Isolation and Characterization of Activators of ERK/MAPK from Citrus Plants

Extracellular signal-regulated kinases 1/2 (ERK1/2), components of the mitogen-activated protein kinase (MAPK) signaling cascade, have been recently shown to be involved in synaptic plasticity and in the development of long-term memory in the central nervous system (CNS). We therefore examined the ability of Citrus compounds to activate ERK1/2 in cultured rat cortical neurons, whose activation might have a protective effect against neurodegenerative neurological disorders. Among the samples tested, extracts prepared from the peels of Citrus grandis (Kawachi bankan) were found to have the greatest ability to activate ERK1/2. The active substances were isolated by chromatographic separation, and one of them was identified to be 3,5,6,7,8,3',4'-heptamethoxyflavone (HMF). HMF significantly induced the phosphorylation of cAMP response element-binding protein (CREB), a downstream target of activated ERK1/2, which appears to be a critical step in the signaling cascade for the structural changes underlying the development of long-term potentiation (LTP). In addition, the administration of HMF into mice treated with NMDA receptor antagonist MK-801 restored the MK-801-induced deterioration of spatial learning performance in the Morris mater-maze task. Taken together, these results suggest that HMF is a neurotrophic agent for treating patients with memory disorders.     

Spherical tokamak generation and merging on UTST using ex‐vessel poloidal field coils only

We successfully generated two spherical tokamaks (ST) at two null points by using ex‐vessel poloidal field (PF) coils only and succeeded in merging them. This scheme is called a double null merging (DNM) scheme. First, two pairs of ex‐vessel PF coils generate two null points where the poloidal field is zero at the upper and lower regions inside the vacuum vessel. Then a poloidal flux swing generates two STs at two null points, because the distance to the wall along the magnetic field is long at the null points. Finally, the coil currents push two STs toward the mid‐plane and merge them into a single ST. Since a magnetic reconnection during merging transforms magnetic energy into thermal energy, this merged ST plasma is expected to have a high beta. It must be noted that the DNM scheme generates an ST without a center solenoid coil. The DNM scheme was demonstrated on the TS‐3/4 (Japan) and MAST (UKAEA). However, these devices have all PF coils inside the vacuum vessels, and the initial plasmas were generated around the PF coils, not the null points. Since internal coils are not feasible in a fusion reactor due to high neutron flux, it is important to demonstrate the DNM scheme by using ex‐vessel PF coils. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(4): 18–24, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21254     

Fabrication of CdS/β-SiC/TiO2 tri-composites that exploit hole- and electron-transfer processes for photocatalytic hydrogen production under visible light

In this work, CdS/SiC/TiO₂ tri-composite photocatalysts that exploit electron- and hole-transfer processes were fabricated using an easy two-step method in the liquid phase. The photocatalyst with a 1:1:1 M ratio of CdS/SiC/TiO₂ exhibited a rate of hydrogen evolution from an aqueous solution of sodium sulfite and sodium sulfide under visible light of 137 μmol h^?1 g^?1, which is 9.5 times that of pure CdS. β-SiC can act as a sink for the photogenerated holes because the valence band level of β-SiC is higher than the corresponding bands in CdS and TiO₂. In addition, the level of the conduction band of TiO₂ is lower than those of CdS and β-SiC, so TiO₂ can act as the acceptor of the photogenerated electrons. Our results demonstrate that hole transfer and absorption in the visible light region lead to an effective hydrogen-production scheme.     

Effect of Carrier Frequency and Circuit Resistance on Iron Loss of Non‐Oriented Electrical Steel Sheet under Single‐Phase Full‐Bridge PWM Inverter Excitation

Because of the development of power electronics technology, pulse width modulation (PWM) inverters are now being used to drive motors in order to achieve precise and energy‐efficient control. Precise estimation of the increase in iron loss due to the high harmonic components of flux, including the carrier frequency, is important in the design of motors excited by a PWM inverter. We measured the iron losses of non‐oriented electrical steel sheets that were excited using a single‐phase full‐bridge PWM inverter, and examined the influence of the carrier frequency and circuit resistance on the iron loss. We showed that the iron loss increased because of the generation of minor loops when the circuit resistance was high. Therefore, the circuit resistance should be decreased in an actual motor system.     

Preparation of modified styrene-divinylbenzene copolymers having different physical structures and their adsorption characteristics of nonionic surfactants

Several α-oxoethylated and α-hydroxyethylated styrene-divinylbenzene (St-DVB) resins having different degrees of crosslinking and porosity were prepared and their adsorption behaviour toward a nonionic surfactant, decaethyleneglycol nonylphenyl monoether, was investigated. The increment of the adsorption capacity caused by the introduction of the α-hydroxyethyl groups was remarkable in the less crosslinked resin. The α-hydroxyethylated resin derived from the St-DVB resin synthesized with 10 vol.-% DVB and 100 – 120 vol.-% of 2,2,4-trimethylpentane showed the highest capacity among the resins tested. The significance of both macroporosity and gel porosity in the effective adsorption of the nonionic surfactant was elucidated. A column operation using proposed resins was carried out and versatility was evaluated in terms of the breakthrough capacity.     

Studies on the alkali metal alloy-chlorine secondary battery

This paper is concerned with an alkali metal-chlorine secondary battery for a load levelling device, and especially with the negative electrode. An alk     

The characterization of asphaltenes and preasphaltenes obtained under various coal liquefaction conditions

A CP-MAS ¹³C NMR study of asphaltenes and preasphaltenes obtained under various coal liquefaction conditions is reported. The carbon aromaticity, f_a, of the solid extracts from the reaction products has a close relation with the reaction conditions. By plotting f_a against the atomatic $\text{H}\text{C}$ ratio for these solid products on the characterization chart for model polycyclic aromatic compounds, the molecular structures with relation to the liquefaction pathway from coal to oil can be proposed.     

Recovery of uranium from seawater V. Preparation and properties of the macroreticular chelating resins containing amidoxime and other functional groups

We have synthesized macroreticular chelating resins containing amidoxime groups from acrylonitrile (AN)-divinylbenzene (DVB)-alkyl acrylate, alkyl methacrylate, or vinylpyridine (VPy) copolymer beads. It was found that the chelating resin (RNMH)-containing amidoxime groups prepared from AN-DVB-methyl acrylate (MA) indicated the highest adsorption ability for uranium in seawater. Hydroxamic acid and carboxylic groups in addition to amidoxime groups were formed during the reaction of the copolymer beads with a methanol solution of hydroxylamine. The adsorption ability for uranium was greatly influenced by the physical pore structure (macropore) and the pore structure formed by the swelling(micropore). RNMH (RNMH10-10) prepared with 10 mol% of DVB and 10 mol% of MA had the highest adsorption ability and physical stability for uranium. On the other hand, improved adsorption ability for uranium was not observed in the case of the macroporous resins (RNPyH) prepared by the copolymerization of VPy as the basic component. After seawater was passed through the column packed with RNMH10-10 at a space velocity (SV) of 180 h^?1 (up-flow) for 10 days, the amount of uranium adsorbed on the resin was about 100 mg/dm³-R and 260 mg/kg-R.     

Functional analysis of peripheral blood B cells in patients with X-linked agammaglobulinemia

X-linked agammaglobulinemia (XLA) is a primary immunodeficiency disease caused by mutations of Bruton tyrosine kinase (Btk); Btk plays an essential role in the development of mature B cells. However, small numbers of B cells ("leaky B cells") are present in the peripheral blood of most XLA patients. In this study, we analyzed the function of these leaky B cells obtained from XLA patients. Enough numbers of B cells were available for analysis from five of nine XLA patients originally screened. Sequence analysis revealed missense mutations of Btk in four of the five XLA patients. No mutation was found in the coding region of Btk in one patient. Western blotting and/or flow cytometric analysis failed to detect Btk protein in all five patients. B cells isolated from peripheral blood of these XLA patients were CD5-, CD20+, CD19+, and CD21-. If stimulated with anti-CD40 and IL-4, XLA B cells proliferated normally and produced significant amounts of IgE. Anti-CD40 stimulation of XLA B cells resulted in normal expression of CD23. In addition, three of the five XLA patients studied were immunized with bacteriophage phiX174 and produced low but detectable levels of antiphage-specific Ab. Similarly, X-linked immunodeficiency mice, which carry a missense mutation in Btk, produced substantial amounts of antiphage Ab. These results indicate that CD40 signaling is intact in B cells lacking demonstrable Btk, and that leaky B cells in XLA patients can proliferate, undergo isotype switching, and differentiate into specific Ab-producing cells.