Molar Ratio of Phytic Acid and Zinc During Cereal Flake Production

The phytic acid content and distribution of phosphorus during cereal flaking were determined as well as the level of some minerals, and the molar ratios of phytic acid: zinc were calculated. Statistical analyses showed that there were no differences in the amount of total phosphorus, between oats and wheat and between rye and barley. The phytic/non-phytic phosphorus ratio was about 3 in wheat and oats, about 2 in barley and about 13 in rye. The technological processing did not affect ( P< 0·05) phytic acid content. The molar ratio of phytic acid: zinc for the flakes was only slightly below that of the whole grain, indicating that the technological process, primarily a hydrothermal treatment and flaking, did not improve zinc availability.     

Polysilazane derived micro/nano Si3N4/SiC composites

The pyrolised polysilazanes poly(hydridomethyl)silazane NCP 200 and poly(urea)silazane CERASET derived Si–C–N amorphous powders were used for preparation of micro/nano Si₃N₄/SiC composites by hot pressing. Y₂O₃–Al₂O₃ and Y₂O₃–Yb₂O₃ were used, as sintering aids. The resulting ceramic composites of all compositions were dense and polycrystalline with fine microstructure of average grain size <1 μm of both Si₃N₄ and SiC phases. The fine SiC nano-inclusions were identified within the Si₃N₄ micrograins. Phase composition of both composites consist of , β modifications of Si₃N₄ and SiC. High weight loss was observed during the hot pressing cycle, 12 and 19 wt.% for NCP 200 and CERASET precursors, respectively. The fracture toughness of both nanocomposites (NCP 2000 and CERASET derived) was not different. Indentation method measured values are from 5 to 6 MPa m^1/2, with respect to the sintering additive system. Fracture toughness is slightly sensitive to the SiC content of the nanocomposite. Hardness increases with the content of SiC in the nanocomposite. The highest hardness was achieved for pyrolysed CERASET precursor with 2 wt.% Y₂O₃ and 6 wt.% Yb₂O₃, HV 23 GPa. This is a consequence of the highest SiC content as well as the chemical composition of additives.     

电信行业能否拯救地球？

近年来，有关全球变暖的原因开始显得越发明显，特别是对温室效应来说。四大商业因素——建筑，履行，交通，以及食物（肉制品极其重要）——占据了全球能源消耗以及二氧化碳排放的四分之三。通讯技术无力独自改变现状，但ICT却是未来低碳世界的一个关键。就中短期而言，我们相信ICT可以提供5％-20％的削减量。最近的研究表明，在全球变暖中，ICT的直接二氧化碳排放量大概占据2％的份额。其中移动通讯占了0．2％，而固定电话（包括宽带）则是0．3％。就全球变暖而言，ICT领域中，电脑以及互联网（特别是数据中心）才是最大最重要的肇事者。     

Effect of fluidized bed drying on properties of dehydrated apples

Three sorts of apple (Idared, Golden Delicious and Jonathan) were dried in a laboratory-type fluidized bed dryer. Apples were cleaned, cored, peeled and cut into 10 × 10 × 10 mm cubes or into slices 5 × 3 mm thick and 40 mm long. A part of the samples was dipped for 3 min prior to drying in 0.1% ascorbic acid solution. Drying temperature was 80 °C. Some physicochemical and sensory properties of fresh and dried apples were determined. Moisture content in dried samples varied between 9 and 12%. Greater quantity of water results in lower sensory characteristics. The sensory characteristics of apples were determined by a scoring system with weighed factors in a 20-point scale. Glucose, fructose, saccharose, citric acid, malic acid and ascorbic acid levels were analysed by enzymatic methods. Contents of glucose, fructose and saccharose in dried apples were substantially unchanged compared to fresh apples. The drying process had the most influence on contents of citric and malic acids. Higher rehydration ratios were measured in spaghetti-like sclices and in ascorbic acid treated samples. Idared had the best characteristics with regard to physicochemical and sensory results.     

Study of Electroless Copper Deposition on Fe Powder

The electrolytic deposition of an electropositive metal is often accompanied by electroless deposition. However, this process is very difficult to control. For that reason, our study has been aimed at the conditions of the electroless deposition of copper coating onto the iron powder particles from sulphate electrolyte. The process consists of two partial reactions; solid iron substrate dissolves into the solution, thus providing the electrons necessary for reduction of copper. The course of the electroless process depends to a large extent on the composition and pH of the electrolyte as well as on the size and concentration of the iron powder particles in the electrolyte. In order to suppress the spontaneous electroless deposition of copper, sodium citrate as complexing agent was used. The following parameters were determined to characterize the reaction course: the heterogeneous rate constant of Fe powder dissolution and degree of Fe conversion as well as thickness of the Cu layer on the Fe powder, both of the latter evaluated upon attaining the stationary state. The main influence exhibited on the reaction course is the efficient surface area available for electroless deposition.     

The A9 Core Sequence from NRPS Adenylation Domain Is Relevant for Thioester Formation

The adenylation (A) domain in nonribosomal peptide synthetases catalyses a two-step reaction in which an amino acid is activated and then transferred to the neighbouring thiolation (T) domain. In this study, we investigated the role of the conserved A9 core sequence of the A-domain of tyrocidine synthetase 1, by analysis of single amino acid mutations in the A9 region. Mutation of an absolutely conserved proline (P490G) significantly reduced the conformational stability of the protein, as evidenced by increased susceptibility to proteolytic cleavage and denaturation. All mutant A-domains were capable of amino acid activation, but the activity in the overall reaction was reduced. Surprisingly, the S491R mutant (mutation at the first residue following the A9 motif) showed elevated overall activity compared to the wild-type protein. Our results suggest that the A9 core sequence plays a role in the second reaction step, in which it could serve as a "clip" for the proper positioning of residues important for the interaction with the T-domain, and/or stabilisation of the thioester-forming conformation.     

Corticosteroid induction of renal and intestinal K(+)-dependent p-nitrophenylphosphatase in young and adult rats

The post-natal development of the K(+)-dependent p-nitrophenylphosphatase (K-NPPase) activity of the Na, K-ATPase complex and its regulation by corticosteroids was studied in renal and intestinal epithelia of the rat using the p-nitrophenylphosphatecerium capture method. The distribution of the phosphatase was analysed in detail in the renal epithelia of the medullary thick ascending limb of Henle's loop and distal convoluted tubule and in the surface epithelial cells of the distal colon. The convoluted tubule and Henle's loop segments showed a stronger reaction for K-NPPase than the colon epithelium both in adult and young animals (suckling and weanling pups). The intensity of staining rose progressively in all three epithelia during early postnatal development and reached the highest levels during the weaning period and in adulthood. The most distinct change was observed between days 10 and 16. Adrenalectomy significantly reduced the density of the final reaction product in weanling and adult rats. Replacement hormone therapy of adrenalectomized weanling rats with the glucocorticoid dexamethasone restored the K-NPPase activity in the two renal epithelia, whereas the mineralocorticoid deoxycorticosterone acetate had no effect on the activity in the medullary thick ascending limb, a very slight effect in distal convoluted tubules, and a strong effect on the distal colon epithelial activity. The observed small effect of the mineralocorticoid in distal convoluted tubule activity may reflect a cross-over into glucocorticoid receptors. We conclude that the postnatal development of Na, K-ATPase is regulated by glucocorticoids in nephron epithelia and predominantly by mineralocorticoids in the surface enterocytes of the distal colon.     

Pulse nickel electrolytic colouring process of anodised aluminium

The influence of frequencies of periodic reverse current on the morphology of nickel-pigmented aluminium finishes has been studied. The pigmentation of the anodised aluminium was realised by electrolytic colouring in electrolytes with additives and in additives-free electrolytes. Additives-free electrolytes generally provide advantageous quality of pigmentation with regular and homogenous nickel morphology on the aluminium substrate at all applied frequencies. The presence of 5-sulphophtalic acid additive strongly influences the deposit quality. The deposits obtained from nickel sulphate electrolytes at all used frequencies with the use of periodic reverse current with citrate acid and sulphosuccinic acid additives provide the similar poor quality of colouring under studied plating conditions.