The authors recently proposed a promising technique for producing monodisperse emulsions using a straight-through microchannel (MC) device composed of an array of microfabricated oblong holes. This research developed new straight-through MC devices with tens of thousands of oblong channels of several microns in size on a silicon-on-insulator plate, and investigated the emulsification characteristics using the microfabricated straightthrough MC devices. Monodisperse oil-in-water (O/W) and W/O emulsions with average droplet diameters of 4.4-9.8 lm and coefficients of variation of less than 6% were stably produced using surface-treated straight-through MC devices that included uniformly sized oblong channels with equivalent diameters of 1.7-5.4 lm. The droplet size of the resultant emulsions depended greatly on the size of the preceding oblong channels. The emulsification process using the straight-through MC devices developed in this research had very high apparent energy efficiencies of 47-60%, defined as (actual energy input applied to droplet generation/theoretical minimum energy input necessary for making droplets) · 100. Straight-through MC devices with numerous oblong microfluidic channels also have great potential for increasing the productivity of monodisperse fine emulsions.

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Pyrolysis of ( N-a-isopropoxyethyl)isobutyramide, which was obtained by the reaction of isobutyramide, 2-propanol, and acetaldehyde in the presence of conc. sulfuric acid, produced N-vinylisobutyramide (NVIBA). The free radical polymerization of NVIBA was carried out in various solvents in the presence of a radical initiator. It was found that the polymerizability of NVIBA is similar to that of N-vinylacetamide. The resulting polyNVIBA showed a lower critical solution temperature (LCST) sharply at 39ЊC. Thermosensitive properties of polyNVIBA were investigated in comparison with poly(N-isopropylacrylamide).

We present a novel microchannel emulsification (MCE) system for mass-producing uniform fine droplets. A 60 9 60-mm MCE chip made of single-crystal silicon has 14 microchannel (MC) arrays and 1.2 9 10 4 MCs, and each MC array consists of many parallel MCs and a terrace. A holder with two inlet through-holes and one outlet through-hole was also developed for simply infusing each liquid and collecting emulsion products. The MCE chip was sealed well by physically attaching it to a flat glass plate in the holder during emulsification. Uniform fine droplets of soybean oil with an average diameter of 10 lm were reliably generated from all the MC arrays. The size of the resultant fine droplets was almost independent of the dispersed-phase flow rate below a critical value. The continuous-phase flow rate was unimportant for both the droplet generation and the droplet size. The MCE chip enabled mass-producing uniform fine droplets at 1.5 ml h -1 and 1.9 9 10 9 h -1 , which could be further increased using a dispersed phase of low viscosity.

Phospholipid‐phospholipid interaction in soybean oil is described. Phosphatidylcholine was effectively removed from soybean oil by degumming (water hydration), whereas phosphatidylethanolamine and phosphatidic acid were hardly hydratable. However, the degree of their hydration increased in the presence of phosphatidylcholine. The spectrophotometric assay based on charge transfer interaction between 7,7,8,8‐tetracyanoquinodimethane and phospholipids at 480 nm was used to determine the formation of phospholipid micelles in soybean oil. The critical micelle concentrations were 0.085, 0.84 and 2.6 mM for phosphatidylcholine, phosphatidylethanolamine and phosphatidic acid, respectively. Phosphatidylcholine interacted with phosphatidylethanolamine or phosphatidic acid to form mixed micelles. The critical micelle concentrations of phosphatidylcholine‐phosphatidylethanolamine mixture and phosphatidylcholine‐phosphatidic acid mixture were 0.16 and 1.3 mM, respectively. The degree of hydration of phospholipids was related to their critical micelle concentrations. Interaction of phosphatidylcholine with phosphatidylethanolamine or phosphatidic acid was confirmed by determining the changes in the chemical shifts of 31PNMR spectra.

We report the mass production of uniformly sized droplets on a liter per hour scale using a large microchannel (MC) emulsification device developed in this study. This MC emulsification device includes a newly designed 40 × 40-mm silicon MC array chip with 24,772 asymmetric MCs, each consisting of a circular microhole (17-μ m dia meter and 200-μ m depth) and a microslot (17 × 119-μ m cross-section and 60-μ m depth). The oil-in-water (O/W) system was composed of n -tetradecane as the dispersed phase and a Milli-Q water solution containing 2.0 wt% Tween-20 as the continuous phase. The MC emulsification results demonstrated the stable mass production of uniformly sized oil droplets with average diameters of 87 μ m and coefficients of variation below 2% over a wide range of volumetric flow rates of the dispersed phase up to 1.4 l/h. Analyses of shear stress at the chip surface and droplet generation via an asymmetric MC verified that the resultant droplet size and size distribution was not influenced by the volumetric flow rate of each phase. The large MC emulsification device has a potential droplet productivity exceeding several tons per year, which could satisfy a minimum industrial-scale production of monodisperse microdispersions containing emulsion droplets, microparticles, and microcapsules. NomenclatureA ch cross-sectional area of upper channel (m 2 ) A MCA total area of MC arrays (m 2 ) CV coeffi cient of variation (-) d droplet diameter (m) d av average droplet diameter (m) d eq,ch equivalent diameter of upper channel (m) f chip droplet generation frequency per MC array chip (s -1 ) f MC droplet generation frequency per MC (s -1 ) h ch height of upper channel (m) h slot depth of microslot (m) J d fl ux of dispersed phase [l/(m 2 h)] L ch wetted perimeter of upper channel (m) Q c fl ow rate of continuous phase (l/h) Q d fl ow rate of dispersed phase (l/h) Re c Reynolds number of cross-fl owing continuous phase (-) U c average velocity of continuous phase (m/s) w ch width of upper channel (m) w s,slot narrow side length of microslot (m) V av average droplet volume (m 3 ) Greek symbols η c viscosity of continuous phase (Pa s) η d viscosity of dispersed phase (Pa s) ρ c density of continuous phase (kg/m 3 ) σ standard deviation (m) τ s shear stress at chip surface (N) ϕ d volume fraction of dispersed phase (%)

Androgen plays a crucial role in initiating and maintaining the expression of male sexual characteristics in mammals. In humans and mice, any defects along the pathway of androgen functions result in congenital urogenital abnormalities. The genital tubercle (GT), an anlage of the external genitalia, differentiates into a penis in males and a clitoris in females. Although masculinization of the external genitalia is androgen-dependent, the molecular pathway of its potential downstream genes is largely unclear. To identify the genes involved in mouse GT masculinization, we performed gene expression analyses, such as real-time quantitative polymerase chain reaction and section in situ hybridization analysis. From our studies we have identified candidate genes, Cyp1b1, Fkbp51 and MafB as potential androgen targets during mouse GT masculinization.

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