Formation of deagglomerated PLGA particles and PLGA-coated ultra fine powders by rapid expansion of supercritical solution with ethanol cosolvent

Rapid expansion of supercritical solution (RESS) was used for preparing polymer particles and polymer coating of ultra fine powders. The polymer of pharmaceutical interest was Poly(lactic-co-glycolic acid) (PLGA with PLA: PGA ratio of 85: 15 and MW of 50,000–75,000) and the simulated core particles were 1.4-μm SiO₂ and 70-nm TiO₂ particles. The supercritical solution was prepared by dissolving PLGA in supercritical carbon dioxide with ethanol as a cosolvent. Supercritical solution of CO₂-PLGA was sprayed through capillary nozzles to ambient conditions, resulting in formation of submicron PLGA particles. Similarly, rapid expansion of supercritical solution of CO₂-PLGA suspended with the core particles could provide solvent evaporation and deposition of submicron PLGA particles on the surface of the core particles, resulting in the formation of coating films on dispersed particles of SiO₂ and agglomerates of TiO₂. The influences of the core particle size, spray nozzle diameter as well as powder-to-polymer weight ratio were also investigated and discussed with respect to the coating performance.     

Automatic electron beam alignment adjustment system and automatic filament current adjustment system for electron beam welder

Recently, the electron beam welders with high acceleration voltage (more than 100 kV) and high electrical power (more than 15 kW) have been reviewed the role of the high-energy electron beam density again, due to space or aircraft development or automobile industry desired high productivity and high accurate welding for saving energy. NEC group have supplied these electron beam welders. This time, the automatic alignment adjustment system of the electron beam orbit and the automatic adjustment system of filament current were developed and put to a practical use. As a result, the great effectiveness for the stability of welding quality was apparent.     

Contribution of Invariant Natural Killer T Cells to the Clearance of Pseudomonas aeruginosa from Skin Wounds

Chronic infections are considered one of the most severe problems in skin wounds, and bacteria are present in over 90% of chronic wounds. Pseudomonas aeruginosa is frequently isolated from chronic wounds and is thought to be a cause of delayed wound healing. Invariant natural killer T (iNKT) cells, unique lymphocytes with a potent regulatory ability in various inflammatory responses, accelerate the wound healing process. In the present study, we investigated the contribution of iNKT cells in the host defense against P. aeruginosa inoculation at the wound sites. We analyzed the re-epithelialization, bacterial load, accumulation of leukocytes, and production of cytokines and antimicrobial peptides. In iNKT cell–deficient (Jα18KO) mice, re-epithelialization was significantly decreased, and the number of live colonies was significantly increased, when compared with those in wild-type (WT) mice on day 7. IL-17A, and IL-22 production was significantly lower in Jα18KO mice than in WT mice on day 5. Furthermore, the administration of α-galactosylceramide (α-GalCer), a specific activator of iNKT cells, led to enhanced host protection, as shown by reduced bacterial load, and to increased production of IL-22, IL-23, and S100A9 compared that of with WT mice. These results suggest that iNKT cells promote P. aeruginosa clearance during skin wound healing.     

Numerical simulation of deflecting flow in a symmetric enlarged channel

Numerical results of three-dimensional separated flow and heat transfer in a rectangular channel with a suddenexpansion are presented in this paper.Numerical simulations of Navier-Stokes and energy equations are carriedout using the finite difference method.The results of three-dimensional calculations are compared with thetwo-dimensional ones,and effects of the aspect ratio of channel upon the flow are shown.The transition fromsymmetric to asymmetric flow appears at lower Reynolds number as increasing the aspect ratio.The details oflocal heat transfer characteristics in two different separated flow regions on two downstream walls are clarified.Two-dimensionality of the flow and heat transfer almost disappears for the aspect ratio considered.     

Measurement of the flood discharge of a small-sized river using an existing digital video recording system

In this study, a closed-circuit television (CCTV) system, installed for surveillance purposes, is utilized to measure the flow rate during a flood. The procedure to determine both the angle and scale-factor of the camera is described. Then, image analysis techniques, namely the direct visual measurement method, Large-Scale PIV (LSPIV) and Space-Time Image Velocimetry (STIV), are applied to the video images recorded by the CCTV camera. The results of these methods and the conventional float measurement are compared. In addition, the accuracy of the respective methods is discussed. A set of low-quality video images of a flood during a thunderstorm that occurred under the dark ambient conditions (midnight) is analyzed using three image-based methods. The transition of the flow rate during the event is successfully estimated.     

Modification of cleanup methods for dioxin analysis in green leafy vegetables and comparison of packing methods for a multi-layer silica gel column

To determine polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) in green leafy vegetables, the cleanup method was modified, and packing methods for a multi-layer silica gel column were compared in food samples. First, the additional cleanup was examined for a mono-ortho PCBs fraction obtained by alumina column chromatography from spinach extract. Small solids such as rough crystals that remained after concentration of the mono-ortho PCBs fraction were identified as long-chain hydrocarbons from leaf epicuticular wax by GC/MS. Cleanup using an activated carbon silica gel column with n-hexane as the washing solvent was effective. Next, multi-layer silica gel columns packed by wet packing and dry packing were compared using komatsuna, salmon and butter as samples. The columns prepared by both methods gave similar values at each isomeric concentration level and showed similar efficiency with favorable recoveries.     

Development and characterization of a photoautotrophic cell line of pak-bung hairy roots

A cell line of photoautotrophic pak-bung hairy roots was established from photomixotrophic ones by acclimation cultivations with a stepwise change of sucrose concentration in a medium with 3.0% CO2-enriched air supplied under continuous light irradiation. The derived photoautotrophic hairy roots had high chlorophyll content and activity of 1,5-ribulose-bisphosphate carboxylase/oxygenase, the values of which were 4.1- and 2.0-fold more than those of the parent photomixotroph, respectively. Electron microscopic observation revealed that the photoautotrophic hairy root cells possessed well-developed chloroplasts. The activities of ascorbate peroxidase and guaiacoal peroxidase found in the hairy roots were comparable to those found in the leaves and roots of parent plants of pak-bung, respectively. The elongation rate of growing points of the hairy roots was maximum at 5.0% CO2 concentration in gas phase and an incident light intensity of 10 W/m2 under the photoautotrophic conditions examined. Although light was indispensable for ensuring photoautotrophy of the hairy roots, it was found that exposure of the roots to strong light resulted in the reduction in the number of viable growing points governing the overall growth rate of the hairy roots.     

Metal-Coated <100>-Cut GaAs Coupled to Tapered Parallel-Plate Waveguide for Cherenkov-Phase-Matched Terahertz Detection: Influence of Crystal Thickness

The influence of crystal thickness of metal-coated <100>-cut GaAs (M-G-M) on Cherenkov-phase-matched terahertz (THz) pulse detection was studied. The M-G-M detectors were utilized in conjunction with a metallic tapered parallel-plate waveguide (TPPWG). Polarization-sensitive measurements were carried out to exemplify the efficacy of GaAs in detecting transverse magnetic (TM)- and transverse electric (TE)-polarized THz waves. The reduction of GaAs’ thickness increased the THz amplitude spectra of the detected TM-polarized THz electro-optic (EO) signal due to enhanced electric field associated with a more tightly-focused and well-concentrated THz radiation on the thinner M-G-M. The higher-fluence THz beam coupled to the thinner M-G-M improved the integrated intensity of the detected THz amplitude spectrum. This trend was not observed for TE-polarized THz waves, wherein the integrated intensities were almost comparable. Nevertheless, good agreement of spectral line shapes of the superposed TM- and TE-polarized THz-EO signals with that of elliptically polarized THz-EO signal demonstrates excellent polarization-resolved detection capabilities of M-G-M via Cherenkov-phase-matched EO sampling technique.     

Effect of catch cup geometry on 3D boundary layer flow over the wafer surface in a spin coating

Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor instruments become more sophisticated. Spin coating is usually used for spreading photoresist on a wafer surface. However, since rotating speed of the disk is very high in spin coating, the dropped photoresist scarers outward and reattaches on the film surface. A catch cup is set up outside the wafer in spin coating, and scattered photoresist mist is removed from the wafer edge by the exhaust flow generated at the gap between the wafer edge and the catch cup. In the dry process of a spin coating, it is a serious concern that the film thickness increases near the wafer edge in the case of low rotating speed. The purpose of this study is to make clear the effect of the catch cup geometry on the 3D boundary layer flow over the wafer surface and the drying rate of liquid film.