Insight into acid-mediated asymmetric spirocyclization in the presence of a chiral diol

Asymmetric spirocyclization based on intramolecular conjugate addition using a combination of a Lewis acid and an optically active cyclohexane-1,2-diol has been studied in connection with 1) the effect of substituents on the cyclohexane-1,2-diol and 2) the effect of substituents on the substrate. This reaction was found to be both thermodynamically and kinetically controlled under restricted conditions.     

Synthesis of NBD-alpha-galactosylceramide and its immunologic properties

[formula: see text] A representative alpha-galactosylceramide (alpha-GalCer), KRN7000, can activate NKT cells through CD1d molecules, which play an essential role in the generation of the strong antitumor activity of KRN7000. Our previous study has demonstrated that alpha-GalCer binds directly to CD1d molecules. However, it is controversial whether CD1d binds alpha-GalCer in endosomal compartments. To address this question, we synthesized NBD-alpha-GalCer, which has strong fluorescent properties. We found that the NBD-alpha-GalCer has immunostimulatory activity that is stronger than that of KRN7000.     

Polynomially convex hulls of graphs on the sphere

Let be the graph of a continuous map of the unit sphere of into , and the polynomially convex hull of . Several examples of for are given, which have different properties from the known ones for .

     

Measured lifetimes of states in 197Au and a critical comparison with the weak-coupling core-excitation model

The lifetimes of five excited states in ¹⁹⁷Au up to an excitation energy of 885 keV were measured by the recoil-distance method (RDM). These levels were populated by Coulomb excitation using both 90 MeV ²⁰Ne and 120 MeV ³⁵Cl ion beams. The experimentally determined spectroscopy of the low-lying levels $\text{3}\text{2}{}^{\mathrm{+}}$ (ground state) and $\text{1}\text{2}{}^{\mathrm{+}}$, $\text{3}\text{2}{}_2{}^{\mathrm{+}}$, $\text{5}\text{2}{}^{\mathrm{+}}$, and $\text{7}\text{2}{}^{\mathrm{+}}$ at 77.3, 268.8, 278.9, and 547.5 keV excitation energy, respectively, has been critically compared with the detailed predictions of the de-Shalit weak-coupling core-excitation model. When the model is taken to represent the case of a $\text{d}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ proton hole coupled to a ¹⁹⁸Hg core, the model parameters obtained are in accord with the criteria implicit for weak core coupling and, at the same time, are in remarkably good agreement with virtually all measured E2 and M1 transition rates.     

Physicochemical properties of alkali metal cation-TCNQ anion radical salts

Simple alkali metal cation-TCNQ anion radical salts are classified in two groups from the differences in their physicochemical properties and crystal structures. Li-, Na-, K-, and Rb(I)-TCNQ are comprised in Group A. Li-TCNQ exhibits distinct behavior from other salts in Group A. Rb(II)- and Cs-TCNQ belong to Group B. Phase transitions, electrical conductivities, and absorption spectra in these simple salts are closely related to their crystal structures.     

Spectrophotometric determination of strychnine and methylatropine by extraction with tetrabromophenolphthalein ethyl ester

A new application of monoacidic dyes is reported for the determination of strychnine and methylatropine. The method is based on solvent extraction into 1,2-dichloroethane of the ion-pair or addition compound formed between tetrabromophenolphthalein ethyl ester and quaternary ammonium salts or alkaloids. The absorbance of the extracts is linearly dependent on the concentration of strychnine or methylatropine initially present in the aqueous solution.     

Semi-stable curves on algebraic surfaces and logarithmic pluricanonical maps

Mathematische Annalen -     

Naturalnes in supersymmetric GUTS

We propose a resummation of QCD radiative corrections in large transverse momentum hadronic processes, based on the introduction of an infrared cut-off, linked to the confinement radius. An analysis of the inclusive reactionspp → π⁰ X andpp → γX and of γ/π⁰ ratio is presented.