Analysis of stability of food emulsions by Eyring's theory: Influence of different biopolymers

Eyring's kinetic theory of liquids was applied to the study of flow behavior of low oil content mayonnaises at different temperatures. These food emulsions were formulated with different biopolymers as stabilizers (polysaccharides such as modified starch, gellan gum, and pectin). The analysis of the values obtained for the parameters of the Eyring equation for viscosity determined the emulsion containing only starch as a stabilizer is the most unstable to stirring. Replacement of part of the starch with gellan gum or pectin enhances the stability of the emulsion. The results for activation energy are quite similar for high shear rates, which can be explained by the evolution of the average drop size distribution. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2653–2657, 2004     

The incorporation of quantum effects in enzyme kinetics modeling

We present an overview of new procedures for including quantum mechanical effects in enzyme kinetics. Quantum effects are included in three ways: (1) The electronic structure of the atoms in the catalytic center is treated quantum mechanically in order to calculate a realistic potential energy surface for the bond rearrangement process. (2) The discrete nature of quantum mechanical vibrational energies is incorporated in the treatment of nuclear motion for computing the potential of mean force. (3) Multidimensional tunneling contributions are included. These procedures are illustrated by applications to proton abstractions catalyzed by enolase and methylamine dehydrogenase and hydride-transfer reactions by alcohol dehydrogenase and xylose isomerase.     

New Method for Evaluating the Peltier Coefficient Based on Temperature Measurements in a Thermoelectric Module

A new method for determining the Peltier coefficient of thermoelectric devices has been developed. The Peltier coefficient has been evaluated by measuring the temperature distribution along the junction of two dissimilar materials X and Y. The energy balance has been used to link the Peltier coefficient with the hot and cold temperatures of the metallic blocks of a thermoelectric module (TEM), thus enabling the evaluation of this coefficient. Data on the thermal conductance of the pellets are also needed. The experimental device used in this paper is a TEM composed of N?=?71 couples of bismuth telluride, suitably doped to provide individual n and p elements. Using nominal values given by the manufacturer for the Seebeck coefficient of the TEM, the Onsager reciprocal relation has been confirmed.     

Corpora compilation for prosody-informed speech processing

Language Resources and Evaluation - Research on speech technologies necessitates spoken data, which is usually obtained through read recorded speech, and specifically adapted to the research needs....     

Determination of the Synthetic Cannabinoids JWH-122, JWH-210, UR-144 in Oral Fluid of Consumers by GC-MS and Quantification of Parent Compounds and Metabolites by UHPLC-MS/MS

The consumption of synthetic cannabinoids (SCs) has significantly increased in the last decade and the analysis of SCs and their metabolites in human specimens is gaining interest in clinical and forensic toxicology. A pilot study has been carried out using a combination of an initial last generation gas chromatography-mass spectrometry (GC-MS) screening method for the determination of JWH-122, JWH-210, UR-144) in oral fluid (OF) of consumers and an ultra-high performance liquid chromatography high resolution mass spectrometry (UHPLC-HRMS) confirmatory method for the quantification of the parent compounds and their metabolites in the same biological matrix. OF samples were simply liquid-liquid extracted before injecting in both chromatographic systems. The developed methods have been successfully validated and were linear from limit of quantification (LOQ) to 50 ng/mL OF. Recovery of analytes was always higher than 70% and matrix effect always lower than 15% whereas intra-assay and inter-assay precision and accuracy were always better than 16%. After smoking 1 mg JWH-122 or UR-144 and 3 mg JWH-210, maximum concentration of 4.00–3.14 ng/mL JWH-122, 8.10–7.30 ng/mL JWH-210 ng/mL and 7.40 and 6.81 ng/mL UR-144 were measured by GC-MS and UHPLC-HRMS respectively at 20 min after inhalation. Metabolites of JWH 122 and 210 were quantified in OF by UHPLC-HRMS, while that of UR144 was only detectable in traces. Our results provide for the first time information about disposition of these SCs and their metabolites in consumers OF. Last generation GC-MS has proven useful tool to identify and quantify parent SCs whereas UHPLC-HRMS also confirmed the presence of SCs metabolites in the OF of SCs consumers.     

Proteomic Tools for the Quantitative Analysis of Artificial Peptide Libraries: Detection and Characterization of Target-Amplified PD-1 Inhibitors

We report a quantitative proteomics data analysis pipeline, which coupled to protein-directed dynamic combinatorial chemistry (DDC) experiments, enables the rapid discovery and direct characterization of protein-protein interaction (PPI) modulators. A low-affinity PD-1 binder was incubated with a library of >100 D-peptides under thiol-exchange favoring conditions, in the presence of the target protein PD-1, and we determined the S-linked dimeric species that resulted, amplified in the protein samples versus the controls. We chemically synthesized the target dimer candidates and validated them by thermophoresis binding and protein-protein interaction assays. The results provide a proof-of-concept for using this strategy in the high-throughput search of improved drug-like peptide binders that block therapeutically relevant protein-protein interactions.