High performance liquid chromatographic determination of 1,5-anhydroglucitol in human plasma for diagnosis of diabetes mellitus.

This paper describes a high performance liquid chromatographic (HPLC) method for determining 1,5-anhydroglucitol in plasma, in which anion exchange chromatography and pulsed amperometric detection are used. Plasma samples deproteinized with trichloroacetic acid are passed through a three-layer column packed with (1) strongly basic anion (BO3(3-) form, the upper layer), (2) strongly basic anion (OH- form, the middle layer) and (3) strongly acidic cation (H+ form, the lower layer) exchange resins. 1,5-Anhydroglucitol is efficiently recovered in the flow-through fraction and interfering substances are completely removed by the column treatment. The analytical response of the method is linear with concentration to 40 mg/L, and it is possible to detect as little as 0.1 mg 1,5-anhydroglucitol per litre of plasma. Analytical recovery is between 96 and 103%, and there is good agreement between the results measured by our method and by a gas/liquid chromatographic method (r = 0.998). The method has been successfully used for the determination of very low 1,5-anhydroglucitol concentrations (less than 1 mg/L) in the plasma of diabetic patients.     

The effect of the anion fraction on the physicochemical properties of EMIm(HF)nF (n = 1.0-2.6)

A series of molten salts EMIm(HF)nF's with different n values has been synthesized by the reaction of EMImHF(2) and anhydrous hydrogen fluoride. The salts contain EMIm cation and some oligomeric fluorohydrogenate anions, (HF)nF-, of which the fraction changes with the change of n. A phase diagram of EMIm(HF)nF's (n = 1.0-2.6) has been constructed which suggests the presence of the stoichiometric compounds, EMIm(HF)1.5F and EMIm(HF)2F, in this range. Compared to the EMIm(HF)2.3F previously reported, EMIm(HF)nF's (n = 1.8-2.0) possess wider liquid temperature ranges because of their similar melting points and superior thermal stabilities at elevated temperatures. The electrochemical windows of EMIm(HF)nF's (n = 1.0-2.6) falls in the range of 2.9-3.4 V. The conductivity of EMIm(HF)nF's (n = 1.0-2.6) increases with the increase of n.     

Improving the performance of solid-state dye-sensitized solar cell using MgO-coated TiO2 nanoporous film

An ultrathin overlayer of MgO on TiO2 is shown to drastically improve the stability of solid-state dye-sensitized solar cell using CuI as a hole conductor in addition to solar energy conversion efficiency.     

Total synthesis of the antitumor acetogenin mosin B: desymmetrization approach to the stereodivergent synthesis of threo/trans/erythro-type acetogenins

A total synthesis of the threo/trans/erythro-type acetogenin mosin B and one of its diastereomers has been achieved. The carbon skeleton is assembled in a convergent fashion from two segments (a THF ring segment and a gamma-lactone segment) through the Nozaki-Hiyama-Kishi reaction. The THF ring segment was stereoselectively constructed by a stereodivergent synthesis starting from a common intermediate (4-cyclohexene-1,2-diol) based on a desymmetrization strategy. The gamma-lactone segment was synthesized by coupling a triflate and a chiral alpha-sulfenyl gamma-lactone. By virtue of these synthetic results, we suggest that the absolute configuration of natural mosin B is 1 a. Antiproliferative effects of 1 a and 1 b were also investigated.     

Superconductivity in the metal rich Li-Pd-B ternary boride

Superconductivity at about 8 K was observed in the metal-rich Li-Pd-B ternary system. Structural, microstructural, electrical, and magnetic investigations for various compositions proved that the Li2Pd3B compound, which has an antiperovskite cubic structure composed of distorted Pd6B octahedrons, is responsible for the superconductivity. This is the first observation of superconductivity in metal-rich ternary borides containing alkaline metal and Pd as a late transition metal. The compound prepared by arc melting has a high density and is relatively stable in the air. The upper critical fields H(c2)(0) estimated by linear extrapolation and the Werthamer-Helfand-Hohenberg theory are 6.2 and 4.8 T, respectively.     

Structural and dehydriding properties of Ca(BH<Subscript>4</Subscript>)<Subscript>2</Subscript>

We have investigated the structural and dehydriding properties of Ca(BH₄)₂. It was found that Ca(BH₄)₂ undergoes a structural phase transformation from an orthorhombic low-temperature (LT) modification into a tetragonal high-temperature (HT) modification between 433 K and 523 K. The amount of hydrogen desorbed from Ca(BH₄)₂ during the pressure–composition (p–c) isotherm measurement was 5.9 mass%. This hydrogen desorption is caused by the partial dehydrogenation of Ca(BH₄)₂ accompanied by the formation of CaH₂ and orthorhombic intermediate phases.