Tailored Synthesis of 162‐Residue S‐Monoglycosylated GM2‐Activator Protein (GM2AP) Analogues that Allows Facile Access to a Protein Library

A synthetic protocol for the preparation of 162‐residue S‐monoglycosylated GM2‐activator protein (GM2AP) analogues bearing various amino acid substitutions for Thr69 has been developed. The facile incorporation of the replacements into the protein was achieved by means of a one‐pot/N‐to‐C‐directed sequential ligation strategy using readily accessible middle N‐sulfanylethylanilide (SEAlide) peptides each consisting of seven amino acid residues. A kinetically controlled ligation protocol was successfully applied to the assembly of three peptide segments covering the GM2AP. The native chemical ligation (NCL) reactivities of the SEAlide peptides can be tuned by the presence or absence of phosphate salts. Furthermore, NCL of the alkyl thioester fragment [GM2AP (1–31)] with the N‐terminal cysteinyl prolyl thioester [GM2AP (32–67)] proceeded smoothly to yield the 67‐residue prolyl thioester, with the prolyl thioester moiety remaining intact. This newly developed strategy enabled the facile synthesis of GM2AP analogues. Thus, we refer to this synthetic protocol as “tailored synthesis” for the construction of a GM2AP library.     

G-lambda: Coordination of a Grid scheduler and lambda path service over GMPLS

At iGrid2005, we conducted a live demonstration where our Grid scheduling system co-allocated computing and network resources with advance reservation through Web services interfaces using the Grid Resource Scheduler (GRS), the Network Resource Management System (NRM), which is capable of GMPLS network resource management, and a GMPLS-based network test-bed, for the first time. The goal of the G-lambda project is to define a standard Web services interface (GNS-WSI) between GRS and NRM that is acceptable for both application service providers and commercial network operators, and which can be used as a tool for realizing new and emerging commercial services.     

International real-time streaming of 4K digital cinema

This paper describes the world’s first real-time, international transmission of 4K digital cinema and 4K Super High Definition (SHD) digital video at iGrid 2005, hosted at the California Institute of Telecommunications and Information Technology (Calit2) at the University of California, San Diego. Nearly six hours of live and pre-recorded 4K motion picture and audio content was streamed to iGrid in San Diego from the Research Institute for Digital Media and Content (DMC) at Keio University in Tokyo.

To implement this demonstration, several new technologies were introduced, including a prototype high-performance 4K compressed multicasting system called “JPEG 2000 Flexcast”, and “Soundscape”, a practical scheme for synchronizing audio and video transmitted from different locations over IP networks.

These iGrid 2005 demonstrations proved that it is now feasible to implement networked professional audio/video applications–production, post-production and distribution–even at 4K quality over IP networks up to 15,000 km long. The demonstrations also showed the new 4K motion picture technology being introduced for digital cinema can be usefully applied to other network applications such as remote telepresence, distance learning and scientific visualization.     

Hardware accelerator for molecular dynamics: MDGRAPE-2

We developed MDGRAPE-2, a hardware accelerator that calculates forces at high speed in molecular dynamics (MD) simulations. MDGRAPE-2 is connected to a PC or a workstation as an extension board. The sustained performance of one MDGRAPE-2 board is 15 Gflops, roughly equivalent to the peak performance of the fastest supercomputer processing element. One board is able to calculate all forces between 10 000 particles in 0.28 s (i.e. 310000 time steps per day). If 16 boards are connected to one computer and operated in parallel, this calculation speed becomes ∼10 times faster. In addition to MD, MDGRAPE-2 can be applied to gravitational N-body simulations, the vortex method and smoothed particle hydrodynamics in computational fluid dynamics.     

Studies on aluminum-doped ZnO films for transparent electrode and antireflection coating of β-FeSi2 optoelectronic devices

β-FeSi₂ can be used for various optoelectronic devices owing to its superior material features including high optical absorption coefficient and direct band gap of about 0.8 eV. Due to its high refractive index (>5.6), however, suitable antireflection coating (ARC) is necessary for practical device applications. In order to increase the effective areas of optoelectronic devices, transparent electrodes should be also developed. In this work, Al-doped ZnO (AZO) films were fabricated by sputtering on β-FeSi₂ thin films and were found suitable for both transparent electrodes and ARC films. Choosing optimum substrate temperature and sputtering rate, high quality AZO films were formed. The conductivity of AZO films was as high as 3×10³ S/cm and ohmic contact was easily achieved between AZO and β-FeSi₂ films, indicating AZO film as an ideal transparent electrode for β-FeSi₂. The transmittance of 400-nm-thick AZO films was >80% and >70% in the wavelength ranges 400-1400 and 1400-1600 nm, respectively. By changing the thickness of AZO film, the central wavelength of minimum reflectance was adjusted to 1550 nm where the total reflectance of AZO/β-FeSi₂/Si structure was reduced below 2%.     

Ozonation combined with electrolysis of 1,4-dioxane using a two-compartment electrolytic flow cell with solid electrolyte

Ozonation combined with electrolysis (ozone-electrolysis) is a new advanced oxidation process for water treatment. The advantages of ozone-electrolysis are (1) that reagents such as hydrogen peroxide or ferrous salts are unnecessary, (2) there is less influence from chromaticity, and (3) electric power is only required for operation. However, electrolysis has a serious limitation, in that it requires electrical conductivity (EC). This research is aimed at developing an ozone-electrolysis reactor that is applicable to wastewater with low EC using a cation exchange membrane as solid electrolyte. Moreover, experimental evidence of hydroxyl radical (.OH) generation via the cathodic reduction of ozone was obtained. Competitive kinetics analysis, based on the experimental data from the ozone-electrolysis of a mixed solution of 1,4-dioxane and tert-butyl alcohol, revealed that .OH contributed to 1,4-dioxane degradation. The ozone-electrolysis reactor was successfully applicable to degradation of 1,4-dioxane in both 1,4-dioxane solution (EC: less than 0.30 microS/cm) and a landfill leachate treated by a low-pressure reverse osmosis membrane (EC: 0.06 mS/cm). The use of a solid electrolyte was also very effective in reducing the electric power required for electrolysis.     

Characterization of polycrystalline SiC films grown by HW-CVD using silicon tetrafluoride

SiC films were synthesized by hot-wire chemical vapor deposition using a tungsten filament and a gas mixture of SiF₄ and CH₄. The etching of the substrate instead of the film growth occurred on the samples prepared using only source gases without H₂ dilution. The atomic or molecular hydrogen was believed to control the density of radicals containing F in a gas phase or on a growth surface. Polycrystalline 3C-SiC(111) films were successfully obtained at substrate temperatures lower than 500 °C by using H₂ dilution. The growth mode limited by source-gas supply was found to be important to obtain polycrystalline SiC films. The SiC film grown at higher deposition pressure was amorphous and contained no Si-H_x bonds but 6% fluorine. In SiF₄/CH₄/H₂ system, the radicals containing F are considered to play very important roles in the reactions both on a growth surface and in a gas-phase.