS developed here will open a way to characterize a solid‐liquid interface quantitatively and understand the chemical reaction of the interface
Diffusion study of nitrogen implanted into α-Hf using the nuclear resonance technique
No full textThe diffusion of nitrogen in a-Hf was studied in the temperature range of (823-1123)K using the ion implantation and nuclear resonance techniques. The measurements show that the diffusion coefficients follow an Arrhenius behaviour D (T) = D0 exp (-Q / RT) with D0 = (5.5 ± 2.0) ×10-7 m2s-1 and Q = (228 ±1) kJ/mol. A comparison of the present results with the previous one is made. The difference between them can be attributed to the different purity of the samples used in each experiment.Fil: Bregolin, F. L.. Universidade Federal do Rio Grande do Sul; BrasilFil: Behar, Andrea Marcela. Universidade Federal do Rio Grande do Sul; BrasilFil: Dyment, Fanny. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Improved Set-Up for the Ytterbium Optical Clock at INRIM
No full textWe present an upgraded setup for cooling and
trapping of ytterbium atoms in a optical clock experiment. The
experiment aims to cool and trap ytterbium atoms in a two stage
magneto-optical trap (MOT) (at 399 nm and 556 nm for the first
and second stage, respectively) and to probe the narrow-line clock
transition at 578 nm in an optical lattice at the magic wavelength
(759 nm). We describe here the generation of all the laser sources
and the design of a new physic package, including the vacuum
chamber and the atomic sourc
Optical Atomic Clocks: From International Timekeeping to Gravity Potential Measurement
No full textPaper SM1F.3 - From the session Optical Clocks (SM1F).We discuss the relation between atomic clocks and gravity from two perspectives: gravity potential measurements for optical clock comparisons and contributions to international timescales and, conversely, the measurement of gravity potential differences using optical clocks.Helen S. Margolis, Heiner Denker, Christian Voigt, Ludger Timmen, Jacopo Grotti, Silvio Koller, Stefan Vogt, Sebastian Häfner, Uwe Sterr, Christian Lisdat, Antoine Rolland, Fred N. Baynes, Michel Zampaolo, Pierre Thoumany, Marco Pizzocaro, Benjamin Rauf, Filippo Bregolin, Anna Tampellini, Piero Barbieri, Massimo Zucco, Giovanni A. Costanzo, Cecilia Clivati, Filippo Levi, and Davide Calonic
Avalia??o da atividade da frutose-1,6-bisfosfato em c?lulas GRX expostas a ferro livre
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Previous issue date: 2014-03-10Hereditary hemochromatosis (HH) is a genetic disease where iron balance is deregulated and this metal accumulates in the liver, causing toxic effects and fibrosis. Fibrosis is an exacerbated wound-healing response with extracellular matrix (ECM) deposition. Hepatic stellate cells (HSC), when activated, are the main responsible for ECM production. Fructose-1,6-bisphosphate (FBP) is a sugar and possess innumerous beneficial effects, like enhance cell antioxidant potential, protects liver from damage and reverts the phenotype of activated HSC. Because of this, we aimed to test the effects of FBP in immortalized HSC line (GRX) exposed to free iron (Fe) tempting to simulate what occurs in patients with HH.Fe (1mg/L) treatment for 8 days increased cell growth, whereas Fe + FBP (1mg/L + 0.6mM) decreased cell proliferation to levels below of control. LDH activity, apoptosis rate and cell cycle were not altered in any group. Oil Red-O (ORO) staining showed a decrease in lipid content when GRX cells were Fe-treated (1mg/L) for 8 days. In Fe + FBP (1mg/L + 0.6mM), GRX cells showed increased lipid content and characteristics of quiescent HSC. PPAR-γ expression was diminished on Fe group and same as control on Fe + FBP group. On the contrary, Fe treatment rose Col-1 expression and Fe + FBP reversed it to control levels. TGF-β1 was unaltered in Fe group. However, on Fe + FBP group, TGF-β1 levelswas far bellow of control and Fe-treated group, showing an antifibrotic activity. FBP didn t present antioxidant activity by DPPH assay. Ferrozine assay showed a decreased absorbance after 120 min in all FBP-tested doses, demonstrating that FBP is an iron chelator. These data demonstrate that FBP reverse the phenotype of GRX cells even when in Fepresence and that this could be caused by regulation of PPAR-γ and COL-1. In conclusion, FBP diminished the growth rate and reversed the phenotype of GRX cell, showing a possible antifibrotic effect.Hemocromatose heredit?ria (HH) ? uma doen?a gen?tica onde o balan?o do ferro est? desregulado e esse metal se acumula no f?gado, causando efeitos t?xicos e, principalmente, fibrose. Fibrose ? uma resposta de cicatriza??o exacerbada com dep?sito de matriz extracelular (ECM). C?lulas estreladas hep?ticas (HSC) quando ativadas s?o as maiores respons?veis pela produ??o de ECM. Frutose-1,6-bisfosfato (FBP) ? um a??car e possui in?meros efeitos ben?ficos, como melhorar o potencial antioxidante da c?lula, proteger o f?gado de les?o e reverter o fen?tipo de HSC ativadas. Por causa disso, nosso objetivo foi testar os efeitos da FBP em uma linhagem imortalizada de HSC (GRX) expostas a ferro livre (Fe), na tentativa de simular o que ocorre em pacientes com HH.O tratamento com Fe (1mg/L) por 8 dias aumentou a prolifera??o celular enquanto o tratamento com Fe + FBP (1mg/L + 0.6mM) a diminuiu para n?veis menores que os do controle. A atividade da LDH, taxa de apoptose e ciclo celular n?o foi alterada em nenhum grupo. A colora??o com OilRed-O (ORO) mostrou uma diminui??o na quantidade de lip?dio intracelular quando as c?lulas foram tratadas com Fe por 8 dias. No grupo Fe + FBP, houve um aumento do conte?do lip?dico e as c?lulas apresentaram caracter?sticas morfol?gicas de c?lulas quiescentes. A express?o de PPAR-γ foi diminu?da no grupo Fe e igual ao controle no grupo Fe + FBP. Ao contr?rio, o Fe aumentou os n?veis de express?o de Col?geno tipo I (Col-1) e o tratamento concomitante com FBP reverteu esse efeito, ficando igual ao controle. A produ??o de TGF-β1 se manteve inalterada no grupo Fe e foi menor que o controle no tratamento com Fe + FBP, mostrando uma atividade antifibr?tica da FBP. O teste de DPPH mostrou que a FBP n?o possui atividade antioxidante em nenhuma dose testada. O teste de Ferrozine mostrou uma diminui??o da absorb?ncia depois de 120 minutos de incuba??o de FBP + Fe em todas as doses testadas, mostrando que a FBP ? um quelante de ferro.Esses dados demonstram que FBP reverte o fen?tipo das c?lulas GRX mesmo quando em presen?a do Fe e que isso pode ser causado pela regula??o da express?o do PPAR-γ e COL-1.Em conclus?o, a FBP diminuiu o crescimentoe reverteu o fen?tipo de c?lulas GRX, mostrando um poss?vel efeito antifibr?tico
Supplementary Material for: The Closure of Patent Foramen Ovale in Preventing Subsequent Neurological Events: A Bayesian Network Meta-Analysis to Identify the Best Device
No full textBackground: Randomized-controlled trials (RCTs) reported a finding on the safety and efficacy of percutaneous patent foramen ovale (PFO) closure to prevent stroke recurrence. It showed that the Amplatzer (AMP) device appears to be superior to medical therapy (MT) in preventing strokes and episodes of atrial fibrillation (AF), than other devices. We performed a network meta-analysis (NMA) to evaluate the closure of PFO in preventing subsequent neurological events while investigating the results obtained by specific devices. Methods: We searched 3 databases (MEDLINE, EMBASE, CENTRAL/CCTR) and identified 6 RCTs until March 2019. We performed an NMA and used pooled ORs. Analyses were done in NetMetaXL1.6-WinBUGS1.4. Results: Six RCTs with 3,560 patients (mean age 45.2–46.2 years) were included in the present NMA. Depending on the device, 4 groups of patients were compared with MT: 1,889 patients undergoing PFO closure were significantly less likely to experience a stroke than 1,671 patients treated with MT (ORs 0.41; 95% Cr.I. 0.27–0.60 with fixed-effects model and ORs 0.22; 95% Cr.I. 0.05–0.70 with random-effects model). The patients with AMP showed a similar risk than those treated with Helex/Cardioform (HLX/CF) or with a group of 11 multiple devices. This suggests the equality between the 2 most currently used devices. When assessing TIA and, for the safety analysis, major bleeding, both models confirm no significant difference between any devices and MT. PFO closure increased the risk of new-onset AF: MT induces AF significantly less than all the devices. In favor of the AMP, there is a reduced number of cases of AF versus MT; however, no device superiority has been established in comparing HLX/CF and other devices in a random effect model. Conclusions: Our NMA provides evidence in favor of PFO closure with all the devices currently in use. We can conclude that these devices are better than MT, but not that 1 device is better than the rest in reducing stroke recurrences and AF episodes in the follow-up
