Elevation of soluble IL-2 receptor and IL-4, and nonelevation of IFN-gamma in sera from patients with allergic asthma

This study is the first demonstration of glial fibrillary acidic protein (GFAP)-immunoreactivity in the retina of the lamprey Lampetra fluviatilis. This immunoreactivity is expressed on one hand, in radial processes and somata which belong to Müller cells and, on the other hand, in horizontal fibers in the intermediate plexus between horizontal cells. The tracing of these fibers to Müller cells or horizontal cells is discussed.     

A functional νMOS circuit for implementing cellular-automaton picture-processing devices

This paper proposes a design of cell circuits for implementing cellular-automaton devices that perform morphological picture processing. To produce the complex cell functions required for the morphological processing, we present the idea of using the silicon functional device, ν-MOS FET. We designed sample cell circuits for several morphological processings, and simulated their operation to show the expected cell operation. We also designed a sample cellular-automaton circuit using the proposed cell circuits, and demonstrated in simulation its example processing (noise cleaning and edge extraction in an image). A low dissipation of about 20 μW per cell circuit can be expected at 1 MHz operation; therefore, 10⁵ or more cells that operate in parallel can be integrated into an LSI.     

A hot hole-induced low-level leakage current in thin silicondioxide films

A new kind of stress-induced low-level leakage current (LLLC) in thin silicon dioxide is reported. It is observed after the stress of hot hole injection at the gate edge. Since voltage dependence of this new kind of LLLC is steeper than that of conventional FN stress-induced LLLC, each conduction mechanism may be different. This LLLC is reduced by both hot electron injection and UV irradiation. These reductions are never observed in FN stress-induced LLLC. The most promising mechanism is sequential tunneling via trapped holes     

Quasi-steady-state voltammetry of rapid electron transfer reactions at the macroscopic substrate of the scanning electrochemical microscope

We report on a novel theory and experiment for scanning electrochemical microscopy (SECM) to enable quasi-steady-state voltammetry of rapid electron transfer (ET) reactions at macroscopic substrates. With this powerful approach, the substrate potential is cycled widely across the formal potential of a redox couple while the reactant or product of a substrate reaction is amperometrically detected at the tip in the feedback or substrate generation/tip collection mode, respectively. The plot of tip current versus substrate potential features the retraceable sigmoidal shape of a quasi-steady-state voltammogram although a transient voltammogram is obtained at the macroscopic substrate. Finite element simulations reveal that a short tip-substrate distance and a reversible substrate reaction (except under the tip) are required for quasi-steady-state voltammetry. Advantageously, a pair of quasi-steady-state voltammograms is obtained by employing both operation modes to reliably determine all transport, thermodynamic, and kinetic parameters as confirmed experimentally for rapid ET reactions of ferrocenemethanol and 7,7,8,8-tetracyanoquinodimethane at a Pt substrate with ～0.5 μm-radius Pt tips positioned at 90 nm-1 μm distances. Standard ET rate constants of ～7 cm/s were obtained for the latter mediator as the largest determined for a substrate reaction by SECM. Various potential applications of quasi-steady-state voltammetry are also proposed.     

Low-power wake-up receiver with subthreshold CMOS circuits for wireless sensor networks

We developed a wake-up receiver comprised of subthreshold CMOS circuits. The proposed receiver includes an envelope detector, a high-gain baseband amplifier, a clock and data recovery (CDR) circuit, and a wake-up signal recognition circuit. The drain nonlinearity in the subthreshold region effectively detects the baseband signal with a microwave carrier. The offset cancellation method with a biasing circuit operated by the subthreshold produces a high gain of more than 100 dB for the baseband amplifier. A pulse-width modulation (PWM) CDR drastically reduces the power consumption of the receiver. A 2.4-GHz detector, a high-gain amplifier and a PWM clock recovery circuit were designed and fabricated with 0.18-μm CMOS process with one poly and six metal layers. The fabricated detector and high-gain amplifier achieved a sensitivity of ?47.2 dBm while consuming only 6.8 μW from a 1.5 V supply. The fabricated clock recovery circuit operated successfully up to 500 kbps.     

Local feedback mode of scanning electrochemical microscopy for electrochemical characterization of one-dimensional nanostructure: theory and experiment with nanoband electrode as model substrate

Local feedback mode is introduced as a novel operation mode of scanning electrochemical microscopy (SECM) for electrochemical characterization of a single one-dimensional (1D) nanostructure, for example, a wire, rod, band, and tube with 1-100-nm width and micrometer to centimeter length. To demonstrate the principle, SECM feedback effects under diffusion limitation were studied theoretically and experimentally with a disk probe brought near a semi-infinitely long band electrode as a geometrical model for a conductive 1D nanostructure. As the band becomes narrower than the disk diameter, the feedback mechanism for tip current enhancement is predicted to change from standard positive feedback mode, to positive local feedback mode, and then to negative local feedback mode. The negative local feedback effect is the only feedback effect that allows observation of a 1D nanostructure without serious limitations due to small lateral dimension, available tip size, or finite electron-transfer rate. In line-scan and approach-curve experiments, an unbiased Pt band electrode with 100-nm width and 2.6-cm length was detectable in negative local feedback mode, even using a 25-microm-diameter disk Pt electrode. Using a 2-microm-diameter probe, both well-defined and defected sites were observed in SECM imaging on the basis of local electrochemical activity of the nanoband electrode. Noncontact and spatially resolved measurement is an advantage of this novel SECM approach over standard electrochemical approaches using electrodes based on 1D nanostructure.     

Two-dimensional DNA gel electrophoresis mapping: a novel approach to diversity analysis of bacterial communities in environmental soil

The diversity analysis of bacteria is useful for the environmental assessment of soil. Traditional molecular-based methods such as denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP) analysis achieve a low-resolution display of bacterial DNA fragments on a gel. To improve the resolution, a novel two-dimensional DNA gel electrophoresis (2-DGE) method was designed. This method can generate a high-resolution DNA map that facilitates the detailed analysis of soil bacteria. This map can be obtained by utilizing 2-DGE to separate genomic DNA fragments produced by polymerase chain reaction (PCR) amplification on the basis of chain length and G+C content. To develop this 2-DGE method further and to apply it to the assessment of bacterial diversity, we carried out a 2-DGE mapping of bacterial DNA fragments from different environmental soils and computed Shannon index as well as plotted rank-abundance curves on the basis of the relative intensity of each spot on the maps. DGGE mapping was also performed to compare the resolution of the two methods. 2-DGE mapping was capable of generating a higher resolution display by a factor of more than 2 using a DGGE fingerprint pattern on a piece of gel. Furthermore, the higher number of detected spots from the 2-DGE map enabled the assessment of differences in bacterial diversity in complex soil systems using a logarithmic normal rank-abundance plot.     

A functional νMOS circuit for implementing cellular-automaton picture-processing devices

This paper proposes a design of cell circuits for implementing cellular-automaton devices that perform morphological picture processing. To produce the complex cell functions required for the morphological processing, we present the idea of using the silicon functional device, ν-MOS FET. We designed sample cell circuits for several morphological processings, and simulated their operation to show the expected cell operation. We also designed a sample cellular-automaton circuit using the proposed cell circuits, and demonstrated in simulation its example processing (noise cleaning and edge extraction in an image). A low dissipation of about 20 μW per cell circuit can be expected at 1 MHz operation; therefore, 10⁵ or more cells that operate in parallel can be integrated into an LSI.