Involvement of follicular basement membrane and vascular endothelium in blood follicle barrier formation of mice revealed by 'in vivo cryotechnique'

The molecular sieve with size- and charge selectivity in ovarian follicles, the so-called blood-follicle barrier (BFB), was examined during follicular development under physiological conditions to reveal ovarian structures responsible for the BFB by using our 'in vivo cryotechnique' (IVCT). Mouse ovary specimens were prepared with different methods including IVCT, immersion, or perfusion chemical fixation and quick-freezing following resection or perfusion. Their paraffin sections or cryosections were stained with hematoxylin-eosin or immunostained for serum proteins with different molecular weights: albumin, immunoglobulin (Ig) G1 heavy chain, inter-alpha-trypsin inhibitor (I alpha I), fibrinogen, and IgM. Their immunoreactivity was better preserved with IVCT. The immunostaining for albumin was clearly observed in blood vessels, interstitium, and developing follicles, but that of IgG1, I alpha I, or fibrinogen was significantly decreased inside the follicles. IgM was immunohistochemically decreased throughout the interstitium outside blood vessels. The immunoreactivities of IgG1 and IgM, as compared with albumin, were clearly changed along follicular basement membranes and around vascular endothelial cells respectively. These findings indicate that BFB functions throughout follicular development, and the follicular basement membrane and the vascular endothelium could play some significant roles in the permselectivity for such soluble proteins with intermediate and high molecular weight respectively.     

Functional expression of a plant hydroxynitrile lyase in Escherichia coli by directed evolution: creation and characterization of highly in vivo soluble mutants

Low protein solubility of recombinantly expressed proteins in Escherichia coli is a major factor hindering their application and analysis. We generated highly in vivo soluble mutants of a hydroxynitrile lyase in E.coli using protein engineering. Structure-guided saturation mutagenesis caused high solubility of single Lys-Pro mutations at positions 176, 199 and 224 of this low soluble wild-type enzyme. The triple Lys-Pro mutant generated at these surface conserved residues showed up to 8-fold increase in specific activity in the cell-free extract. Random mutagenesis also created a mutant of His103Met with 18.5-fold increase. The main expression form was reversed from insoluble to the soluble fraction following both types of above-mentioned mutations in E.coli at 37°C. The findings challenge the rationale of producing recombinant proteins in this host at 37°C. Formerly wild type low soluble protein was then present as soluble protein by these mutations, which also elevated the total soluble protein fraction in E.coli. Saturation mutagenesis of His103 provided other highly soluble mutants with hydrophobic substitutions. These mutations caused only minor secondary structural changes as determined by circular dichroism and Fourier-transform infrared spectroscopy and affected catalytic efficiency slightly for the purified mutants (0.82-1.6-fold for benzaldehyde and 0.9-1.9-fold for mandelonitrile). The stability of the mutants was differed from that of the wild type at high temperatures and at pH >8. Exchanging the buried basic-polar residue His103 with hydrophobic amino acids is in line with the overall structure of the enzyme, i.e. having hydrophilic residues in solvent-exposed areas and hydrophobic residues in the core.     

Recent studies on the application of microfabrication technologies for improving tribological properties

The relationships between nanometer‐scale surface textures of periodic asperity arrays and friction force in unlubricated conditions and the relationships between micrometer‐scale surface textures of two‐tier structures and friction force in mixed lubrication conditions were investigated. The friction force and pull‐off force were measured on the asperity array in an unlubricated condition. Each force was proportional to the radius of the curvature of the asperity peak. The pull‐off force was determined by the Laplace pressure of the capillary condensed water. The friction force was measured on the micrometer‐scale surface textures of a two‐tier structure in lubricated conditions. The friction coefficient increased with higher bearing characteristic numbers at the higher B, though the friction coefficient was constant at the lower B. The roughness of the pin surface and the geometry of the two‐tier structure affected the friction coefficient at the lower B and higher B, respectively. Copyright © 2010 John Wiley & Sons, Ltd.     

Study on the retention behavior of hydrogen isotopes and the change of chemical states of boron film exposed to hydrogen plasma in LHD

The behavior of hydrogen retention and the change of chemical states of boron film exposed to hydrogen plasma in LHD were investigated. The sample was prepared in LHD, and atomic concentrations for the boron film after hydrogen plasma exposure were changed from 75% for boron, 15% for carbon and 8% for oxygen to 53%, 18% and 22%, respectively. BC bond was a major chemical state of the boron film after hydrogen plasma exposure, although abundance of BB bond was the highest before the plasma exposure. Total hydrogen retention measured by TDS was evaluated to be 1.7 × 10²⁰ H m^?2, and the retentions of hydrogen as BHB, BH and BCH bonds were, respectively, 4.8 × 10¹⁹, 7.2 × 10¹⁹ and 5.2 × 10¹⁹ H m^?2. It was concluded that the hydrogen retention could be estimated by taking account not only of chemical states of impurities, but also of hydrogen depth profile.     

Crystal structure change of Li2+xTiO3+y tritium breeder under moist air

To investigate the aging behavior of Li_2+xTiO_3+y, the materials Li_2.0TiO_3+y, Li_2.2TiO_3+y and Li_2.4TiO_3+y were stored under moist air at ambient temperature. Under these conditions the weight of Li_2.0TiO_3+y increased by only 1% in 100 days, which provides evidence for the high chemical stability of Li₂TiO₃. In comparison, under the same storage conditions the weights of Li_2.2TiO_3+y and Li_2.4TiO_3+y increased by 14% and 18%, respectively. The observed weight gain is attributed to the uptake of water, and to the reaction of a by-product of Li_2+xTiO_3+y with water and carbon dioxide. The weight gain curves were evaluated by the Jander equation. From the analysis, it was possible to obtain the diffusion coefficient of water through Li₂TiO₃ particles at ambient temperature. The determined value was 2 × 10⁻¹⁷ m²/s.     

Double-stub structure for resonant-type optical modulators using 20-/spl mu/m-thick electrode

We propose a resonant-type LiNbO/sub 3/ optical modulator with low halfwave voltage. We optimize the phase constant of the electric wave with thick electrodes to reduce the halfwave voltage. The halfwave voltage of the fabricated modulator with 20-/spl mu/m-thick electrodes is 5.8 V at 10.6 GHz.     

Distributed control system utilizing a MAP-based LAN

We developed the ADMAP ADvanced MAP) system as a local area network for our Distributed Instrumentaion Control System (DCS) with a broadcast communications function. ADMAP is an open system based on the Manufacturing Automation Protocol (MAP), which is advancing as an international standard, but also providing real-time performance, which is weak in MAP.

The new MAP-based LAN can be used not only for electrical and computer control. This paper describes the new MAP-based LAN and discusses distributed control systems using this LAN to integrate instrumentation, electrical, and computer controls.     

Motion control of wearable-type walking support system based on the spring-mass model

Many systems and control methods have been proposed as mobility supports for the physically disabled and elderly individuals. In this research, we focus on a wearable-type system that supports the elderly with their walking. Different from typical control methods of wearable-type walking support systems, we propose a simple control method based on the spring–mass model. As a walking aid that does not require additional motions, such as sit-to-stand, this simple system is beneficial for two reasons. First, it reduces the calculation cost of deriving the support joint torque of the user; second, the wearable device hardware can be simply constructed from low-power actuators and springs rather than high-power actuators. In stance phase support mode, our motion control method compensates for a part of the force applied to the upper body as a leg muscle support. During the swing phase, walking is supported by a trajectory-following method using the impedance control as well as the spring–mass model. The proposed methods are applied to a prototype of a wearable-type walking support system, and evaluated in a series of experiments on human subjects.     

Multi‐primary‐color LCD: Its characteristics and extended applications

Abstract— The development of multi‐primary‐color (MPC) display systems is one of the big paradigm shifts in recent display technologies and induces new potentials of display devices. The development of MPC display systems for different goals is briefly reviewed. Especially, by employing MPC systems, it is possible to reproduce the real material colors faithfully and efficiently. For signal processing, MPC systems have a big advantage in the so‐called color‐reproduction redundancy. A number of applications can be derived from this characteristic, such as improving the viewing‐angle dependency issue and power savings. On the other hand, MPC systems have a typical trade‐off versus RGB‐standardized input signals, especially for reproducing bright green. New algorithms to moderate this trade‐off on MPC systems by employing color‐reproduction redundancy are proposed. The goal of our algorithms is to maintain the compatibility with RGB‐based input signals though the initial display design so that the characteristics of MPC systems are not changed or lost. These algorithms indicate that MPC display systems are applicable not only for a specifically limited objective but also for other applications, e.g., TV broadcasting.