Search results for "VIEILLISSEMENT"
showing 10 items of 57 documents
Sugar reduction in extruded cereal based products : impact of water content on the structure and molecular dynamics in such material
2019
Low-moisture biopolymer-based systems are commonly encountered in food. Obviously, understanding the physical basis of their quality: e.g texture, or performance over time or as a function of their composition is of primary importance. The objectives of this work were to evaluate how the presence of sucrose and water content affects physico-chemical properties. The physical stability of these materials were monitored through an insight at different molecular scales. Then the relations between the multi-scale studies were investigated. The effect of sucrose (0–20%) and feed water (10 and 15%) on extrusion blends was studied using a twin screw extruder under the same processing settings. The …
Génération de supercontinuum infrarouge et enjeux de vieillissement au sein de fibres optiques à coeur suspendu hautement non linéaires en verre de c…
2014
The work reported in this thesis deals with the fabrication of suspended core chalcogenide microstructured optical fibers (MOFs) for supercontinuum generation (SCG) beyond 6 μm. In this context, As2S3-based suspended-core MOFs were fabricated under vacuum, and loss threshold of 1-2 dB/m at 2.9µm were systematically registered. In addition, MOFs were designed with core diameter ranging from 1.5 to 3.5µm, allowing therefore to control the MOF's dispersive properties and to shift corresponding zero dispersion wavelength to 2.0-2.5 µm range. SCG experiments were performed by pumping the fabricated MOFs in their anomalous dispersion regime by means of tunable femtosecond laser source. Simultaneo…
Contribution to the development of natural fibers' use in structural composites. Study of a Flax / Epoxy composite’s behavior when exposed to hygroth…
2018
In recent years there is renewed interest for bio-sourced composites, including those based on flax fibers, and especially in the field of transport, mobility and leisure. In fact, the lower energy cost and environmental impact of flax fiber give it an advantage over glass fiber, while competing with its specific mechanical properties. However, flax fibers based composites long-term behavior remains poorly known in damp environments and constitutes an obstacle to a wider use. This work aims to provide adapted parameters to produce a high-grade flax/epoxy composite and to contribute to improve the durability knowledge of these materials. First, the influence of many processing parameters [(i…
Influence du vieillissement hygrothermique sur la tenue à l'impact de stratifiés quasi-isotropes/quasi homogènes
2011
International audience; La présente étude a pour objectif de déterminer l'influence du vieillissement hygrothermique sur la tolérance à l'impact de stratifiés possédant des propriétés particulières d'isotropie. Trois stratifications de 24 plis carbone/époxy ont été étudiées. Deux d'entre elles conduisent à des propriétés d'isotropie en membrane et en flexion, la troisième est isotrope en membrane et anisotrope en flexion. Les stratifiés obtenus après cuisson suivant le cycle préconisé par le fabricant ont été découpés pour obtenir des éprouvettes carrées destinées au vieillissement et à l'impact. Le vieillissement a été réalisé grâce à une enceinte climatique à une température de 70 °C sous…
Introduction : Mobilité et vulnérabilités
2020
La mobilité des individus est un élément clé de la vie quotidienne car elle permet de réaliser des activités à l'extérieur de son domicile. Les difficultés à se déplacer, pouvant entraîner la sédentarité ou une mobilité réduite, peuvent en effet constituer un frein à la participation et à l'insertionsociale et faire ainsi apparaître des inégalités. Ce numéro de la revue populations vulnérables propose d'interroger la mobilité, valeur essentielle de notre société, sous l'angle des vulnérabilités.
G6PD protects from oxidative damage and improves healthspan in mice
2016
S.N.-P. and P.J.F.-M. have been funded by the Spanish Association Against Cancer(aecc). Work in the laboratory of M.S. is funded by the CNIO and by grants from the Spanish Ministry of Economy co-funded by the European Regional Development Fund(SAF project), the European Research Council (ERC Advanced Grant), the Regional Government of Madrid co-funded by the European Social Fund (ReCaRe project), the European Union (RISK-IR project), the Botin Foundation and Banco Santander(Santander Universities Global Division), the Ramon Areces Foundation, and the AXA Foundation. Work in the laboratory of J.V. was supported by grants SAF2013-44663-R,from the Spanish Ministry of Education and Science (MEC…
Evidence for different patterns of chemosensory alterations in the elderly population: impact of age versus dependency
2015
The present experiment aimed to explore the interindividual variability in chemosensory abilities among the elderly population. The chemosensory abilities of 559 subjects, aged from 65 to 99 years, were evaluated. Various categories of the elderly, including people who were living at home either without or with assistance, and people who were living in a nursing home, were interviewed. The results revealed that 43% of the sample presented well-preserved chemosensory abilities, whereas 21% of the participants presented a moderate impairment. Of the sample, 33% presented well-preserved olfactory abilities but strong impairment in gustatory abilities and 3% were nearly anosmic but remained abl…
Wine metabolomic analysis : "chemical messages in a bottle"
2014
The main objective of this work was to develop non-targeted metabolomics analyses of bottled wines in order to decipher chemical informations from the time-related evolution of their composition. This original research was based on the hypothesis that, when analyzed, bottled wines would still hold chemical memories of envionmental parameters (vineyard management, oenological practices, climate, terroir…) at the moment of their elaboration, even after several years of ageing. A second hypothesis was that in order to anticipate the future evolution of the wine quality in terms of chemical composition, it is necessary to know what it was in the past. To that purpose, and for the first time in …
Participation des facteurs nutritionnels et environnementaux au vieillissement de la rétine et aux rétinopathies liées à l’âge
2012
Aging is defined by all the physiological processes that alter the structure and functions of the body. With advanced age, aging of the human retina can evolve into pathological forms, agerelated macular degeneration (AMD) or diabetic retinopathy (DR). The mechanisms involved in the transition from normal aging to a pathologic state are poorly understood. Oxidative stress and advanced glycation end-products are promoting factors for aging of the retina. Meanwhile, epidemiological studies suggest that a diet rich in long-chain omega-3 polyunsaturated fatty acids (LC-PUFA) such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), potentially protects against the development of AMD a…
La confection législative de la pénibilité : la médecine du travail convoquée pour faire vieillir le senior ?
2012
National audience