Measurement of the rotational inertia of bodies by using mechanical spectroscopy

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

Impedance-derived electrochemical capacitance spectroscopy for the evaluation of lectin-glycoprotein binding affinity

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

Predicting soluble solid content in intact jaboticaba [Myrciaria jaboticaba (Vell.) O. Berg] fruit using near-infrared spectroscopy and chemometrics

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

Spectroscopic, luminescence and in vitro biological studies of solid ketoprofen of heavier trivalent lanthanides and yttrium(III)

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

Novel estimation of the humification degree of soil organic matter by laser-induced breakdown spectroscopy

Soil organic matter (SOM) constitutes an important reservoir of terrestrial carbon and can be considered an alternative for atmospheric carbon storage, contributing to global warming mitigation. Soil management can favor atmospheric carbon incorporation into SUM or its release from SOM to atmosphere. Thus, the evaluation of the humification degree (HD), which is an indication of the recalcitrance of SOM, can provide an estimation of the capacity of carbon sequestration by soils under various managements. The HD of SOM can be estimated by using various analytical techniques including fluorescence spectroscopy. In the present work, the potential of laser-induced breakdown spectroscopy (LIBS) to estimate the HD of SUM was evaluated for the first time. Intensities of emission lines of Al, Mg and Ca from LIBS spectra showing correlation with fluorescence emissions determined by laser-induced fluorescence spectroscopy (LIFS) reference technique were used to obtain a multivaried calibration model based on the k-nearest neighbor (k-NN) method. The values predicted by the proposed model (A-LIBS) showed strong correlation with LIFS results with a Pearson's coefficient of 0.87. The HD of SUM obtained after normalizing A-LIBS by total carbon in the sample showed a strong correlation to that determined by LIFS (0.94), thus suggesting the great potential of LIBS for this novel application. (C) 2014 Elsevier B.V. All rights reserved.

High-throughput sugarcane leaf analysis using a low cost closed-vessel conductively heated digestion system and inductively coupled plasma optical emission spectroscopy

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

Physical and chemical matrix effects in soil carbon quantification using laser-induced breakdown spectroscopy

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

Fast determination of beef quality parameters with time-domain nuclear magnetic resonance spectroscopy and chemometrics

The noteworthy of this study is to predict seven quality parameters for beef samples using time-domain nuclear magnetic resonance (TD-NMR) relaxometry data and multivariate models. Samples from 61 Bonsmara heifers were separated into five groups based on genetic (breeding composition) and feed system (grain and grass feed). Seven sample parameters were analyzed by reference methods; among them, three sensorial parameters, flavor, juiciness and tenderness and four physicochemical parameters, cooking loss, fat and moisture content and instrumental tenderness using Warner Bratzler shear force (WBSF). The raw beef samples of the same animals were analyzed by TD-NMR relaxometry using Carr-Purcell-Meiboom-Gill (CPMG) and Continuous Wave-Free Precession (CWFP) sequences. Regression models computed by partial least squares (PLS) chemometric technique using CPMG and CWFP data and the results of the classical analysis were constructed. The results allowed for the prediction of aforementioned seven properties. The predictive ability of the method was evaluated using the root mean square error (RMSE) for the calibration (RMSEC) and validation (RMSEP) data sets. The reference and predicted values showed no significant differences at a 95% confidence level.

Luminescent solar concentrators: challenges for lanthanide-based organic-inorganic hybrid materials

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

In-Office dental bleaching efficacy assessment in function of the light exposure regime by digital colometric reflectance spectroscopy

In-office dental bleaching has been subject of several studies. Generally those studies quantify through visual analysis, the shade reduction of the teeth submitted to different bleaching protocols (light sources, bleaching agent concentrations and irradiation time). The objective of this work is the determination of the influence of four irradiation protocols on the obtainment of better aesthetic results using a colorimetric spectrophotometer that quantifies color changes in each situation imposed. Forty bovine incisors were selected in function of similar anatomic characteristics; a concentrated coffee solution was used to stain the teeth. A commercial spectrophotometer was used to measure the color changes during evolution of the experiment (stain and bleaching phases) and the obtained data was analyzed by the ANOVA test. The obtained data showed the evolution of teeth color during the staining period, as well as, the color reduction that each bleaching protocol achieved. Based on our findings it is possible to conclude that bleaching protocols with larger irradiation periods did not showed significant differences when compared with shorter irradiation protocols, in that way the use of protocols with 30 min or more of consecutive irradiation are not clinically justified and also can cause several side effects.

Complexos heterobilantanídicos luminescentes sob excitação UV e raios X

Pós-graduação em Química - IQ

Artificial neural network associated to UV/Vis spectroscopy for monitoring bioreactions in biopharmaceutical processes

Currently, mammalian cells are the most utilized hosts for biopharmaceutical production. The culture media for these cell lines include commonly in their composition a pH indicator. Spectroscopic techniques are used for biopharmaceutical process monitoring, among them, UV–Vis spectroscopy has found scarce applications. This work aimed to define artificial neural networks architecture and fit its parameters to predict some nutrients and metabolites, as well as viable cell concentration based on UV–Vis spectral data of mammalian cell bioprocess using phenol red in culture medium. The BHK-21 cell line was used as a mammalian cell model. Off-line spectra of supernatant samples taken from batches performed at different dissolved oxygen concentrations in two bioreactor configurations and with two pH control strategies were used to define two artificial neural networks. According to absolute errors, glutamine (0.13 ± 0.14 mM), glutamate (0.02 ± 0.02 mM), glucose (1.11 ± 1.70 mM), lactate (0.84 ± 0.68 mM) and viable cell concentrations (1.89 105 ± 1.90 105 cell/mL) were suitably predicted. The prediction error averages for monitored variables were lower than those previously reported using different spectroscopic techniques in combination with partial least squares or artificial neural network. The present work allows for UV–VIS sensor development, and decreases cost related to nutrients and metabolite quantifications.

Estudo de nanocompósitos luminescentes baseados em complexos de Eu(III) e Ir(III) ancorados à nanopartículas de sílica por bases de Schiff

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Encapsulation of paclitaxel into a bio-nanocomposite. a study combining inelastic neutron scattering to thermal analysis and infrared spectroscopy

The anticancer drug paclitaxel was encapsulated into a bio-nanocomposite formed by magnetic nanoparticles, chitosan and apatite. The aim of this drug carrier is to provide a new perspective against breast cancer. The dynamics of the pure and encapsulated drug were investigated in order to verify possible molecular changes caused by the encapsulation, as well as to follow which interactions may occur between paclitaxel and the composite. Fourier transformed infrared spectroscopy, thermal analysis, inelastic and quasi-elastic neutron scattering experiments were performed. These very preliminary results suggest the successful encapsulation of the drug.

Determination of quality parameters for mustard sauces in sealed packets using time-domain nuclear magnetic resonance spectroscopy and chemometrics

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)