166 resultados para hydrophilic


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Isoflurane is a volatile halogenated anesthetic used especially for anesthesia maintenance whereas propofol is a venous anesthetic utilized for anesthesia induction and maintenance, and reportedly an antioxidant. However, there are still controversies related to isoflurane-induced oxidative stress and it remains unanswered whether the antioxidant effects occur in patients under propofol anesthesia.Taking into account the importance of better understanding the role of anesthetics on oxidative stress in anesthetized patients, the present study was designed to evaluate general anesthesia maintained with isoflurane or propofol on antioxidant status in patients who underwent minimally invasive surgeries.We conducted a prospective randomized trial in 30 adult patients without comorbidities who underwent elective minor surgery (septoplasty) lasting at least 2 h admitted to a Brazilian tertiary hospital.The patients were randomly allocated into 2 groups, according to anesthesia maintenance (isoflurane, n = 15 or propofol, n = 15). Peripheral blood samples were drawn before anesthesia (baseline) and 2-h after anesthesia induction.The primary outcomes were to investigate the effect of either isoflurane or propofol anesthesia on aqueous plasma oxidizability and total antioxidant performance (TAP) by fluorometry as well as several individual antioxidants by high-performance liquid chromatography. As secondary outcome, oxidized genetic damage (7,8-dihydro-8-oxoguanine, known as 8-oxo-Gua) was investigated by the comet assay.Both anesthesia techniques (isoflurane or propofol) for a 2-h period resulted in a significant decrease of plasma α-tocopherol, but not other antioxidants including uric acid, carotenoids, and retinol (P > 0.05). Propofol, in contrast to isoflurane anesthesia, significantly increased (P < 0.001) anti-inflammatory/antioxidant plasma γ-tocopherol concentration in patients. Both anesthesia types significantly enhanced hydrophilic antioxidant capacity and TAP, with no significant difference between them, and 8-oxo-Gua remained unchanged during anesthesia in both groups. In addition, both anesthetics showed antioxidant capacity in vitro.This study shows that anesthesia maintained with either propofol or isoflurane increase both hydrophilic and total antioxidant capacity in plasma, but only propofol anesthesia increases plasma γ-tocopherol concentration. Additionally, both types of anesthetics do not lead to oxidative DNA damage in patients without comorbidities undergoing minimally invasive surgery.

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

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Nanotubes have been subject of studies with regard to their ability to promote differentiation of several cells lines. Nanotubes have been used to increase the roughness of the implant surfaces and to improve bone tissue integration on dental implant. In this study TiO2 nanotube layer prepared by anodic oxidation was evaluated. Nanotube formation was carried out using Glycerol-H2O DI(50-50 v/v)+NH4F(0,5 a 1,5% and 10-30V) for 1-3 hours at 37ºC. After nanostructure formation the topography of surface was observed using field-emission-scanning-microscope (FE-SEM). Contact angle was evaluated on the anodized and non-anodized surfaces using a water contact angle goniometer in sessile drop mode with 5 μL drops. In the case of nanotube formation and no treatment surface were presented 39,1° and 75,9°, respectively. The contact angle describing the wettability of the surface is enhanced, more hydrophilic, on the nanotube surfaces, which can be advantageous for enhancing protein adsorption and cell adhesion.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

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Aims: Hypochlorous (HOCl) and hypobromous (HOBr) acids are among the most powerful oxidants produced by the innate immune cells. Albumin is the predominant protein in most body fluids and is considered the most important antioxidant of blood plasma. Study Design: Oxidation of bovine albumin (BSA) and study of its structural and functional alterations. Place and Duration of Study: Faculty of Science and Faculty of Pharmaceutical Science, University of the State of Sao Paulo UNESP, between June and December 2012. Methodology: BSA was oxidized with excess of HOCl or HOBr and its structural and functional alterations were analyzed by spectroscopic techniques as UV-Vis absorption, intrinsic and synchronous fluorescence, fluorescence quenching, Rayleigh scattering and circular dichroism. Results: Both oxidants were able to deplete the intrinsic fluorescence of BSA, but HOBr was more effective than HOCl. The alterations in the synchronous fluorescence, UV-Vis absorption, and the appearance of a fluorescence band centered at 450 nm confirmed the difference between the oxidants. The oxidation did not induce aggregation of BSA as measured by Rayleigh scattering. The far-UV circular dichroism spectra showed a loss in the helical content and the near-UV-circular dichroism showed an alteration in the tertiary structure; HOBr was the more effective of the oxidants in this case. However, the oxidations did not induce significant alterations in the binding capacity of BSA, which was evaluated using hydrophobic (norfloxacin) and hydrophilic (ascorbic acid) drugs. Conclusion: These results suggest that, although highly susceptible to oxidation, the alterations did not inhibit BSA’s physiological function as a transport protein.

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Purpose: In the present work, a susceptibility and efficacy of the Ti–7.5Mo alloy and Ti alloy to bacterial biofilm formation after surface treatment was evaluated. Methods and materials: The alloy Ti–7.5Mo was obtained in arc furnace under an argon atmosphere. Ingots were then homogenized under vacuum at 1100 °C for 86.4 ks to eliminate chemical segregation and after cold worked discs were cutting. Samples were immersed in NaOH aqueous solution (5 M) and treated at 450 °C. Biofilms were grown in Ti–7.5Mo discs immersed in sterile brain heart infusion broth (BHI)containing 5% sucrose, inoculated with microbial suspension (106 cells/ml) and incubated for 5 days. Next, the discs were placed in tubes with sterile physiological solution 0.9% sodium chloride (NaCl) and sonicated for to disperse the biofilms. Tenfold serial dilutions were carried and aliquots seeded in selective agar, which were then incubated for 48 h. Then, the numbers CFU/ml (log 10) were counted and analyzed statistically. Scanning electron microscopy (SEM) on discs with biofilms groups was performed, atomic force microscope (AFM) and contact angle. Results: The results show that there is a 5% difference in bacterial adhesion between pure titanium and Ti–7.5Mo alloy. Conclusion: It was concluded that the greater the roughness, the greater the hydrophilic effect.

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Pós-graduação em Ciência dos Materiais - FEIS

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)