Effect of two cooking procedures on phytochemical compounds,total antioxidant capacity and colour of selected frozen vegetables

The effect of boiling and steaming on content of phytochemicals (carotenoids, chlorophylls, polyphenols and ascorbic acid) all evaluated by HPLC, total antioxidant capacity (TAC) measured by means of TEAC and FRAP assays and colour (L^∗, a^∗, b^∗, C, H°) of three frozen vegetables (carrot, cauliflower and spinach) was evaluated. Steaming increased the content of polyphenols in all vegetables and limited the depletion of carotenoids in spinach. Accordingly, TAC remained unvaried or increased both for steamed carrot and spinach. Boiling had a more marked effect on nutritional pattern of frozen vegetables in comparison with steaming, leading to a general loss of phytochemical compounds and TAC for all vegetables. Ascorbic acid was detected only in cauliflower and decreased after both treatments. Colour of frozen vegetables was only slightly influenced by cooking, probably due to blanching pre-treatment. Slight decrements of redness (a^∗) for carrot in relation with loss of carotenoids and greenness (−a^∗) for steamed spinach, due to a significant loss of total chlorophylls, were observed.     

Abnormal Grain Growth in Alumina: Synergistic Effects of Yttria and Silica

Abnormal grain growth without strong anisotropy or faceting of the grains has been observed in high-purity yttria-doped alumina specimens, often starting at the surface and spreading right through the bulk at higher sintering temperatures. This appears to occur because of an interaction between Si contamination from sintering and the yttria doping; no such effect is seen for undoped samples. Similar microstructures were observed after deliberate Y/Si codoping. Analytical STEM showed that some grain boundaries bordering on large grains contained more Si than Y. HRTEM and diffuse dark-field imaging revealed thin (0.5–0.9 nm) disordered layers at some boundaries bordering large grains. It appears that Si impurities are accumulating at some boundaries and together with the Y inducing a grain boundary structural transformation that accounts for the dramatically increased mobility of these boundaries.     

The role of the environment in agreement technologies

The notion of Multi-Agent System environment is currently considered as a mediating entity, functioning as enabler but possibly also as a manager and constrainer of agent actions, perceptions, and interactions. In this paper, we analyze how the environment could be a first class abstraction to support the building, the development and the management of Agreements in decentralized and open systems between autonomous agents. To this aim we analyze the synergies between the environment and the foundational dimensions of agreement technologies such as semantics, norms, organizations, argumentation & negotiation, trust.     

Reconstitution and anchoring of cytoskeleton inside giant unilamellar vesicles

Among the requirements for all life forms is the ability to self-replicate. In eukaryotic cellular systems, this division is achieved through cytokinesis, and is facilitated by the (re)arrangement and interaction of cytoskeletal proteins with lipids and other proteins localized to the plasma membrane. A fascinating challenge of modern synthetic biology is the bottom-up reconstitution of such processes for the generation of an artificial cell. One crucial step towards this goal is the functional reconstitution of the protein-anchoring machinery to facilitate cytokinesis into lipid vesicles. True to the ideal of a minimal cell-like system, we here describe the formation of an actin-based cytoskeleton within giant unilamellar vesicles (GUVs) made from porcine brain lipid extracts. We demonstrate that the actin filaments are localised and anchored to the interior walls of the GUVs through the spectrin/ankyrin proteins, and produce tightly packed actin bundles. These studies allow for the examination of cytoskeletal rearrangements within a cell-like model membrane system and represent important first steps in reconstituting the minimal machinery required for the division of an artificial cell. In addition, the study of such minimal systems can shed light on protein functions that are commonly unobservable or hidden within the overwhelming complexity of cells.     

Catalytic epoxidation of unsaturated alcohols on Ti-MCM-41

The catalytic epoxidation of a series of unsaturated terpenic alcohols was carried out on titanium-containing MCM-41 mesoporous materials with tert-butylhydroperoxide. A direct comparison between in-framework Ti-MCM-41 and Ti-grafted MCM-41 showed a better performance of the latter, even if the difference between them becomes lower as the alcoholic group approaches the C=C double bond. At 358 K and in both acetonitrile and ethyl acetate, the epoxidation rate of the double bond is ruled, on these catalysts, mainly by electronic factors, which cause the preferential oxidation of internal unsaturations instead of the terminal ones. It is also governed by the OH-function position, so that, particularly in ethyl acetate, the closer the hydroxyl group to the unsaturation, the higher is the conversion rate of the terpene.     

Processing effects on poly(ethylene terephthalate) from bottle scraps

Processing of virgin and recycled poly(ethylene terephthalate) (PET) in a twin screw extruder evidences the degradative effect caused by thermal decomposition of poly(vinyl chloride) (PVC) and other impurities, e.g. adhesives, at the processing temperature. Lower melt viscosity and molecular weight, along with higher carboxylic end group concentration, were observed for recycled PET, the extent depending on PET purity. In an attempt to investigate the correlation between the kinetics of degradation phenomena and the level of thermomechanical stress, a novel dynamic method of evaluating thermal stability in processing conditions was developed. Such a method allows the achievement of long equivalent residence times while using lab-scale extruders. As a result of these experiments, PVC-rich recycled PET was shown to reach very low melt viscosity after less than 10 min in processing conditions, while virgin PET retained high viscosity even after 30 min.