O estado da arte da cromatografia associada à espectrometria de massas acoplada à espectrometria de massas na análise de compostos tóxicos em alimentos

Chromatography combined with several different detection systems is one of the more used and better performing analytical tools. Chromatography with tandem mass spectrometric detection gives highly selective and sensitive analyses and permits obtaining structural information about the analites and about their molar masses. Due to these characteristics, this analytical technique is very efficient when used to detect substances at trace levels in complex matrices. In this paper we review instrumental and technical aspects of chromatography-tandem mass spectrometry and the state of the art of the technique as it is applied to analysis of toxic substances in food.

Lo que no es nuevo puede ser actual: hacia distintos puntos de mira de la didáctica del arte What is not new can be current - towards different approaches of the didactics of art

With this article we want to present a state of affairs of the didactics of art in our context, and at the same time we want todiscuss on its pluri- and interdisciplinary construction. We check the different disciplines that configure it and we analysethe paradigm of artistic education as a discipline (DBAE) and its passage to post-modernity. This example focuses thediscussion about the opportunity of adapting holistic educative models and the transition of the current educativeinnovation towards skill models

Como si fuera posible recoger sentimientos = As if it were possible to collect suffering

Se trata de una propuesta como resultado del trabajo conjunto entre la escuela de Arte Pigment y el ESPAI ZERO1 del Museu Comarcal de la Garrotxa, destinado exclusivamente a exposiciones temporales de creación contemporánea y como continuidad de propuestas anteriores de colaboración: REPLICA23 y SONESNAT JUNIOR. Com si fos possible recollir el sofriment es un proyecto de la artista Anna Manel.la, y se consideró una propuesta interesante y un reto para conversar, intercambiar y crear con los alumnos sobre el tema de la exposición: la muerte y el sufrimiento. Asimismo porque es una artista conocida por los alumnos de la escuela Pigment, ya que anteriormente habían realizado un proyecto de apadrinamiento de esculturas y habitualmente ella participa en programas divulgativos en la escuela. El trabajo desarrollado centra el aprendizaje en la creación y en la investigación artística como ejes de los procesos de conceptualización con el objetivo de atender las dinámicas y los estímulos característicos de los niños. Facilitando procesos de búsqueda, exploración y manipulación sin condicionantes y promoviendo procesos autónomos en los que los mismos niños se planteen dudas e interrogantes y se enfrenten a situaciones cada vez mas complejas

O estado da arte da cromatografia líquida de ultra eficiência

Ultra Performance Liquid Chromatography (UPLC) retains the same principles as High Performance Liquid Chromatography (HPLC), but uses 1-2.1 mm i.d. columns with sub-2 µm particles. It is considered the newest advance in analytical separation science. The use of these small particles with mobile phases at high linear velocities increases resolution and detectability and decreases analysis time. Thus, the analyses are faster, the solvent volume is smaller, the efficiency is higher and the detectability is 2-3 times higher when compared with HPLC analysis.

Eletrocromatografia capilar: contextualização, estado da arte e perspectivas

Capillary electrochromatography (CEC) is a separation technique in which the mobile phase flow is based on the application of a voltage across a packed capillary, which generates an electroosmotic flow that transports the analytes along the capillary toward the detector. As it combines the separation mechanisms of high-performance liquid chromatography (HPLC) and of capillary electrophoresis (CE), CEC can be considered a hybrid of HPLC and CE. This review presents some fundamental aspects of CEC and is focused on the instrumental advances of the technique, such as column technology, operation modes and detection systems, presenting recent papers on these topics and some applications and perspectives about CEC.

Estado da arte de figuras de mérito em calibração multivariada

The validation of an analytical procedure must be certified through the determination of parameters known as figures of merit. For first order data, the acuracy, precision, robustness and bias is similar to the methods of univariate calibration. Linearity, sensitivity, signal to noise ratio, adjustment, selectivity and confidence intervals need different approaches, specific for multivariate data. Selectivity and signal to noise ratio are more critical and they only can be estimated by means of the calculation of the net analyte signal. In second order calibration, some differentes approaches are necessary due to data structure.

De gemmis arte procreandis

Painovuosi nimekkeestä.

Quimioterapia da doença de Chagas: estado da arte e perspectivas no desenvolvimento de novos fármacos

Neglected diseases are a major global cause of illness, long-term disability and death. Chagas' disease is a parasitic infection widely distributed throughout Latin America, with devastating consequences in terms of human morbidity and mortality. The existing drug therapy suffers from a combination of drawbacks including poor efficacy, resistance and serious side effects. In 2009, we celebrate the 100th anniversary of the discovery of Chagas' disease, facing the challenges of developing new, safe and effective drugs for the treatment of this disease. This brief review attempts to highlight the state of the art, limitations and perspectives of Chagas' disease drug development.

De gemmis arte procreandis

Painovuosi nimekkeestä.

De gemmis arte procreandis

Painovuosi nimekkeestä.

De arte natandi

Invocatio: Q.F.F.Q.S.

O estado da arte da síntese de semicondutores nanocristalinos coloidais

Colloidal semiconductor nanocrystals, also known as quantum dots, have attracted great attention since they have interesting size-dependent properties due to the quantum confinement effect. These nanoparticles are highly luminescent and have potential applications in different technological areas, including biological labeling, light-emitting diodes and photovoltaic devices. The synthetic methods of semiconductor nanocrystals have progressed in the last 30 years, and several protocols were developed to synthesize monodisperse nanocrystals with good optical properties, different compositions and morphologies. This review describes the main methods used to synthesize nanocrystals in the II-VI and III-V systems, and the recent approaches in this field of research.

Cromatografia líquida capilar: estado da arte e aplicações

This review describes the advantages and disadvantages of using capillary liquid chromatography (CLC), which is considered the newest member in the analytical separation science arsenal. Although CLC has tremendous potential for being the next major innovation in separatory analysis, it has not yet obtained great popularity compared to conventional high performance (and ultra-high performance) liquid chromatography. Comparisons are made between these techniques and some of the reasons that CLC has not yet reached its potential will be advanced.

Um exemplo de aplicação da Microscopia Raman na autenticação de obras de arte

In the present work, Raman Microscopy was employed in the characterization of the pigments used in a drawing assigned to Tarsila do Amaral, one of the most important Brazilian artists. The work (colored pencil on paper), supposedly produced in the 1920 decade, is of a very simple composition, where blue, green and brown were the colors used. Prussian Blue was found as the blue pigment, whereas green was a mixture of copper phthalocyanine and a yellow dye, probably a diarylide; the brown pigment was a carbonaceous compound. Prussian Blue was replaced by phthalocyanine as pigment since the end of the 1930's and the possibility that it could have been used as pigment in the 1920's can be ruled out.

O estado da arte na determinação de resíduos de medicamentos veterinários em alimentos de origem animal empregando técnicas cromatográficas acopladas à espectrometria de massas

The determination of veterinary drug residues in foods of animal origin is an important issue because of the risk these compounds pose to human health in addition to their persistence and tendency to bioaccumulate. In recent years, significant progress has been made in the area and this review presents the state of the art in sample preparation procedures associated with chromatographic techniques coupled to mass spectrometry for multiresidue determination of veterinary drugs in food of animal origin at concentration levels suitable for the control of residues and contaminants in food.