Fluctuation of Global Gene Expression by Endogenous miRNA Response to the Introduction of an Exogenous miRNA

Most of the intracellular endogenous microRNAs (endo-miRNAs) are considered to be saturated in Argonaute (Ago) proteins in the RNA-induced silencing complexes (RISCs). When exogenous miRNAs (exo-miRNAs) are introduced into cells, endo-miRNAs in the RISC may be replaced with exo-miRNAs or exo-miRNAs, and endo-miRNAs might also compete for the position in the newly synthesized RISC with each other. This would lead to the fluctuation of global gene expression not only by repression of exo-miRNA target gene expression, but also by the increase of the endo-miRNA target gene expression. In the present study, we quantified the changes in the expression levels of target genes of exo-miRNA and endo-miRNA in the cells transfected with fifteen different exo-miRNAs by microarray experiments. Different exo-miRNAs increased ratios of expression levels of target genes of a given endo-miRNA to different extents, suggesting that the replacement efficiencies might differ according to the exo-miRNA types. However, the increased ratios in the expression levels of each endo-miRNA target genes by the transfection of any particular exo-miRNA were mostly equivalent, suggesting that the endo-miRNAs present in the RISC might be replaced with excessive exo-miRNAs at similar levels, probably because they exist in single-stranded forms in the RISC.     

Experimental Evaluation of the Acceptor-States Compensation in Positive-Temperature-Coefficient-Type Barium Titanate

Experimental evidence shows that the acceptor-state levels in Sb-doped positive-temperature-coefficient-type BaTiO₃ are compensated up to a critical acceptor-state density. Using the slope of the natural logarithm of the resistivity with respect to 1/ T , instead of maximum resistivity as a measure for the acceptor-state density, it is possible to estimate this critical value. The value obtained (4.2 × 10¹⁷ m⁻²) is believed to be the first reported estimate based on experimental data. It is in good agreement with the estimate of 6 × 10¹⁷ m⁻² (first reported by Jonker) obtained from the spontaneous polarization of BaTiO₃. This shows that the ferroelectric behavior of BaTiO₃ is indeed a feasible explanation for the low resistivity below the Curie point, as proposed by Jonker.     

High‐current lightning discharges in winter

Lightning electric‐field waveforms related to power line faults in winter have been identified. Most of those waveforms appear to be associated with upward lightning discharges with absolute peak currents of over 100 kA. They are quite different from common return‐stroke waveforms, and the lightning discharges which produce these characteristic waveforms are called GC (Ground to Cloud) flashes. These high‐current lightning discharges are distributed around the coastline in different ways depending on their polarities. The spatial distributions of high‐current lightning discharges around Japan are also investigated. It is revealed that the region of Honshu Island along the coastline of the Sea of Japan belongs to the area in which the density of high‐current lightning flashes is the highest in Japan through the year. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(1): 8–15, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20874     

Application of magneto-optical sensors for fault location in an air-insulated substation bus

A new fault location system using optical current transducers (CTs) to detect faulted sections in the bus bars of directly grounded 275-kV substations has been developed. This system detects fault current by combining optical CTs with wound-type CTs. The new type of optical CT applies a bulk-type Faraday sensor to the combination of windings around a magnetic iron core and a solenoid coil. The optical CT was capable of current measuring over 50 kA. A current differential discriminator combining an optical CT and a wound-type CT verified the operational performance with 40-kA currents. The intended level of fault detection performance was obtained. Based on these results, a system is being made for actual application in 275-kV substations. © 1997 Scripta Technica, Inc. Electr Eng Jpn 119(2): 10–17, 1997     

Design of energy‐efficient train speed profiles considering fixed‐block signaling system

In dense traffic railway networks, trains may often slow down or stop between stations owing to previous train delays. If preceding train trajectory can be predicted, energy‐efficient driving can be achieved by suppressing unnecessary speed changes. In this paper, we propose an algorithm to find energy‐efficient driving considering fixed‐block signaling (FBS) system by using dynamic programming (DP). DP is suitable for use because it can optimize the control inputs with discrete and state constraints. In this paper, we discuss energy‐efficient driving by considering a FBS system using some case studies of simulation. In the simulation, we examine a technique to drive an express train in an energy‐efficient way when the preceding local train is running toward the station with passing loops. The results show that the proposed method can derive complex speed profiles for energy‐efficient driving and the train can be operated with a maximum reduced energy consumption of 8.3%.     

Operating principles of pin diodes

Analytical models of the pin diode in a small‐current operation are not known yet. This article presents a simple analytical model of the pin diode operation with its confirmation by a numerical simulation. At the onset, carrier recombinations are not included for the sake of simplicity. The exact J_F?V_F characteristic could have been induced only by accounting for the Boltzmann distribution of each carrier across the junctions and the diffusion current of each minority carrier in a p‐anode or n‐cathode. Based on this new model, the modifications of hole–electron densities product (n_en_h) across junctions, a rough estimation of the large operational current, its carrier distributions, and the effect of carrier recombination on the carrier distribution are plainly estimated and are also compared with the simulation results. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(4): 47–56, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20844     

Mechanism of enhanced impact strength of poly(vinyl chloride) modified by acrylic graft copolymer

The mechanism of enhanced PVC impact strength of poly(vinyl chloride) modified by an acrylic graft copolymer was studied by the three-point bending test on a U-notched bar. In the mechanism, the void formation from the modifier released the constrained strain. The release suppresses the stress below the fibril strength in the material; consequently, stable deformation can develop over a large area and, thus, the impact strength of PVC modified by the acrylic graft copolymer is improved. © 1996 John Wiley & Sons, Inc.     

Cytokine Networks in the Pathogenesis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic systemic inflammation causing progressive joint damage that can lead to lifelong disability. The pathogenesis of RA involves a complex network of various cytokines and cells that trigger synovial cell proliferation and cause damage to both cartilage and bone. Involvement of the cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-6 is central to the pathogenesis of RA, but recent research has revealed that other cytokines such as IL-7, IL-17, IL-21, IL-23, granulocyte macrophage colony-stimulating factor (GM-CSF), IL-1β, IL-18, IL-33, and IL-2 also play a role. Clarification of RA pathology has led to the development of therapeutic agents such as biological disease-modifying anti-rheumatic drugs (DMARDs) and Janus kinase (JAK) inhibitors, and further details of the immunological background to RA are emerging. This review covers existing knowledge regarding the roles of cytokines, related immune cells and the immune system in RA, manipulation of which may offer the potential for even safer and more effective treatments in the future.