Molecular layer deposition - chemistry and morphology of thin polyurethane layers on native metals

Polymers play an increasing role in thin films and coatings. The properties of such polymer layers can differ substantially from their bulk behaviour. Molecular Layer Deposition (MLD) is an emerging thin film deposition technique. In this work polyurethane (PU) layers are prepared by MLD onto native surfaces of Al and Cu oxides and their chemistry, morphology and stability are assessed. Alcohol and isocyanate deposits show a significant different behaviour. Alcohols do only undergo weak physical interactions with the metal oxides as they rapidly desorb. Isocyanates form stable layers. Part of it undergoes a strong attachment to the substrate that involves the formation of urethane-like functionalities between the isocyanate groups and hydroxide/oxide from the metal surface. Sequential deposition of isocyanate and alcohol reveal further singular properties. The topography of the layers is metal specific and dependant on the deposited alcohol and the deposition sequence. In each case rough deposits are achieved. Stability of all prepared layers against THF is poor. No crosslinked polymer network is formed but rather short-chained oligomers. Significant improvement is achieved through increased storage temperature. Beside faster urethane formation, topography is much more homogeneous and stability is significantly better.Polymere spielen in dünnen Beschichtungen eine immer größere Rolle. Die Eigenschaften solcher Polymerschichten können sich erheblich vom Bulk unterscheiden. Molecular Layer Deposition (MLD) ist eine neue Technik zur Abscheidung dünner Schichten. Polyurethanschichten (PU) werden mittels MLD auf nativen Oberflächen von Al- und Cu-Oxiden hergestellt und ihre Chemie, Morphologie und Stabilität bewertet. Alkohol- und Isocyanatschichten zeigen ein deutlich unterschiedliches Verhalten. Alkohole gehen nur schwache physikalische Wechselwirkungen mit den Metalloxiden ein. Isocyanate bilden stabile Schichten. Ein Teil davon geht eine starke Bindung mit dem Substrat ein, bei der sich zwischen den Isocyanatgruppen und den Hydroxiden/Oxiden der Metalloberfläche urethanähnliche Funktionalitäten bilden. Durch die sequentielle Abscheidung von Isocyanat und Alkohol werden weitere Eigenschaften sichtbar. Die Topographie der Schichten ist metallspezifisch und abhängig vom abgeschiedenen Alkohol und der Abscheidungsreihenfolge. In jedem Fall werden raue Schichten erzielt. Die Stabilität gegenüber THF ist schlecht. Es bildet sich kein Polymernetzwerk, sondern eher kurzkettige Oligomere. Eine signifikante Verbesserung wird durch eine Erhöhung der Lagertemperatur erreicht. Neben der schnelleren Urethanbildung ist die Topographie wesentlich flacher und die Stabilität ist deutlich besser

Effets des procédés de transformation sur la valeur nutritionnelle des formulations de bouillies de complément à base de sorgho

La présente étude a évalué l’effet des procédés de transformation sur la valeur nutritionnelle de trois types de bouillies à base de sorgho. Il s’agit de: la bouillie de sorgho fermentée; la bouillie à base de sorgho, desoja et de fretin et la bouillie à base de sorgho, de niébé et d’arachide. Du point de vue nutritionnel, la bouillie de sorgho fermentée contient, sur la base sèche, 6,7% de protéines, 2,3% de lipides, et 1,17% de minérauxtotaux. La bouillie à base de sorgho, de soja et de fretin contient 21% de protéines, 5,4% de lipides et 3,14% de minéraux totaux. La bouillie à base de sorgho, de niébé et d’arachide contient 17% de protéines, 0,98% g de lipides et 2,6 % de minéraux totaux. Le trempage des graines de sorgho pendant environ 23 heures, le tamisage après mouture et la fermentation ont entraîné une réduction significative (P<0,05) des teneurs en phénols totaux et en anthocyanes.Mots clés: aliment de complément, sorgho, valeur nutritionnelle, phénols, anthocyanes

Inhibitory Effects of Prior Low-dose X-irradiation on Ischemia-reperfusion Injury in Mouse Paw

We have reported that low-dose, unlike high-dose, irradiation enhanced antioxidation function and reduced oxidative damage. On the other hand, ischemia-reperfusion injury is induced by reactive oxygen species. In this study, we examined the inhibitory effects of prior low-dose X-irradiation on ischemia-reperfusion injury in mouse paw. BALB/c mice were irradiated by sham or 0.5 Gy of X-ray. At 4 hrs after irradiation, the left hind leg was bound 10 times with a rubber ring for 0.5, 1, or 2 hrs and the paw thickness was measured. Results show that the paw swelling thickness by ischemia for 0.5 hr was lower than that for 2 hrs. At 1 hr after reperfusion from ischemia for 1 hr, superoxide dismutase activity in serum was increased in those mice which received 0.5 Gy irradiation and in the case of the ischemia for 0.5 or 1 hr, the paw swelling thicknesses were inhibited by 0.5 Gy irradiation. In addition, interstitial edema in those mice which received 0.5 Gy irradiation was less than that in the mice which underwent by sham irradiation. These findings suggest that the ischemia-reperfusion injury is inhibited by the enhancement of antioxidation function by 0.5 Gy irradiation

Production and quantification of odd carbon fatty acids produced by Brettanomyces and Dekkera

The odd carbon number fatty acids produced by Brettanomvces and Dekkera in white table wine were studied. The fatty acids were extracted by ether and analyzed by high performance liquid chromatography (HPLC) with an Econosphere C18 column. In order to find out the time of fatty acids produced by these two yeasts, the samples were taken during and after fermentation of must. Besides, samples taken from the addition of 20%, 5.5% and 1% reducing sugar to the fermentation of must were also studied. N-valeric acid (C5) was identified in samples taken during and after fermentation. In samples inoculated with both Saccharomvces and Dekkera. no n-valeric acid was found during fermentation; however, a trace amount of n-valeric acid was determined in the samples after fermentation. Also, n-valeric acid was found in the samples inoculated with both Saccharomvces and Brettanomvces during the last 2 days, and upon completion, of fermentation