Analysis of conjugated linoleic acids as 9-anthrylmethyl esters by reversed-phase high-performance liquid chromatography with fluorescence detection

A simple and highly sensitive method for determining the fatty acid composition of food lipids containing conjugated linoleic acid (CLA) is described. The method is based on the separation of the 9-anthrylmethyl ester derivatives of saturated and unsaturated (conjugated and non-conjugated) fatty acids by reversed-phase high-performance liquid chromatography with fluorescence detection. Just like the other fatty acids, CLA reacts readily with 9-anthryldiazomethane at room temperature to produce 9-anthrylmethyl esters without isomerization and decomposition of the conjugated double bonds. Clear resolution of the individual fatty acids as their 9-anthrylmethyl esters is achieved on a highly efficient octadecylsilylated silica column (150- x 3-mm i.d., 3-microm particle size) using a stepwise gradient elution with methanol-water. The method is standardized with commercially available CLA isomers (cis-9, trans-11 and trans-10, cis-12-octadecadienoic acids, and their cis,cis and trans,trans isomers) and applied for determination of the fatty acid compositions of milk and sdairy products.     

Domain growth in systems with multiple-degenerate ground states

We develop a statistical theory of growing domain structures in quenched systems with multiple-degenerate ground states where the order parameter is not conserved. Exact formulas are derived for the non-equilibrium structure functions for growing domains. As concrete examples the theory is applied to the p-state Johnson-Mehl model and the p-state cell model where the structure functions of the growing domains and the volume fraction of the metastable domain are calculated explicitly.     

A series of new compounds A3+Fe2 O4 (A = Ho,Er, Tm,Yb, and Lu)

A series of new compounds A Fe₂ O₄ (A = Ho, Er, Tm, Yb, and Lu) have been successfully synthesized under the lower oxygen partial pressures at 1200°C and their unit cell dimensions were determined.     

Structure of thiotropocin,a new sulfur-containing 7-membered antibiotic

The structure of a new antibiotic thiotropocin is described.     

The boundary between the spin-glass and ferromagnetic states of the bond-random Ising model in the square lattice at T = 0

The bond-random (±J) Ising model in the square lattice is considered in the square cluster approximation. The boundary between the ferromagnetic and spin-glass states at T = 0 is obtained as the transition point from the asymmetric distribution of the effective fields to the symmetric distribution. The concentration of this transition, P_FG is obtained by solving the integral equation for the distribution function of the effective fields.     

Metal-containing sensor proteins sensing diatomic gas molecules

Diatomic gas molecules such as O2, CO and NO act as signaling molecules in many biological systems, where metal-containing gas sensor proteins sense their effector gas molecules by using prosthetic groups such as heme, iron-sulfur clusters and non-heme iron as the active center for gas sensing. When the gas sensor proteins sense their effector gas molecules, intramolecular and intermolecular signal transductions take place to regulate many physiological functions including gene expression, aerotaxis, and change in metabolic pathways, etc. The metal-containing prosthetic groups in these sensor proteins play a crucial role for selective sensing of their effectors. In this perspective, I will discuss the structure and function of some O2-, CO- and NO-sensor proteins, especially focussing on the structural, biochemical and biophysical properties of the active centers of these sensor proteins.