Studies on cerebral protective agents. II. Novel 4-arylpyrimidine derivatives with anti-anoxic and anti-lipid peroxidation activities. (2).

In a search for new cerebral protective agents with anti-anoxic (AA) and anti-lipid peroxidation (ALP) activities, a series of 4-arylpyrimidines, bearing an amino moiety in the C-5 position of the pyrimidine nucleus, was synthesized and tested for AA and ALP activities. Among them, 6-methyl-5-(4-methylpiperazin-1-ylcarbonyl)-4-(3-nitrophenyl )-2-phenylpyrimidin e (41, FK360) was most effective on both assays and on arachidonate-induced cerebral edema in rats. Structure-activity relationships in regard to AA activity of this series of compounds are also discussed.     

A novel silver catalyst prepared by using superheated-steam as a heating medium for ethylene oxide production

A high-performance catalyst for the production of ethylene oxide by vapor phase oxidation of ethylene was developed and commercialized. High performance was achieved by the usage of a high surface area carrier with controlled pore distribution and surface acid-base properties, by the adoption of mixed amines to dissolve heat-decomposable silver salt, by the addition of effective additives, and by the introduction of a uniquely developed heat-treatment technology using superheated-steam as the heating medium. The catalyst thus prepared showed high activities because of homogeneously and highly dispersed silver and additive elements within the carrier. As a result, the reaction temperature could be lowered, which led to the improvement of not only the selectivity but also the catalyst life. Heat treatment with superheated-steam proved to have many advantages in producing high-performance catalysts and it is commercially favorable because it needs only a very short processing time.     

Capillary electrophoresis of small anions in complex samples with a hollow fiber sampling inlet end.

A hollow fiber sampling inlet end of capillary electrophoresis (CE) for small ions in complex samples is described. A short piece of hollow fiber, which only permits small ions to pass through its wall, was directly connected to one end of a capillary. Small ions in complex samples were injected into the capillary through the hollow fiber by an electrokinetic method. The experimental results of CE for standard anion mixture solutions, river water, and milk samples show that the hollow fiber sampling inlet end is a simple and useful method for the CE of complex samples. Furthermore, it has been shown that the method can be used to study small anion changes during the milk storing process.     

Quantum phase transitions of spin chiral nanotubes

Recently many interesting magnetic nanostructures have been fabricated and much attention is arising on the rich magnetic properties that originate in the quantum effects eminent in the nanoscale world. One of the peculiar aspects of the quantum effects is the spin excitation gap. In the spin-1/2 low-dimensional systems, the spin gap often appears when the lattice dimerization or the frustration in the spin–spin interaction are introduced. In the present study, we investigate the ground-state property of the spin-1/2 antiferromagnetic spin chiral nanotubes with the spatial modulation in the spin–spin interaction. The ground-state phase diagrams of them are determined by observing the behavior of the expectation value of the Lieb–Schultz–Mattis slow-twist operator calculated by the quantum Monte Carlo method with the continuous-time loop algorithm. We discuss the relation between the characteristic of the topology of the phase diagram and the chiral vector of the nanotubes.     

Automatic Alignment of Optical System Using Shape Memory Alloy

Properties of the shape memory alloy of 29 μm thick Ni-Ti foil are investigated as an actuator to align optical elements. Since the intrinsic properties of the Ni-Ti foil are not satisfactory in reproducibility and hysteresis, a simple feedback control is used. A pinhole integrated with a surrounding position sensor is proposed to realize a confocal optical system having an automatic alignment function. Large displacement (mm) and precision at the level of the optical wavelength are found to be possible.Present at 1996 International Workshop on Interferometry (IWI ‘96), August 27-29, Saitama, Japan.     

Temperature dependence of hole saturation velocity in silicon

Thep ⁺ np ⁺ diode is used to determine the hole drift velocity versus field curves in silicon as a function of temperature. By taking the analytical expression of the hole drift velocity,v=v _m (E/E _c )/(1+E/E _c ),v _m andE _c are obtained in the temperature range from 210–420 K.v _m varies from 1.04×10⁷ cm/sec at 210 K to 1.11×10⁷ cm/sec at 420 K, whileE _c increases from 1.05×10⁴ V/cm at 210 K to 5.3×10⁴ V/cm at 420 K. The curve at 300 K is very close to the result of Norris and Gibbons.     

Levels in 74Se, 78, 80Kr and 84Sr and systematics of quasi-γ bands

Quasi-band structures in ⁷⁴Se, ^{78, 80}Kr and ⁸⁴Sr have been investigated using (p, 2nγ) reactions. The members of the quasi-γ band have been observed up to 5⁺ in ⁷⁴Se, ^{78, 80}Kr and up to 3⁺ in⁸⁴Sr. The analyses of the energy systematics of the quasi-γ bands studied in this mass region as well as in other regions make clear the evolution of the quasi-γ band to the γ-band in well-deformed nuclei. In addition to these positive-parity bands, negative-parity levels were observed in ⁷⁴Se, ⁸⁰Kr and ⁸⁴Sr.     

A facile cyclopropanol synthesis from β-halo ester with grignard reagent-samarium(II) diiodide couple

Transformation of ,β-halo ester to the cyclopropanols by a coupled reagent of samarium(II) diiodide with Grignard reagent in tetrahydrofuran-hexamethylphosphoric triamide was very successfully under mild conditions.     

Characteristics of the H(+)-translocating adenosine triphosphatase of Vibrio parahaemolyticus

We have characterized H(+)-translocating adenosine triphosphatase (ATPase) in membrane vesicles of Vibrio parahaemolyticus. The ATPase required high concentrations (about 0.5 M) of Na2SO4 (or other salts) for its maximum activity. Magnesium ion stimulated the ATPase activity, but Ca2+ did not. The activity of ATPase was inhibited by tetrachlorosalicylanilide, an H+ conductor, but not by another H+ conductor, carbonylcyanide-m-chlorophenylhydrazone. The activity was strongly inhibited by dicyclohexylcarbodiimide or Zn2+, and partially inhibited by azide, but not at all by vanadate.     

Preparation and properties of surface-active organocobalt complexes having long-chain alkyl groups

New types of surface-active organocobaltocenium(I) complexes, η-C_nH_2n+1X-C₅H₄(ηC₅H₅)₂Co⁺Y^? and(η-C_nH_2n+1X-C₅H₄)Co⁺Y^? (n = 6–16; X not present, NHCO or OCO; Y = Cl or PF₆) were prepared and their surface character studied. (1) The critical micelle concentrations of the cobaltocenium chlorides were much lower than those of corresponding trimethylammonium-type cationic surfactants. (2) The surface-active character of the cobaltocenium chlorides in aqueous solution (and the redox potentials of the hexafluorophosphates in acetonitrile) were affected by the substituents (X) in the cyclopentadienyl groups. (3) The surface activities of the cobaltocenium salts were lost on reduction with NaBH₄ to afford (alkyl-substituted cyclopentadiene) cyclopentadienylcobalt (0) complexes which were surface-inactive but could be re-oxidized to afford the surface-active cobaltoceium(I) salts. The cobalt complexes mentioned above may be the first examples of redoxresponsive surfactants.