Preparation of micron-scale monodisperse oil-in-water microspheres by microchannel emulsification

Micron-scale monodisperse oil-in-water (O/W) micropheres (MS) were prepared using a novel microchannel (MC) emulsification technique. The characteristics of the MS preparation and the O/W-MS prepared were studied. Soybean oil and medium-chain triacyglycerol (MCT) were used as the disprrsed phase, and physiological saline was used as the continuous phase. Silicon MC with 1 to 3μm-equivalent channel diameters were employed. A novel MC module was devised to easily recover the O/W-MS prepared. The effects of the channel shape on the behavior of MS formation, on the MS size, and on the distribution were investigated. An MC with a terrace at the MC outlet stably yielded micron-scale monodisperse O/W-MS; the MS had diameters of about 5 μm, and their coefficients of variation were below 9%. Monodisperse food-grade O/W-MS with diameters of about 4 μm could be obtained by using polyglycerol fatty acid ester as the surfactant. The size and size distribution of the recovered O/W-MS remained almost constant over 60 d, demonstrating their long-term stability.     

Construction of an expression system of insect lysozyme lacking thermal stability: the effect of selection of signal sequence on level of expression in the Pichia pastoris expression system

Expression systems of human and silkworm lysozymes were constructedusing the methylotrophic yeast Pichia pastoris as a host. Theleader sequence and its prepro peptide of     

Rapid evaluation of oxidation catalysis by gas sensor system: total oxidation, oxidative dehydrogenation, and selective oxidation over metal oxide catalysts

The rapid evaluation of catalysis is an indispensable technology for the success of combinatorial chemistry. A small-sized, less expensive, easily operating screening is desirable for parallel settings which dramatically shortens the evaluation time. Recent advances in gas sensors have enabled us to use them for the rapid evaluation of oxidation catalysis. Three typical catalytic oxidations over metal oxide catalysts were evaluated by gas sensor systems optimized for each catalytic system. The first one is the total oxidation of carbon monoxide in air. Five catalytic combustion-type gas sensors were used in a parallel reactor system to shorten the evaluation time. The second one is the oxidative dehydrogenation (ODH) of ethane over the mixed oxide of nickel and iron. The evaluation of the ODH catalysis was performed by a selective olefin sensor which determines the concentration of C₂H₄ in C₂H₆. The third one is the selective oxidation catalysis of propane over alkali modified Fe/SiO₂. The effluents including CO, CO₂, aldehydes and ketones in propane were analyzed by the CO, CO₂ and semiconductor-type gas sensors selective toward aldehydes and ketones. These evaluation results indicated that gas sensors have a good potential for the rapid evaluation of oxidation catalysts.     

Impact fracture behavior of ethylene ionomer and structural change after stretching

We carried out tensile impact test and very low speed tensile test on ethylene‐based Ionomers (E/15wt %MAA) to clarify the relation between impact toughness and high‐ordered structure. We also studied the changes in high‐ordered structure under deformation by observing Differential Scanning Calorimetory (DSC) and Small‐Angle X‐ray Scattering (SAXS) of fractured surface. Na Ionomers showed ductile fracture in both high speed tensile impact (3 m/s) and very low speed tensile (2 mm/min). The disappearance of secondary melting point (Ti) in Na Ionomers was due to the destruction of ordered structure surrounding the ionic aggregate. Similar behavior was observed in 60% (or less) neutralized Zn Ionomers. However, 80% neutralized Zn Ionomer showed brittle failure in high‐speed tensile impact, and Ti did not disappear. SAXS studies of Na and Zn Ionomers after fracture, show no change both after molding (no aging) and after aging. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1712–1720, 2001     

Thermodynamic Properties of Ionic Semiclathrate Hydrate Formed with Tetrabutylammonium Propionate

The phase equilibrium temperature and dissociation heat of tetrabutylammonium propionate (TBAPr) hydrate are reported. TBAPr hydrate is a type of ionic semiclathrate hydrates and also could potentially be used as thermal energy storage material. The temperature‐composition phase diagram of the TBAPr hydrate was determined in a defined range of mass fractions. Considering the dissociation heat of differential scanning calorimetry (DSC) measurements, multiple peaks of heat flow were observed in the TBAPr‐water system at the TBAPr mass fraction lower than 0.35, and there was a single peak at the mass fraction higher than 0.37.     

Oral Secretions Affect HIPVs Induced by Generalist (<Emphasis Type="Italic">Mythimna loreyi</Emphasis>) and Specialist (<Emphasis Type="Italic">Parnara guttata</Emphasis>) Herbivores in Rice

Plants synthesize variable mixtures of herbivore-induced plant volatiles (HIPVs) as part of their evolutionary conserved defense. To elucidate the impact of chewing herbivores with different level of adaptation on HIPV profiles in rice, we measured HIPVs released from rice seedlings challenged by either the generalist herbivore Mythimna loreyi (MYL) or the specialist Parnara guttata (PAG). Both herbivores markedly elicited the emission of HIPVs, mainly on the second and third days after attack compared to control plants. In addition, side-by-side HIPV comparisons using MYL and PAG caterpillars revealed that generalist feeding induced comparably more HIPVs relative to specialist, particularly on day two as highlighted by multivariate analysis (PLS-DA) of emitted HIPVs, and further confirmed in mimicked herbivory experiments. Here, mechanically wounded plants treated with water (WW) released more VOCs than untreated controls, and on top of this, oral secretions (OS) from both herbivores showed differential effects on volatile emissions from the wounded plants. Similar to actual herbivory, MYL OS promoted higher amounts of HIPVs relative to PAG OS, thus supporting disparate induction of rice indirect defenses in response to generalist and specialist herbivores, which could be due to the differential composition of their OS. (196 words).     

Pilot-Scale Operation of a Concrete Sludge Recycling Plant and Simultaneous Production of Calcium Carbonate

A pilot-scale plant to treat concrete sludge and produce calcium carbonate (CaCO₃) and an environmental purification agent (phosphorus adsorbent derived from concrete sludge, PAdeCS®) was designed, constructed, and operated. Concrete sludge from a concrete pile and pole production plant, boiler gas containing CO₂, and groundwater were used in the plant. The process involved calcium extraction from concrete sludge into water, followed by reaction of the calcium with CO₂ to produce crystalline CaCO₃. The pilot-scale plant was operated for 1 week, and the mass flows, conversion of CO₂ to CaCO₃, and net CO₂ emissions of the process were estimated. High-purity CaCO₃ (>97%) suitable for industrial use was obtained. Based on the power consumption of the process and the amount of CO₂ sequestered into CaCO₃, a net reduction in CO₂ emissions can be achieved using this process. The produced PAdeCS can be used as an inexpensive substitute for calcium series environmental purification agents.     

Acceleration of the Rate of Silver Nanoparticle Formation Using Microbubbles in a Sonochemical Process

The effect of the addition of microbubbles on the formation of silver nanoparticles produced in an ultrasonic radiation-mediated process was investigated. The addition of microbubbles with an area-based median diameter of 26.0?µm and a bubble volume density of 0.18?cm³/L significantly increased the silver nanoparticle formation rate during the sonochemical process. The size distribution of the silver nanoparticles was largely unaffected by the addition of the microbubbles. The influence of changes in the microbubble volume density on the formation of the silver nanoparticles was also investigated; it was confirmed that the rate of formation of the silver nanoparticles increased moderately with increasing volume density. The gradient in absorption spectra was approximately 30 times larger for the case when microbubbles (median diameter: 28.3?µm) were added at 0.74?cm³/L, compared with the case without microbubbles. The results suggested that the microbubbles provided reaction sites similar to cavitation bubbles in the ultrasonic reaction.     

Grazing-incidence wide-angle X-ray diffraction study on molecular aggregation state of imprinted polyimide film before and after hard baking

Nanoimprint lithography (NIL) was carried out on precursor of polyimide (PI), poly(amic acid) film, and then hard baking to obtain imprinted PI film. The molecular aggregation states of imprinted PI films before and after hard baking were investigated by grazing-incidence wide-angle X-ray diffraction comparing with the one of flat PI film. It was found that NIL and hard baking can strongly affect the molecular aggregation states of PI film. Before hard baking, PI chain is aligned parallel to the line direction on the line. After hard baking, the alignment in ordered domain was changed to that the PI molecule of which chain axis is perpendicular to the line direction is significantly increased, while, PI molecule of which chain axis is parallel to the line direction is decreased after hard baking. Through comparing with the flat PI, crystallinity of imprinted PI film has been significantly enhanced.