Search results for "liquid"

Article 40. Résolution d'un plan de continuation, Ouverture d'une deuxième procédure, Créances nées pendant la période d'observation de la première p…

1995

International audience; (Com. 28 juin 1994, URSSAF de Paris c/ SA Boucherie Carteau et autres ; Com. 12 juill. 1994, Percepteur de Hoerdt c/ M. Stoll et autre)

A critical size for emergence of nonbulk electronic and geometric structures in dodecanethiolate-protected Au clusters.

2014

We report on how the transition from the bulk structure to the cluster-specific structure occurs in n-dodecanethiolate-protected gold clusters, Au(n)(SC12)m. To elucidate this transition, we isolated a series of Au(n)(SC12)m in the n range from 38 to ∼520, containing five newly identified or newly isolated clusters, Au104(SC12)45, Au(∼226)(SC12)(∼76), Au(∼253)(SC12)(∼90), Au(∼356)(SC12)(∼112), and Au(∼520)(SC12)(∼130), using reverse-phase high-performance liquid chromatography. Low-temperature optical absorption spectroscopy, powder X-ray diffractometry, and density functional theory (DFT) calculations revealed that the Au cores of Au144(SC12)60 and smaller clusters have molecular-like elec…

Metabolic Profiling of Glucose-Fed Metabolically Active Resting Zymomonas mobilis Strains

2020

Zymomonas mobilis is the most efficient bacterial ethanol producer and its physiology is potentially applicable to industrial-scale bioethanol production. However, compared to other industrially important microorganisms, the Z. mobilis metabolome and adaptation to various nutritional and genetic perturbations have been poorly characterized. For rational metabolic engineering, it is essential to understand how central metabolism and intracellular redox balance are maintained in Z. mobilis under various conditions. In this study, we applied quantitative mass spectrometry-based metabolomics to explore how glucose-fed non-growing Z. mobilis Zm6 cells metabolically adapt to change of oxygen avai…

Il fenomeno delle dipendenze patologiche: alcol e droghe illecite. Protocollo di analisi delle sostanze di abuso nei liquidi biologici con finalità d…

2011

Supported ionic liquid asymmetric cathalysis. A new method for chiral catalyst recycling

2004

A new method for chiral catalysts recycling, based on the supported ionic liquid asymmetric catalysis concept, has been developed. This concept involves the treatment of a monolayer of covalently attached ionic liquid on the surface of silica gel with additional ionic liquid. These layers serve as the reaction phase in which the homogeneous chiral catalyst is dissolved. As first application of this concept the L-proline-catalyzed aldol reaction has been carried out. Good yields and ee values, comparable with those obtained under homogeneous conditions have been obtained. Moreover, this material shows high regenerability.

Passive sampling in monitoring of nonylphenol ethoxylates and nonylphenol in aquatic environments

2012

The present practices for determining the concentration levels of various pollutants are in many respects insufficient and for this reason, there is an urgent need especially to develop more cost-effective sampling methods. In this study, a novel passive sampling tool (the Chemcatcher®) for monitoring nonylphenol ethoxylates (NPEOs) and nonylphenol (NP) in aqueous media was tested. These environmentally harmful substances have been widely used in different household and industrial applications and they affect aquatic ecosystems, for example, by acting as endocrine disrupting compounds. The highest accumulation of NPEOs and NP in laboratory-scale tests was obtained when using an SDB-XC (stan…

Fast blue B functionalized silica-polymer composite to evaluate 3,5-dihy-droxyhydrocinnamic acid as biomarker of gluten intake

2021

Celiac disease is an immune-mediated systemic disorder elicited by gluten and related prolamines in genetically susceptible individuals. The current treatment is a strict and lifelong gluten-free diet. However, compliance with the gluten-free diet is not always adequate and many food products contain low concentrations of gluten. The determination of dietary transgressions is a challenge for patients, physicians and dietitians. Alkylresorcinols (AR) have been proposed as sensitive and specific biomarkers of gluten consumption. In this work silica-polymer composites doped with fast blue B reagent (FB) have been used to estimate alkylresorcinols in biological samples. The proposed colorimetri…

FUNZIONALIZZAZIONE DELLA SUPERFICIE DELL’ALLOSITE MEDIANTE RISCALDAMENTO A MICROONDE

2012

L’allosite (Al2Si2O5•2H2O), è un alluminosilicato naturale, chimicamente simile al caolino; essa ha una struttura tubolare cava dell’ordine dei micrometri (0.5-1 μm ) e un diametro interno dell’ordine dei nanometri (15 nm ). I nanotubi di allosite (HNT) presentano sulla superficie esterna gruppi SiO2 mentre su quella interna gruppi AlOH. Viste le caratteristiche strutturali, HNT trovano applicazioni come Host, fungendo in alcuni casi da nanoreattori. Tali applicazioni sono però limitate dall’idrofilia della superficie, sia interna che esterna. In questo lavoro è stata sviluppata una nuova metodologia sintetica che prevede l’ultilizzo delle microonde per ancorare organosilani come precursori…

Biochemical and structural features of a novel cyclodextrinase from cow rumen metagenome.

2007

A novel enzyme, RA.04, belonging to the alpha-amylase family was obtained after expression of metagenomic DNA from rumen fluid (Ferrer et al.: Environ. Microbiol. 2005, 7, 1996-2010). The purified RA.04 has a tetrameric structure (280 kDa) and exhibited maximum activity (5000 U/mg protein) at 70 degrees C and was active within an unusually broad pH range from 5.5 to 9.0. It maintained 80% activity at pH 5.0 and 9.5 and 75 degrees C. The enzyme hydrolyzed alpha-D-(1,4) bonds 13-fold faster than alpha-D-(1,6) bonds to yield maltose and glucose as the main products, and it exhibited transglycosylation activity. Its preferred substrates, in the descending order, were maltooligosaccharides (C3-C…

Enrichment of amino acids by supported liquid membrane extraction using Aliquat 336 as a carrier

1998

Abstract The possible application of Aliquat 336 (trioctylmethyl ammonium chloride) as a carrier for liquid membrane extraction of amino acids was investigated. The extraction is performed from an aqueous donor phase with pH > 11 to an acceptor phase containing a salt solution through a supported liquid membrane with Aliquat 336 as a carrier in the membrane to facilitate amino acid transport. Counter-coupled transport of chloride anions from the acceptor phase to the donor phase is the driving force of the mass transfer in this system. The extraction efficiency depends on the donor phase pH, the carrier concentration in the liquid membrane, the composition of the acceptor phase and the hydr…