Plasma spectroscopy for polymer deposition

Optical spectroscopy of plasma for polymer deposition has been performed for two capacitive discharges : LF 10-100 kHz and HF 13.6 MHz at gas pressure of 1-2 torr and mean electrical power of 10-30 Watts Emission of the negative glow near the substrate was analysed by emission and absorption spectroscopy. Mixtures of argon with reactive gases (1-10 %) such as H2, O2, C2H 2, (CH3)6Si,NH and (CH3)3SiOC 2H5 have been investigated. Optical emissions of specific species have been identified in each gas mixture. Ionization and intensity of reactive species were found to be higher in LF than in HF. Inversely in the HF discharge the Ar( 3P2) metastable levels were more populated. Impurity emissions such as from CN and N2 in argon are discussed.La spectroscopie optique de plasmas pour le dépôt de polymères a été réalisée dans deux décharges capacitives : LF 10-100 kHz et HF 13,6 MHz à des pressions de gaz entre 1 et 2 torr et des puissances électriques moyennes de 10 à 30 Watts. L'émission de la lueur négative proche du substrat a été analysée par spectroscopie d'émission et d'absorption. Des mélanges d'argon avec des gaz réactifs (1-10 %) tels H2, O2, C2H2 , (CH3)6Si2NH et (CH3) 3SiOC2H5 ont été étudiés. Les émissions optiques d'espèces spécifiques ont été identifiées dans chaque mélange de gaz. L'ionisation et les intensités des espèces réactives ont été trouvées plus intenses en LF qu'en HF. Inversement, les niveaux métastables Ar(3P2 ) sont plus peuplés dans la décharge HF. Les émissions des impuretés telles CN et N2 dans l'argon sont discutées

Biochemical and morphological modifications during the growth of Tuber borchii mycelium

The work describes the biochemical and morphological modifications occurring in Tuber borchii mycelium during the growth in vitr

Biochemical and morphological modifications during the growth of Tuber borchii mycelium

The work describes the biochemical and morphological modifications occurring in Tuber borchii mycelium during the growth in vitr

Biochemical characterisation and antioxidant activity of mycelium of Ganoderma lucidum from Central Italy

Ganoderma lucidum species is Currently popular and used in the formulation of nutraceuticals and as functional foods, but a broad biochemical characterisation of its mycelium has not yet been reported. In this study new Italian and Chinese isolates, both identified as G. lucidum, were molecularly and biochemically characterised and compared. The mycelia differ both in terms of the enzymatic activities and in protein content revealed by 2D-PAGE electrophoretograms. The ethanolic extracts were screened for their possible antioxidant activities using three different tests: chelating activity on Fe(2+), lipoxygenase assay and DPPH(center dot) free radical scavenging. Only a fraction containing the low molecular weight compounds (L) showed antioxidative properties, whereas the soluble intracellular polysaccharides fraction (P) was ineffective. The correlation between total phenol content and scavenging activity on DPPH(center dot) assay was also discussed. Increased interest in the identification of natural molecules with good antioxidant properties suggests further investigations into the use of Italian G. lucidum in the formulation of nutraceuticals and functional food