Observation of finite excess noise in the voltage-biased quantum Hall regime as a precursor for breakdown

We performed noise measurements in a two-dimensional electron gas to investigate the nonequilibrium quantum Hall effect (QHE) state. While excess noise is perfectly suppressed around the zero-biased QHE state reflecting the dissipationless electron transport of the QHE state, considerable finite excess noise is observed in the breakdown regime of the QHE. The noise temperature deduced from the excess noise is found to be of the same order as the energy gap between the highest occupied Landau level and the lowest empty one. Moreover, unexpected finite excess noise is observed at a finite source-drain bias voltagesmaller than the onset voltage of the QHE breakdown, which indicates finite dissipation in the QHE state and may be related to the prebreakdown of the QHE.Comment: 8 pages, 8 figure

Kampo Medicines for Mite Antigen-Induced Allergic Dermatitis in NC/Nga Mice

We have established an allergic dermatitis model in NC/Nga mice by repeated local exposure of mite antigen for analyzing atopic dermatitis. We examined how four Kampo medicines, Juzen-taiho-to, Hochu-ekki-to, Shofu-san and Oren-gedoku-to, on the dermatitis model to obtain basic information on their usefulness for treating atopic dermatitis. Mite antigen (Dermatophagoides farinae crude extract) solution at a concentration of 10 mg/ml was painted on the ear of NC/Nga mice after tape stripping. The procedure was repeated five times, at 7 day intervals. An apparent biphasic ear swelling was caused after the fourth and fifth antigen exposures with elevated serum IgE levels and accumulation of inflammatory cells. In the cervical lymph nodes and ear lobes, the five procedures of antigen exposure induced interleukin-4 mRNA expression but reduced interferon-γ mRNA expression. Oral administration of all four Kampo medicines inhibited the formation of ear swelling and inflammatory cell accumulation. Juzen-taiho-to and Hochu-ekki-to apparently prevented the elevation of serum IgE level. Furthermore, the four Kampo medicines showed a tendency to prevent not only the increase in interleukin-4 mRNA expression but also the decrease in interferon-γ mRNA expression. The present results indicate that Juzen-taiho-to, Hochu-ekki-to, Shofu-san and Oren-gedoku-to may correct the Th1/Th2 balance skewed to Th2, and this activity helps inhibit dermatitis in NC/Nga mice. The ability of the Kampo medicines to correct the Th1/Th2 balance seems to underlie their effectiveness in treating of atopic dermatitis

The inhibitory effects of Orengedokuto on inducible PGE2 production in BV-2 microglial cells

[Background and aim] Reactive microglia has been associated with neuroinflammation caused by the production of proinflammatory molecules such as cytokines, nitric oxide, and prostaglandins. The overexpression of these molecules may provoke neuronal damage that can cause neurodegenerative diseases. A traditional herbal medicine, Orengedokuto (OGT), has been widely used for treating inflammation-related diseases. However, how it influences neuroinflammation remains poorly understood. [Experimental procedure] This study investigated the effects of OGT on inflammatory molecule induction in BV-2 microglial cells using real-time RT-PCR and ELISA. An in vivo confirmation of these effects was then performed in mice. [Results and conclusion] OGT showed dose-dependent inhibition of prostaglandin E2 (PGE2) production in BV-2 cells stimulated with lipopolysaccharide (LPS). To elucidate the mechanism of PGE2 inhibition, we examined cyclooxygenases (COXs) and found that OGT did not suppress COX-1 expression or inhibit LPS-induced COX-2 upregulation at either the transcriptional or translational levels. In addition, OGT did not inhibit COX enzyme activities within the concentration that inhibited PGE2 production, suggesting that the effect of OGT is COX-independent. The inhibitory effects of OGT on PGE2 production in BV-2 cells were experimentally replicated in primary cultured astrocytes and mice brains. OGT can be useful in the treatment of neuroinflammatory diseases by modulating PGE2 expression

Spiral Tissue Microarrays as Next Evolutionary Step in the High-density Tissue Microarray Technology

Tissue microarray (TMA) is a well-established technique that connects basic research with clinical applications that allow the validation of many pathobiologic events from gene expression dysregulation to genomic aberrations. However, conventional TMAs have several limitations such as limited representation of tissue heterogeneity, destruction of donor tissue blocks due to coring and usage of particular specimens that have limited evaluable material (tissue from thin specimens or needle biopsies). We have developed a novel method, which we termed "Spiral TMA" that generates TMAs that allow for improved representation of the donor tissue while keeping the architectural details of the donor block intact. This technology is ideal for specimens with limited tissue without the need to punch holes into the original block and therefore preserving the tissue integrity. In this report, we describe the methodology of constructing Spiral TMA and demonstrate the validation of tumor representation and tissue heterogeneity by comparing Spiral TMA to conventional TMA using immunohistochemical staining to EGFR and CK7

A New Milky Way Satellite Discovered In The Subaru/Hyper Suprime-Cam Survey

We report the discovery of a new ultra-faint dwarf satellite companion of the Milky Way based on the early survey data from the Hyper Suprime-Cam Subaru Strategic Program. This new satellite, Virgo I, which is located in the constellation of Virgo, has been identified as a statistically significant (5.5 sigma) spatial overdensity of star-like objects with a well-defined main sequence and red giant branch in their color-magnitude diagram. The significance of this overdensity increases to 10.8 sigma when the relevant isochrone filter is adopted for the search. Based on the distribution of the stars around the likely main sequence turn-off at r ~ 24 mag, the distance to Virgo I is estimated as 87 kpc, and its most likely absolute magnitude calculated from a Monte Carlo analysis is M_V = -0.8 +/- 0.9 mag. This stellar system has an extended spatial distribution with a half-light radius of 38 +12/-11 pc, which clearly distinguishes it from a globular cluster with comparable luminosity. Thus, Virgo I is one of the faintest dwarf satellites known and is located beyond the reach of the Sloan Digital Sky Survey. This demonstrates the power of this survey program to identify very faint dwarf satellites. This discovery of VirgoI is based only on about 100 square degrees of data, thus a large number of faint dwarf satellites are likely to exist in the outer halo of the Milky Way.Comment: typos are corrected, 6 pages, 4 figures, accepted for publication in Ap