Spectroscopic, thermal and biological studies of the coordination compounds of sulfasalazine drug: Mn(II), Hg(II), Cr(III), ZrO(II), VO(II) and Y(III) transition metal complexes.
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The complexations of sulfasalazine (H3Suz) with some of transition metals have been investigated. Three types of complexes, [Mn(HSuz)-2(H2O)4] x 2H2O, [M(HSuz)-2(H2O)2] x xH2O (M=Hg(II), ZrO(II) and VO(II), x=4, 8 and 6, respectively) and [M(HSuz)-2(Cl)(H2O)3] x xH2O (M=Cr(III) and Y(III), x=5 and 6, respectively) were obtained and characterized by physicochemical and spectroscopic methods. The IR spectra of the complexes suggest that the H3Suz behaves as a bidentate ligand. The thermal decomposition of the complexes as well as thermodynamic parameters (DeltaE*, DeltaH*, DeltaS* and DeltaG*) were estimated using Coats-Redfern and Horowitz-Metzger equations. In vitro antimicrobial activities of the H3Suz and the complexes were tested. (+info)
Use of yttrium phosphate as a coprecipitant for separation/concentration of lanthanoids.
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A useful method to separate/concentrate lanthanoids was developed based on a rapid coprecipitation technique using yttrium phosphate. Lanthanoids, which were quantitatively coprecipitated at pH 3 with yttrium phosphate, could be readily determined by inductively coupled plasma atomic emission spectrometry with indium used as an internal standard element. The detection limits ranged from 0.0003 microg (Yb, Lu) to 0.0099 microg (Er) in 100 mL of sample solutions. The proposed method was applicable to the separation/concentration of lanthanoids in NIST SRM 1515 (apple leaves). (+info)
CAD/CAM Zirconia vs. slip-cast glass-infiltrated Alumina/Zirconia all-ceramic crowns: 2-year results of a randomized controlled clinical trial.
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Ultrasonic cleaning of silica-coated zirconia influences bond strength between zirconia and resin luting material.
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The purpose of this study was to evaluate how ultrasonic cleaning of silica-coated zirconia surfaces would influence the latter's bond strength to resin luting material. Forty zirconia specimens were divided into four groups: one air abrasion group and three silica-coated groups. Silica-coated specimens were cleaned with distilled water using an ultrasonic cleaner after tribochemical silica coating and then divided into three groups according to cleaning durations: 1 minute, 5 minutes, or without cleaning. Following which, resin luting material was polymerized against the specimens. After storage in water for 24 hours, the specimens were subjected to shear bond strength test. Shear bond strength of silica-coated group without cleaning was significantly higher than the other three groups, but there were no statistically significant differences among the three latter groups. SEM images suggested visible differences among the treatment methods. With EDXS analysis, it was revealed that ultrasonic cleaning decreased the silica content on the treated surfaces. Therefore, results showed that ultrasonic cleaning of tribochemically silica-coated zirconia surfaces decreased the adhesion efficacy to resin luting material. (+info)
The inhibition of neuronal calcium ion channels by trace levels of yttrium released from carbon nanotubes.
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Effect of surface roughness on initial responses of osteoblast-like cells on two types of zirconia.
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The aim of this study was to evaluate the effect of surface roughness on the initial attachment of mouse osteoblast-like cells on ceriastabilized zirconia/alumina nanocomposite (NANOZR) and yttria-stabilized zirconia (3Y-TZP) in comparison to those on pure titanium (Ti) and alumina oxide (AO). Specimens with smooth and rough surfaces were prepared by grinding with diamond paper or by sandblasting, respectively. For four substrates examined, the number of attached cells on the rough surface specimens was significantly higher than that on the smooth surface specimens (p < 0.05). Integrin alpha(5) and beta(1) expression had a greater increase in rough surface specimens than in smooth surface specimens. Actin cytoskeleton organization was, however, similar for both smooth and rough surface specimens. NANOZR and 3Y-TZP produced good cell attachment, similar to Ti and AO. The overall results demonstrated that NANOZR and 3Y-TZP with rough surface could provide good initial cell responses, adequate for future implant usage. (+info)