OBJECTIVE To analyze the influence of food preparation methods on the composition of fatty acids and cholesterol in foods. METHODS The chemical composition of cholesterol and fatty acids was analyzed in eight different types of meat and feijoada in relation to different methods of preparation. RESULTS Feijoada, when prepared with the beans and meats in separate pots, has less cholesterol (1...

Frozen-thawed (FT) embryo transfer is a procedure used for the storage and transfer of excess embryos obtained during in vitro fertilization- intracytoplasmic sperm injection cycles. In recent years, improvements in laboratory conditions and limitations on the number of embryos to be transferred have led to a progressive increase in FT embryo transfer cycles. However, the best solution for endo...

Despite best efforts at controlling nanoparticle (NP) surface chemistries, the environment surrounding nanomaterials is always changing and can impart a permanent chemical memory. We present a set of preparation and measurement methods to be used as the foundation for studying the surface chemical memory of engineered NP aggregates. We attempt to bridge the gap between controlled lab studies an...

Today, a wide variety of techniques is available for the preparation of (semi-) solid, liquid and gaseous samples, prior to their instrumental analysis by means of capillary gas chromatography (GC) or, increasingly, comprehensive two-dimensional GC (GC 9 GC). In the past two decades, a large number of ‘modern’ sample-preparation techniques has been introduced, which have partly superseded their...

This review covers all of the common methods for the syntheses of aromatic and heterocyclic perfluoroalkyl sulfides, a class of compounds which is finding increasing application as starting materials for the preparation of agrochemicals, pharmaceutical products and, more generally, fine chemicals. A systematic approach is taken depending on the mode of incorporation of the SR(F) groups and also...

—New preparation methods of superconducting materials and other multicomponent systems. We discuss the synthesis of multicomponent oxides such as the superconducting phase YBa2Cu307 in the form of powders and thick fílms. They are prepared from hydrolyzed solutions which yield viscous gels suitable for spin-coating or precipitates, precursors of ceramics. We discuss the role of the precursors, ...

Sample preparation and DNA extraction protocols for DNA amplification by PCR, which can be applied in human fecal samples for taeniasis diagnosis, are described. DNA extracted from fecal specimens with phenol/chloroform/isoamilic alcohol and DNAzol reagent had to be first purified to generate fragments of 170 pb and 600 pb by HDP2-PCR. This purification step was not necessary with the use of QI...

This article reviews the recent developments in Bio-Analytical sample preparation techniques and gives an update on basic principles, Applications and comparative discussion on the advantages and limitations of each technique. Conventional Solid-Phase Extraction (SPE), Molecularly Imprinted Polymer SPE techniques are have been considered as methods of past. Developments in SPE techniques such a...