Análise morfológica dos folículos primordiais de ovários de ovino criopreservados em EG, DMSO e sua associaçã o

Objective: Compare the cryoprotectants Dimethyl Sulphoxide (DMSO), Ethylene Glycol (EG) and their association for cryopreservation of sheep ovarian cortex. Methodology: Fragments collected from ovaries were divided into 3 parts. 1. One part from sample was destined for analysis of fresh material. 2. The second part was incubated with solution of freezing having 1,5M EG or 1,5M DMSO or 1,5MEG + 1,5M DMSO and washed for dilution of the cryoprotectants. 3. The third part was submitted to cryopreservation using the same cryoprotectans (EG 1,5M; DMSO 1,5M and EG + DMSO 1,5M) and cryopreserved. In all groups, one part of sample was submitted to pre-antral follicles isolation and the remainder was destined to ultra-structural analysis. Results: After isolation of fresh primordial follicles (control), the percentage of viable follicles was 78,9%. The percentage of viable follicles only exposed to cryoprotectants 1,5M EG, 1,5M DMSO and 1,5M EG + 1,5M DMSO was 77,1%, 68,4% and 60,7% respectively. After cryopreservation were 75%, 60% and 55,6% respectively. Ultra-structural analysis of the primordial follicles derived from fresh ovarian fragments or from fragments just exposed to the cryoprotectants showed similar morphology. However, in frozen samples, alterations of mitochondria were observed in all groups. Despite this, the integrity of the remained organelles was preserved in follicles cryopreserved with EG, while that in others groups (DMSO and association) an excess of vacuolizaton in cytoplasm of oocytes and swelling of nuclear membrane was observed indicating degeneration. Conclusion: The Ehilene Glycol seems to be the cryoprotector more adequated for cryopreservation of sheep ovarian tissue.

Effect of weathering and thickness on roughness of acrylic resin and ocular button

Purpose: The aim of this study was to evaluate the roughness of colorless ocular button and four brands of colorless acrylic resins designed to fabricate ocular prosthesis as a function of weathering (1008 h) and different thickness (1 and 3.5 mm). Materials and methods: One-hundred-and-twenty specimens were fabricated and distributed in 12 groups. The analysis was carried out by means of digital roughness meter. Results: Data were analyzed statistically by ANOVA and Tukey test at 1% significance. The results showed that there was no statistically significant difference after the weathering period. Both the Vipi Cril acrylic resin with 3.5 mm in thickness and ocular button with 1 mm in thickness presented the lowest roughness values (0.12. Ra). Conclusion: The roughness of the acrylic resins and the ocular button was not affect by the weathering of 1008 h. However, the thickness of the specimens proved to have a major influence on roughness property. © 2010.

Micropatterned nanocomposite hydrogels for biosensing applications

This paper describes the use of Au nanoparticle (NP)-containing hydrogel microstructures in the development of electrochemical enzyme-based biosensors. To fabricate biosensors, AuNPs were conjugated with glucose oxidase (GOX) or horseradish peroxidase (HRP) molecules and were dispersed in the prepolymer solution of poly(ethylene glycol) diacrylate (PEG-DA). Vinylferrocene (VF) was also added into the prepolymer solution in order to lower operating potential of the biosensor and to prevent oxidation of interfering substances. The prepolymer solution was photolithographically patterned in alignment with an array of Au electrodes fabricated on glass. As a result, electrode arrays became functionalized with AuNP/GOX- or AuNP/HRP-carrying hydrogel microstructures. Performance of the biosensors was characterized by impedance spectroscopy, chronoapmerometry and cyclic voltammetry. Impedance measurements revealed that inclusion of Au nanoparticles improved conductivity of PEG hydrogel by a factor of 5. Importantly, biosensors based on AuNP-GOX complex exhibited high sensitivity to glucose (100μAmM -1cm -2) in the linear range from 0.1 to 10mM. The detection limit was estimated to be 3.7×10- 7M at a signal-to-noise ratio of 3. Biosensors with immobilized AuNP/HPR had a linear response from 0.5 to 5.0μM of hydrogen peroxide with sensitivity of 1.4mAmM -1cm -2. The method for fabricating nanoparticle-carrying hydrogel microstructures described in this paper should be widely applicable in the development of robust and sensitive electrochemical biosensors. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Yield and phytochemical characterization of essential oil from Ocimum selloi B. obtained by hydrodistillation and supercritical fluid extraction

The yield and chemical composition of essential oils from leaves of Ocimum selloi B. submitted to organic and mineral fertilization, obtained by hydrodistillation and supercritical fluid extraction (SFE) were compared. Essential oil was extracted in a Clevenger-type apparatus for 2 h 30 min and analyzed by GC-MS (Shimadzu, QP 5050-DB-5 capillary column - 30 m × 0.25 mm × 0.25 μm). Carrier gas was helium (1.7 ml/min); split ratio: 1:30. Temperature program: 50°C, rising to 180°C at 5°C/min, 180°C, rising to 280°C at 10°C/min. Injector temperature: 240°C and detector temperature: 230°C. Identifications of chemical compounds were made by matching their mass spectra and Kovat's indices (IK) values with known compounds reported in the literature. An Applied Separations-apparatus (Speed SFE, model 7071, Allentown, PA, EUA) was used for SFE extractions. They were conducted at pressure 200 bar and temperature 30°C (20 min in static mode and 40 min in dynamic mode). The supercritical CO2 flow rate was (6.8±0.7)×10-5 kg-CO2/s. The essential oil collected was immersed in ethylene glycol bath (5°C). The yield of essential oils obtained by SFE was larger than hydrodistillation in both fertilization treatments (279 and 333% for organic and mineral fertilizations, respectively). There were no differences between the fertilization treatments. The amount of the volatile components showed by GC-MS chromatogram was highest in the essential oil obtained by hydrodistillation than SFE. The main volatile constituents of the essential oils were trans-anethole (Hydrodistillation: organic - 52.4%; mineral - 55.0%/ SFE: Hydrodistillation - 62.8%; mineral - 66.8%) and methyl-chavicol (Hydrodistillation: organic - 37.3%; mineral - 38.3%/ SFE: organic - 8.4%; mineral - 4.3%). A reduction of methyl-chavicol relative proportion of essential oil obtained by SFE was observed. Cys-anethole, α-copaene, trans-cariofilene, germacrene-D, β-selinene, biciclogermacrene and spathulenol were expressed only in hydrodistillation. The extraction of essential oil by SFE presented larger yield of essential oil than hydrodistillation technique, presenting, however, these essential oils, different phytochemical profiles.

Development and validation of an environmentally friendly attenuated total reflectance in the mid-infrared region method for the determination of ethanol content in used engine lubrication oil

Lubricating oils are crucial in the operation of automotive engines because they both reduce friction between moving parts and protect against corrosion. However, the performance of lubricant oil may be affected by contaminants, such as gasoline, diesel, ethanol, water and ethylene glycol. Although there are many standard methods and studies related to the quantification of contaminants in lubricant oil, such as gasoline and diesel oil, to the best of our knowledge, no methods have been reported for the quantification of ethanol in used Otto cycle engine lubrication oils. Therefore, this work aimed at the development and validation of a routine method based on partial least-squares multivariate analysis combined with attenuated total reflectance in the mid-infrared region to quantify ethanol content in used lubrication oil. The method was validated based on its figures of merit (using the net analyte signal) as follows: limit of detection (0.049%), limit of quantification (0.16%), accuracy (root mean square error of prediction=0.089% w/w), repeatability (0.05% w/w), fit (R 2 =0.9997), mean selectivity (0.047), sensitivity (0.011), inverse analytical sensitivity (0.016% w/w-1) and signal-to-noise ratio (max: 812.4 and min: 200.9). The results show that the proposed method can be routinely implemented for the quality control of lubricant oils. © 2013 Elsevier B.V. All rights reserved.

Vitrification of immature feline oocytes with a commercial kit for bovine embryo vitrification

The aim of this study was to evaluate the suitability of a commercial kit for bovine embryo vitrification for cryopreserving cat oocytes and to evaluate comparatively the effects of its use with slow freezing procedure on cryotolerance in terms of morphology and oocyte resumption of meiosis. Germinal vesicle stage oocytes isolated from cat ovaries were either vitrified (n=72) using a vitrification kit for bovine embryo or slow frozen (n=69) by exposing oocyte to ethylene glycol solution before being transferred to a programmable embryo freezer. After thawing and warming, oocytes were cultured for 48h and then were examined for meiosis resumption using bisbenzimide fluorescent staining (Hoechst 33342). Fresh immature oocytes (n=92) were used as the control group. The proportion of oocytes recovered in a morphologically normal state after thawing/warming was significantly higher in frozen oocytes (94.5%) than in the vitrified ones (75%, p<0.01). Morphological integrity after culture was similar in vitrified (73.6%) and slow frozen oocytes (76.8%); however, only 37.5% of the morphologically normal oocytes resumed meiosis after vitrification compared to 60.9% of those submitted to slow freezing procedure (p<0.01). Fresh oocytes showed higher morphological integrity (91.3%) and meiosis resumption rates (82.6%, p<0.002) than cryopreserved oocytes, irrespective of the procedure used. These results suggest that immature cat oocytes vitrified with a kit for bovine embryos retain their capacity to resume meiosis after warming and culture, albeit at lower rates than slow frozen oocytes. Vitrification and slow freezing methods show similar proportions of oocytes with normal morphology after culture, which demonstrate that thawed and warmed oocytes that resist to cryodamage have the same chances to maintain their integrity after 48h of culture. © 2012 Blackwell Verlag GmbH.

Nephrocalcinosis induced by hyperoxaluria in rats

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

Luminescent properties of hybrid materials prepared by the polymeric precursor method

Rare earth complexes (RE) can be incorporated in silica matrixes, originating organic/inorganic hybrid materials with good thermal stability and high rare earth emission lines. In this work, the hybrid material was obtained by the polymeric precursor method and ultrasonic dispersed with spherical silica particles prepared by the Stöber Method. The Raman spectra indicated that the Eu3+ ions are involved in a polymeric structure formed as consequence of the chelation and polyesterification reactions of this ion with citric acid and ethylene glycol. After the ultrasonic stirring, 2-hydroxynicotinic ligand will also compose this polymeric rigid structure. The TGA/DTA analysis showed that this polymeric material was thermal decomposed at 300 °C. Moreover, this process allows the chelating process of the 2-hydroxynicotinic acid ligand to the Eu3+ ions. The 29Si NMR showed that the ultrasonic dispersion of the reactants was not able to promote the functionalization of the silica particles with the 2-hydroxynicotinic acid ligand. Moreover, heat treatment promotes the [Eu(HnicO2)3] complex particles incorporation into silica pores. At this temperature, the TGA curve showed that only the thermal degradation of ethylene glycol and citric acid used during the experimental procedure occurs. The silica and hybrid materials are composed by spherical and aggregated particles with particle size of approximately 450 nm, which can be influenced by the heat treatment. These materials also present an absorption band located at 337 nm. The photoluminescent study showed that when the hybrid samples were excited at 337 nm wavelength, the ligand absorbs the excitation light. Part of this energy is transferred to the Eu3+ ion, which main emission, 5D0→ 7F2, is observed in the emission spectrum at 612 nm. As the heating temperature increases to 300 C, the energy transfer is more favorable. The lifetime values showed that the Eu3+ emission is enhanced due to the energy transfer process in the powders. © 2013 Elsevier B.V. All rights reserved.

Otimização das condições de síntese de amostras cerâmicas do composto Y'Ba IND. 2''Cu IND. 3''O IND. 7'-δ através do Método Pechini

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Nefrocalcinose induzida pela hiperoxalúria: modelo experimental em ratos

Pós-graduação em Bases Gerais da Cirurgia - FMB

Síntese de filmes finos do sistema PMN-PT pelo método dos precursores óxidos

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

Síntese, caracterização e avaliação eletroquímica de nanopartículas intermetálicas ordenadas PtSb e PtSn

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Filmes finos obtidos a plasma em reagentes contendo ácido cítrico/etilenoglicol

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Vitrificação de embriões bovinos produzidos in vivo e in vitro após lipólise química

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

Viabilidade de embriões ovinos vitrificados ou congelados submetidos às técnicas direta e indireta de inovulação

Pós-graduação em Medicina Veterinária - FMVZ