Chiba Institute of Technology

About: Chiba Institute of Technology is a education organization based out in Narashino, Japan. It is known for research contribution in the topics: RNA & Magnet. The organization has 2663 authors who have published 4999 publications receiving 56870 citations. The organization is also known as: Chiba kōgyō daigaku & Kōa Institute of Technology.

Specific HIV-1 env gene silencing by small interfering RNAs in human peripheral blood mononuclear cells.

Abstract: RNA interference (RNAi) is triggered by the presence of a double-stranded RNA (dsRNA) in the cell, and results in the silencing of homologous gene expression by the specific degradation of an mRNA containing the same sequence. dsRNA-mediated RNAi can be used in a wide variety of eucaryotes to induce the sequence-specific inhibition of gene expression. Synthetic 21-23 nucleotide (nt) small interfering RNAs (siRNAs) with 2-nt 3' overhangs were recently found to mediate efficient sequence-specific mRNA degradation in mammalian cells. Here, we show that synthetic siRNAs targeted against the viral structural Env proteins encoded by HIV-1 can specifically suppress the expression of HIV-1 genes. The siRNA-mediated RNAi also had advantages over antisense RNA-mediated inhibition, in terms of both the ease of designing effective antiviral agents and their potency. Especially, our best env-specific siRNAs, E7145 targeted to the central region of the V3 loop and E7490 targeted to the CD4 binding site of conserved regions on gp120, significantly inhibited the HIV-1 gene expression. Furthermore, E7145 and E7490 were effective against HIV-1(NL4-3) replication in PBMCs for a relatively long time (14 days). Therefore, the use of synthetic siRNAs provides a simple, rapid, and cost-effective tool for new anti-HIV-1 gene therapeutics.

Au Nanoparticle-Embedded Carbon Films for Electrochemical As3+ Detection with High Sensitivity and Stability

Abstract: Au nanoparticle (AuNP)-embedded carbon films were formed with a one-step reproducible process by using unbalanced magnetron (UBM) cosputtering to make it possible to detect As3+ in water. The sputtered Au components formed NPs (typically 5 nm in diameter) spontaneously in the carbon films, owing to the poor intermiscibility of Au with carbon. The surface contents of embedded AuNPs in the carbon film were widely controllable (Au = 13–21 at %) by regulating the target powers of Au and carbon individually. The obtained film had a flat surface (Ra = 0.1 nm) despite the fact the AuNPs were partially exposed at the surface. By anodic stripping voltammetry (ASV) As3+ detection, a limit of detection of 0.55 ppb and linear dynamic range of 1–100 ppb were obtained with our electrode. These values meet the requirements imposed by international regulation. Moreover, our electrode structure realized good electrode stability for repetitive ASV measurements (relative standard deviation (RSD) = 11.7%, n = 15) because the...

Thermal Evolution and Lifetime of Intrinsic Magnetic Fields of Super-Earths in Habitable Zones

Abstract: We have numerically studied the thermal evolution of different-mass terrestrial planets in habitable zones, focusing on the duration of dynamo activity to generate their intrinsic magnetic fields, which may be one of the key factors in habitability of the planets. In particular, we are concerned with super-Earths, observations of which are rapidly developing. We calculated the evolution of temperature distributions in the planetary interior using Vinet equations of state, the Arrhenius-type formula for mantle viscosity, and the astrophysical mixing-length theory for convective heat transfer modified for mantle convection. After calibrating the model with terrestrial planets in the solar system, we apply it for 0.1-10 M{sub +} rocky planets with a surface temperature of 300 K (in habitable zones) and Earth-like compositions. With the criterion of heat flux at the core-mantle boundary (CMB), the lifetime of the magnetic fields is evaluated from the calculated thermal evolution. We found that the lifetime slowly increases with planetary mass (M{sub p} ), independent of the initial temperature gap at the CMB ({Delta}T{sub CMB}), but beyond the critical value M{sub c,p} ({approx}O(1) M{sub +}) it abruptly declines from the mantle viscosity enhancement due to the pressure effect. We derived M{sub c,p} as a function ofmore » {Delta}T{sub CMB} and a rheological parameter (activation volume, V*). Thus, the magnetic field lifetime of super-Earths with M{sub p} >M{sub p,c} sensitively depends on {Delta}T{sub CMB}, which reflects planetary accretion, and V*, which has uncertainty at very high pressure. More advanced high-pressure experiments and first-principle simulation, as well as planetary accretion simulation, are needed to discuss the habitability of super-Earths.« less

Biomimetic deposition of apatite coatings on micro-arc oxidation treated biomedical NiTi alloy

Abstract: The biomedical NiTi alloy was treated by micro-arc oxidation in an electrolytes containing sodium aluminate and sodium hypophosphite at 400 V constant voltages for 30 min. The MAO-treated NiTi has a porous microstructure on its surface and coatings consisting only of the γ-Al 2 O 3 phase. The ceramic coating prepared by micro-arc oxidation is composed of Al, Ti, Ni, O, and P with the atomic concentration of 26.98%, 3.67%, 3.33%, 65.30% and 0.72%, respectively. The MAO-treated NiTi was soaked in a simulated body fluid (1.0SBF) to investigate the biomimetic deposition of apatite on the surface of Al 2 O 3 coated NiTi alloy. It was found that Al 2 O 3 coated NiTi alloy shows an excellent apatite-forming ability after soaking in a simulated body fluid (1.0SBF) for 14 days, while no apatite-forming ability was observed on bared NiTi alloy even though soaking time is up to 28 days.