Construção de modelos multivariados para determinação de lipídios totais e unidade em leite em pó comercial utilizando espectroscopia no infravermelho próximo

In this work calibration models were constructed to determine the content of total lipids and moisture in powdered milk samples. For this, used the near-infrared spectroscopy by diffuse reflectance, combined with multivariate calibration. Initially, the spectral data were submitted to correction of multiplicative light scattering (MSC) and Savitzsky-Golay smoothing. Then, the samples were divided into subgroups by application of hierarchical clustering analysis of the classes (HCA) and Ward Linkage criterion. Thus, it became possible to build regression models by partial least squares (PLS) that allowed the calibration and prediction of the content total lipid and moisture, based on the values obtained by the reference methods of Soxhlet and 105 ° C, respectively . Therefore, conclude that the NIR had a good performance for the quantification of samples of powdered milk, mainly by minimizing the analysis time, not destruction of the samples and not waste. Prediction models for determination of total lipids correlated (R) of 0.9955, RMSEP of 0.8952, therefore the average error between the Soxhlet and NIR was ± 0.70%, while the model prediction to content moisture correlated (R) of 0.9184, RMSEP, 0.3778 and error of ± 0.76%

Determinação do teor de diclofenaco sódico em comprimidos por espectroscopia no infravermelho próximo NIR com calibração multivariada PLS

This work is combined with the potential of the technique of near infrared spectroscopy - NIR and chemometrics order to determine the content of diclofenac tablets, without destruction of the sample, to which was used as the reference method, ultraviolet spectroscopy, which is one of the official methods. In the construction of multivariate calibration models has been studied several types of pre-processing of NIR spectral data, such as scatter correction, first derivative. The regression method used in the construction of calibration models is the PLS (partial least squares) using NIR spectroscopic data of a set of 90 tablets were divided into two sets (calibration and prediction). 54 were used in the calibration samples and the prediction was used 36, since the calibration method used was crossvalidation method (full cross-validation) that eliminates the need for a validation set. The evaluation of the models was done by observing the values of correlation coefficient R 2 and RMSEC mean square error (calibration error) and RMSEP (forecast error). As the forecast values estimated for the remaining 36 samples, which the results were consistent with the values obtained by UV spectroscopy

Espectroscopia no infravermelho próximo e métodos de calibração multivariada aplicados à determinação simultânea de parâmetros bioquímicos em plasma sanguíneo

In this work, the quantitative analysis of glucose, triglycerides and cholesterol (total and HDL) in both rat and human blood plasma was performed without any kind of pretreatment of samples, by using near infrared spectroscopy (NIR) combined with multivariate methods. For this purpose, different techniques and algorithms used to pre-process data, to select variables and to build multivariate regression models were compared between each other, such as partial least squares regression (PLS), non linear regression by artificial neural networks, interval partial least squares regression (iPLS), genetic algorithm (GA), successive projections algorithm (SPA), amongst others. Related to the determinations of rat blood plasma samples, the variables selection algorithms showed satisfactory results both for the correlation coefficients (R²) and for the values of root mean square error of prediction (RMSEP) for the three analytes, especially for triglycerides and cholesterol-HDL. The RMSEP values for glucose, triglycerides and cholesterol-HDL obtained through the best PLS model were 6.08, 16.07 e 2.03 mg dL-1, respectively. In the other case, for the determinations in human blood plasma, the predictions obtained by the PLS models provided unsatisfactory results with non linear tendency and presence of bias. Then, the ANN regression was applied as an alternative to PLS, considering its ability of modeling data from non linear systems. The root mean square error of monitoring (RMSEM) for glucose, triglycerides and total cholesterol, for the best ANN models, were 13.20, 10.31 e 12.35 mg dL-1, respectively. Statistical tests (F and t) suggest that NIR spectroscopy combined with multivariate regression methods (PLS and ANN) are capable to quantify the analytes (glucose, triglycerides and cholesterol) even when they are present in highly complex biological fluids, such as blood plasma

Determinação de parâmetros (sólidos solúveis, pH e acidez titulável) em ameixas intactas usando espectroscopia no infravermelho próximo e seleção de comprimento de onda

The aim of this study was to evaluate the potential of near-infrared reflectance spectroscopy (NIRS) as a rapid and non-destructive method to determine the soluble solid content (SSC), pH and titratable acidity of intact plums. Samples of plum with a total solids content ranging from 5.7 to 15%, pH from 2.72 to 3.84 and titratable acidity from 0.88 a 3.6% were collected from supermarkets in Natal-Brazil, and NIR spectra were acquired in the 714 2500 nm range. A comparison of several multivariate calibration techniques with respect to several pre-processing data and variable selection algorithms, such as interval Partial Least Squares (iPLS), genetic algorithm (GA), successive projections algorithm (SPA) and ordered predictors selection (OPS), was performed. Validation models for SSC, pH and titratable acidity had a coefficient of correlation (R) of 0.95 0.90 and 0.80, as well as a root mean square error of prediction (RMSEP) of 0.45ºBrix, 0.07 and 0.40%, respectively. From these results, it can be concluded that NIR spectroscopy can be used as a non-destructive alternative for measuring the SSC, pH and titratable acidity in plums

Uso da espectroscopia do infravermelho próximo e técnicas multivariadas para diferenciar escherichia coli e salmonella enteritidis inoculadas em polpa de fruta (abacaxi)

Aiming to consumer s safety the presence of pathogenic contaminants in foods must be monitored because they are responsible for foodborne outbreaks that depending on the level of contamination can ultimately cause the death of those who consume them. In industry is necessary that this identification be fast and profitable. This study shows the utility and application of near-infrared (NIR) transflectance spectroscopy as an alternative method for the identification and classification of Escherichia coli and Salmonella Enteritidis in commercial fruit pulp (pineapple). Principal Component Analysis (PCA), Independent Modeling of Class Analogy (SIMCA) and Discriminant Analysis Partial Least Squares (PLS-DA) were used in the analysis. It was not possible to obtain total separation between samples using PCA and SIMCA. The PLS-DA showed good performance in prediction capacity reaching 87.5% for E. coli and 88.3% for S. Enteritides, respectively. The best models were obtained for the PLS-DA with second derivative spectra treated with a sensitivity and specificity of 0.87 and 0.83, respectively. These results suggest that the NIR spectroscopy and PLS-DA can be used to discriminate and detect bacteria in the fruit pulp

Estudo da potencialidade da espectroscopia de infravermelho próximo na análise de cabelo utilizando ferramentas quimiométricas para diferenciar fumantes de não fumantes

This paper investigates the potential of near infrared spectroscopy (NIR) for forensic analysis of human hair samples in order to differentiate smokers from nonsmokers, using chemometric modeling as an analytical tool. We obtained a total of 19 hair samples, 9 smokers and 10 nonsmokers varying gender, hair color, age and duration of smoking, all collected directly from the head of the same great Natal-RN. From the NIR spectra obtained without any pretreatment of the samples was performed an exploratory multivariate chemical data by applying spectral pretreatments followed by principal component analysis (PCA). After chemometric modeling of the data was achieved without any experimental data beyond the NIR spectra, differentiate smokers from nonsmokers, by demonstrating the significant influence of tabacco on the chemical composition of hair as well as the potential of the methodology in forensic identification

Caracterização estrutural de Perovskitas Lax-1AxCoO3 (x=0 e 0,2) ,dopadas com cálcio e bario, por espectroscopia de absorção de raios X (XAS).

In this work, the structures of LaCoO3, La0,8Ba0,2CoO3 and La0,8Ca0,2CoO3 perovskites were characterized as a function of temperature (LaCoO3 structure being analyzed only at room temperature). The characterization of these materials were made by X-Ray Absorption Spectroscopy (XAS), in the cobalt K-edge, taking into account the correlated Einstein model X-ray absorption fine structure (EXAFS). The first part of the absorption spectrum corresponded the X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). These materials were prepared by the combustion method. The combustion products were calcinated at 900 0C, for 6 hours in air. Noted that the sample LaCoO3 at room temperature and samples doped with Calcium and Barium in the temperature range of 50 K to 298 K showed greater distortion to monoclinic symmetry with space group I2/a. However, the sample doped with barium at the temperatures 50 K, 220 K, and 260 K showed a slight distortion to rhombohedral symmetry with space group R-3c. The La0,8Ca0, 2CoO3 structure was few sensitive to temperature variation, showing a higher local distortion in the octahedron and a higher local thermal disorder. These interpretations were in agreement with the information electronic structural on the XANES region and geometric in the EXAFS region

Influência do pré-aquecimento na adaptação marginal de dois materiais seladores de fóssulas e fissuras, analisada através de tomografia de coerência ótica

Among the non-invasive techniques employed in the prevention of caries highlights the sealing pits and fissures which is a conservative maneuver, in order to obliterate them to protect them from attack acid bacteria. Influenced by the studies of pre-heating composite resin, which has experienced great improvement in some of their physical properties, this study aimed to evaluate in vitro the superficial and internal marginal adaptation of different materials and sealants in pre-heating or not. A total of 40 extracted human third molars (n=10) that had their occlusal surfaces prepared to receive sealant. We tested two types of sealing materials: resin sealant (Fluoroshield) and low-viscosity resin (Permaflo), where 50% of previously received heated material and the other half received sealant material at room temperature. All samples were subjected to thermal cycling and pH, simulating a cariogenic oral environment, and later were analyzed appliance OCT (optical coherence tomography). The images obtained alterations were recorded and analyzed statistically. Change was considered as the emergence of bubbles, gaps and cracks in the sealant. Comparisons of the same material, assessing the fact that it is not sealed or preheated material, as well as comparisons between different materials subjected to the same temperature were carried out. The nonparametric Tukey test was used (p < 0,05). The results showed that there was statistically significant difference between both the materials analyzed, as between the situations in which the sealant material was submitted (preheated or not). On the issue of marginal adaptation and internal surface, seen through Optical coherence tomography, may suggest that there is a difference between the use of one type or another of the sealing material analyzed, with superiority attributed to resin Permaflo compared to sealant Fluroshield, telling is the same for the different techniques used

Fiat voluntas tua! Vício e pecado na ética de Abelardo

Abélard, à son éthique, préfère, à la notion de vice, celle de péché. Ce mouvement n'est pas um préssupposé de l'auteur, mais se suit, nécessairement, à sa position de logicien et, aussi bien, à sa critique aux philosophes stoïciens qu'il a pu connaître.

Ética na pesquisa em turismo: percepções de discentes de programas de pós-graduação stricto sensu em turismo UFRN, UCS e UNIVALI

This study analyzed the perception of ethics on the part of students of Post-graduation in Tourism, to develop their academic research. It is characterized as exploratory-descriptive, being considered quantitative with some elements analyzed qualitatively. Data were collected through an electronic questionnaire, originated in google docs and sent via e-mail to 54 students in three graduate programs in Tourism: The Tourism Master of the Federal University of Rio Grande do Norte (UFRN), the Master in Tourism and Hospitality of the University of Vale do Itajai (UNIVALI) and Master of Tourism at the University of Caxias do Sul (UCS), resulting in 22 responses. The study presents a profile of the dissertation research of post-graduate students, their perception about research ethics, as well as the difficulties encountered in the research process. Notes that research of dissertation are geared mostly for the historical and cultural aspects of tourism and the choice of topics for the essays came in first place, due to the influence of the guiding lines of research and, secondly, due to social relevance. The methods used in post-graduate research are descriptive, the literature and exploratory. It also notes that most students graduate in tourism (81%) attaches great importance to ethics in carrying out their dissertation research, students claim that ethics brings credibility and seriousness to research. Furthermore, it was realized that they have no knowledge about the practice of misconduct by researchers in the field of Tourism. Demonstrate that the major ethical challenge encountered by students is in relationship with the research subject, what happens during data collection. It also notes that none of the respondents sent any project to be evaluated by an Ethics Committee (CEP), moreover, most do not know the resolution 196/96, which has the main guidelines on research ethics at national level. Concludes that the students post-graduate in tourism have little knowledge about the standards and guidelines on research ethics. They demonstrate ignore the benefits of research ethics in regarding the protection and preservation of the participant, as well as the benefits it generates for society

Utilização de indicadores financeiros e não-financeiros na gestão de hotéis no Rio Grande do Norte: um estudo sob a ótica do Balanced Scorecard

This study presents the results of a research on the use of financial and non-financial performance indicators used by medium and large hotels. The research was conducted in Rio Grande do Norte, a Brazilian State. The objective is to identify the usage of performance measures by these companies. Hotel industry is one of the most important sectors in the Rio Grande do Norte economy. The research takes the Balanced Scorecard as a conceptual framework, since it represents an original contribution to the literature of managerial accounting, for rethinking old issues, pointing out themes that were forgotten or badly interpreted, to discuss the requirements imposed by the economy environment, dominated by competitive companies, and increasing the understanding of the relationship between strategy and operation. The objective of the research is to investigate if the hotel managers make use of a managerial information system or not, when evaluating the performance of their business unit. The research reveals the usage of performance evaluation using a large variety of measures. Among them is worth mention: the usage of accounting profit altogether with the EVA/MVA, the process cycle time, total quality management, process transformation, strategic mission, vision, strategic measures, measures related to feedback, risk, costs, productivity, incomes, customers retention, customer satisfaction and profitability, measures using time as a component, quality of the process, cost of the processes, employees capabilities, information systems, motivation, empowerment and alignment. The research leads to the conclusion that the usage of the deriving concepts of Balanced Scorecard can improve the performance measurement systems used by hotels

Constitucionalismo internacional: direitos humanos sob a ótica da globalização

The work presented here is the result of research on the issue of human rights in the face of conflicting issues such as the incorporation of international treaties, the sovereignty of states, globalization and multuculturalism. Specifically, we will investigate the origin of human rights, alongside his growing recognition, from the Revolutions until its completion in the Universal Declaration of Human Rights in 1948. The question, however, has become broader, when analyzed from the perspective of the internationalization of these rights as conditions and limits of democracy. Given the convergence on the reception of international treaties on human rights, we analyze a series of positions, including recent placements of the Supreme Court, and Constitutional Amendment n.45/2004. The study aims to review the classical concept of sovereignty, now within a new perspective based on the appearance of certain limitations of the state and a crisis in the face of the protection of human rights. We analyze the phenomenon of globalization in light of its complexity and its relation to sovereignty and human rights in pursuit of an expansion of democracy. The theme is consistent also with the line of contemporary constitutionalism, since their approach has a close connection with the issues of sovereignty and globalization, as well as a current relationship with the protection of human rights. The research aims to analyze the formation of a new society within a global vision of the constitutionalization of international law. It seeks to glimpse the invocacion model of foreign precedents and the possibility of dialogue betweem States as a way of protecting and enforcing the protection of human rights

A doação de sangue sob a ótica de escolares: concepções e valores

Nesta pesquisa investigou-se o nível de informação, percepção, motivos e sentimentos de escolares sobre a doação de sangue. 145 escolares do pré, 2ª, 4ª séries com seis, oito e 10 anos de idade foram submetidos a provas piagetianas, responderam uma entrevista, se posicionaram frente a um dilema. Verificou-se pouca informação e informações errôneas sobre a doação. A escola foi a fonte de informação menos citada. A maioria dos entrevistados tanto na entrevista, como no dilema, justificou a doação de sangue como um ato solidário, permitindo supor que valores como generosidade podem ser adquiridos na fase pré-operatória. Discute-se o papel da escola nos programas de Educação em Saúde voltados a comportamentos que serão emitidos a longo prazo e que beneficiam a coletividade.

Prática profissional e ética no contexto das políticas de saúde

Foram estudadas práticas profissionais em saúde, no contexto das poilítcas sociais em um município paulista. Objetivou-se conhecer as influências dessas políticas nas práticas profissionais e na observância de princípios éticos e de preceitos legais do Sistema Único de Saúde. Foram entrevistados profissionais de saúde, responsáveis pela gestão do sistema de saúde do município, coordenação de instituições de saúde e chefias de unidades. Os entrevistados fizeram referências à gravidade da situação atual do sistema de saúde, manifestando percepção fatalista e visão mecanicista dos fatos, influenciadas pela concepção liberal. Como conseqüência, buscam soluções alternativas individuais, nem sempre lícitas ou éticas.

A importância da saúde bucal na ótica de pacientes hospitalizados

A percepção da condição bucal é um importante indicador de saúde, pois sintetiza a condição real de saúde, as respostas subjetivas, os valores e as expectativas culturais. O estudo avaliou a importância da saúde bucal segundo a percepção de pacientes internados em um hospital da cidade de Araçatuba (SP). Foi aplicado um questionário semi-estruturado para a coleta de dados e utilizado para análise estatística o programa Epi Info 2000. Os resultados mostraram que metade dos pacientes haviam realizado a última visita ao cirurgião-dentista em um período compreendido entre seis a doze meses devido a problemas periodontais (35%) e cárie dentária (20%). Observou-se que, embora todos os pacientes considerassem ter uma boa higiene bucal, o tratamento periodontal foi identificado como o de maior necessidade entre os pacientes (67,93%). A presença do cirurgião-dentista no corpo clínico hospitalar foi considerada por todos os entrevistados como fundamental para contribuir no cuidado integral à saúde dos pacientes hospitalizados. Quanto ao papel do dentista em um hospital, a grande maioria dos pacientes (90,63%) afirmou ser o cuidar dos dentes. Assim, conclui-se que todos os pacientes têm conhecimento do quão é importante a manutenção das condições adequadas de saúde bucal, principalmente em pacientes hospitalizados.