Intérêt des laits fermentés chez l'enfant diarrhéique malnutri

L'objectif de cette étude était de comparer, chez des enfants diarrhéiques malnutris, l'effet thérapeutique d'un yaourt manufacturé à flore vivante et d'un lait fermenté enrichi préparé de façon artisanale (soow). De novembre 1988 à juillet 1989, 50 enfants non sevrés présentant une diarrhée aigüe associée à une malnutrition (indice poids/taille < 80 % des références NCHS) ont été admis dans l'étude; la répartition entre les groupes (soow contre yaourt) a été faite par tirage au sort et les deux groupes étaient comparables pour la réhabilitation nutritionnelle de ces enfants; le gain de poids moyen a été de 16 g/kg/j et le protocole n'a jamais dû être interrompu du fait d'une aggravation de la diarrhée ou d'une perte de poids. Sur le plan biologique, les résultats confirment l'intérêt du dosage de la transthyrétine associé à celui des protéines inflammatoires pour l'évaluation et le suivi du déficit nutritionnel. L'ensemble de ces résultats suggère que la réalimentation précoce à l'aide de laits fermentés enrichis, associée à la réhydratation orale, apparaît comme bénéfique en cas de diarrhée aiguë associée à une malnutrition. (Résumé d'auteur

Dielectric relaxations in PEEK by combined dynamic dielectric spectroscopy and thermally stimulated current

The molecular dynamics of a quenched poly (ether ether ketone) (PEEK) was studied over a broad frequency range from 10-3 to 106 Hz by combining dynamic dielectric spectroscopy (DDS) and thermo-stimulated current (TSC) analysis. The dielectric relaxation losses e00 KK has been determined from the real part e0 T(x) thanks to Kramers–Kronig transform. In this way, conduction and relaxation processes can be analyzed independently. Two secondary dipolar relaxations, the c and the b modes, corresponding to non-cooperative localized molecular mobility have been pointed out. The main a relaxation appeared close to the glass transition temperature as determined by DSC; it has been attributed to the delocalized cooperative mobility of the free amorphous phase. The relaxation times of dielectric relaxations determined with TSC at low frequency converge with relaxation times extracted from DDS at high frequency. This correlation emphasized continuity of mobility kinetics between vitreous and liquid state. The dielectric spectroscopy exhibits the ac relaxation, near 443 K, which has been associated with the rigid amorphous phase confined by crystallites. This present experiment demonstrates coherence of the dynamics of the PEEK heterogeneous amorphous phase between glassy and liquid state and significantly improve the knowledge of molecular/dynamic structure relationships

Space Charge at Nanoscale: Probing Injection and Dynamic Phenomena Under Dark/Light Configurations by Using KPFM and C-AFM

International audienc

Dielectric measurements in large frequency and temperature ranges of an aromatic polymer

The characterization of the BPDA/PDA polyimide (PI) at high temperature up to 400 °C, thanks to dielectric relaxation spectroscopy (DRS) in the 10-1 Hz to 106 Hz frequency range, allows the determination of the dc electrical conductivity (σdc). In such a high temperature range, the dielectric spectra are modified by the extrinsic electrode polarization phenomenon (EP) response. A model is proposed which coupled to the DRS results allows evidencing and quantifying the effect of the EP. The proposed method gives a simple way to determine the intrinsic σdc values from the effective ac dielectric response, improving the accuracy and reducing the duration of measurement. For BPDA/PDA PI, the resulting σdc values range from 4 × 10-11 to 8 × 10-6 Ω-1 m-1 for temperatures between 200 and 400 °C, with an activation energy of the conduction phenomenon of 0.55 eV

Graphene-based polymer composites: What about it for the HV electrotechnical Arena?

In this study, considerations of recent work and new acquired data by the present authors were used to propose an appreciation of the use of graphene-based polymer composites for electrotechnical applications. In particular, electrical charge behavior of specially prepared Polyethyle-Graphene Oxide (GO) was studied and the results exemplified important traits of GO polymer composites. It turns out that the resulting compound PE-GO falls into the category of nanostructured microcomposites, is sensitive to moisture contamination, yet was found to exhibit reduction of space charge accumulation as compared to the behavior observed for the neat matrix. One of the major challenges remains to transfer the magnificent graphene properties to a polymer matrix. In spite of this, polymers containing very low-content of GO show potential for high-voltage applications

Low frequency dielectric response of multilayer graphene/epoxy nanocomposites

International audienc