Structure and microstructure of PbTiO3 thin films obtained from hybrid chemical method

PbTiO3 thin films were deposited on Si(100) via hybrid chemical method and crystallized between 400 and 700 degreesC to study the effect of the crystallization kinetics on structure and microstructure of these materials. X-ray diffraction (XRD) technique was used to study the structure of the crystallized films. In the temperature range investigated, the lattice strain (c/a) presented a maximum value (c/a = 1.056) for film crystallized at 600 degreesC for I h. Atomic force microscopy (AFM) was used in investigation of the microstructure of the films. The rms roughness of the films linearly increases with temperature and ranged from 1.25 to 9.04 nm while the grain sizes ranged from 130.6 to 213.6 nm. Greater grain size was observed for film crystallized at 600 degreesC for 1 h. (C) 2002 Elsevier B.V. S.A. All rights reserved.

Plasma hormones, muscle mass and strength in resistance-trained postmenopausal women

Objective: To associate changes of body composition, muscle strength (MS) and plasma hormones (PH) in resistance-training protocol in sedentary postmenopausal women (PMW).Design: This randomized controlled trial, Brazilian 43 PMW (45-70-year-old) able for physical exercises were selected after they have accomplished medical and ethical criteria. They were assigned in two groups: RT, resistance training (n = 22); and CT, not trained control (n = 2 1); with supervision sessions of two to three exercise for large and one exercise for smaller groups in three series of 8-12 rep. (60-80% 1RM) for each exercise. The training period lasted 16 weeks and was preceded by low-load exercise (40-50% 1RM) adaptation period of 4 weeks (3/(times week)). Body weight, height, body mass index (BMI), and composition (BIA) along with fast-PH (FSH, LH, estrachol, cortisol, IGF-1 and testosterone) were assessed before (MO) and after (M 16) the 4 weeks period with the MS (1RM) determined also at 8 weeks (W). The values were correlated by Person's test and the means compared by Student's t-test and ANOVA.Results: At baseline both groups were similar in age, time of PMW, body composition, MS and fast-PH. However after 16 weeks, RT presented higher BMI (2. 1 %), IGF- 1 (37.8%) and MM gain (1.8 +/- 0.8 kg) than CT. MM correlated positively with IGF-1 (r = 0.45, p < 0.05) and MS progressively increased in all exercise greater in pectoral than legs and upper arms.Conclusion: Former sedentary postmenopausal women submitted to resistance training gained MM and MS irrespectively of fat mass changes but significantly associated with IGF-1 increase. (C) 2008 Elsevier B.V. All rights reserved.

Direct Detection of Mycobacterium bovis in Bovine Lymph Nodes by PCR

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of disinfection and storage on the flexural strength of ocular prosthetic acrylic resins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Direct detection of infectious bursal disease virus from clinical samples by in situ reverse transcriptase-linked polymerase chain reaction

The presence of the very virulent (vv) Brazilian strain of infectious bursal disease virus (IBDV) was determined in the bursa of Fabricius, thymus and liver of 2-week-old broilers from a flock with a higher than expected mortality. For this purpose, a direct in situ reverse transcriptase (RT)-linked polymerase chain reaction (PCR) method was developed using specific primers for vvIBDV. Unlabelled forward and reverse biotinylated oligonucleotides were used for RT-PCR in a one-step method and the respective products were revealed by a direct enzymatic reaction. The results were compared with those obtained by standard RT-PCR using general primers for IBDV and virus isolation. The virus isolation, RT-PCR and in situ RT-PCR revealed positive results on the bursa of Fabricius in 86%, 80% and 100%, respectively. The in situ RT-PCR detected vvIBDV in all tested thymus and liver samples, whereas the standard RT-PCR detected virus in 80% and 90% of the samples, respectively. After three consecutive passages on chicken embryonated eggs, IBDV was isolated from 64% of the thymus samples and 30% of the liver samples. In the present study, no classical or antigenic variants of IBDV were detected. The developed in situ RT-PCR assay was able to detect the very virulent strain of IBDV with a higher sensitivity than the conventional RT-PCR and virus isolation.

Effect of relining, water storage and cyclic loading on the flexural strength of a denture base acrylic resin

Objectives: This study investigated the effect of relining, water storage and cyclic loading on the ultimate flexural strength (FSU) and on the flexural strength at the proportional limit (FSPl) of a denture base acrylic resin (Lucitone 550-L).Methods: Rectangular bars of L were made (64 mm x 10 mm x 2 mm) and relined (1.3 mm) with four relining resins (Kooliner-K, Ufi Gel Hard-UGH, Tokuso Rebase Fast-TR and New Truliner-NT). In addition, specimens relined with L and intact L specimens were made (64 mm x 10 mm x 3.3 mm). A three-point flexural test was applied on the specimens (n = 10) after (1) polymerization; (2) water storage (30 days); (3) cyclic loading (10,000 cycles at 5 Hz) and (4) water storage (30 days) + cyclic loading. Data (MPa) were analyzed with three-way ANOVA and Tukey's HSD tests (alpha = 0.05). To test for a possible correlation between FSU and FSPl, a linear regression coefficient 'r' was calculated.Results: After water storage, L-UGH and L-TR demonstrated an increased FSU (41.4950.64 MPa and 49.95-57.36 MPa, respectively) (P < 0.05). Only L-TR demonstrated an increased FSPl (20.58-24.21 MPa) after water storage (P < 0.05). L-L had the highest FSU (between 78.57 and 85.09 MPa) and FSPl (between 31.30 and 34.17 MPa) (P < 0.05). The cyclic loading decreased the FSU and FSPl of all materials (P < 0.05). Regression analysis showed a strong linear correlation between the two variables (r = 0.941).Conclusions: Water storage improved the FSU of L-UGH and L-TR and the FSPl of L-TR. L-L produced the highest FSU and FSPl. The FSU and FSPl of all materials were detrimentally influenced by cyclic loading.

Effect of thermocycling on the flexural and impact strength of urethane-based and high-impact denture base resins

Objective: Mechanical properties of the acrylic resins used for denture fabrication may be influenced by water and temperature. Thus, the aim of this study was to evaluate the effect of thermocycling on the flexural and impact strength of a high-impact (Lucitone 199) and a urethane-based denture material (Eclipse).Materials and methods: Flexural strength (64 x 10 x 3.3 mm) and impact strength (60 x 6 x 4 mm) specimens were made following the manufacturers' instructions and assigned to two groups (n = 10): control (C) - not thermocycled - and T - thermocycled (5000 cycles between 5 and 55 degrees C). Specimens were submitted to three-point bending and Charpy impact tests.Results: Flexural strength (MPa) and impact strength (kJ/m(2)) data were analysed with two-way ANOVA (p = 0.05). The flexural strength of material Eclipse (C, 136.5; T, 130.7) was significantly higher than that of resin Lucitone 550 (C, 99.4; T, 90.1). Material Eclipse exhibited significantly higher impact strength (C, 6.9; T, 5.3) than the resin Lucitone 550 (C, 3.5; T, 3.0). For both materials, a significant decrease in flexural and impact strengths was observed when the specimens were thermocycled.Conclusion: Flexural and impact strengths were higher for Eclipse than for Lucitone 550, in both groups. Thermocycling decreased the flexural and impact strengths of Eclipse and Lucitone 550.

Diametral tensile strength and film thickness of an experimental dental luting agent derived from castor oil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of water storage on the shear strength and fatigue limit of the reline resin bond to denture base resins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Study of Toxoplasma infection in Brazilian wild mammals: Serological evidence in Dasypus novemcinctus Linnaeus, 1758 and Euphractus sexcinctus Wagler, 1830

Toxoplasmosis is a worldwide distributed zoonosis that affects man and most warm-blooded animals, with a great economic impact in animal and public health. Serum samples from nine 9-banded armadillos, three 6-banded armadillos, three coatimundis, two opossums and one nutria were submitted for anti-Toxoplasma gondii antibody detection by means of a modified direct agglutination method. Encephalic tissue of three 6-banded armadillos, one 9-banded armadillo, one coatimundi and one nutria were digested in acid pepsin solution and inoculated into Swiss mice for parasite isolation. Only one serum sample from a nine-banded armadillo and two from six-banded armadillos reacted producing titers equal to 256, 512 and 512, respectively. T gondii was isolated in two 6-banded armadillos, one of which was not positive in the serological test. (c) 2005 Elsevier B.V. All rights reserved.

Aerobic biodegradation of butanol and gasoline blends

This work aimed to assess the aerobic biodegradation of butanol/gasoline, blends (5; 10; 15 and 20% v/v), being the latter compared to the ethanol/gasoline blend (20% v/v). Two experimental techniques were employed, namely the respirometric method and the redox indicator DCPIP test. in the former, experiments simulating the contamination of natural environments (addition of 50 mL of fuel kg(-1) of soil from a non-contaminated site and 20 mL of fuel L(-1) of water from a river) were carried out in biometer flasks (250 mL), used to measure the microbial CO(2) production. The DCPIP test assessed the capability of four inocula to biodegrade the blends of 20%. The addition of butanol at different concentrations enhanced the biodegradation of gasoline in soil. However, no practical gains were observed for concentrations of butanol above 10%. Ethanol showed to have a much faster biodegradation rate than butanol, particularly in water, and the following order of biodegradability was found: ethanol > butanol > gasoline. The addition of the alcohols to the gasoline resulted in positive synergic effects on the biodegradation of the fuels in soil and water matrices. Furthermore, results suggest that, in soil, butanol better enhanced the biodegradation of gasoline than ethanol. (C) 2009 Elsevier Ltd. All rights reserved

Effect of Airborne-Particle Abrasion and Mechanico-Thermal Cycling on the Flexural Strength of Glass Ceramic Fused to Gold or Cobalt-Chromium Alloy

Purpose: To evaluate the effect of airborne-particle abrasion and mechanico-thermal cycling on the flexural strength of a ceramic fused to cobalt-chromium alloy or gold alloy.Materials and Methods: Metallic bars (n = 120) were made (25 mm x 3 mm x 0.5 mm): 60 with gold alloy and 60 with Co-Cr. At the central area of the bars (8 mm x 3 mm), a layer of opaque ceramic and then two layers of glass ceramic (Vita VM13, Vita Zahnfabrick) were fired onto it (thickness: 1 mm). Ten specimens from each alloy group were randomly allocated to a surface treatment [(tungsten bur or air-particle abrasion (APA) with Al(2)O(3) at 10 mm or 20 mm away)] and mechanico-thermal cycling (no cycling or mechanically loaded 20,000 cycles; 10 N distilled water at 37 degrees C and then thermocycled 3000 cycles; 5 degrees C to 55 degrees C, dwell time 30 seconds) combination. Those specimens that did not undergo mechanico-thermal cyclingwere stored inwater (37 degrees C) for 24 hours. Bond strength was measured using a three-point bend test, according to ISO 9693. After the flexural strength test, failure types were noted. The data were analyzed using three factor-ANOVA and Tukey's test (alpha = 0.05).Results: There were no significant differences between the flexural bond strength of gold and Co-Cr groups (42.64 +/- 8.25 and 43.39 +/- 10.89 MPa, respectively). APA 10 and 20 mm away surface treatment (45.86 +/- 9.31 and 46.38 +/- 8.89 MPa, respectively) had similar mean flexural strength values, and both had significantly higher bond strength than tungsten bur treatment (36.81 +/- 7.60 MPa). Mechanico-thermal cycling decreased the mean flexural strength values significantly for all six alloy-surface treatment combinations tested when compared to the control groups. The failure type was adhesive in the metal/ceramic interface for specimens surface treated only with the tungsten bur, and mixed for specimens surface treated with APA 10 and 20 mm.Conclusions: Considering the levels adopted in this study, the alloy did not affect the bond strength; APA with Al(2)O(3) at 10 and 20 mm improved the flexural bond strength between ceramics and alloys used, and the mechanico-thermal cycling of metal-ceramic specimens resulted in a decrease of bond strength.

Flexural Strength of Glass-Infiltrated Zirconia/Alumina-Based Ceramics and Feldspathic Veneering Porcelains

Purpose: To compare the flexural strength of two glass-infiltrated high-strength ceramics and two veneering glass-ceramics.Materials and Methods: Four ceramic materials were tested: two glass-infiltrated high-strength ceramics used as framework in metal-free restorations [In-Ceram Zirconia IZ (Gr1) and In-Ceram Alumina IA (Gr2)], and two glass-ceramics used as veneering material in metal-free restorations [Vita VM7 (Gr3) and Vitadur-alpha (Gr4)]. Bar specimens (25 x 5 x 2 mm(3)) made from core ceramics, alumina, and zirconia/alumina composites were prepared and applied to a silicone mold, which rested on a base from a gypsum die material. The IZ and IA specimens were partially sintered in an In-Ceram furnace according to the firing cycle of each material, and then were infiltrated with a low-viscosity glass to yield bar specimens of high density and strength. The Vita VM7 and Vitadur-alpha specimens were made from veneering materials, by vibration of slurry porcelain powder and condensation into a two-part brass Teflon matrix (25 x 5 x 2 mm(3)). Excess water was removed with absorbent paper. The veneering ceramic specimens were then removed from the matrix and were fired as recommended by the manufacturer. Another ceramic application and sintering were performed to compensate the contraction of the feldspar ceramic. The bar specimens were then tested in a three-point bending test.Results: The core materials (Gr1: 436.1 +/- 54.8; Gr2: 419.4 +/- 83.8) presented significantly higher flexural strength (MPa) than the veneer ceramics (Gr3: 63.5 +/- 9.9; Gr4: 57.8 +/- 12.7).Conclusion: In-Ceram Alumina and Zirconia were similar statistically and more resistant than VM7 and Vitadur-alpha.

Opaque Layer Firing Temperature and Aging Effect on the Flexural Strength of Ceramic Fused to Cobalt-Chromium Alloy

Purpose: To evaluate the effect of the opaque layer firing temperature and mechanical and thermal cycling on the flexural strength of a ceramic fused to commercial cobalt-chromium alloy (Co-Cr). The hypotheses were that higher opaque layer temperatures increase the metal/ceramic bond strength and that aging reduces the bond strength.Materials and Methods: Metallic frameworks (25 x 3 x 0.5 mm(3); ISO 9693) (N = 60) were cast in Co-Cr and airborne-particle abraded (Al(2)O(3): 150 mu m) at the central area of the frameworks (8 x 3 mm(2)) and divided into three groups (N = 20), according to the opaque layer firing temperature: Gr1 (control)-900 degrees C; Gr2-950 degrees C; Gr3-1000 degrees C. The opaque ceramic (Opaque, Vita Zahnfabrick, Bad Sackingen, Germany) was applied, and the glass ceramic (Vita Omega 900, Vita Zahnfabrick) was fired onto it (thickness: 1 mm). While half the specimens from each group were randomly tested without aging (water storage: 37 degrees C/24 hours), the other half were mechanically loaded (20,000 cycles; 50 N load; distilled water at 37 degrees C) and thermocycled (3000 cycles; 5 degrees C to 55 degrees C, dwell time: 30 seconds). After the flexural strength test, failure types were noted. The data were analyzed using 2-way ANOVA and Tukey's test (alpha = 0.05).Results: Gr2 (19.41 +/- 5.5 N) and Gr3 (20.6 +/- 5 N) presented higher values than Gr1 (13.3 +/- 1.6 N) (p = 0.001). Mechanical and thermal cycling did not significantly influence the mean flexural strength values (p > 0.05). Increasing the opaque layer firing temperature improved the flexural bond strength values (p < 0.05). The hypotheses were partially accepted.Conclusion: Increasing of the opaque layer firing temperature improved the flexural bond strength between ceramic fused to Co-Cr alloy.

Strength of a feldspar ceramic according to the thickness and polymerization mode of the resin cement coating

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)