IL-2基因的突变及其与肠毒素融合基因的克隆和表达

由金黄色葡萄球菌分泌到胞外的单亚基蛋白中有肠毒素A和B。近年来两种毒素在肿瘤治疗研究方面取得了很大进展。白介素-2作为靶向分子，在抗肿瘤的药物中很有应用前景。本文分别对肠毒素A、肠毒素B和白介素-2进行了克隆和表达，并将白介素-2（125Ala）分别与肠毒素A227AI。肠毒素B进行了融合表达。从筛选到的天然金黄色葡萄球菌STSw的基因组中，通过PCR方法扩增出seb基因，同时突变了该基因两端几个稀有密码子。并将其克隆到7ZTS载体上进行表达，表达量占细胞总蛋白的33.5％。以seam基因为模板，通过重叠PCR将其227位天冬氨酸突变为丙氨酸，以降低其毒性。该突变基因重组到7ZTS载体中，并在JM109（DE3）中表达，表达量占细胞总蛋白的51.5％。通过重叠PCR法，对人的IL-2基因进行定点突变。共突变60个碱基，涉及51个氨基酸，其中第125位的半肤氨酸被突变为丙氨酸。该基因在大肠杆菌中表达量占总蛋白的30％。分别对上述三个工程菌的表达条件进行了探索。先制备出融合基因，再对融合基因进行表达，得到两种融合蛋白。它们是以6个甘氨酸和1个苏氨酸为链，将IL一2（125Ala）与肠毒素A227（Ala）、B分别连接起来，即IL-2（125Ala）-SEA227（Ala）和IL-2（125Ala）-SEB二者在大肠杆菌中表达量分别占总蛋白的10％和12％。以上实验结果为将几种蛋白开发成抗肿瘤靶向药物奠定了坚实基础。

多分量对偶超导理论和口袋模型；Multi-component Dual Superconductor Theory and Bag Model

基于联络新参数化方案研究了多分量对偶超导模型。给出了多分量Ginzburg-Landau模型中的自对偶解,并研究了磁通量子数趋于无穷大时的墙涡旋解,以及与口袋模型之间的联系。

IL-2与金黄色葡萄球菌肠毒素A和B融合基因的克隆及表达

目的 :IL - 2与金黄色葡萄球菌肠毒素A和B融合基因的克隆及表达。方法 :分别在金黄色葡萄球菌肠毒素A2 2 7Ala、B基因的两端克隆上两个酶切位点HindⅢ ,KpnⅠ。将IL - 2基因突变 ,设计一段linker使之分别与SEA2 2 7Ala和SEB相连并克隆到PET表达载体中 ,在大肠杆菌DH5α(DE3) -Pass中表达。结果 :表达的蛋白占总蛋白 15 %。结论 :IL - 2与金黄色葡萄球菌肠毒素A和B融合蛋白能在大肠杆菌中有效表达

定点突变提高IL-4免疫毒素对淋巴瘤的选择性和杀伤活性

采用软件分析选择与IL-4分子结合与活性相关的重要位点13T,121R,通过定点突变得到IL-4突变基因cpIL4(13D121E),将其与绿脓杆菌外毒素突变基因PE38KDEL融合,成功地构建了编码免疫毒素cpIL4(13D121E)-PE38KDEL的融合基因.该基因在原核表达系统中得到了高效表达,表达量占细胞全蛋白的30%以上.表达产物经亲和色谱和阴离子交换色谱纯化后,进行细胞毒性实验,证明其对表达型IL-4受体的淋巴瘤细胞Daudi具有良好的细胞毒作用,活性是同类型IL-4免疫毒素的2倍,而对表达型IL-4受体的内皮细胞活性较低.

On Combining Morphological Component Analysis and Concentric Morphology Model for Mammographic Mass Detection

Mammographic mass detection is an important task for the early diagnosis of breast cancer. However, it is difficult to distinguish masses from normal regions because of their abundant morphological characteristics and ambiguous margins. To improve the mass detection performance, it is essential to effectively preprocess mammogram to preserve both the intensity distribution and morphological characteristics of regions. In this paper, morphological component analysis is first introduced to decompose a mammogram into a piecewise-smooth component and a texture component. The former is utilized in our detection scheme as it effectively suppresses both structural noises and effects of blood vessels. Then, we propose two novel concentric layer criteria to detect different types of suspicious regions in a mammogram. The combination is evaluated based on the Digital Database for Screening Mammography, where 100 malignant cases and 50 benign cases are utilized. The sensitivity of the proposed scheme is 99% in malignant, 88% in benign, and 95.3% in all types of cases. The results show that the proposed detection scheme achieves satisfactory detection performance and preferable compromises between sensitivity and false positive rates.

Synthesis and characterization of a novel two-component organogelator based on ion-bonded discotic complex

A novel ion-bonded discotic complex was prepared from 2,3,6,7,10,11-hexakis(N,N-dimethylaminopropylaminocarbonylmethoxy)triphenylene (HDTP) and 4'-dodecyloxybiphenyl-4-carboxylic acid (DBC) by ionic self-assembly (ISA) route and characterized by Fourier transform infrared (FTIR) spectrum. We found that the complex can self-assemble into stable gels in aromatic hydrocarbons. Nanofibers with diameters of 50-130 nm were observed in the gels by transmission electron micrograph (TEM).

Alternating copolymerization of carbon dioxide and propylene oxide by single-component cobalt salen complexes with various axial group

A series of single-component cobalt salen complexes, N,N'-bis(salicylidene)-1,2phenylenediamino cobaltIII X(X = Cl (1a), Br (1b), NO3 (1c), CF3COO (1d), BF4 (le), and N3 (If)) (SalphCoX), were prepared for alternating copolymerization of carbon dioxide and propylene oxide(PO) under mild condition. The axial anion X group of the SalenphCoX played important role in tailoring the catalytic activity, polymeric/cyclic carbonate selectivity, as well as stereochemistry of carbonate unit sequence in the polymer chain. SalenphCoX with an electron-withdrawing axial X group (complex 1c) was an ideal catalyst for the copolymerization of CO2 and PO to selectively produce polycarbonate with similar to 99% carbonate linkage and over 81% head-to-tail structure.

Solution-processible multi-component cyclometalated iridium phosphors for high-efficiency orange-emitting OLEDs and their potential use as white light sources

The synthesis and photophysical studies of several multifunctional phosphorescent iridium(III) cyclometalated complexes consisting of the hole-transporting carbazole and fluorene-based 2-phenylpyridine moieties are reported. All of them are isolated as thermally and morphological stable amorphous solids. Extension of the pi-conjugation through incorporation of electron- pushing carbazole units to the fluorene fragment leads to bathochromic shifts in the emission profile, increases the highest oc- cupied molecular orbital levels and improves the charge balance in the resulting complexes because of the propensity of the carbazole unit to facilitate hole transport. These iridium-based triplet emitters give a strong orange phosphorescence light at room temperature with relatively short lifetimes in the solution phase. The photo- and electroluminescence properties of these phosphorescent carbazolylfluorene-functionalized metalated complexes have been studied in terms of the coordinating position of carbazole to the fluorene unit. Organic light-emitting diodes (OLEDs) using these complexes as the solution-processed emissive layers have been fabricated which show very high efficiencies even without the need for the typical hole-transporting layer.I These orange-emitting devices can produce a maximum current efficiency of similar to 30 cd A(-1) corresponding to an external quantum efficiency of similar to 10 % ph/el (photons per electron) and a power efficiency of similar to 14 Im W-1.

Self-immobilized catalysts for ethylene polymerization: neutral, single-component salicylaldiminato phenyl nickel(II) complexes bearing allyl substituents

A new family of self-immobilized ethylene polymerization catalysts, derived from neutral, single-component salicylaldiminato phenyl nickel complexes, is described.

Molecular component structures mediated formation of self-assemblies

Molecular recognition directed self-assemblies from complementary molecular components, melamine and barbituric acid derivatives were studied by means of NMR, fluorescence, and TEM. It was found that both the process of the self-assembly and the morphologies of the resulted self-assemblies could be mediated by modifying the structures of the molecular components used. The effect of the structures of the molecular components on the formation of the self-assemblies was discussed in terms of intermolecular interactions.

Polymerization of methyl methacrylate with organolanthanides as single-component catalysts

It was first found that Ind(2)Y(mu -Et)(2)AlEt2 and Ind(2)LnN(i-Pr)(2) (Ln = Y, Yb) exhibit extremely high catalytic activity in the polymerization of methyl methacrylate. The reactions can be carried out over a quite broad range of polymerization temperatures from -30 to 50 degreesC. PMMA with high molecular weight (7.8 x 10(-5)) and high isotacticity (94%) can be obtained by using Ind(2)Y(mu -Et)(2)AlEt2, and narrow molecular weight distribution (M-w/M-n < 1.5) can be obtained by using Ind(2)LnN(i-Pr)(2) (Ln = Y, Yb).

Polymerization of acrylonitrile with organolanthanides as single-component catalysts

Ind(2)Y(mu -Et)(2)AlEt2 and Ind(2)LnN(i-Pr)(2) (Ln = Y, Yb) were used as a single-component catalyst for the polymerization of acrylonitrile (AN) respectively. The regularity of polymerization of AN and stereoregularity of polyacrylonitrile (PAN) were also studied in both cases. Both catalysts can produce PAN with molecular weight from 10,000 to 30,000. In addition, the catalytic activity and molecular weights were increased by the addition of PhONa.

CURE AND IONIC-CONDUCTIVITY OF A 2-COMPONENT EPOXY NETWORK POLYMER ELECTROLYTE

In order to raise the room temperature ionic conductivity and improve the mechanical strength of a PEO-based polymer electrolyte, a non-crystalline two-component epoxy network was synthesized by curing diglycidyl ether of polyethylene glycol (DGEPEG) with triglycidyl ether of glycerol (TGEG) in the presence of LiClO4 salt, which acts in this system as both a ring opening catalyst and a source of ionic carrier. The structure of the precursors, the curing process and the cured films have been characterized by C-13 NMR, IR, DSC and ionic conductivity measurement techniques. The electrolyte system exhibits an ionic conductivity as high as similar to 10(-5) S/cm at 25 degrees C and is mechanically self-supportable. The dependence of ionic conductivity was investigated as a function of temperature, salt content, MW of PEG segment in DGEPEG and the proportion of DGEPEG in DGEPEG/TGEG ratio.