Augmentation des cinétiques de diffusion des composés de la pellicule des raisins rouge et blanc par des champs électriques pulsés

In recent years, Pulsed Electric Field (PEF) technology has been developing in laboratories and is starting to be established in the industry, mainly in the agri-food sector. So far all experimentations on the use of PEF in the wine industry was carried out at the laboratory scale on some kilograms of grapes, or liters of wines. Since 2015, we are studying the interest of the use of PEF on grape polyphenols extraction on a semi-industrial scale of 2 tons per hour. The first tests were carried out by comparing the PEF technology to a control, and a conventional thermovinification with liquid phase vinification and traditional vinification with different fermentation times. The first results obtained are encouraging. Vinified in the liquid phase, the grapes treated with PEF give wines with a color intensity of 20 to 30% higher than the control and a higher TPI of 7 to 17%. In the liquid phase, the treatment of the harvest by PEF does not make it possible to obtain the extraction level of the thermovinification. After a short maceration of 3 days, the polyphenols extraction level is similar to the thermovinification, and greater after 14 days, and so is the color (respectively +12 and +16%). No change in IBMP content was observed. The wines resulting from treatment of the harvest by PEF do not have the aromatic profile of thermovinification wines. The PEF has a fruity character comparable to the control and accentuates the aromatic characteristics of the grape variety. The wine are often judged less aggressive and astringent by reinforcing the perception of sweetness and full bodied. A few tests in white grape harvest by PEF, shows a significant gain of the thiols and terpenols

International Expert Opinions and Recommendations on the Use of Melatonin in the Treatment of Insomnia and Circadian Sleep Disturbances in Adult Neuropsychiatric Disorders

Introduction: Insomnia and circadian rhythm disorders, such as the delayed sleep phase syndrome, are frequent in psychiatric disorders and their evaluation and management in early stages should be a priority. The aim of this paper was to express recommendations on the use of exogenous melatonin, which exhibits both chronobiotic and sleep-promoting actions, for the treatment of these sleep disturbances in psychiatric disorders. Methods: To this aim, we conducted a systematic review according to PRISMA on the use of melatonin for the treatment of insomnia and circadian sleep disorders in neuropsychiatry. We expressed recommendations for the use of melatonin in psychiatric clinical practice for each disorder using the RAND/UCLA appropriateness method. Results: We selected 41 studies, which included mood disorders, schizophrenia, substance use disorders, attention deficit hyperactivity disorders, autism spectrum disorders, neurocognitive disorders, and delirium; no studies were found for both anxiety and eating disorders. Conclusion: The administration of prolonged release melatonin at 2–10 mg, 1–2 h before bedtime, might be used in the treatment of insomnia symptoms or comorbid insomnia in mood disorders, schizophrenia, in adults with autism spectrum disorders, neurocognitive disorders and during sedative-hypnotics discontinuation. Immediate release melatonin at <1 mg might be useful in the treatment of circadian sleep disturbances of neuropsychiatric disorders

Active Membrane Fluctuations Studied by Micropipet Aspiration

We present a detailed analysis of the micropipet experiments recently reported in J-B. Manneville et al., Phys. Rev. Lett. 82, 4356--4359 (1999), including a derivation of the expected behaviour of the membrane tension as a function of the areal strain in the case of an active membrane, i.e., containing a nonequilibrium noise source. We give a general expression, which takes into account the effect of active centers both directly on the membrane, and on the embedding fluid dynamics, keeping track of the coupling between the density of active centers and the membrane curvature. The data of the micropipet experiments are well reproduced by the new expressions. In particular, we show that a natural choice of the parameters quantifying the strength of the active noise explains both the large amplitude of the observed effects and its remarkable insensitivity to the active-center density in the investigated range. [Submitted to Phys Rev E, 22 March 2001]Comment: 14 pages, 5 encapsulated Postscript figure

Revealing low-dose radiation damage using single-crystal spectroscopy

Data on the rapid reduction of haem proteins in the X-ray beam at synchrotron sources are presented. The use of single-crystal spectroscopy to detect these changes and their implication for diffraction data collection from oxidized species is also discussed

Protein Conformational Changes in the Bacteriorhodopsin Photocycle: Comparison of Findings from Electron and X-Ray Crystallographic Analyses

Light-driven conformational changes in the membrane protein bacteriorhodopsin have been studied extensively using X-ray and electron crystallography, resulting in the deposition of >30 sets of coordinates describing structural changes at various stages of proton transport. Using projection difference Fourier maps, we show that coordinates reported by different groups for the same photocycle intermediates vary considerably in the extent and nature of conformational changes. The different structures reported for the same intermediate cannot be reconciled in terms of differing extents of change on a single conformational trajectory. New measurements of image phases obtained by cryo-electron microscopy of the D96G/F171C/F219L triple mutant provide independent validation for the description of the large protein conformational change derived at 3.2 Å resolution by electron crystallography of 2D crystals, but do not support atomic models for light-driven conformational changes derived using X-ray crystallography of 3D crystals. Our findings suggest that independent determination of phase information from 2D crystals can be an important tool for testing the accuracy of atomic models for membrane protein conformational changes

Augmentation des cinétiques de diffusion des composés de la pellicule des raisins rouge et blanc par des champs électriques pulsés

In recent years, Pulsed Electric Field (PEF) technology has been developing in laboratories and is starting to be established in the industry, mainly in the agri-food sector. So far all experimentations on the use of PEF in the wine industry was carried out at the laboratory scale on some kilograms of grapes, or liters of wines. Since 2015, we are studying the interest of the use of PEF on grape polyphenols extraction on a semi-industrial scale of 2 tons per hour. The first tests were carried out by comparing the PEF technology to a control, and a conventional thermovinification with liquid phase vinification and traditional vinification with different fermentation times. The first results obtained are encouraging. Vinified in the liquid phase, the grapes treated with PEF give wines with a color intensity of 20 to 30% higher than the control and a higher TPI of 7 to 17%. In the liquid phase, the treatment of the harvest by PEF does not make it possible to obtain the extraction level of the thermovinification. After a short maceration of 3 days, the polyphenols extraction level is similar to the thermovinification, and greater after 14 days, and so is the color (respectively +12 and +16%). No change in IBMP content was observed. The wines resulting from treatment of the harvest by PEF do not have the aromatic profile of thermovinification wines. The PEF has a fruity character comparable to the control and accentuates the aromatic characteristics of the grape variety. The wine are often judged less aggressive and astringent by reinforcing the perception of sweetness and full bodied. A few tests in white grape harvest by PEF, shows a significant gain of the thiols and terpenols