Study of urinary nucleosides as biological marker in cancer patients analyzed by micellar electrokinetic capillary chromatography

Thirteen normal and modified nucleosides, primarily degradation products of transfer ribonucleic acid (tRNA), were evaluated as potential tumor markers for cancer patients. Their urinary concentrations were determined by means of micellar electrokinetic capillary chromatography (MEKC) in the urine from 54 healthy adults and 70 cancer patients, then quantitatively expressed as a function of creatinine excretion. It was found that urinary nucleosides for cancer patients were on the average significantly higher than those for healthy controls, however, no significant differences were found between male and female or between different ages. Based on 13 urinary nucleoside concentrations, principal component analysis (PCA) could be used to classify 72% of cancer patients from the healthy controls. The present study shows that the precise measurement of urinary nucleosides by MEKC in combining with PCA technique may provide a clinically useful approach for diagnosis of cancer.     

环境和生物样品中铂族金属的分析研究进展

评述了近年来环境和生物样品中痕量铂族金属的分析研究进展，重点介绍了样品的预处理和分离富集技术以及检测手段等。     

Study of the interaction of Zn^2＋ with Aβ（10-21） by fluorescamine assay

Zinc may play a role as a co-factor in the pathogenesis of Alzheimer's disease(AD)through influencing the conformation and neurotoxicity of amyloidβ-protein(Aβ).Using the fluorescamine assay,we show for the first time that Zn~(2 )induced Aβ(10-21) aggregate in a concentration-dependent manner.These results indicate that Aβ(10-21)can be used as an in vitro model in Zn~(2 )- induced Aβaggregation and that the region 10-21 to be the minimal fragment of zinc-binding domain of full length Aβ(1-42).     

互通多孔碳/二氧化锰纳米复合材料的原位水热合成及电化学性能

以互通多孔碳（IPC）为载体，水热条件下在碳表面原位反应生成纳米结构的二氧化锰（MnO₂），制备互通多孔碳/二氧化锰纳米（IPC/MnO₂）复合电极材料. 采用扫描电镜（SEM），透射电镜（TEM），X射线衍射（XRD），热重分析（TGA）对其结构进行表征；采用循环伏安法、恒流充放电和交流阻抗对其电化学性能进行研究. 结果表明：生成的MnO₂均匀地负载在碳的表面，形成多层次结构，并且随着温度的升高IPC表面负载的MnO₂由纳米颗粒变为纳米片状结构；MnO₂纳米片具有典型的K-Birnessite 型晶体结构；复合物中MnO₂的含量约为34%（w）. 在100 ℃制备的IPC/MnO₂复合材料在三电极系统中最高比电容达到了411 F·g^-1；随着反应温度的升高,比容量先增长后基本保持不变. 以IPC/MnO₂为正极，活性炭（AC）为负极，1 mol·L^-1 Na₂SO₄溶液为电解液组装成IPC/MnO₂//AC 混合超级电容器，发现IPC/MnO₂电极的电容器其电位窗口从1 V扩展到1.8 V，容量可达86F·g^-1，且表现出良好的电容特性和大电流放电性能.     

Sesquiterpene Lactone Glycosides from Carpesium macrocephalum

Two new sesquiterpene lactone glycosides were isolated from the seeds of Carpesium meacrocephalum. Their structures were elucidated as 2α-O-β-D-glucopyranosy-5α,11αH-eudesma-4(15)-en-12,8β-olide and 2α-O-β-D-glucopyranosy-5αH-eudesma-4(15),11(13)-dien-12,8β-olide by spectral methods (HRMS,1D and 2D NMR).     

Separation, identification, and interaction of heparin oligosaccharides with granulocyte-colony stimulating factor using capillary electrophoresis and mass spectrometry

A capillary electrophoresis (CE) method was developed for the separation of heparin oligosaccharides compatible to study the interactions between the oligosaccharides and granulocyte-colony stimulating factor (G-CSF). Unfractionated heparin was eliminitively degraded to heparin oligosaccharides by an endolytic heparinase. The degraded smaller oligosaccharides (M(r) < 1000) were baseline-separated by CE under a 50 mM phosphate buffer (pH 9.0) in 10 min. Standard heparin disaccharides and larger oligosaccharides (1000 < M(r) < 8000) were all separated under optimized separation conditions. Compared with standard heparin disaccharides, smaller oligosaccharides contained one nonsulfated, two monosulfated, and two disulfated disaccharides, but trisulfated disaccharides were not found. The smaller oligosaccharides were also identified and molecular mass was deduced by electrospray ionization-mass spectrometry (ESI-MS). Furthermore, interactions between G-CSF and the oligosaccharides were studied by using capillary zone electrophoresis (CZE) under the above separation conditions. It was found that larger oligosaccharides could interact with G-CSF while smaller oligosaccharides were not observed to bind to G-CSF under the experimental conditions. In conclusion, the purified heparinase could selectively degrade heparin into oligosaccharides and the interaction between G-CSF and heparin was correlated with the chain length of heparin.     

基于天然氨基酸的双环手性季铵盐相转移催化剂的合成及催化性能研究

以L－脯氨酸及L－羟基脯氨酸为原料合成了4个新型手性季铵盐磁相转移催化 剂，并用于催化不对称查耳酮环氧化反应，高产率得到相应环氧化合物，ee最高达 9％。     

土壤重金属生物有效性的评价方法

土壤重金属污染已成为人们广泛关注的全球性的环境问题之一。重金属生物有效性已成为污染生态学研究的前沿。对国内外土壤重金属生物有效性评价方法的研究进展作了简要综述，并对今后的研究作了展望。     

Coarse-grained rigid blob model for soft matter simulations

We have developed a coarse-grained multiscale molecular simulation method for soft matter systems that directly incorporates stereochemical information. We divide the material into disjoint groups of atoms or particles that move as separate rigid bodies; we call these groups "rigid blobs," hence the name coarse-grained rigid blob model. The method is enabled by the construction of transferable interblob potentials that approximate the net intermolecular interactions, as obtained from ab initio electronic structure calculations, other all-atom empirical potentials, experimental data, or any combination of the above. We utilize a multipolar expansion to obtain the interblob potential-energy functions. The series, which contains controllable approximations that allow us to estimate the errors, approaches the original intermolecular potential as the number of terms increases. Using a novel numerical algorithm, we can calculate the interblob potentials very efficiently in terms of a few interaction moment tensors. This reduces the labor well beyond what is required in standard molecular-dynamics calculations and allows large-scale simulations for temporal scales commensurate with characteristic times of nano- and mesoscale systems. A detailed derivation of the formulas is presented, followed by illustrative applications to several systems showing that the method can effectively capture realistic microscopic details and can easily extend to large-scale simulations.