Universidade Federal de Santa Catarina

About: Universidade Federal de Santa Catarina is a education organization based out in Florianópolis, Brazil. It is known for research contribution in the topics: Population & Context (language use). The organization has 28408 authors who have published 55433 publications receiving 714461 citations.

Anxiolytic effect in the elevated plus-maze of the NMDA receptor antagonist AP7 microinjected into the dorsal periaqueductal grey

Abstract: In order to localise the often reported anxiolytic action of N-methyl-D-aspartate (NMDA) receptor antagonists, 2-amino-7-phosphonoheptanoic acid (AP7) was injected into the dorsal periaqueductal grey (DPAG) of rats exposed to the elevated plus-maze model of anxiety. Doses of 0.2, 2 and 20 nmol AP7 caused a dose-dependent increase in the percentage of open arm entries, the effect of the last two doses being significantly different from control. A non-significant tendency to increase the percentage of time spent on the open arms of the maze was also noticed. In contrast, the total number of entries into either the open or enclosed arms was not affected. Injections of AP7 localized outside the DPAG were ineffective. Therefore, microinjection of AP7 into the DPAG caused a selective anxiolytic effect in the elevated plusmaze. It may be suggested that the DPAG is a site of the anxiolytic action of NMDA antagonists reported following systemic administration.

GPx-Like activity of selenides and selenoxides: experimental evidence for the involvement of hydroxy perhydroxy selenane as the active species.

Abstract: The reaction mechanism of the GPx-like oxidation of PhSH with H(2)O(2) catalyzed by selenoxides proceeds via formation of the hydroxy perhydroxy selenane, which is a stronger oxidizing agent than selenoxide. A hydroxy perhydroxy selenane intermediate was observed by electrospray ionization mass spectrometry and (77)Se NMR spectroscopy in reactions of selenoxide 8 with H(2)O(2).The initial velocity of oxidation of PhSH by H(2)O(2) with selenoxide 8 is 4 orders of magnitude higher than that of 8 without peroxide. Selenoxide 8 is not reduced to selenide 6 by PhSH in the presence of H(2)O(2). While electronic substituent effects have minimal impact on the catalytic performance of selenoxides, chelating groups increase the rate of catalysis.

Marginal and internal fit of four-unit zirconia fixed dental prostheses based on digital and conventional impression techniques.

Abstract: Objectives The aim of this in vitro study was to evaluate the marginal and internal fit of CAD/CAM-generated four-unit zirconia fixed dental prostheses made with digital and conventional impressions. Materials and method A titanium master model was used. For group conventional impression (CI), 12 polyether impressions of the master model with Impregum TM were made. For group digital impression (DI), 12 digital impressions of the master model using Lava TM C.O.S. system were made. The replica technique was applied. The Mann–Whitney U statisticaltestwasappliedtodetectstatisticaldifferencesbetweenthe groups, in terms of marginal and internal fit. Face-by-face comparisons between groups were also carried out. Results Groups DI and CI presented mean marginal fit of 63.96 and 65.33 μm, respectively, and showed no statistically significantdifference.GroupsDIandCIpresentedsignificantly different internal fit with mean values of 58.46 and 65.94 μm, respectively. Group DI showed statistically significantly lower values for marginal and internal fit on premolar mesial face, and on molar distal and palatal faces. Conclusions Frameworks fabricated from digital and conventional impressions showed clinically acceptable marginal fit. Frameworks fabricated from digital impression demonstrated better internal fit than ones fabricated from conventional impression. Reviewing each retainer face, digital impression showed better marginal and internal fit at the premolar mesial and molar distal faces. Clinical relevance The results of this in vitro study show that digital impressions made with the Lava TM C.O.S. sys