Preparation of <Superscript>131</Superscript>I–betulinic acid and its biodistribution in murine model of hepatocellular tumor

The aim of this study was to examine the radioiodinating condition of betulinic acid and understand the possibility of ¹³¹I–betulinic acid (¹³¹I–BA) as a potential tumor radiotherapy agent through in vitro uptake and in vivo biodistribution studies ¹³¹I–BA was prepared by the reaction of betulinic acid with Na¹³¹I in the presence of hydrogen peroxide, and then purified by HPLC. The labeling yield was about 80%, and the radiochemical purity was greater than 95%. ¹³¹I–BA was found to be stable at 4 °C in saline containing 1% ethanol. In vitro studies showed that ¹³¹I–betulinic acid accumulated in the cancer cell lines (BEL-7402 and NCI-H446) in comparison with free ¹³¹I⁻. In vivo biodistribution study in KM mice bearing HepA tumor showed that ¹³¹I–BA stayed longer time in tumors than free ¹³¹I⁻. A significant differences were seen in tumor/muscle ratio at 4 h postinjection between ¹³¹I–BA and free ¹³¹I⁻. In vivo and in vitro studies showed the higher fraction of ¹³¹I–BA can be utilized for therapy and a higher dose will be delivered per targeting event. ¹³¹I–BA is a promising radiopharmaceutical in nuclear medicine, especially for hepatocellular tumor targeted radionuclide brachytherapy.     

Topological Aspects of Superconductors at Dual Point

We study the properties of the Ginzburg-Landau model at the dual point for the superconductors. By making use of the U（1） gauge potential decomposition and the φ-mapping theory, we investigate the topological inner structure of the Bogomol＇nyi equations and deduce a modified decoupled Bogomol＇nyi equation with a nontrivial topological term, which is ignored in conventional model. We find that the nontrivial topological term is closely related to the N-vortex, which arises from the zero points of the complex scalar field, Furthermore, we establish a relationship between Ginzburg Landau free energy and the winding number.     

Topological Vortices in a Spin-Triplet Superconductor

Based on the complex three-component order parameter model of a spin-triplet superconductor, by using the C-mapping theory, we derive a new equation describing the distribution of the magnetic field for vortices, which can be reduced to the modified London equation in the case of ｜ψ^2｜^2 ~- ｜ψ^3｜^2 = 0 and Wl^1= 1. A magnetic flux quantization condition for vortices in a spin-triplet superconductor is also derived, which is topological-invariant. Fhrthermore, the branch processes during the evolution of the vortices in a spin-triplet superconductor are discussed. We also point out that the sum of the magnetic flux quantization that those vortices carried is 2nФo （Фo is the unit magnetic flux）, that is to say, the sum of winding number is even, which needs to be proved by experiment.     

Topological Aspects of Solitons in Ferromagnets

Two kinds of topological soliton （skyrmion and magnetic vortex ring） in ferromagnets are studied. They have the common topological origin, a tensor Hαβ = n→·（δαn→×βδn→）, which describes the non-trivial distribution of local orientation of magnetization n→ at large distances in space. The topological stability of skyrmion is protected by the winding number. Knot-like topological defect as magnetic vortex rings is also studied. On the assumption that magnetic vortex rings are geometric lines, we present their δ-function distribution in ferromagnetic materials. Furthermore, it is briefly shown that Hopf invariant is a proper topological invariant to describe the topology of magnetic vortex rings.     

One-pot synthesis of Ag-Fe3O4 nanocomposite: a magnetically recyclable and efficient catalyst for epoxidation of styrene

With the assistance of PVP, a novel magnetically recyclable Ag-based catalyst has been synthesized in one pot, and it is found that this catalyst is highly efficient in selectively catalyzing styrene conversion to styrene oxide.     

Determination of Micro Amounts of Proteins by Their Quenching Effect on the Rayleigh Light Scattering of Colloidal Silver Chloride

It is of great importance to determine proteins in analytical biochemistry, clinical chemistry and foods assay.     

合成的近红外花菁染料测定痕量血清蛋白质

染料结合法测定蛋白质在生化及临床分析中已有广泛应用,常用的染料有溴甲酚绿、溴酚蓝、考马斯亮蓝及铬天青S等,这些染料的最大吸收波长均处于可见光区.近年来,近红外染料越来越引起人们的注意.     

荧光各向异性法研究酸度对四磺基铝酞菁与牛血清白蛋白相互作用的影响

对酞菁类化合物与白蛋白相互作用的研究有助于了解其在血液中的存在形式,从而探索其光敏作用机制[1].荧光各向异性法是研究小分子与蛋白质相互作用的有力工具[2].本文将荧光各向异性的原理和方法应用于由光敏剂四磺基铝酞菁(AlS4Pc)与牛血清白蛋白(BSA)组成的体系,考察了AlS4Pc的荧光各向异性随酸度变化的规律.结果表明,BSA对AlS4Pc有较强的结合能力,提示血清白蛋白对酞菁类光敏剂可起到储存和转运的作用.1　实验部分1.1　试剂及仪器　四磺基铝酞菁的合成与纯化参照文献[3]方法进行.产物经聚酰胺层析、紫外可见吸收光谱、荧光光谱、红…     

Dnd点群的几点释疑

Point group in crystallography is one of the important subjects in structural chemistry.Some topics are very difficult to understand.To name a few, why does point group of D_2d belong to tetragonal? Why are D_4d and D_6d not included in 32 kinds of crystallographic point groups? The two questions are easy to answer if we understand the following topic:for the D_nd point group, when n is odd, it contains an I_n symmetry axis; when n is even, it contains an I_2n symmetry axis.In this work, graphic method and matrix method are adopted to clarify why the D_nd point group includes an S_2n axis, and thus give explanations that D_2d belongs to tetragonal as well as D_4d and D_6d are not included in 32 kinds of crystallographic point groups.