Avaliação de sistemas lipidicos nanoestruturados utilizados como estratégia para melhorar as propriedades biofarmaceuticas do praziquantel no tratamento da esquistossomose

Pós-graduação em Nanotecnologia Farmacêutica - FCFAR

Obtenção de compósitos de borracha natural com resíduo industrial de couro reticulados com diferentes peróxidos

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Analysis of fluoxetine and norfluoxetine in human plasma by HPLC-UV using a high purity C18 silica-based SPE sorbent

This paper reports on the development and validation of a simple and sensitive method that uses solid phase extraction (SPE) and liquid chromatography with ultraviolet detection to analyze fluoxetine (FLX) and norfluoxetine (NFLX) in human plasma samples. A lab-made C18 SPE phase was synthesized by using a sol–gel process employing a low-cost silica precursor. This sorbent was fully characterized by nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) to check the particles' shape, size and C18 functionalization. The lab-made C18 silica was used in the sample preparation step of human plasma by the SPE-HPLC-UV method. The method was validated in the 15 to 500 ng mL 1 range for both FLX and NFLX using a matrix matched curve. Detection limits of 4.3 and 4.2 ng mL 1 were obtained for FLX and NFLX, respectively. The repeatability and intermediary precision achieved varied from 7.6 to 15.0% and the accuracy ranged from 14.9 to 9.1%. The synthesized C18 sorbent was compared to commercial C18 sorbents. The average recoveries were similar (85–105%), however the lab-made C18 silica showed fewer interfering peaks in the chromatogram. After development and validation, the method using the lab-made C18 SPE was applied to plasma samples of patients under FLX treatment (n ¼ 6). The concentrations of FLX and NFLX found in the samples varied from 46.8–215.5 and 48.0–189.9 ng mL 1 , respectively.

Modificação superficial de nanopartículas de óxido de ferro por poli(ácido aspártico) reticulado

Pós-graduação em Química - IQ

Desenvolvimento de revestimentos siloxano-PMMA reforçados por nanotubos de carbono, óxido de grafite e óxido de grafite reduzido para aplicações anticorrosivas

Pós-graduação em Química - IQ

Preparação e Modificação Química de Nanoestruturas de Octa(aminopropil) silsesquioxano para Aplicações Analíticas

Pós-graduação em Ciência dos Materiais - FEIS

Influência de diferentes métodos de esterilização de esmalte dental sobre a sua morfologia, composição química, estrutura e formação de biofilmes in vitro

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

Quantificação eletroquímica de analitos de interesse ambiental e biológico, empregando novos materiais preparados a partir de silsesquioxanos funcionalizados

Pós-graduação em Ciência dos Materiais - FEIS

Influence of beta-cyclodextrin on the properties of norfloxacin form A

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

Structural properties of cerium doped siloxane-PMMA hybrid coatings with high anticorrosive performance

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

Biocellulose-based flexible magnetic paper

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

Porous silica matrix obtained from pyrex class by hydrothermal treatment: Characterization and nature of the porosity

A novel porous silica matrix has been prepared from Pyrex glass, using hydrothermal treatment under saturated-steam condition. This process makes it possible to obtain, in one step, a silica support formed of a homogeneously distributed and interconnected macropore microstructure. The new matrix contains silanol groups that can be used in reactions of surface modification to provide a hybrid material and a selective macrofiltration membrane, and also it can improve chemical inertness. The porous matrix is noncrystalline as obtained and, after thermal treatment at temperatures higher than 950degreesC, exhibits an X-ray pattern characteristic of alpha-cristobalite and low volume contraction. The present samples were characterized by scanning electron microscopy, mercury intrusion porosimetry, nitrogen adsorption-desorption isotherms, infrared spectroscopy, X-ray powder diffractometry, atomic absorption, and high-resolution solid-state nuclear magnetic resonance. The results present a new way of producing a macroporous silica matrix.

Nuclear magnetic relaxation for the spin-degenerate Anderson model

A renormalization-group calculation of the temperature-dependent nuclear spin relaxation rate for a magnetic impurity in a metallic host is reported. The calculation follows a simplified procedure, which produces accurate rates in the low-temperature Fermi-liquid regime, although yielding only qualitatively reliable results at higher temperatures. In all cases considered, as the temperature T diminishes, the rates peak before decaying linearly to zero in the Fermi-liquid range. For T → 0, the results agree very well with Shiba's expression relating the low-temperature coefficient of the relaxation rate to the squared zero-temperature susceptibility. In the Kondo limit, the enhanced susceptibility associated with the Kondo resonance produces a very sharp peak in the relaxation rate near the Kondo temperature. © 1991.

Silsesquioxane organofunctionalized with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole: preparation and subsequent reaction with silver and potassium hexacyanoferrate(III) for detection of l-cysteine

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

Filmes híbridos PMMA-siloxano modificados com nanotubos de carbono para proteção de materiais metálicos contra corrosão

Using the sol-gel process, organic-inorganic hybrid coatings were synthesized by incorporation of different concentrations of functionalized carbon nanotubes, to improve their mechanical strength and thermal resistance without changing its passivation character. The siloxane-PMMA hybrids were prepared by radical polymerization of methyl methacrylate (MMA) with 3-methacryloxipropiltrimethoxisilane (MPTS) using the thermal initiator benzoyl peroxide (BPO), followed by acid catalyzed hydrolysis and condensation of tetraethoxysilane (TEOS). The analysis of pristine and functionalized carbon nanotubes was carried out using Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy and Raman Spectroscopy. Structural analysis of hybrids was performed by Nuclear Magnetic Resonance, Atomic Force Microscopy and Raman Spectroscopy. For analysis of mechanical strength and thermal stability were performed mechanical compression tests and thermogravimetric analysis, respectively. Electrochemical Impedance Spectroscopy was used to evaluate the corrosion resistance in saline environment. The results showed an effective functionalization of carbon nanotubes with carboxyl groups and conservation of its structure. The hybrids showed high siloxane network connectivity and roughness of approximately 0.3 nm. The incorporation of carbon nanotubes in the hybrid matrix did not change significantly their thermal stability. Samples containing carbon nanotubes exhibit good corrosion resistance (on the order of MΩ in saline environment), but the lack of complete dispersion of carbon nanotubes in the hybrid, resulted in a loss of mechanical and corrosion resistance compared to hybrid matrix.