螺恶嗪化合物在有机溶液中的酸致变色研究

合成了四种螺恶嗪光致变色化合物,并对它们在有机溶剂中所表现的酸致变色现象进行了研究。发现它们与盐酸在室温下形成的复合物(SP.HCl),随溶液极性的增加,其吸光强度增大,吸收光谱发生蓝移。     

Starch-binding domains in the post-genome era

Starch belongs to the most abundant biopolymers on Earth. As a source of energy, starch is degraded by a large number of various amylolytic enzymes. However, only about 10% of them are capable of binding and degrading raw starch. These enzymes usually possess a distinct sequence-structural module, the so-called starchbinding domain (SBD). In general, all carbohydrate-binding modules (CBMs) have been classified into the CBM families. In this sequence-based classification the individual types of SBDs have been placed into seven CBM families: CBM20, CBM21, CBM25, CBM26, CBM34, CBM41 and CBM45. The family CBM20, known also as a classical C-terminal SBD of microbial amylases, is the most thoroughly studied. The three-dimensional structures have already been determined by X-ray crystallography or nuclear magnetic resonance for SBDs from five CBM families (20, 25, 26, 34 and 41), and the structure of the CBM21 has been modelled. Despite differences among the amino acid sequences, the fold of a distorted β-barrel seems to be conserved together with a similar way of substrate binding (mainly stacking interactions between aromatic residues and glucose rings). SBDs have recently been discovered in many non-amylolytic proteins. These may, for example, have regulatory functions in starch metabolism in plants or glycogen metabolism in mammals. SBDs have also found practical uses. Received 25 May 2006; received after revision 26 June 2006; accepted 3 August 2006     

高职院校"软件蓝领"人才培养的探索与实践

结合教学实践,介绍了高职高专院校如何以管理信息系统课程的实践性教学为切入点培养"软件蓝领"人才的实践。     

分子筛负载HPA/TiO2催化剂的性能

报道了分子筛负载杂多酸和二氧化钛催化剂MS／HPA／TiO2的制备及其对品红溶液降解的效果，系统研究了催化品红溶液降解的优化条件。实验表明，MS／HPA／TiO2具有良好的催化活性且容易回收。当MS：HPA：TiO2=1：10：1，品红的浓度为0．005％（10mL），催化剂的用量为10mg，反应时间为10min，品红的降解率达到96．87％。     

Autophagy and other vacuolar protein degradation mechanisms

Autophagic degradation of cytoplasm (including protein, RNA etc.) is a non-selective bulk process, as indicated by ultrastructural evidence and by the similarity in autophagic sequestration rates of various cytosolic enzymes with different half-lives. The initial autophagic sequestration step, performed by a poorly-characterized organelle called a phagophore, is subject tofeedback inhibition by purines and amino acids, the effect of the latter being potentiated by insulin and antagonized by glucagon. Epinephrine and other adrenergic agonists inhibit autophagic sequestration through a prazosin-sensitive ₁-adrenergic mechanism. The sequestration is also inhibited by cAMP and by protein phosphorylation as indicated by the effects of cyclic nucleotide analogues, phosphodiesterase inhibitors and okadaic acid.Asparagine specifically inhibits autophagic-lysosomal fusion without having any significant effects on autophagic sequestration, on intralysosomal degradation or on the endocytic pathway. Autophaged material that accumulates in prelysosomal vacuoles in the presence of asparagine is accessible to endocytosed enzymes, revealing the existence of an amphifunctional organelle, the amphisome. Evidence from several cell types suggests that endocytosis may be coupled to autophagy to a variable extent, and that the amphisome may play a central role as a collecting station for material destined for lysosomal degradation.Protein degradation can also take place in a salvage compartment closely associated with the endoplasmic reticulum (ER). In this compartment unassembled protein chains are degraded by uncharacterized proteinases, while resident proteins roturn to the ER and assembled secretory and membrane proteins proceed through the Golgi apparatus. In thetrans-Golgi network some proteins are proteolytically processed by Ca²⁺-dependent proteinases; furthermore, this compartment sorts proteins to lysosomes, various membrane domains, endosomes or secretory vesicles/granules. Processing of both endogenous and exogenous proteins can occurr in endosomes, which may play a particularly important role in antigen processing and presentation. Proteins in endosomes or secretory compartments can either be exocytosed, or channeled to lysosomes for degradation. The switch mechanisms which decide between these options are subject to bioregulation by external agents (hormones and growth factors), and may play an important role in the control of protein uptake and secretion.     

电化学降解含酚焦化废水的研究

选用Ti／Ir2O3／RuO2为阳极，C-PTFE气体扩散电极为阴极降解模拟含酚焦化废水。利用正交实验，求出最佳操作条件。考察了苯酚浓度、电流密度、电解质浓度、pH值等因素对苯酚去除效率的影响。对电化学降解苯酚进行动力学分析，蛄果证明了其反应为一级动力学反应。     

有毒生物难降解有机污染物的研究进展

对有毒生物难降解有机污染物（Persistent Toxic Substances,简称PTS）的特性、分布、迁移及来源进行了介绍,综述了目前对PTS的分析和控制处理方法,对光催化高级氧化技术处理PTS进行了阐述.     

醋酸对玻璃负载TiO2膜光催化的影响

以钛酸丁酯、乙醇、硝酸为原料,采用溶胶-凝胶法制备玻璃负载型TiO2膜,用醋酸浸渍对其进行表面修饰以增加其光催化活性,用直接耐晒蓝染料模拟废水中难降解的有机污染物.研究结果表明,醋酸浸渍可以增加坡璃负载型TiO2膜光催化活性,当采用0 25mol/L醋酸浸渍玻璃负载型TiO2膜1h,TiO2膜120min内降解率由13 8%提高到42%.     

H2O2氧化降解壳聚糖的动力学

为制备分子量分布较窄的可溶性低分子量壳聚糖，研究了简单均相体系下双氧水降解壳聚糖的过程与机理，考察了温度、双氧水浓度和时间对降解反应的影响，实验结果显示均相条件下壳聚糖的氧化降解符合无规降解动力学规律．同一降解体系中，同一反应时刻下，水解产物的分子量的倒数与反应温度成正比．     

TiO2薄膜光催化降解二氯乙酸和三氯乙酸水溶液

用常压化学气相沉积法镀TiO2薄膜,以紫外灯为光源,对二氯乙酸和三氯乙酸溶液进行光催化降解,并证实了此过程符合一级反应动力学方程。结果表明:卤代度以及不同的半导体化合物底物均对二氯乙酸和三氯乙酸溶液的降解有影响,卤代度低的二氯乙酸比卤代度高的三氯乙酸降解效果要好;同样条件下半导体的带隙能越低,降解效果越好。