Liquid-liquid distribution behavior of quaternary ammonium salts

1価陰イオンを対イオンとする第四級アンモニウム塩,テトラフェニルアルソニウム塩,テトラフェニルホスホニウム塩の抽出挙動考察のために,炭素数及び形状の異なる16種の陽イオンを用いて水-クロロホルム系での抽出定数を求めた.得られた抽出定数から次の知見を得た.(1) 1価無機陰イオンの抽出性は結晶イオン半径の大きいものほど良く,過塩素酸イオン>チオシアン酸イオン>ヨウ化物イオン>四フッ化ホウ素イオン>臭化物イオン>硝酸イオン>塩化物イオン>亜硝酸イオン>水酸イオン>フッ化物イオンの順となった. (2) アルキル鎖のメチルン基一つ当たりの抽出定数への寄与分は0.59(log単位)であり,フェニル基,ナフチル基の寄与分は2.90, 4.43であった. (3) 炭素数の同じ陽イオンの抽出性は, R-N(CH(3))(3)+>R'(4)N(+)>(C(6)H(5))(4)P(+)≈(C(6)H(5))(4)As+の順となった.これらの知見を基にイオン会合体の抽出定数の推定についても考察し,計算値と実測値との良い一致をみた.The ion association extraction of quaternary ammonium ions with univalent anions was carried out. The extraction constants (log K(ex)) for these ion-as-sociates between aqueous and chloroform phases were determined. The linear relationship was obtained between log K(ex) and the number of carbon atoms in quaternary ammonium ion, and the contribution of a methylene group to the extraction constant, π(CH(2)), was on the average 0.59. The order of the extractability of inorganic anions was F(-)R'(4)N(+)>(C(6)H(5))(4)P(+)≈(C(6)H(5))(4)(-)As(+), and the differences in log K(ex) between the respective cations in this order averaged 1.2 and 1.1 in turn. The π values for C(6)H(5)- and C(10)H(7)(-) groups were 2.90 and 4.43, respectively. By using these empirical parameters, the extraction constants for several ion associates were estimated, and the extraction constants calculated were in good agreement with those obtained experimentally in this work and those reported by other workers

Regulation of Marginal Zone B Cell Development by MINT, a Suppressor of Notch/RBP-J Signaling Pathway

AbstractWe found that Msx2-interacting nuclear target protein (MINT) competed with the intracellular region of Notch for binding to a DNA binding protein RBP-J and suppressed the transactivation activity of Notch signaling. Although MINT null mutant mice were embryonic lethal, MINT-deficient splenic B cells differentiated about three times more efficiently into marginal zone B cells with a concomitant reduction of follicular B cells. MINT is expressed in a cell-specific manner: high in follicular B cells and low in marginal zone B cells. Since Notch signaling directs differentiation of marginal zone B lymphocytes and suppresses that of follicular B lymphocytes in mouse spleen, the results indicate that high levels of MINT negatively regulate Notch signaling and block differentiation of precursor B cells into marginal zone B cells. MINT may serve as a functional homolog of Drosophila Hairless

beta-Secretase inhibitors: Modification at the P-4 position and improvement of inhibitory activity in cultured cells

Recently, we reported potent and small-sized P-secretase (BACE1) inhibitors KMI-570 and KMI-684 in which we replaced carboxylic acid groups at the P-1(') position of KMI-420 and KMI-429, respectively, with tetrazole derivatives as carboxylic acid bioisosteres. These modifications improved significantly BACE1 inhibitory activity and chemical stability. In this study, the acidic tetrazole ring of the P-4 position of KMI-420 and KMI-570, respectively, was replaced with various hydrogen bond acceptor groups. We found BACE1 inhibitor KMI-574 that exhibited potent inhibitory activity in cultured cells as well as in vitro enzymatic assay. (c) 2006 Elsevier Ltd. All rights reserved

Development of an RT-LAMP Assay for the Rapid Detection of SFTS Virus

Detection of severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) during the early phase of the disease is important for appropriate treatment, infection control, and prevention of further transmission. The reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a nucleic acid amplification method that amplifies the target sequence under isothermal conditions. Here, we developed an RT-LAMP with a novel primer/probe set targeting a conserved region of the SFTSV L segment after extraction of viral RNA (standard RT-LAMP). Both the Chinese and Japanese SFTSV strains, including various genotypes, were detected by the standard RT-LAMP. We also performed RT-LAMP using the same primer/probe set but without the viral RNA extraction step (called simplified RT-LAMP) and evaluated the diagnostic efficacy. The sensitivity and specificity of the simplified RT-LAMP were 84.9% (45/53) and 89.5% (2/19), respectively. The simplified RT-LAMP can detect SFTSV in human sera containing >103.5 copies/mL viral RNA. The two RT-LAMP positive but quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) negative samples were positive in the conventional RT-PCR, suggesting that there was no false positive reaction in the RT-LAMP. Both the standard and simplified RT-LAMP are useful for detecting the SFTSV genome in patients during the early phase of the disease

Achievement of Precise Assembly of the JT-60SA Superconducting Tokamak

The JT-60 Super Advanced (JT-60SA) tokamak construction has been achieved respecting the requirements of very tight tolerance for the assembly and by handling very heavy components in a very close space environment. The construction of this large superconducting tokamak represents a big step forward in the world nuclear fusion history, opening the road for ITER and DEMO. Precise assembly is required, not only to avoid mechanical interference, but also to obtain good plasma performance by less magnetic error field. To complete this work, unique and well-considered procedures were introduced. In this paper, the developed technologies and their results are reported, focusing on the assembly of the final sector of vacuum vessel, central solenoid and in-vessel components.28th IAEAFusion Energy Conferenc