石油卟啉的合成进展

综述了近年来石油卟啉的合成方法,重点是带五元环的卟啉DPEP的合成进展。讨论了各种方法的优缺点。

合成生物技术生产甾体激素中间体的研究展望

甾体类药物是销售额仅次于抗生素的世界第二大类药物,不同的甾体药物分子结构均由甾体激素中间体衍生而来。甾体激素中间体的传统生产方法包括植物提取皂素法和化学全合成法,其对环境有害,反应产物结构不唯一且成本较高,不利于工业化生产。目前主要的生产工艺是利用微生物对特殊原料进行转化的半合成法,但会遇到微生物酶转化率低、发酵周期长等问题。合成生物学的出现为构建利用糖为唯一碳源生产甾体激素中间体的人工细胞提供了理论上的可行性和可靠的技术支持。重点综述了合成生物技术在甾体激素中间体生产中的应用,以有利于工业发酵的酿酒酵母、分枝杆菌等为底盘细胞,通过引入外源合成功能模块,实现胆甾醇、雄烯二酮等甾体激素中间体的生物合成,并对合成生物技术在医药生产方式转变中的应用进行了展望,以期推动甾体类药物生物制造技术的进步。

Information Fusion Methods in Computer Pan-vision System

Aiming at concrete tasks of information fusion in computer pan vision (CPV) system, information fusion methods are studied thoroughly. Some research progresses are presented. Recognizing of vision testing object is realized by fusing vision information and non vision auxiliary information, which contain recognition of material defects, intelligent robot’s autonomous recognition for parts and computer to defect image understanding and recognition automatically.

Synthesis and characterization of polyfunctional aziridine/polyester microcapsules by multiple emulsion-solvent evaporation method

Polyfunctional aziridine/polyester microcapsules as control-release waterborne cross-linker were synthesized by multiple emulsion-solvent evaporation method. The results show that,a lower surface free energy with shell polyester is more favourable for the formation of microcapsules. Full encapsulating microcapsules are synthesized with the polyester with a surface free energy of 34.5 mJ/m2. Shell-to-core feeding mass ratio has a significant influence on the morphology and core content of the resulting microcapsules. Well defined spherical microcapsules with uniform shell thickness and core content at around 22% are produced at a shell-to-core mass ratio of 1:1. When 2.5% of colloid stabilizer is used,hollow spherical microcapsules are obtained. A high solvent evaporation rate results in wrinkling and porosity of the microcapsules,and an evaporation rate equivalent to solvent elimination in about 2 h provides a uniform rate of surface hardening. The characterization of the microcapsules by SEM and FTIR demonstrates that polyfunctional aziridine is encapsulated at the centre of the microcapsule. The microcapsules synthesized can be broken at a high shear rate.

C–H bond activation in the total syntheses of natural products

The transition metal-mediated C–H bond activation has emerged as a powerful and ideal method for the total syntheses of natural products and pharmaceuticals, and has had a significant impact on synthetic planning and strategy in complex natural products.In this review, we describe selected recent examples of the transition metal-mediated C–H bond activation strategies for the rapid syntheses of natural products.

Total synthesis of dansyl and biotin functionalized ganglioside GM3 by chemoenzymatic method

Ganglioside GM3, as well as other gangliosides, offers a variety of modifications in its sialic acid and ceramide moieties GM3 exhibits various types of important biological activities, due to the inability to effectively observe the trafficking of ganglioside GM3, developing sensitive research tools for specific monitoring of GM3 expression and activity is thus desirable. The total synthesis of a dansyl and biotin bifunctionalized fluorescent ganglioside GM3 were reported in this article. From lactose after 13 reaction steps, the compound of 2′ -biotinoylaminoethyl-6-N-dansylamido-6-deoxy-β-D-galatopyranosyl-(1→4)-β-D-glucopy-ranoside was obtained in total yield of 16.2%. Sialylation of dansyl and biotin functionalized lactose by enzymatic method gave dansyl and biotin labeled ganglioside GM3. The fluorescent property of this compound was also investigated.

Preserving privacy information flow security in composite service evolution

After a composite service is deployed, user privacy requirements and trust levels of component services are subject to variation. When the changes occur, it is critical to preserve privacy information flow security. We propose an approach to preserve privacy information flow security in composite service evolution. First, a privacy data item dependency analysis method based on a Petri net model is presented. Then the set of privacy data items collected by each component service is derived through a privacy data item dependency graph, and the security scope of each component service is calculated. Finally, the evolution operations that preserve privacy information flow security are defined. By applying these evolution operations, the re-verification process is avoided and the evolution efficiency is improved. To illustrate the effectiveness of our approach, a case study is presented. The experimental results indicate that our approach has high evolution efficiency and can greatly reduce the cost of evolution compared with re-verifying the entire composite service.