Operational stability of immobilised lipase/acyltransferase during interesterification of fat blends

The lipase/acyltransferase from Candida parapsilosis is an unusual enzyme that preferably catalyses alcoholysis over hydrolysis in biphasic aqueous/organic media. The aim of this study was to evaluate the operational stability of an immobilised form of this enzyme during the interesterification of fat blends containing n-3 polyunsaturated fatty acids, in solvent-free media, at 60 7C, carried out continuously and batchwise. When the interesterification was performed in a continuous fluidised-bed reactor, an operational half-life of 9 h was estimated. The biocatalyst was also reused in consecutive 23-h batches, in a total of four batches, either using fresh medium with no water addition or adding water to rehydrate the biocatalyst. When no water and extra water was added to the reaction medium, the obtained half-lives were 10 and 18 h, respectively. Thus, the loss of activity may be explained by a progressive dehydration occurring along the reaction rather than by product or substrate inhibition effects. The interesterification activity was accompanied by changes in the acylglycerol profile. An increase in compounds of low equivalent carbon number (ECN) and in triacylglycerols (TAG) of ECN 42 and 44 was observed. This increase was accompanied by the consumption of TAG of ECN 46, 48 and 5

Effects of Smoking on Lipid Content, Macromolecular Structure and Rheological Properties of Hevea brasiliensis Sheet Rubber

ABSTRACT Natural rubber ribbed smoked sheet (RSS) production process involves a drying step in a wood smoke dryer. The purpose of this work was to know whether this smoke drying step affected the lipid composition and the properties of sheet rubber. This study consisted of a comparative study between unsmoked sheets (USS) and ribbed smoked sheets (RSS) obtained from monoclonal latices from RRIM600, BPM24 and PB235 clones. The rubber was sampled in Chantaburi province, Thailand. It was found that the smoking process increased significantly the amount of lipid extract but decreased significantly the free fatty acid content. No significant effect of smoking was detected on macromolecular parameters such as gel content or molar mass distribution and on rheological parameters such as initial plasticity (P 0 ) and Mooney viscosity (ML (1+4)100 ). In terms of resistance to thermal oxydation estimated by Plasticity retention index (PRI), smoked sheets displayed a tendency to have lower PRI than unsmoked sheets. This difference was significant for PB235 clone. A clonal effect was detected for most of the measured parameters. Indeed, PB235 clone displayed a higher lipid extract, higher P 0 , higher ML (1+4)100 , higher molar mass than those of the other studied clones while its PRI was lower

Hypovitaminosis D is associated with depression and anxiety in schizophrenia: results from the national FACE-SZ cohort. Running title: hypovitaminosis D, depression and anxiety in schizophrenia

International audienceBackground. Guidelines have been edited for the treatment of schizophrenia (SZ) and bipola

Cocaine Is Low on the Value Ladder of Rats: Possible Evidence for Resilience to Addiction

International audienceBACKGROUND:Assessing the relative value of cocaine and how it changes with chronic drug use represents a long-standing goal in addiction research. Surprisingly, recent experiments in rats--by far the most frequently used animal model in this field--suggest that the value of cocaine is lower than previously thought.METHODOLOGY/PRINCIPAL FINDINGS:Here we report a series of choice experiments that better define the relative position of cocaine on the value ladder of rats (i.e., preference rank-ordering of different rewards). Rats were allowed to choose either taking cocaine or drinking water sweetened with saccharin--a nondrug alternative that is not biologically essential. By systematically varying the cost and concentration of sweet water, we found that cocaine is low on the value ladder of the large majority of rats, near the lowest concentrations of sweet water. In addition, a retrospective analysis of all experiments over the past 5 years revealed that no matter how heavy was past cocaine use most rats readily give up cocaine use in favor of the nondrug alternative. Only a minority, fewer than 15% at the heaviest level of past cocaine use, continued to take cocaine, even when hungry and offered a natural sugar that could relieve their need of calories.CONCLUSIONS/SIGNIFICANCE:This pattern of results (cocaine abstinence in most rats; cocaine preference in few rats) maps well onto the epidemiology of human cocaine addiction and suggests that only a minority of rats would be vulnerable to cocaine addiction while the large majority would be resilient despite extensive drug use. Resilience to drug addiction has long been suspected in humans but could not be firmly established, mostly because it is difficult to control retrospectively for differences in drug self-exposure and/or availability in human drug users. This conclusion has important implications for preclinical research on the neurobiology of cocaine addiction and for future medication development

La laïcité de l’État : des principes en débat

Laïcité et système polémique de principes La laïcité de l’État, de manière flamboyante ou à bas bruit, fait l’objet de polémiques depuis sa promulgation, en 1905. Elle a ses critiques, ses adversaires, voire ses ennemis, – et ses partisans qui, parfois, s’opposent sur l’interprétation qu’ils en font. Les débats internes, qui diffèrent en nature des attaques externes, conduisent à poser que, loin d’être une idée indécomposable ou une doctrine infrangible, la laïcité résulte plutôt d’un équilib..