Construction of the glucose isomerase deficient strain ofStreptomyces M1033 by homologous recombination

After the establishment of the transformation conditions ofStreptomyces diastaticus No.7 Strain M1033, the integration plasmid pXW for homologous recombination, which contains a 600 bp fragment of incompleteGI (G138P. G247D) gene, has been constructed in order to realize the stable overexpression of theGI (G138P. G247D) which is valuable for large-scale industrial production. The Gigene’s disruption has been realized by pXW’s integration into M1033 chromosomes via homologous recombination andGI deficient strain ofStreptomyces M1033 has been obtained. The reliability of introduction of mutation has been proved by analysis of recombinant fragment and affirmance of existence of the mutation, as well as detection of the stability of the deficient strain.     

Mechanism for chronic pain generation

Neuropathic pain and the other abnormalities of sensation induced by axon injury or by peripheral nerve inflammation should result from functional compensations of the injured neurons during their regeneration. Ectopic distribution of proteins related to Na⁺, K⁺ and Ca²⁺ channels as well as of receptors on both membranes of injured axon and its cell body becomes a main pacemaker from which spontaneous ectopic afferent of primary sensatory neurons and crosstalk between neurons occur. Abnormal ectopic afferent activities lead to disorders of the sensation, such as hyperalgesia, allodynia, spontaneous pain and paraesthesia. Administration of some ion channel agents and/or α2-adrenergic blockers has shown efficiency in preventing neuropathic pain development and in relieving neuropathic pain.     

Analysis on the types of chemokines expressed by the murine thymic epithelial cell line MTEC1

Six kinds of chemokines including SDF-1α, IP-10, KC, RANTES, MCP-1 and Lymphotactin have been amplified using the primers designed by ourselves with RT-PCR from the total RNA of a medullary-type murine thymic epithelial cell line MTEC1 cells. The amplified cDNA fragments of the chemokines have been identified by nucleotide sequencing and Northern blot analysis. The results demonstrate that there are two different splicing forms of SDF-1 mRNA existing in MTEC1. The concentrated culture supernatant of MTEC1 shows an intermediate level of chemotaxis to CD4⁻CD8⁻ thymocytes, which conforms to the biological function of SDF-1.     

Studies on kinetics of reactions between phycobiliproteins and hydroxyl radicals by a pulse radiolytic technique

Scavenging of hydroxyl radical (· OH) by phycobiliproteins (C-phycocyanin, Allophycocyanin and R-phycoerythrin) was studied by competitive kinetics methods. Hydroxyl radicals were generated from pulse radiolysis of aqueous systems saturated with nitrous oxide (N₂O). The experimental results indicated that the three types of phycobiliproteins are all strong scavengers of · OH, the rate constants are around (2.8-5.6)×10⁹ L · mol^-1 · s^-1.     

The electron-beam (EB) irradiation and grafting of acrylic monomers onto EPDM copolymer

Radiation techniques (electron-beam, γ-ray, etc.) are usually used for improving the compatibility between polymer and ingredients in composite materials. Electron-beam pre-irradiation has been used for the first time to enhance the flame retardance of EVA copolymer. Efforts are being made to decline the flammability for EPDM copolymer by EB technique and remarkable reduction has been attained through a series of treatments: pre-irradiation, grafting and saponification.     

基于单片机的电力通信规约转换器的设计与应用

结合工程实例设计出一种基于单片机的电力系统通信规约转换器, 它能够实现主站、RTU以及IEDs设备之间不同通信规约的转换,其工程化应用可为中小型变电所综合自动化系统的改造减少一大笔资金投入.     

高浓度甲基橙低压湿式催化氧化及动力学研究

采用低压湿式催化氧化法（ＬＰＷＣＯ）处理高浓度模拟偶氮染料甲基橙溶液,考察了温度、Ｈ２Ｏ２浓度、Ｆｅ＾２＋浓度等因素对去除效果的影响,结果表明,ＬＰＷＣＯ法能有效云除废水颜色,同时用一级反应模型拟合了甲基橙溶液脱色的ＬＰＷＣＯ反应,由实验数据确定了反应速率方程。     

Bi(Ⅲ)──硫氰酸盐──罗丹明B──阿拉伯树胶体系光度法测铋的研究

研究在表面活性剂阿拉伯树胶存在时,铋（Ⅲ）－ＳＣＮ－一罗丹明Ｂ高灵敏显色体系．缔合物λmax=580nm,ε580=2. 84×105L·mol-1· cm-1.铋在0μg/25 mL～8μg/25mL范围内服从比耳定律．     

深穿透屏蔽计算的离散坐标法

建立了堆芯几何和孔道几何边界源相耦合的离散坐标法。并用于计算反应堆孔道的深穿透屏蔽问题;推导出可用于堆芯几何屏蔽计算的半对称求积基,以及用于孔道几何屏蔽计算的偏向求积基。     

两自由度塑性碰撞振动系统的周期运动与稳定性

用三维映射表示具有单侧刚性约束的两自由度振动系统在塑性碰撞时的动力学方程。借助理论分析与数值方法分析了系统周期ｎ－１振动的存在与稳定性,描述了系统周期ｎ－１振动的特点。