Aromatic hydrocarbon-catalyzed direct reaction of sulfur and sodium in a heterogeneous system: selective and facile synthesis of sodium monosulfide and disulfide

Sodium disulfide and monosulfide were selectively formed via the direct reaction of sulfur and an equimolar amount of sodium in 1,2-dimethoxyethane at 70 degrees C in the presence of a catalytic amount of aromatic hydrocarbons and ketone.     

Dictyodendrins A-E,the first telomerase-inhibitory marine natural products from the sponge Dictyodendrilla verongiformis

Five new alkaloids, dictyodendrins A-E (1-5), were isolated from the Japanese marine sponge Dictyodendrilla verongiformis as telomerase inhibitors. Their structures were elucidated by spectroscopic and chemical methods. Dictyodendrins are tyramine-based pyrrolocarbazole derivatives containing three or four p-hydroxybenzene groups. They inhibited telomerase completely at a concentration of 50 microg/mL.     

Semiconductor Optical Amplifier (SOA)-Fiber Ring Laser for Sensor Application

A bi-directional fiber ring laser with a semiconductor optical amplifier has been developed in which a frequency difference between the counter-propagating oscillations is controlled by an introduced birefringent medium. With the material which causes the retardation change by a physical phenomenon to be measured, the laser in this study is applicable to a novel fiber sensor of which the sensing signal is obtained in a frequency domain.     

Coulomb dissociation of 8B and the low-energy cross section of the 7Be(p,gamma)8B solar fusion reaction

An exclusive measurement of the Coulomb breakup of 8B into 7Be+p at 254A MeV allowed the study of the angular correlations of the breakup particles. These correlations demonstrate clearly that E1 multipolarity dominates and that E2 multipolarity can be neglected. By using a simple single-particle model for 8B and treating the breakup in first-order perturbation theory, we extract a zero-energy S factor of S17(0)=18.6+/-1.2+/-1.0 eV b, where the first error is experimental and the second one reflects the theoretical uncertainty in the extrapolation.     

Segal-Bargmann transforms of one-mode interacting Fock spaces associated with Gaussian and Poisson measures

Let and denote the Gaussian and Poisson measures on , respectively. We show that there exists a unique measure on such that under the Segal-Bargmann transform the space is isomorphic to the space of analytic -functions on with respect to . We also introduce the Segal-Bargmann transform for the Poisson measure and prove the corresponding result. As a consequence, when and have the same variance, and are isomorphic to the same space under the - and -transforms, respectively. However, we show that the multiplication operators by on and on act quite differently on .

     

Studies on pyrazines. 15. A convenient synthesis of 2,5-dihydroxypyrazines

The reaction of 2,5-dimethoxypyrazines with iodotrimethylsilane followed by hydrolysis was investigated to prepare the title compounds.     

INDO Studies on the structure of benzosemiquinone radicals

The spin densities of the radical anions from 4-methylcatechol, 4-carboxylic catechol, and 3-methylcatechol were calculated by means of the INDO method with the geometrical parameter adjusting method. The observed protion hyperfine coupling constants were exactly reproduced.     

Discovery of deeply bound π− states in the 208Pb(d,3He) reaction

Zeitschrift für Physik A Hadrons and nuclei - Narrow lines were observed around 133 MeV excitation energy in the 208Pb(d,3He) reaction at T d = 300 MeV/u using the Fragment Separator System at...     

Synthesis of (1-substituted piperidin-4-yl)-1H-benzimidazoles and (1-substituted piperidin-4-yl)-3,4-dihydroquinazolines as possible antihypertensive agents

Structural modifications of 4-piperidylbenzimidazolinones (I) by replacing the benzimidazolinone group with other heterocycles (2-cyanoamino, 2-ethoxy, and 2-methylbenzimidazole and 2-cyanoamino-3,4-dihydroquinazoline) has been made and a number of new piperidines (II) were synthesized as potential antihypertensive agents.