一种新型非晶态分子材料的非线性光学折射率和吸收特性

用单光束扫描法测量了在532nm处一种新型非晶态分子材料5,5′Bis(dimesitylboryl)2,2′bithiophene的非线性折射率和吸收系数样品非线性透射特性的分析表明,在靠近线性吸收区的532nm处有饱和吸收存在由三能级饱和模型和Zscan法确定了饱和强度、非线性折射率的实部和虚部研究结果表明:这种新型非晶态分子材料具有非常好的光子学应用前景.     

VX680 binding in Aurora A: π-π interactions involving the conserved aromatic amino acid of the flexible glycine-rich loop

The regulation of protein kinases requires flexibility, especially near the ATP binding site. The cancer drug target Aurora A is inhibited by the ATP site inhibitor VX680, and published crystal structures show two distinct conformations. In one, a refolded glycine-rich loop creates a stacked π-π interaction between the conserved aromatic residue of the glycine-rich loop hairpin turn (F144) and the inhibitor. This refolding, associated with binding to a peptide derived from the cofactor TPX2, is absent in the other structure. We use surface plasmon resonance to measure VX680 binding to native and mutant F144A Aurora A kinase domains, with and without the TPX2 peptide. Results show that the F144 aromatic side chain contributes 2 kcal/mol to the VX680 binding energy, independent of the TPX2 peptide. This indicates that distinct VX680 bound conformations of Aurora A cannot be simply correlated with TPX2 binding and that Aurora A retains flexibility when inhibitor-bound. Molecular dynamics simulations show that alternate geometries for the π-π interactions are feasible in the absence of the rigidifying packing interactions seen in the crystal lattice.     

固定平滑参数的Pickands估计量的大分位数之估计

{X_i}_(i=1)~∞是具有公共分布函数F(x)的i.i.d序列,F(x)属于吸引场D(G_γ)(γ∈R)之一.在一定条件下,给出了固定平滑参数的F(x)的大分位数估计量的渐进分布,进而可得其渐进置信区间.     

Correlation between Enterococcus faecalis biofilms development stage and quantitative surface roughness using atomic force microscopy.

Biofilms are assemblages of microorganisms and their associated extracellular products at an interface and typically with an abiotic or biotic surface. The study of the morphology of biofilms is important because they are associated with processes of biofouling, corrosion, catalysis, pollutant transformation, dental caries, drug resistance, and so forth. In the literature, biofilms have been examined by atomic force microscopy (AFM), which has proven to be a potent tool to study different aspects of the biofilm development on solid surfaces. In this work, we used AFM to investigate topographical changes during the development process of Enterococcus faecalis biofilms, which were generated on sterile cellulose nitrate membrane (CNM) filters in brain heart infusion (BHI) broth agar blood plates after 24, 36, 72, 192, and 360 h. AFM height images showed topographical changes due to biofilm development, which were used to characterize several aspects of the bacterial surface, such as the presence of extracellular polymeric substance, and the biofilm development stage. Changes in the development stage of the biofilm were shown to correlate with changes in the surface roughness as quantified through the mean roughness.     

铽—镧—磺基水杨酸共发荧光体系的研究和应用

研究发现,稀土离子Ｌａ＾３＋的存在可使二元配合物Ｔｂ＾２＋－磺基水杨酸体系的荧光强度增强５７倍,通过试验确定了Ｔｂ＾３＋－Ｌａ＾３＋磺基水杨酸共发荧光体系的形成条件与影响因素,并研究了该体系的荧光特性。在最佳条件下,Ｔｂ＾３＋浓度在４．８×１０＾－１０－８．０×１０＾－７ｍｇ·Ｌ＾－１范围内与荧光强度成正相关关系,检出限为１．１×１０＾－１０ｍｇ·Ｌ＾－１。利用该体系完成了合成样品与 标准稀土氧化     

Characteristics of equilibrium and kinetic for U(VI) adsorption using novel diamine-functionalized hollow silica microspheres

Journal of Radioanalytical and Nuclear Chemistry - The diamine-functionalized hollow silica microspheres (DA-HSM) were successfully synthesized for highly efficient sorption of U(VI). The sorption...