Precise measurement of the magnetic moment of17F(I x =5/2+,T 1/2=64.5 s) and its hyperfine interactions in ionic crystals

Hyperfine interactions of β-emitting¹⁷F implanted in single crystals of NaF and CaF₂ were studied. The nuclear magnetic moment of theT ^π=5/2⁺ state was determined with an improved precision to be |μ(¹⁷F;π=5/2⁺,T _1/2=64.5s|=4.72130±0.00025. nm. Isoscalar magnetic moments of the doubly closed shell ±1 nucleon nuclei around mass number 16 were derived and the effective nucleon mass in the nucleus was discussed.     

Electric field gradient in Mg and Zn detected by β-emitters,8Li and12x0392;x0392;x0392;

The quadrupole coupling constants of⁸Li and¹²B in hcp Mg and Zn are determined by use of a newly developed nuclear quadrupole resonance technique (NNQR) as ¦eqQ(⁸Li in Mg)/h¦=3.0±0.3 kHz, ¦eqQ(⁸Li in Zn)/h¦=33.5±2 kHz, and ¦eqQ(¹²B in Mg)/h¦=47.0±0.1 kHz. Correspondingly, the electric field gradients at room temperature are deduced: ¦q(⁸Li in Mg)¦=(3.81±0.39)×10¹⁸, ¦q(⁸Li in Zn)¦=(4.25±0.27)×10¹⁹, and ¦q(¹²B in Mg)¦=(1.47±0.03)×10²⁰, all in V/m². The experiments are compared with the results of first-principles super-cell band structure calculations which can treat local lattice relaxations around the impurity nuclei. The calculations show that the most favorable location of these light interstitials in hcp Mg is not the octahedral-like sites which have the biggest interstitial volume, but the basal trigonal sites with a local lattice expansion of as big as 30%. Calculated electric field gradients at the impurity nuclei reproduce the experimental values fairly well.     

Rapid enantioseparation of 1-aminoindan by microchip electrophoresis with linear-imaging UV detection.

Chiral separations of 1-aminoindan (AI) by cyclodextrin electrokinetic chromatography (CDEKC) were investigated on microfluidic quartz chips. By using a microchip electrophoresis (MCE) instrument equipped with a linear-imaging UV detector, the separation process of the enantiomeric compounds was observed. When sulfated beta-cyclodextrin was employed as a chiral selector, the baseline separation of AI could be achieved within 1 min with a high repeatability. The relative standard deviation of the migration time was less than 6%. The fastest separation was achieved in 14 s, utilizing a separation length of only 6.1 mm. These results show that the MCE analysis employing a linear imaging UV detector has a significant potential for fast chiral analysis.     

Structural and spectroscopic characterization of (mu-hydroxo or mu-oxo)(mu-peroxo)diiron(III) complexes: models for peroxo intermediates of non-heme diiron proteins

(mu-Hydroxo or oxo)(mu-1,2-peroxo)diiron(III) complexes having a tetradentate tripodal ligand (L) containing a carboxylate sidearm [Fe2(mu-OH or mu-O)(mu-O2)(L)2]n+ were synthesized as models for peroxo-intermediates of non-heme diiron proteins and characterized by various physicochemical measurements including X-ray analysis, which provide fundamental structural and spectroscopic insights into the peroxodiiron(III) complexes.     

Aryloxyacetic acid diuretics with uricosuric activity. II. Substituted [(4-oxo-4H-1-benzopyran-7-yl)oxy]acetic acids and the related compounds.

Di- and tri-substituted [(4-oxo-4H-1-benzopyran-7-yl)oxy]acetic acids, and 4-oxo-3-phenyl-4H-furo[2,3-h]-[1]benzopyran-8-carboxylic acid were synthesized and tested for natriuretic and uricosuric activities. Among the compounds tested, 3,5-disubstituted [(4-oxo-4H-1-benzopyran-7-yl)oxy]acetic acids (6c-f, h, n and x) showed potent natriuretic and uricosuric activities, whereas 4-oxo-3-phenyl-4H-furo[2,3-h][1]benzopyran-8-carboxylic acid (6dd) possessed only potent natriuretic activity. The structure-activity relationships are also discussed.     

Enhanced skin permeation of salicylate by ion-pair formation in non-aqueous vehicle and further enhancement by ethanol and l-menthol

Enhancement of skin permeability of salicylate from non-aqueous vehicle by ion-pair formation with either alkylamines or benzylamine as model cationic ions was examined in excised guinea pig dorsal skin. Solubility of salicylate in isopropyl myristate (IPM) was increased by the addition of either alkylamines or benzylamine as counter ions. The increase was more significant in the presence of amines with longer alkyl chains. Flux of salicylate increased in the presence of these amines due to the increase in the solubility. Maximum flux was observed in the presence of n-hexylamine, which induced an 11-fold increase due to 137-fold increase in solubility. Flux and permeability coefficients of salicylate in the presence of n-butylamine, n-hexylamine, iso-octylamine and benzylamine as counter ions in IPM were larger than those of the non-ionic form of salicylic acid. Flux of 3-methylsalicylate (3-CH3 substituent) and that of 5-hydroxysalicylate (5-OH substituent) were smaller than that of salicylate in the presence of n-hexylamine. After partition to the skin surface, the ion-pair is suggested to dissociate and permeate separately according to the study using lidocaine as the counter ion. Flux of salicylate increased in the presence of benzylamine as the counter ion by the addition of 15% ethanol and 15% ethanol plus 1% l-menthol due to further improvement in the solubility as well as an increase in the permeability coefficient.