Development of a 1 MJ SMES with quench enthalpy protection

As a quench protection method in an SMES, a dumping resistor method and an enthalpy method are considered. The former is a conventional method, but the latter has not been experimentally examined yet, although it has been shown to be suitable for future SMES. In addition, a new control method, QI simultaneous control, has been also developed as a practical application of the SMES. The performance or the enthalpy protection technique is verified by a helium dumping method, and the QI simultaneous control is also successfully examined using a power network simulator     

Effect of YM294, recombinant human interleukin-11, on carboplatin-induced thrombocytopenia in rats

We investigated the effects of YM294, recombinant human interleukin-11, on changes in blood cell levels in carboplatin-treated rats. Continuous infusion of YM294 was carried out by either intravenous or subcutaneous injection (10 and 100 micrograms/rat/day) for 14 days via an implanted osmotic pump. Carboplatin (30 mg/kg iv) significantly decreased platelet counts on days 7-9; counts subsequently increased to levels greater than the initial level by day 21. Intravenous administration of YM294 inhibited this decrease in platelet count by carboplatin and increased the platelet count in the recovery phase in a dose-dependent manner. YM294 also showed effects on carboplatin-induced changes in white blood cell and red blood cell counts; these effects seemed, however, to be neither consistent nor dose-dependent. The effects of YM294 on subcutaneous infusion were similar to those on intravenous infusion. The effect of YM294 on the survival of rats treated with a higher dose of carboplatin (60 mg/kg iv) was also investigated. YM294 (100 micrograms/rat/day) given by continuous intravenous infusion increased the 30-day survival rate. These results confirm the utility of YM294 in the treatment of thrombocytopenia after chemotherapy.     

Specific isoprenyl group linked to transducin gamma-subunit is a determinant of its unique signaling properties among G-proteins

Among 11 subtypes of heterotrimeric G-protein gamma-subunit, gamma1 (rod), gamma8 (cone) and gamma11 are modified with farnesyl while the others are modified with geranylgeranyl at the C-terminus. To understand the role of specific isoprenylation (farnesylation) of retinal transducin, we examined how and to what extent the type of isoprenyl group affects transducin-beta gamma (beta1 gamma1) functions such as interactions with membranes, Galpha/receptor, and effectors. To this end, the C-terminal farnesylation signal sequence (CVIS) of gamma1 was replaced by a geranylgeranylation signal (CVIL), and the resultant mutant (S74L) or wild-type (WT) gamma1 was coexpressed with beta1 in the baculovirus-Tn5 insect cell system. Both gamma1WT and gamma1S74L expressed as a beta gamma complex were mixtures modified with farnesyl and geranylgeranyl groups. The ratio of farnesyl to geranylgeranyl in preparations of beta1 gamma1WT and beta1 gamma1S74L purified from the Tn5 cell membrane fraction was about 1:2 and 1:6, respectively. These two forms of recombinant beta1 gamma1 and retinal beta1 gamma1 were different in their abilities to associate with rod outer segment membranes with the following rank order: beta1 gamma1S74L > beta1 gamma1WT > retinal beta1 gamma1. Functionally, beta1 gamma1S74L was the most potent to promote pertussis toxin-catalyzed ADP ribosylation of transducin-alpha (Talpha), to stimulate metarhodopsin II-catalyzed GTPgammaS-binding reaction to Talpha and to modulate adenylyl cyclase and phospholipase C activities. All of the beta1 gamma1 functions absolutely required the isoprenylation of the gamma-subunit. As for the interaction with Goalpha and adenylyl cyclase, predominantly geranylgeranylated beta1 gamma1S74L was less effective than geranylgeranylated beta1 gamma2 purified from bovine brain. These results demonstrate that the properties of Gbeta gamma are strongly affected by the type of functionally indispensable isoprenylation in addition to the amino acid sequence of Ggamma. The relative contribution of the two factors depends on proteins with which Gbeta gamma interacts.     

Effects of the IVa element addition on the composite-processed superconducting Nb3Sn

The effect of the IVa element addition to the niobium core and that of gallium addition to the matrix on the composition, growth rate and superconducting properties of the composite-processed Nb₃Sn have been studied. The IVa elements added to the niobium core enhance the growth rate of Nb₃Sn, and prevent the grain coarsening of Nb₃Sn. A much larger amount of titanium is incorporated into Nb₃Sn than zirconium or hafnium. T_c shows a slight maximum against the IVa element concentration in the niobium core. J_c at high magnetic fields is more significantly increased by titanium addition than zirconium or hafnium additions. The gallium substitution for tin in the matrix is effective for increasing T_c and J_c in high fields, except for the specimen with Nb-Ti alloy core. The simultaneous addition of hafnium and gallium is most effective for the enhancement of J_c in high fields.     

Memory encoding by theta phase precession in the hippocampal network

Recent experimental evidence on spike-timing-dependent plasticity and on phase precession (i.e., the theta rhythm dependent firing of rat hippocampal cells) associates the contribution of phase precession to episodic memory. This article aims at clarifying the role of phase precession in memory storage. Computer simulations show that the memory storage in the behavioral timescale varies in timescale of the temporal sequence from half a second to several seconds. In contrast, the memory storage caused by traditional rate coding is restricted to the temporal sequence within 40 ms. During phase precession, memory storage of a single trial experience is possible, even in the presence of noise. It is therefore concluded that encoding by phase precession is appropriate for memory storage of the temporal sequence in the behavioral timescale.     

Anisotropic proton-conducting membranes prepared from swift heavy ion-beam irradiated ETFE films

Poly(ethylene-co-tetrafluoroethylene) (ETFE) films were irradiated by swift heavy ion-beams of ¹²⁹Xe²³⁺ with fluences of 0, 3 × 10⁶, 3 × 10⁷, 3 × 10⁸ and 3 × 10⁹ ions/cm², followed by γ-ray pre-irradiation for radiation grafting of styrene onto the ETFE films and sulfonation of the grafted ETFE films to prepare highly anisotropic proton-conducting membranes. The fluence of Xe ions and the addition of water in the grafting solvent were examined to determine their effect on the proton conductivity of the resultant membranes. It was found that the polymer electrolyte membrane prepared by grafting the styrene monomer in a mixture of 67% isopropanol and 33% water to the ETFE film with an ion-beam irradiation fluence of 3.0 × 10⁶ ions/cm² was a highly anisotropic proton-conducting material, as the proton conductivity was three or more times higher in the thickness direction than in the surface direction of the membrane.     

Intra-molecular mobility of holes along rod-like helical Si backbones in optically active polysilanes

Intra-molecular mobility of positive charge carriers in poly(n-hexyl-[S]-2-methylbutylsilane) (PHMBS) films doped with N,N′-bis(2,5-di-tert-buthylphenyl)-3,4,9,10-perylenedicarboximide (PDI) is studied by time-resolved microwave conductivity (TRMC) measurements. PHMBS with optically active side chains has a rod-like tightly locked Si catenation with unlikely long persistence length compared with conventional dialkyl-substituted polysilanes. It was found that PDI is a suitable electron acceptor for PHMBS as it provides the high product of photo carrier generation yield ? as ～0.08% under an excitation at 355 nm. The efficient electron transfer reaction from PHMBS to PDI gives clear conductivity transients ascribed to the positive charges on the Si catenation of PHMBS by TRMC measurements. The estimated value of isotropic mobility along the tightly locked Si catenation is 0.36 cm² V^?1 s^?1, suggesting the presence of mobile holes on the backbones of PHMBS.     

Neutronic potential of water cooled reactor with actinide closed fuel cycle

Neutronic potential of water-cooled reactor on the efficient use of Uranium by multiple recycling of all actinides have been examined after a brief-review of alternative coolants to sodium which are applicable for fast neutron reactors. The water-cooled reactor which was designed to have tight lattice and lower Hydrogen/Heavy-Metal number density ratio (H/HM<0.5) showed enough neutronic potential to make the fuel cycle closed for actinides and could be feasible to be operated not as a breeder but as a self-fuel sustainer. The recycle system requires no external fissile supply and generates no actinide as waste except for the inevitable recovery loss, therefore the Uranium resource could be efficiently used and sustained for a long period similar to the case of sodium cooled system.