Standardization of BSE rapid test performances and experiences gathered during the implementation of large-scale testing

The accumulation of pathological prion protein is used as a diagnostic marker for transmissible spongiform encephalopathies. According to European Union (EU) regulations cattle older than 30 months of age (Germany, France, Italy, and Spain by national law >24 months) and slaughtered for human consumption must be tested by using rapid tests for bovine spongiform encephalopathy (BSE). Likewise fallen stock and clinically affected animals must be tested. This article gives a short overview of the incidence of BSE in Europe. The diagnostic hierarchy, i.e., the officially approved methodology for the confirmation of suspect rapid test cases, and the organization of the numerous laboratories involved in this large-scale testing for BSE are described. Special emphasis is given to necessary quality control measures currently in place for BSE rapid testing laboratories and to measures intended to assure a consistent performance of the commercially available rapid test kits.Presented at BERM-9—Ninth International Symposium on Biological and Environmental Reference Materials, 15–19 June 2003, Berlin, Germany.     

Structural and electrical properties of crystalline (1−x)Ta2O5−xTiO2 thin films fabricated by metalorganic decomposition

Polycrystalline (1−x)Ta₂O₅−xTiO₂ thin films were formed on Si by metalorganic decomposition (MOD) and annealed at various temperatures. As-deposited films were in the amorphous state and were completely transformed to crystalline after annealing above 600 °C. During crystallization, a thin interfacial SiO₂ layer was formed at the (1−x)Ta₂O₅−xTiO₂/Si interface. Thin films with 0.92Ta₂O₅–0.08TiO₂ composition exhibited superior insulating properties. The measured dielectric constant and dissipation factor at 1 MHz were 9 and 0.015, respectively, for films annealed at 900 °C. The interface trap density was 2.5×10¹¹ cm⁻² eV⁻¹, and flatband voltage was −0.38 V. A charge storage density of 22.8 fC/μm² was obtained at an applied electric field of 3 MV/cm. The leakage current density was lower than 4×10⁻⁹ A/cm² up to an applied electric field of 6 MV/cm.     

TiZSM—48型分子筛的快速合成及性能

在Na_2O-1.6-C_6H_(14)N_2-SiO_2-TiO_2-H_2O体系中首次用快速动态法和静态法合成了TiZSM-48型分子筛,考察了两种合成方法的晶化动力学。利用XRD、IR、XPS、SEM、DRS、TG-DTA等测试手段对TiZSM-48型分子筛进行了表征,结果表明,Ti进入了分子筛骨架,动态法合成比静态法合成快得多,且样品的晶粒较小。热分析表明,两种方法合成的样品热稳定性均较好。     

Residual stress and deformation during rapid cooling process in an epoxy plate

Residual stress in the epoxy plate during a rapid cooling process was measured by the layer removal method and calculated by the linear thermoviscoelastic theory considering specific volume relaxation. The relaxations of the tensile modulus and specific volume were measured by an Instron thermomechanical analyzer. When the starting temperature of the cooling process was near the glass transition temperature of the cured epoxy, the residual stress in the epoxy plate was smaller than when the starting temperature was higher than the glass transition temperature. However, the transient stress in the cured epoxy plate was higher when the starting temperature was near the glass transition temperature than when the starting temperature was higher than the glass transition temperature. The quenched epoxy plate was compressed in the direction parallel to the surface and expanded in the thickness direction.     

熔体快速冷凝过程的微观结构演化

采用分子动力学模拟技术研究了金属间化合物AuCu3熔体的双体分布函数、键对、多面体、配位数等在快速凝固条件下随温度的变化情况，详细考察了AuCu3中微观组团随温度的演化特点.结果表明，AuCu3熔体降温至700 K时双体分布函数的第二峰已发生劈裂，液态金属中已经产生了非晶态；同时液体中的键对数及多面体数与温度的关系都表明，在上述向非晶转变的过程中，AuCu3熔体的确发生了微观结构组态的变化，其中以液体中的缺陷多面体随温度变化最为剧烈.     

High throughput screening of O-glycosylation conditions

We report a novel methodology for rapid and quantitative screening of O-glycosylation reactions of application to the analysis of parallel reaction systems. Our system exploits perdeuterated benzyl (Bn-d₇) ether, and stereoselectivity and yield are evaluated by ¹H NMR and MALDI-TOF MS, respectively. This paper summarizes over 240 screenings of 1 → 3 linkage formation between glucose residues targeting the α-isomer in high yield.     

用计算模拟方法研究Al_3P_4O_(16)~(3-)计量比的二维层状磷酸铝中的有机胺模板能力

将快速 Monte Carlo方法与分子动力学方法相结合 ,研究了不同种类有机分子在 Al3P4 O3- 1 6 计量比的二维层状磷酸铝形成中的模板能力 .依据主 -客体之间非键相互作用能 (包括范德华能、氢键能和库仑能 ) ,可合理地解释已知实验现象 ,并能有效地预测出适于形成某一特定无机层结构的有机胺模板剂 .通过选择理论预测的有机胺分子作为模板剂 ,成功地合成了二维层状磷酸铝化合物 Al3P4 O1 6 · 1 .5 H3NC6 H1 0 NH3.     

Photopolymers for Rapid Prototyping of Soluble Mold Materials and Molding of Cellular Biomaterials

Summary. To substitute cross-linked photopolymers in rapid prototyping of mold materials and therefore extend the range of materials which can be casted, organo-soluble photopolymers were developed. Branched bisalkylacrylamides were suitable as base component for such formulations, due to their high reactivity, good mechanical properties, and excellent solubility of the formed polymers. These molding materials were used to prepare cellular biocompatible materials which could be used as bone replacement materials. Biocompatible crosslinkers based on methacrylates from hydrolyzed gelatine or lactic acid ethyleneglycol blockcopolymers and commercially available reactive diluents are the base components of such a formulation. Biocompatibility was investigated by osteoblast-like cells. Cellular biocompatible parts were obtained by thermal polymerization in soluble mould materials prepared by 3D-photoshaping.     

Chromatographie par complexe de transfert de charge. Application à l'analyse d'hydroliquéfiats du charbon par HPLC

Résumé L'analyse de coupes lourdes (huile de distillation sous vide et huile issue du séparateur à chaud) provenant de l'hydroliquéfaction catalytique du charbon a été réalisée par mise en ouvre de différentes techniques chromatographiques. L'identification des principales structures résulte de l'application de la chromatographie par couplage de transfert de charge en mode HPLC et des spectroscopies UV et de masse.

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Donotor-acceptor complex chromatography —Application to analysis of coal liquefaction products by HPLC

Summary A Vacuum gas oil and the corresponding residue of a coal liquefaction product were investigated by means of HPLC and MS. Nearly a complete identification was performed by chromatographic, UV-spectroscopic methods and MS.