Characterization of {v μ+1 + 2v μ,v μ + 2v μ − 1;t,q}-min · hypers and its applications to error-correcting codes

Recently, Hamada [5] characterized all {v ₂ + 2v ₁,v ₁ + 2v ₀;t,q}-min · hypers for any integert 2 and any prime powerq 3 wherev _l = (q ^l – 1)/(q – 1) for any integerl 0. The purpose of this paper is to characterize all {v _{+ 1} + 2v ,v + 2v _{– 1};t,q}-min · hypers for any integerst, and any prime powerq such thatt 3, 2 t – 1 andq 5 and to characterize all (n, k, d; q)-codes meeting the Griesmer bound (1.1) for the casek 3, d = q ^k-1 – (2q ^-1 +q ) andq 5 using the results in Hamada [3, 4, 5].     

Molecular recognition by chiral cationic micellar and micelle-like aggregates in electrokinetic capillary chromatography

We examined the enantiomer separation with micelles and a micelle-like polymer made with trimethylammonium-terminated surfactants all of whose hydrocarbon chains contain hydrogen bonding valinediamide moieties in electrokinetic chromatography (EKC). The surfactants used were 3-(N-dodecanoyl-L-valylamino)-propyltrimethylammonium bromide (surfactant 1) and 6-(N-nonanoyl-L-valylamino)hexyl-trimethylammonium bromide (surfactant 2); the micelle-like polymer was derived from 3-(N-10-undecenoyl-L-valyl)aminopropyltrimethylammonium bromide (surfactant 3). N-Acylamino acids and their isopropyl esters were separated with enantiomers with the same configuration as the chiral surfactant and which were retained to a greater extent than the counterparts in micelles. The micellar hydrophobic environment, in which amides function as hydrogen bonding sites with solutes, and ceased micellar kinetic association-dissociation with polymerization are discussed.     

The Raman,infrared and proton nmr spectra and structures of dimethyl chalcogenides

The Raman spectra and polarization parameters of the liquid dimethyl chalcogenides, CH₃-X-CH₃ (X = 0, S, Se, Te) and the infrared spectra of the gaseous compounds¹ have been measured; analysis of these data allow us to deduce much information about the molecular structure. The observed band contours, band types, simplicity of the spectra and the mutual exclusions in the Raman and infrared, are in excellent agreement with the theoretical expectations for a model of D_3d symmetry, with a linear C-X-C skeleton.The proton NMR spectra of the molecules CH₃-X-CH₃ show only one signal.     

Fundamental study of the influence of pixel size on the quality of scintigrams

The effect of pixel size on image quality was investigated. The image quality was examined by abnormality detection and image preference for clinical images displayed with different pixel sizes. Smaller pixel size was found to be superior to large one in image quality using large field of gamma camera (FWHM 6.42 mm), 1.6mm pixel size (a 256 x 256 matrix) was found to be the best in image quality. Examined image minification effect, 3.2 mm pixel size (image size: 5 cm phi) was found to be superior to 1.6 mm pixel size (image size: 10 cm phi) in image preference and to be almost equal to 1.6 pixel size in abnormality detection.     

Estimation of thermodynamic interactions between polyethylene and n-alkanes by means of melting point measurements

Summary The thermodynamic interaction parameters for linear polyethylene-n-alkanes were investigated with n-C₆H₁₄, n-C₇H₁₆, n-C₈H₁₈, n-C₁₈H₃₈, and n-C₃₂H₆₆ as diluents, by determining the melting temperatures of polyethylene in its mixtures with n-alkanes. It follows that, with increasing the number of carbon atom in n-alkanes, the entropy parameter ₁ increases, the enthalpy parameter ₁ remains approximately equal to zero, and the free energy parameter ₁ decreases and approaches to zero. The change of the interaction parameters with the number of carbon atom in n-alkanes were discussed byPrigogine's theory.

---

Zusammenfassung Die thermodynamischen Wechselwirkungsparameter für das System lineares PolyÄthylen/n-Alkane wurden durch die Schmelzpunktsmessungen von PolyÄthylen in den Mischungen mit n-Alkanen bestimmt. Die als Verdünnungsmittel verwandten n-Alkane waren n-C₆H₁₄, n-C₇H₁₆, n-C₈H₁₈, n-C₁₈H₃₈ und n-C₃₂H₆₆. Es wurde gefunden, da\ mit steigender Zahl der Kohlenstoffatome in den n-Alkanen der Entropieparameter ₁ zunimmt, wÄhrend der Enthalpieparameter ₁ annÄhernd Null bleibt. Der Parameter der freien Energie ₁ nimmt ab und nÄhert sich Null. Die VerÄnderung der Wechselwirkungsparameter von der Zahl des Kohlenstoffatome in den n-Alkanen wurden nach der Prigogineschen Theorie diskutiert.

     

P-chirogenic binaphthyl-substituted monophosphines: synthesis and use in enolate vinylation/arylation reactions

[reaction: see text] New phosphine ligands possessing both axial chirality and a chirogenic phosphorus center were prepared from (R)-2-bromo-2'-N,N-(dimethylamino)-1,1'-binaphthyl (1) via a simple Li-halogen exchange protocol. The asymmetric vinylation of a ketone enolate with (R,R(P))-2-(tert-butylphenylphosphino)-2'-N,N-(dimethylamino)-1,1'-binaphthyl (2a) afforded the coupling product with good enantiomeric excess.     

Development of a new class of chiral phosphorus ligands: P-chirogenic diaminophosphine oxides. A unique source of enantioselection in Pd-catalyzed asymmetric construction of quaternary carbons

[reaction: see text] We have recently developed a new class of chiral phosphorus ligands: P-chirogenic diaminophosphine oxides. These pentavalent phosphorus compounds have been successfully applied to Pd-catalyzed asymmetric construction of tertiary and quaternary carbons. The actual ligand structure was the trivalent phosphorus species 17, which was generated in situ by BSA-induced P(V) to P(III) transformation of 6, the preligand. Detailed mechanistic studies, including asymmetric amplification and initial rate kinetics, revealed that complex 18 [Pd-17 (1:2) complex] was the active catalyst. The important function of the nitrogen atom on the sidearm in the ligands was also clarified. The source of enantioselection in the construction of asymmetric quaternary carbons was the secondary ligand substrate interaction mediated by N-Zn coordination.     

The first stereoselective total synthesis of lankanolide. Part 1: Computer-assisted design and lactonization of model seco-acid derivatives

To design easily cyclizable seco-acid derivatives of lankanolide, the conformation of several model seco-acids was calculated and the lactonization experiments of the seco-acids were carried out to elucidate the efficiency of the cyclization of the model seco-acid.     

NMR structure elucidation of cyclic sialyl 6-sulfo Lewis x, a biologically dormant form of L-selectin ligand

The structure of cyclic sialyl 6-sulfo Lewis x, a new biologically dormant form of L-selectin ligand, was determined unambiguously by the accurate NMR analysis to have the lactamized ^{[5.], (a), (b), [2.], (a) and (b)}B conformation of its sialic acid. For the NMR structure elucidation were used various informations, such as chemical shifts values, appearance of amide proton, and NOE.