Catalysis at the toluene/water interface: shape-selective hydrolysis of esters having some rings and lactones promoted by octadecyl immobilized H-ZSM-5 catalyst

Shape-selective properties of octadecyltrichlorosilane-treated H-ZSM-5, abbreviated as H-ZSM-5-C₁₈, have been observed in the hydrolysis of esters having some rings and lactones in toluene-water solvent system. The shape-selectivity for the reaction has been evaluated by the ratio of the relative rate constants in comparison with the rate constant of methyl acetate. The selectivity became higher with increase in bulkiness of the substrate. Substrates having the minimum diameter larger than 6.5 Å, significantly larger in size than the pore openings of ZSM-5, could not react in this system.     

Development of virtual and real-field construction management systems in innovative, intelligent field factory

In this study, we proposed a concept of virtual and real-field construction management systems (VR-Coms), which is integrated with virtual construction simulation, planning, scheduling, and performance management systems to evaluate productivity and safety in virtual simulated and real-field constructions. And, we built up a computational environment to develop the VR-Coms. The VR-Coms offer supporting modules for learning and discovering solutions with objective to manage construction at right speed with improved humanware and constructability. The configuration of VR-Coms is described. This paper also shows an application of agent theory to construction management.     

Evaluation of pinhole defect in DLC film prepared by hybrid process of plasma-based ion implantation and deposition

Pinhole defect in diamond-like carbon (DLC) film prepared by a hybrid process of plasma-based ion implantation and deposition using toluene plasma was evaluated by the critical passivation current density in the anodic polarization method. The area ratio of pinhole defects to the SUS304 bare substrate was decreased exponentially with increasing DLC film thickness and reached about 3×10^-6% at film thickness. As a result, it is found that the corrosion resistance of DLC-coated specimens was improved with increasing film thickness. The production of an interfacial mixing layer by ion implantation from methane and acetylene plasmas between the DLC film and the substrate material reduced pinhole defects in the film.     

Specific affinity extraction method for small molecule-binding proteins

Validation of the targets of candidate drugs is critical for rapid and efficient drug discovery and development and for understanding the pharmacological action and potential toxicities of the prospective therapeutic agent. Due to the nonspecific binding of abundant proteins to small molecule-immobilized gels, it is difficult to identify the protein targets of small molecules from crude biological samples by affinity extraction. To address this problem, we have developed an affinity gel for the specific extraction of small molecule-binding proteins. We immobilized small molecules on the agarose gel through a disulfide linker that is cleavable by mild reduction. This system has allowed specific and noncovalent complex formation between the small molecule and the target protein, keeping the effect of the nonspecific abundant proteins adsorbed on both the linker and gel surface to minimum. By preparing this affinity matrix with deoxycholate as a model small molecule, we captured two independent deoxycholate-binding proteins of different affinities from mouse ascites, anti-deoxycholate antibody, and serum albumin. As other proteins were not captured, this affinity extraction method should contribute significantly to the accurate and rapid drug discovery and development.     

Preparation of a single-chain variable fragment and a recombinant antigen-binding fragment against the anti-malarial drugs, artemisinin and artesunate, and their application in an ELISA

Two different recombinant antibodies, a single-chain variable fragment (scFv) and an antigen-binding fragment (Fab), were prepared against artemisinin (AM) and artesunate (AS) and were developed for use in an enzyme-linked immunosorbent assay (ELISA). The recombinant antibodies, which were derived from a single monoclonal antibody against AM and AS (mAb 1C1) prepared by us, were expressed by Escherichia coli cells and their reactivity and specificity were characterized. As a result, to obtain sufficient signal in indirect ELISA, a much greater amount of a first antibody was needed in the use of scFv due to the differences of the secondary antibody and conformational stability. Therefore, we focused on the development of the recombinant Fab antibodies and applied it to indirect competitive ELISA. The specificity of the Fab was similar to that of mAb 1C1 in that it showed specific reactivity toward AM and AS only. The sensitivity of the icELISA (0.16 μg/mL to 40 μg/mL for AM and 8.0 ng/mL to 60 ng/mL for AS) was sufficient for analysis of antimalarial drugs, and its utility for quality control of analysis of Artemisia spp. was validated. The Fab expression and refolding systems provided a good yield of high-quality antibodies. The recombinant antibody against AM and AS provides an essential component of an economically attractive immunoassay and will be useful in other immunochemical applications for the analysis and purification of antimalarial drugs.     

Nitrogen-doped titanium dioxide photocatalysts for visible response prepared by using organic compounds

In order to utilize visible light in photocatalytic reactions, nitrogen atoms were doped in commercially available photocatalytic TiO₂ powders by using an organic compound such as urea and guanidine. Analysis by X-ray photoelectron spectroscopy (XPS) indicated that N atoms were incorporated into two different sites of the bulk phase of TiO₂. A significant shift of the absorption edge to a lower energy and a higher absorption in the visible light region were observed. These N-doped TiO₂ powders exhibited photocatalytic activity for the decomposition of 2-propanol in aqueous solution under visible light irradiation. The photocatalytic activity increased with the decrease of doped N atoms in O site, while decreased with decrease of the other sites. Degradation of photocatalytic activity based on the release of nitrogen atoms was observed for the reaction in the aqueous suspension system.     

Characterization of chitosan/citrate and chitosan/acetate films and applications for wound healing

In this work, we aimed to develop a scaffold of chitosan (CS) with a porous sponge structure for an artificial skin. The scaffolds were prepared from both CS/citric and CS/acetic solutions. In addition, the cast films were also prepared from the same solutions to compare some of their properties. They were characterized using WAXD, FTIR, DSC, tensile measurements, and SEM observation. It was found that CS/acetate had low crystallinity but CS/citrate was in an amorphous state, resulting in a large ductility with rubbery softness. Despite the different morphologies of CS/citrate and CS/acetate scaffolds, both scaffolds exhibited the wound healing effect available for tissue engineering. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

DC‐balanced perfect classified channel for hiding framing signals

Perfect classified channel (PCC) was proposed as a hardware‐based Layer‐1 encryption system that prevents of leakage of packet information and any indication of the existence of packets. PCC can provide high‐throughput communication, which is encrypted using AES encryption hardware, while maintaining DC balancing, which is generally managed using the 8B/10B or 64B/66B coding algorithms. In this paper, we propose two methods to classify a framing signal that indicates a boundary between packets, for PCC. These methods facilitate an improved level of security compared with existing communication channels and make PCC more secure. This paper describes the details of the PCC architecture including the hardware costs while also verifying the DC‐balance performance of PCC and the confidentiality of framing signals. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Improvement in microstructure of SBT thin films

Abstract

Various attempts to improve the microstructure of SBT thin films were carried out. One was to employ ultra-thin BT film as a top layer on the conventional SBT thin film. After optimization of the BT top layer thickness, a very smooth SBT surface was successfully achieved. Particularly, the insulation break down field was improved to more than 1.0 MV/cm. Next we used UV exposure during the baking process. By optimizing the UV assisted process, surface morphology was successfully improved with fine grain microstructure. The break down field was improved to more than 1.0 MV/cm. Also, these two process combinations successfully lead to more reliable SBT thin films. The break down field was drastically improved to more than 1.2 MV/cm.     

Doping and electrical characteristics of in-situ heavily B-doped Si1−x−yGexCy films epitaxially grown using ultraclean LPCVD

Doping and electrical characteristics of in-situ heavily B-doped Si_1−x−yGe_xC_y (0.22<x<0.6, 0<y<0.02) films epitaxially grown on Si(100) were investigated. The epitaxial growth was carried out at 550°C in a SiH₄–GeH₄–CH₃SiH₃–B₂H₆–H₂ gas mixture using an ultraclean hot-wall low-pressure chemical vapor deposition (LPCVD) system. It was found that the deposition rate increased with increasing GeH₄ partial pressure, and only at high GeH₄ partial pressure did it decrease with increasing B₂H₆ as well as CH₃SiH₃ partial pressures. With the B₂H₆ addition, the Ge and C fractions scarcely changed and the B concentration (C_B) increased proportionally. The C fraction increased proportionally with increasing CH₃SiH₃ partial pressures. These results can be explained by the modified Langmuir-type adsorption and reaction scheme. In B-doped Si_1−x−yGe_xC_y with y=0.0054 or below, the carrier concentration was nearly equal to C_B up to approximately 2×10²⁰ cm⁻³ and was saturated at approximately 5×10²⁰ cm⁻³, regardless of the Ge fraction. The B-doped Si_1−x−yGe_xC_y with high Ge and C fractions contained some electrically inactive B even at the lower C_B region. Resistivity measurements show that the existence of C in the film enhances alloy scattering. The discrepancy between the observed lattice constant and the calculated value at the higher Ge and C fraction suggests that the B and C atoms exist at the interstitial site more preferentially.