The chemistry of the azanonaborane cluster RNH2---B8H11NHR

The preparation and properties of the R¹R²NH---B₈H₁₁NHR cluster are described. The cluster is stable to aqueous solutions and can be made water-soluble by the introduction of a few hydrophilic groups. This makes the cluster a good candidate as the boron moiety in compounds for boron neutron capture therapy. The chemistry of the cluster preparation, the stability of the cluster, and conditions for reactions of the organic moieties are reviewed. Pyridine derivatives of the cluster show electronic interaction between the cluster and the pyridine.     

Derivatives of the closo-dodecaborate anion and their application in medicine

The paper presents a comparative analysis of the possibilities and characteristic features of the application of various polyhedral boron compounds, viz., the closo-decaborate anion [B₁₀H₁₀]^2–, the closo-dodecaborate anion [B₁₂H₁₂]^2–, the carba-closo-dodecaborate anion [CB₁₁H₁₂]^–, carboranes C₂B₁₀H₁₂, and the bis(dicarbollide) complexes [M(C₂B₉H₁₁)₂]^– (M = Fe, Co, or Ni), in boron neutron capture therapy (BNCT) for cancer. The requirements on compounds used in BNCT are formulated and the advantages of the application of the closo-dodecaborate anion are considered. The data on the synthesis of various derivatives of the closo-dodecaborate anion, which either already found use in BNCT or are most promising in this field, are summarized. The possibilities of the application of agents derived from the closo-dodecaborate anion in medical diagnostics are discussed.     

Liner as the Key of Injection Optimization in Pesticide Analysis

Regulations for pesticide residue analysis in food require very low detection limits; thus requiring maximum sensitivity in the gas chromatographic determination. This is accomplished by an overall method optimisation, which includes optimisation of injector parameters. Here we study the effect of the inlet liner design on the optimisation by comparing five liner designs in splitless and pulsed splitless injection modes, using a test mixture of fifteen pesticides analyzed by GC-ECD. Possible links between the injection parameters and liner types were evaluated, with the result that, accurate choice of inlet liner and injection parameters can reduce detection limits by up to 300%. Revised: 25 October 2005 and 9 January 2006     

Multidimensional separation of isomeric species of chlorinated hydrocarbons such as PCB,PCDD, and PCDF

A multidimensional GC-system containing two capillary columns of different polarities, operated within a double oven instrument, was used for the optimized separation of complex isomeric mixtures of various types of chlorinated aromatic compounds such as PCB, PCDD, or PCDF. Electron capture was applied parallel to flame ionization detection to obtain sensitive signals of the PCB or PCDD and the n-alkane standards required for identification by Kovats indices, respectively. Electron capture detection within a valvelessly operated MDGC system forced changes in the usual instrumental set-up, the live-switching coupling piece being located within the second oven of the double oven instrument. This oven is operated isothermally to ensure optimal and interference-free detection, for stable flow conditions within the coupling piece and for the determination of the isothermal retention indices (Kovats), which are much more suitable for identification by retention than the so-called “linear” indices.     

毛细管气相色谱法同时测定水产品中的多氯联苯和有机氯农药残留量

建立了毛细管气相色谱法同时测定水产品中多氯联苯和有机氯农药的方法，用高氯酸与冰乙酸的混合溶液消化样品，以石油醚提取，浓硫酸净化后，用毛细管气相色谱法测定，方法的回收法为88％－110％，相对标准偏差为8％－19％（n=6)，检出限为0．08－0．60ug/kg，方法简便，快速，结果准确。     

Application of recombinant phage display antibody system in study of Codakia orbicularis gill proteins

We used the recombinant phage display antibody system (RPAS) to obtain chimeric single-chain fragment variable (ScFv) antibodies to gill proteins of the white clam Codakia orbicularis (Linné, 1758). After three rounds of selection on immunotubes loaded with total gill protein extract, recombinant phages exhibiting antibodies to gill proteins were isolated and tested by enzyme-linked immunosorbent assay (ELISA). Clones exhibiting a high affinity for the mollusk proteins were selected for production of soluble ScFv antibodies, which were purified for subsequent analysis. ScFv antibodies exhibited a reaction specific for a protein whose molecular mass was about 15,000 Daltons and that was detected by the antigen capture technique followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting.     

Galactose-Grafted 2D Nanosheets from the Self-Assembly of Amphiphilic Janus Dendrimers for the Capture and Agglutination of Escherichia coli

High aspect ratio, sugar-decorated 2D nanosheets are ideal candidates for the capture and agglutination of bacteria. Herein, the design and synthesis of two carbohydrate-based Janus amphiphiles that spontaneously self-assemble into high aspect ratio 2D sheets are reported. The unique structural features of the sheets include the extremely high aspect ratio and dense display of galactose on the surface. These structural characteristics allow the sheet to act as a supramolecular 2D platform for the capture and agglutination of E. coli through specific multivalent noncovalent interactions, which significantly reduces the mobility of the bacteria and leads to the inhibition of their proliferation. Our results suggest that the design strategy demonstrated here can be applied as a general approach for the crafting of biomolecule-decorated 2D nanosheets, which can perform as 2D platforms for their interaction with specific targets.     

An Ultra-Microporous Metal–Organic Framework with Exceptional Xe Capacity

Molecular confinement plays a significant effect on trapped gas and solvent molecules. A fundamental understanding of gas adsorption within the porous confinement provides information necessary to design a material with improved selectivity. In this regard, metal–organic framework (MOF) adsorbents are ideal candidate materials to study confinement effects for weakly interacting gas molecules, such as noble gases. Among the noble gases, xenon (Xe) has practical applications in the medical, automotive and aerospace industries. In this Communication, we report an ultra-microporous nickel-isonicotinate MOF with exceptional Xe uptake and selectivity compared to all benchmark MOF and porous organic cage materials. The selectivity arises because of the near perfect fit of the atomic Xe inside the porous confinement. Notably, at low partial pressure, the Ni–MOF interacts very strongly with Xe compared to the closely related Krypton gas (Kr) and more polarizable CO₂. Further ¹²⁹Xe NMR suggests a broad isotropic chemical shift due to the reduced motion as a result of confinement.     

路由器端电子邮件拦截与放行设计与实现

针对实时电子邮件传输过程中安全性和可靠性的需求,提出一种在路由器端基于特征分析的拦截与放行方法。通过对电子邮件传输协议和内核机制的分析,以及对特征文件的解析,在内核态下采用多模式匹配方法对数据包进行识别及时的做出判断。实验结果表明,在满足可行性的前提下,对邮件实现安全性过滤,该方法具有很好的时效性。     

Synthesis and cytotoxicity of novel cholesterol–cobalt bis(dicarbollide) conjugates

The novel conjugates of cholesterol with cobalt – bis(dicarbollide) were synthesized by the ring-opening reactions of the cyclic oxonium derivatives of [3,3′-Co(C₂B₉H₁₁)₂]^– with the OH group of cholesterol 2-hydroxyethyl ether. The compounds obtained were tested for toxicity to glioblastoma U-87 MG cells and human embryo fibroblasts FECH-15 cells