Synthesis and spectroscopic analysis of chromophoric lipids inducing pH-dependent liposome fusion

We design novel chromophoric amphiphiles 6a-c, which lead to pH-dependent membrane fusion of egg phosphatidylcholine (eggPC) liposome containing them. Lipids 6a-c comprise double alkyl chains, a single chain with a 2-nitrophenol group as a pH trigger, and dipeptide (Asp-Asp) between them. The pKa values of 2-nitrophenol groups of 6a-c in liposome are larger than that of hydrophilic compound 9 in an aqueous solution. Absorption spectra indicate that the fields around 2-nitrophenol of 6a-c situated in liposome membranes are more hydrophobic than that of 9 in an aqueous solution, whereas the environments around deprotonated 2-nitrophenolate of 6b and 6c are not so hydrophobic as that of 6a. This means that protonated 2-nitrophenol groups of 6a-c are embedded in bilayer membranes. Deprotonated 2-nitrophenol groups of 6b and 6c must be located in less hydrophobic circumstances, while that of 6a is still embedded in bilayer membranes because of its larger hydrophobicity. Absorption spectra and (1)H NMR spectra respectively suggest that protonated 2-nitrophenol groups of 6a and those of 6c might take face-to-face associations in bilayer membranes.     

Lambertellols A and B, novel 3,4-dihydronaphthalen-1(2H)-ones with spiro-butenolide produced by Lambertella sp.1346

[structure: see text] Lambertella sp. 1346 was found to produce lambertellols A (1) and B (2) carrying a novel dihydronaphthalen-1(2H)-ones with spiro-1-furan-2(5'H)-one. The spiro-lactone ring moiety of both 1 and 2 were easily migrated to afford lambertellin, a known metabolite of Lambertella corni-maris. The absolute stereochemistry of these compounds was established on the basis of CD spectrum after chemical derivatization.     

Construction of molecular wires based on a gold(I) bis-sigma-acetylide building block incorporated into ruthenium(II) polypyridyl complexes

An Ru(II)-Au(I)-Ru(II) triad has been synthesized from [Ru(bpy)2(3-ethynylphenanthroline)]2+ with Au(tht)Cl and characterized by spectroscopic means such as NMR and ESI-MS; the Ru(II)-Au(I)-Ru(II) triad shows an intense emission at 620 nm upon excitation at 360 nm, which suggests an efficient energy transfer from the Au site to Ru sites via extended pi-conjugation through the ethynyl units.     

基于暗通道先验和区间估计的视频去雾方法

为了提高雾天视频的可用性,提出了一种基于暗通道先验和区间估计的视频去雾方法。利用暗通道先验知识,采用区间估计的方式,运用图像融合的思想,通过背景图像求取大气光值和介质传输率,并应用于视频的所有帧以去除雾气。与几种典型的视频去雾方法相比,具有较快的运算速度,能有效地避免去雾视频中出现颜色跳变的问题。以暗通道先验理论为基础,采用区间估计的方式对大气光值和介质传输率进行估计,从而能有效地提高去雾视频的整体亮度、清晰度和对比度,同时获得较好的图像颜色。     

Ranging correlated motion (1.5 nm) of two coaxially arranged rotors mediated by helix inversion of a supramolecular transmitter

For a long-range transmission of motion between two movable parts apart from each other, transmitters that can precisely correlate these two motions should be properly incorporated into the system. However, such a motional relay is yet to be realized in artificial systems because of the lack of reliable methodologies for arranging a discrete number of motional parts. Herein, we report a correlated motion of two rotor molecules, which are coaxially arranged at a distance of 1.5 nm, through either Ag (+)- or Hg (2+)-assembled helical transmitters, leading to different frequencies of synchronized motion. A helix inversion in the transmitter was proven to strongly correlate the motions of both terminals. The X-ray analysis of the entity determined a quadruple-decker nonanuclear structure of the metal complex comprising two terminal rotor-like ligands closely attached to a central transmitter moiety. (1)H NMR analysis fully demonstrated the synchronized motion of the two rotors coaxially stacked and connected through the transmitter. Since the transmitter is composed of simple helical repeating units, the principle of helix inversion would be an efficient and widely applicable strategy for the long-range transmission of molecular motion.     

Development of a New Distyrylbenzene-Derivative Amyloid-β-aggregation and Fibril Formation Inhibitor

Several new amyloid-β (Aβ) aggregation inhibitors were synthesized according to our theory that a hydrophilic moiety could be attached to the Aβ-recognition unit for the purpose of preventing amyloid plaque formation. A distyrylbenzene-derivative, DSB(EEX)(3), which consider the Aβ recognition unit (DSB, 1,4-distyrylbenzene) and expected to bind to amyloid fibrils (β-sheet structure), was combined with the hydrophilic aggregation disrupting element (EEX) (E, Glu; X, 2-(2-(2-aminoethoxy)ethoxy)acetic acid). This DSB(EEX)(3) compound, compared to several others synthesized similarly, was found to be the most active for reducing Aβ toxicity toward IMR-32 human neuroblastoma cells. Moreover, its inhibition of Aβ-aggregation or fibril formation was directly confirmed by transmission electron microscopy and atomic force microscopy. These results suggest that the Aβ aggregation inhibitor DSB(EEX)(3) disrupts clumps of Aβ protein and is a likely candidate for drug development to treat Alzheimer's disease.     

Development of calculation and analysis methods for the dynamic first hyperpolarizability based on the ab initio molecular orbital-quantum master equation method

We develop novel calculation and analysis methods for the dynamic first hyperpolarizabilities β [the second-order nonlinear optical (NLO) properties at the molecular level] in the second-harmonic generation based on the quantum master equation method combined with the ab initio molecular orbital (MO) configuration interaction method. As examples, we have evaluated off-resonant dynamic β values of donor (NH(2))- and/or acceptor (NO(2))-substituted benzenes using these methods, which are shown to reproduce those by the conventional summation-over-states method well. The spatial contributions of electrons to the dynamic β of these systems are also analyzed using the dynamic β density and its partition into the MO contributions. The present results demonstrate the advantage of these methods in unraveling the mechanism of dynamic NLO properties and in building the structure-dynamic NLO property relationships of real molecules.     

�й�ITERʵ�����ģ���Ű�ȫ��������

使用有限元分析方法,初步分析了中国ITER实验包层模块(CHHCSBTBM)在等离子体大破裂时的电磁安全特性。根据CHHCSBTBM设计结构建立了TBM及其子模块的电磁分析模型,模拟了等离子体大破裂情况下的电磁场边界条件,对CHHCSBTBM及其子模块进行了涡流、应力计算,得到了相应的感生涡流和应力分布。根据得到的应力分布,计算出在等离子体大破裂的不同时刻CHHCSBTBM及其子模块受到的电磁扭矩。用计算结果与材料的容许值相比较,确定了TBM设计的电磁安全性。     

ITER ƫ�������Ѷ�̽�����������ƽ�չ

基于中国ITER氦冷固态增殖剂试验包层(CHHCSBTBM)3×3模块化结构设计,借助一维中子输运计算程序ONEDANT和二维中子输运计算程序TWODANT,对ITER实验包层模块(TBM)设计的中子学问题进行计算。计算出产氚增殖比以及不同材料区的功率密度、中子通量分布和产氚增殖率,并对计算结果进行分析比较。