Meson loop effect on high density chiral phase transition

We test the stability of the mean field solution in the Nambu-Jona-Lasinio model in a semi-quantitative manner. For stable solutions with respect to both the σ and π directions, we investigate effects of the mesonic loop corrections of 1/N _c , which correspond to the next-to-leading order in the 1/N _c expansion, on the high density chiral phase transition. The corrections weaken the first order phase transition and shift the critical chemical potential to a lower value. At N _c = 3, however, instability of the mean field effective potential prevents us from determining the minimum of the corrected one.      

Transfer effects on sound localization performances from playing a virtual three-dimensional auditory game

Transfer effects of playing an auditory game with a virtual auditory display (VAD) were investigated. Furthermore, we analyzed the effects of playing the VAD game on sound localization performance under subjects’ own head-related transfer functions (HRTFs) and HRTFs fitted from those of 16 other adults. Participants performed sound localization tasks initially and 2 weeks later to show the effects. The VAD game players were of three groups, using own HRTFs, fitted HRTFs, and no playing (control). The VAD game-playing results revealed that: (1) the hit rate of the sound localization task for real sound sources increased approximately 20%; (2) the vertical and horizontal localization error decreased significantly; (3) sound localization performance using fitted HRTFs was similar to performance using own HRTFs. Follow-up tests revealed that transfer effects persisted more than 1 month, suggesting that the effects of playing the VAD game transfer to sound localization performance.     

Catalytic C-C bond cleavage and C-Si bond formation in the reaction of RCN with Et3SiH promoted by an iron complex

Catalytic C-C bond cleavage of acetonitrile and C-Si bond formation have been attained in the photoreaction of MeCN with Et3SiH in the presence of an iron complex, Cp(CO)2FeMe. This catalytic system can be applied for arylnitrile C-C bond cleavage.     

Catalytic radical addition of carbonyl compounds to alkenes by Mn(II)/Co(II)/O(2) system

The radical addition of enolizable carbonyl compounds such as malonates and malononitrile to alkenes was successfully achieved through a catalytic process using the Mn(II)/Co(II)/O(2) system to afford the corresponding adducts in fair to good yields. Dimethyl malonate added to 1,5-cyclooctadiene to produce a fused bicycle compound.     

Pd-catalyzed sulfinylzincation of activated alkynes with 1-alkynyl sulfoxides as a sulfinyl source

Unprecedented Pd-catalyzed sulfinylzincation with 1-alkynyl sulfoxide as a sulfinyl source was developed. Bis-sulfinyl alkenes were formed in good yields on treatment of 1-alkynyl sulfoxides with Et(2)Zn in the presence of a Pd-catalyst, wherein zinc sulfenate (or sulfinylzinc) species would be generated in situ to undergo highly syn-selective conjugate addition to the 1-alkynyl sulfoxides. By using 3,3-dimethyl-1-butynyl sulfoxides, formation of the bis-sulfinyl alkenes was completely suppressed and the sulfinylzincation of activated alkynes was accomplished. The reaction tolerates various functionalities, and was promoted considerably by the neighboring group participation of the heteroatom at the delta-position in the alkynoates. Stereodivergent synthesis of two diastereomeric vinylic sulfoxides and reaction of the resulting vinylzinc species with electrophiles were also described.     

Nickel-Catalyzed Tandem Coupling of alpha,beta-Enones, Alkynes, and Alkynyltins for the Regio- and Stereoselective Synthesis of Conjugated Enynes

The nickel-catalyzed reaction of alpha,beta-enones 2 with alkynes 1, alkynyltins 6, and Me(3)SiCl was carried out by the successive construction of two carbon-carbon bonds to give enol silyl ethers 5, which were then hydrolyzed to conjugated enynes 7, with high regio- and stereoselectivities (isomeric purities: 92-98%).     

Nuclear magnetic resonance studies for the chiral recognition of the novel chiral stationary phase derived from 18-crown-6 tetracarboxylic acid

Enantioselectivities observed in high-performance liquid chromatography (HPLC) with the novel chiral stationary phase (CSP-18C6I) derived from (+)-18-crown-6 tetracarboxylic acid (18C6H₄) were investigated by using nuclear magnetic resonance (NMR) spectrometry. The elution orders in CSP-18C6I, that is, the S-enantiomer of 1-(1-naphthyl)ethylamine (1-NEA) and the

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-enantiomer (S-form) of alanine-β-naphthylamide (Ala-β-NA) eluted prior to each corresponding enantiomer, were successfully explained on the basis of the apparent binding constants (K_a) of the enantiomers to the CSP moiety which were calculated from ¹H-NMR experiments. Detailed HPLC and NMR studies for the chiral recognition of racemic amino compounds with 18C6H₄ hosts showed that ¹H-NMR spectrometry is a useful technique for the investigation of the chiral recognition mechanism in HPLC. Additionally, it was found 18C6H₄ can be recommended as a useful chiral shift reagent for the enantiomeric excess determination by ¹H-NMR.     

An efficient construction of bridged chiral tetracyclic indolidines, a core structure of asperparaline, via stereocontrolled catalytic Pauson-Khand reaction

A reaction of chiral enyne 22 derived from l-proline with a catalytic amount of cobalt (0) octacarbonyl in the presence of N-methylmorphorine N-oxide gave tricyclic enone 24 in 54% yield (73% based on consumed starting material). Treatment of enone 11 with aqueous methylamine followed by silica gel afforded bridged tetracyclic indolidine 1, a common structural motif of natural metabolites, an asperparaline series of compounds and also a potential intermediate for the synthesis of a paralytic alkaloid, asperparaline C (4), in 70% yield.     

Prediction of solubility of drugs by conductor-like screening model for real solvents

The solubility of drugs in solvents is fundamentally important for drug development and manufacturing. As the experimental measurements of the solubility are extremely laborious tasks, reliable prediction methods are highly required. We have employed the conductor-like screening model for real solvents (COSMO-RS) in predicting the solubility of drugs and drug-like compounds in various solvent systems. We also evaluated the salt effect on the solubility of caffeine using this method. The present results demonstrated that COSMO-RS has reasonably reproduced the experimental data and have proved that this method is generally available in predicting the solubility of drugs.     

Quantitative visualization of high-Schmidt-number turbulent mixing in grid turbulence by means of PLIF

Abstract  

Quantitative visualization of high-Schmidt-number scalar fields has been performed in grid turbulence by means of a planar laser-induced fluorescence (PLIF) technique. The Reynolds number based on a mesh size of the grid is 2500 and the Schmidt number of the scalar is around 2100. To correct for the effects of various spatiotemporal variations such as quantum yield, a recently proposed correction method was introduced in the present experiment. In the present work, a PLIF experiment in combination with a calibration region installed outside of the test section is proposed. Visualizations of the instantaneous fluctuating scalar field suggest that mushroom-like structures accompanied by a pair of stirring structures, called engulfments, exist and contribute to large-scale scalar transfer. Visualization of the scalar dissipation field in the horizontal plane suggests that accumulation of the filament structures, which can be related to the mixing transition, locally exists around large-|c| regions, where |c| is the absolute value of the instantaneous fluctuating concentration. Thus, accumulation of the filament structures should be considered in the development of a turbulent mixing model for high-Schmidt-number scalar transfer.