Antioxidant activity and polyphenol content in milling fractions of purple wheat

The aim of this study was to evaluate the antioxidant activity of four milling fractions of purple wheat breeding lines grown in 2010. Radical scavenging activity by the DPPH assay and reducing power of the samples were determined, as well as the content of polyphenols, flavonoids and anthocyanins. The obtained results showed that flour fractions (break and reduction flour) had lower total antioxidant potential than bran fractions (fine and coarse bran). A significant correlation was obtained between the DPPH and reducing power assay (R2 = 0.87). The correlation between antioxidant assays and polyphenol, flavonoid and anthocyanin content suggested that polyphenols in cereals are responsible for the antioxidant activities

Mechanisms and rate determining steps in plasma induced high rate CVD of silicon an germanium: similarities and differences

The recent progress in the understanding of the reaction mechanism of plasma induced CVD of silicon from silane and the identification of the rate determining steps enabled us to significantly increases the deposition rate of device quality a–Si, $\mu$c–Si and epi–Si. The mechanism is similar to that found for thermal CVD. The first step is the fragmentation of monosilane into SiH$_2$ and H$_2$ followed by fast insertion and formation of disilane and trisilane. The higher silanes represent the reactive intermediates for the silicon deposition because their reactive sticking coefficients are orders of magnitude larger than that of monosilane. All these features of the mechanism are well documented by experimental data from our and several other laboratories and by theoretical calculations which will be summarized here. 
 The understanding of plasma CVD of germanium from monogermane is less complete. Our recent data show that there are at least two different kinetic regimes with a different reaction mechanism. The data show that, unlike in the case of silicon, higher germanes are probably not involved in the process. A very preliminary interpretation of the data suggests that divalent fragments and possibly other radical species are the dominant precursors for the deposition of germanium. Significant differences between silicon and germanium are found also regarding the amorphous-to-crystalline transition