抗微囊藻毒素单链抗体基因的构建、表达及初步鉴定

利用RT-PCR方法从抗微囊藻毒素-LR(MC-LR)单克隆抗体的杂交瘤细胞中扩增出抗体的V_H和V_L基因,构建了抗MC-LR分子的单链抗体(scFv)基因。SDS-PAGE和Western blot分析结果显示,该单链抗体基因在大肠杆菌Origami 2中特异性表达出分子量约为30kD的融合蛋白。通过Ni-NTA金属亲和层析法对可溶性表达产物进行纯化,获得的目的蛋白浓度为0.115mg/mL。ELISA反应结果表明该单链抗体能与MC-LR特异性结合。此研究为制备多价高亲和力抗MC-LR抗体奠定了基础。     

Synthesis of an extremely stable ceramic in the system Si/B/C/N using 1-(trichlorosilyl)-1-(dichloroboryl)ethane as a single-source precursor

 A new material discovered in the Si/B/C/N system was found to remain in the amorphous state up to a very high temperature of 2000°C. This material, with the composition Si₂B₂N₅C₄, is the only material in this system which does not undergo any microstructural changes until such high temperatures. Furthermore, the substance shows an extremely high resistance to oxidation up to 1500°C. The synthesis of amorphous Si₂B₂N₅C₄ was achieved by using the novel single-source precursor 1-(trichlorosilyl)-1-(dichloroboryl)ethane (TSDE), which can be synthesized in high yields from inexpensive starting materials in a simple single pot reaction. Examination of the structural properties of the pyrolytic ceramic reveals a substructure consisting of tetrahedrally and trigonally-planar coordinated silicon and boron, respectively. Si-C- and B-C-bonds present in the molecular precursor could not be distinguished from Si-N- and B-N-bonds in the fully pyrolized ceramic. EDX and X-ray-diffraction showed the material to have a homogeneous elemental distribution, and no phase separation could be detected. Received: 15 August 1998 / Reviewed and accepted: 24 September 1998     

Influence of the processing conditions on charge transfer and transport properties in poly(2-methoxy-5-(2′-ethylhexyloxy)1-4-phenylenevinylene):C60 composites for photovoltaics

Polymer-based photovoltaic devices have been elaborated by blending the conjugated polymer, poly(2-methoxy-5-(2′-ethylhexyloxy)1-4-phenylenevinylene) (MEH-PPV) with the buckminsterfullerene, C₆₀. The solvent used has a main influence on the optical and electrical properties of the photoactive layers. This could be attributed to different dispersion abilities of C₆₀ in the polymer layers shown by Atomic Force Microscopy and Scanning Electron Microscopy. Its effect on the transfer and transport properties has been studied. Thin film processing conditions have been modified by the preparation of blends of solutions of the polymer in Tetrahydrofuran and fullerene in Ortho-dichlorobenzene. The resulting spin casted layers show improved morphologies implying better dispersion of the fullerenes and increased short circuit currents. A decrease in the fullerene critical concentration to form percolation paths has been demonstrated. The improvement of the photovoltaic properties of the MEH-PPV/C₆₀ composites has been attributed to the nanosized fullerene domains formed upon phase separation. We used optical spectroscopy to study the charge transfer efficiency and electrical measurements to investigate charge transport properties in MEH-PPV:C₆₀.