Antimicrobial properties of grape seed extracts and their effectiveness after incorporation into pea starch films

Chemical analysis and antimicrobial nature of grape seed extracts (GSE) and their Reisling Vitis vinifera L. application as fortificants for edible starch films were investigated. GSE possessed an antioxidant activity of 17.18 ± 1.29 mmol TROLOX equivalents g_extract⁻¹ and total phenolic content of 327.58 ± 7.24 mmol gallic acid equivalents g_extract⁻¹ mainly attributed to their flavonoid and phenolic acid composition determined by high-performance liquid chromatography accomplished to a diode array detector and a electrospray ionisation mass spectrometer in negative mode (HPLC-DAD/ESI-MS). GSE inhibited the growth of Gram-positive food-borne pathogens while Gram-negatives were not inhibited. After GSE were incorporated into pea starch films, thickness of enriched films increased and the puncture and tensile strength decreased compared to control films. Furthermore, migration of phenolic compounds from the films to different food simulants, aqueous, acidic and alcoholic solution was determined according to 89\109\EEC directive. A higher particle migration in acidic simulants was found. Finally, the effect of GSE incorporated pea starch films was tested in vitro with pork loins infected with Brochothrix thermosphacta. GSE films reduced the bacterial growth in 1.3 log colony forming units mL⁻¹ after 4 days incubation at 4 °C.     

Space shuttle meteoroid and orbital debris impact damage

Post-flight surveys of meteoroid and orbital debris (M&OD) impacts on the Space Shuttle Orbiter are conducted to identify damage caused by hypervelocity impacts from M&OD and to identify the source (i.e., whether meteoroid or orbital debris) of the projectiles responsible [1,2] This report provides data on Orbiter M&OD impacts for a five-year period and describes in detail the 39 most significant impacts. For the period 6/92 through 12/99 there were 49 Shuttle Transportation System (STS) missions (STS-50 through STS-103) of which 38 had post-flight inspections to identify M&OD impacts. Approximately 10% of the vehicle is surveyed in the M/OD inspections. The data for the 39 most significant impacts based on size found during the inspections are summarized in Table 1. This work contains estimates of impactor size which were determined using appropriate impact damage penetration equations that were derived by hypervelocity impact (HVI) test and analysis on relevant Orbiter materials. Although predictions for numbers of impacts are produced for each STS mission, we do not compare those predictions to the actual damage reported here as further efforts must be made to analyze the as-flown attitude timeline and adjust the predicted damage accordingly.     

Influence of nonionic emulsifiers on the properties of vinyl acetate/VeoVa10 and vinyl acetate/ethylene emulsions and paints

This paper presents results on the influence of the nonionic surfactant on the properties of vinyl acetate/VeoVa10^® and vinyl acetate/ethylene emulsions and paints made thereof. Emulsions were prepared in which the concentration of the nonionic surfactant and its degree of ethoxylation were varied. An increase of the nonionic emulsifier concentration and of the length of the ethylene oxide chain leads to dispersions with smaller particles and higher viscosities. Using these emulsions as binders in high pigmented paints, it was observed that the pigment binding capacity of the interior paints goes through a maximum which is located at a emulsifier concentration of about 2–3% and at a degree of ethoxylation of 17–28 mol ethylene oxide (EO). In (semi-) gloss paints, the gloss of the paint films improves with an increase of the emulsifier concentration and reaches a constant value at around 4% or a degree of ethoxylation of ca. 17 EO-moieties per molecule. The blocking of the films shows a drastic increase at a concentration above 4% and at a chain length of greater than 17 EO-moieties.     

Flame retardancy mechanisms of triphenyl phosphate,resorcinol bis(diphenyl phosphate) and bisphenol A bis(diphenyl phosphate) in polycarbonate/acrylonitrile–butadiene–styrene blends

The flame retardancy mechanisms of three aryl phosphates, triphenyl phosphate (TPP), resorcinol bis(diphenyl phosphate) (RDP) and bisphenol A bis(diphenyl phosphate) (BDP), in a polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) blend are investigated and compared. Further, the influence of polytetrafluorethylene (PTFE) on viscosity and thermal decomposition is discussed in the systems PC/ABS and PC/ABS + BDP. Mechanisms are proposed based on the results of various methods. Thermogravimetric analysis, Fourier transform infrared spectroscopy and kinetics are used to study the pyrolysis. The fire behaviour is studied by means of cone calorimeter measurements at different heat fluxes and the flammability is specified by limiting oxygen index (LOI) and UL 94. Rheology measurements are used to illuminate the changed dripping behaviour due to PTFE. TPP shows only a gas phase action. RDP shows mainly a gas phase action and some condensed phase action. BDP shows a crucial condensed phase action in addition to a gas phase action. TPP and RDP are somewhat superior in terms of flammability (LOI), whereas BDP shows superior performance in forced flaming combustion (cone calorimeter). Synergistic effects between PTFE and BDP are found. Copyright © 2007 Society of Chemical Industry     

MA‐NOTMP: A Triazacyclononane Trimethylphosphinate Based Bifunctional Chelator for Gallium Radiolabelling of Biomolecules

In the past few years, gallium‐68 has demonstrated significant potential as a radioisotope for positron emission tomography (PET), and the optimization of chelators for gallium coordination is a major goal in the development of radiopharmaceuticals. Methylaminotriazacyclononane trimethylphosphinate (MA‐NOTMP), a new C‐functionalized triazacyclononane derivative with phosphinate pendant arms, presents excellent coordination properties for ⁶⁸Ga (low ligand concentration, labelling at low pH even at room temperature). A “ready‐to‐be‐grafted” bifunctional chelating agent (p‐NCS‐Bz‐MA‐NOTMP) was prepared to allow ⁶⁸Ga labelling of sensitive biological vectors. Conjugation to a bombesin_(7–14) derivative was performed, and preliminary in vitro experiments demonstrated the potential of MA‐NOTMP in the development of radiopharmaceuticals. This new chelator is therefore of major interest for labelling sensitive biomolecules, and further in vivo experiments will soon be performed.     

Detailed Structure–Function Correlations of Bacillus subtilis Acetolactate Synthase

Isobutanol is deemed to be a next‐generation biofuel and a renewable platform chemical. 1 Non‐natural biosynthetic pathways for isobutanol production have been implemented in cell‐based and in vitro systems with Bacillus subtilis acetolactate synthase (AlsS) as key biocatalyst. 2 – 6 AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg²⁺ as cofactors. AlsS also catalyzes the conversion of 2‐ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol. Our phylogenetic analysis suggests that the ALS enzyme family forms a distinct subgroup of ThDP‐dependent enzymes. To unravel catalytically relevant structure‐function relationships, we solved the AlsS crystal structure at 2.3 Å in the presence of ThDP, Mg²⁺ and in a transition state with a 2‐lactyl moiety bound to ThDP. We supplemented our structural data by point mutations in the active site to identify catalytically important residues.