Antagonistic effect of the Ainu-selected traditional beneficial plants on the transformation of an aryl hydrocarbon receptor

Transformation of an aryl hydrocarbon receptor (AhR) is the initial step to express the multiple toxicity of halogenated and polycyclic aromatic hydrocarbons (HAHs and PAHs) including dioxins. Therefore, it has been suggested that suppression of the transformation induced by HAHs and PAHs leads to reduce their toxicological effects. In this study, the antagonistic effect of 110 indigenous plants (192 plant parts) used as medicine and/or food by the Ainu on the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced AhR transformation was investigated. Of these, a stalk of Aralia elata (Miq.) Seemann and a bark of Fraxinus mandshurica Rupr. var. japonica Maxim. exhibited the strong antagonistic effect in a dose-dependent manner. An antioxidative activity and polyphenol content were also measured, and the strong correlation (r= 0.96) between these two parameters could be confirmed. However, correlation coefficients of the antagonistic effect of 192 extracts compared to their antioxidative activity and polyphenol content were 0.17 and 0.20, respectively. These results suggest that the Ainu-selected traditional beneficial plants are useful source for findings of novel AhR antagonists, and the antagonistic activity of these plants may be independent on their antioxidative activity and polyphenol content. PRACTICAL APPLICATION: Our findings lead to discovery of the valuable plants used by the Ainu and the novel active compounds useful for human's life, and furthermore, may contribute to the development of new medicines and functional foods.     

Wettability, surface tension, and reactivity of the molten manganese/zirconia-yttria ceramic system

A basic research study for improvement of plasma-sprayed zirconia coatings has been conducted. The contact angle and surface tension of the molten manganese/zirconia-yttria ceramic system were measured at 1573 K by the sessile drop method, suggesting that molten manganese would spontaneously infiltrate open pores in zirconia coatings. Structure and elementary composition development of zirconia ceramics caused by reaction with manganese were examined by using scanning electron microscopy (SEM), an electron probe microanalyzer (EPMA), and an X-ray diffractometer (XRD). Manganese not only stabilized cubic zirconia but also contributed to the growth and volume increase of zirconia particles. In this article, the mechanism of making zirconia coatings dense with manganese is discussed based on the results of experiments. M. SONODA, formerly Graduate Student, Department of Materials Science and Engineering, Kyushu Institute of Technology.     

Cloning and mapping of the U2af1-rs2 gene with a high transmission distortion in interspecific backcross progeny

We have cloned and analyzed the mouse U2af1-rs2 gene based on its sequence similarity to the imprinted gene U2af1-rs1 (SP2). Sequence analysis of this U2af1-rs2 cDNA revealed that it contained an open reading frame encoding a protein of 462 amino acid residues. The predicted amino acid sequence showed 72.7 and 35.8% identity to the U2af1-rs1 and U2 small nuclear ribonucleoprotein auxiliary factor, respectively. Interspecific backcross analysis showed this gene to map to the distal region of the X chromosome and also indicated that there was significant distortion of transmission ratio of the U2af1-rs2 allele in the backcrossed progeny from (C57BL/6J x Mus spretus)F1 females mated to Mus spretus males.     

A new technique for nonconvex primal-dual decomposition of a large-scale separable optimization problem

The primal-dual approach is quite effective in decomposing a convex separable optimization problem into several subproblems of smaller sizes. In this paper, we present a new technique which extends the primal-dual approach to nonconvex problems. Since a straightforward application of the multiplier method destroys separability, a new Lagrangian function is proposed which preserves separability. Based on this new function we develop a new iterative method for finding an optimal solution to the problem and show that the method is locally convergent to an optimal solution. Furthermore, the effect of certain parameters on the ratio of convergence is investigated and simple examples are given to illustrate the proposed approach.     

Binderless moulding of green cokes delivered from solvent refined coal and ethylene tar pitch

Green cokes, derived from the co-carbonization of Solvent Refined Coals with ethylene tar pitch, have been moulded into discs without using a binder. Cokes with a range of size of optical texture have been prepared by control of the ratios of the two components of the carbonization blend. The appearance of the discs was assessed by optical and scanning microscopy after calcination to 1200° C. The most acceptable disc was prepared by moulding carbon of a heat treatment temperature (HTT) of 440° C. With cokes of HTT< 440° C excessive dilation adversely decreased the density of the disc. With cokes of HTT > 440° C, dimished cohesion of the coke grains prevented the development of a strong disc on calcination. It is considered that the presence of benzene-soluble (BS) and benzene-insoluble/quinoline-soluble (BI/QS) fractions in the pitch systems contribute to cohesion of coke particles having a HTT of 440° C.