Quantification of the Total Amount of Artemisinin in Leaf Samples by Thin Layer Chromatography: FH – HES

Artemisinin is a natural molecule highly active against malaria. At present, the extraction of this molecule from the leaves of Artemisia annua L. remains the only viable method to produce cheaply large quantities of artemisinin. Agronomic research on this plant species aims to improve agricultural yields, to decrease production costs and to ensure a steady global supply of artemisinin. These research activities require an easy, rapid, low cost, and reliable analytical technique to quantify the artemisinin content in the leaves. Thin layer chromatography (TLC) methods to quantify this molecule have already been published. However, this method does not allow the quantification of the total artemisinin content in the leaves. In order to validate the TLC method, results obtained with this method were related to results for the same samples obtained by accelerated solvent extraction and high pressure liquid chromatography with an evaporative light scattering detector (ASE-HPLC-ELSD). Using the Nernst partition law, a corrective factor of 1.21 is suggested to enable information about the true total amount of artemisinin in leaf samples to be obtained within a range of 0.25 to 3%. In conclusion, this study proposes for the first time a corrective factor in order to quantify the total artemisinin content of A. annua leaves with TLC

Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

Caractérisation des composés phénoliques présents dans deux espèces du genre Alchemilla

L’objectif de ce travail est de séparer, d’isoler, de caractériser et de quantifier les composés phénoliques majoritaires d’extraits de drogues du genre Alchemilla puis d’évaluer leurs activités antioxydantes et anti-radicalaires

Scale-up of phosphate remobilization from sewage sludge in a microbial fuel cell

Phosphate remobilization from digested sewage sludge containing iron phosphate was scaled-up in a microbial fuel cell (MFC). A 3 litre triple chambered MFC was constructed. This reactor was operated as a microbial fuel cell and later as a microbial electrolysis cell to accelerate cathodic phosphate remobilization. Applying an additional voltage and exceeding native MFC power accelerated chemical base formation and the related phosphate remobilization rate. The electrolysis approach was extended using a platinum-RVC cathode. The pH rose to 12.6 and phosphate was recovered by 67% in 26 h. This was significantly faster than using microbial fuel cell conditions. Shrinking core modelling particle fluid kinetics showed that the reaction resistance has to move inside the sewage sludge particle for considerable rate enhancement. Remobilized phosphate was subsequently precipitated as struvite and inductively coupled plasma mass spectrometry indicated low levels of cadmium, lead, and other metals as required by law for recycling fertilizers

Scale-up of phosphate remobilization from sewage sludge in a microbial fuel cell

Phosphate remobilization from digested sewage sludge containing iron phosphate was scaled-up in a microbial fuel cell (MFC). A 3 litre triple chambered MFC was constructed. This reactor was operated as a microbial fuel cell and later as a microbial electrolysis cell to accelerate cathodic phosphate remobilization. Applying an additional voltage and exceeding native MFC power accelerated chemical base formation and the related phosphate remobilization rate. The electrolysis approach was extended using a platinum-RVC cathode. The pH rose to 12.6 and phosphate was recovered by 67% in 26 h. This was significantly faster than using microbial fuel cell conditions. Shrinking core modelling particle fluid kinetics showed that the reaction resistance has to move inside the sewage sludge particle for considerable rate enhancement. Remobilized phosphate was subsequently precipitated as struvite and inductively coupled plasma mass spectrometry indicated low levels of cadmium, lead, and other metals as required by law for recycling fertilizers. (C) 2015 Elsevier Ltd. All rights reserved