Nanostructured Pd-based electrocatalysts have a large impact on cost, performance, and durability in the development of fuel cells. This review article provides an overview of recent advances in Pd-based electrocatalysts with a well-defined structure that can be applied for alcohol oxidation and oxygen reduction in an alkaline medium in direct alcohol fuel cells. These Pd-based catalytic materials include Pd electrocatalysts with different morphologies, monodisperse bimetallic Pd-based nanoparticles with different compositions and Pd-based nanoparticles with a well-controlled shape. Emphasis is placed on the atomic-level design of the nanoparticles' structure, and the origin of their electrochemical activity. The ways to enhance the electrocatalytic performance and design principles for Pd-based catalysts are discussed. This will help to shed light on the future development of non-Pt catalysts for fuel cells and accelerate the commercialization of fuel cell technology.

Recombinant monogene and double gene expression vectors pIG-neo, pIN-neo, pVG, pVN, pIGN and pVGN were constructed by inserting the G and N gene into pIRES1neo and pVAX1, respectively. Span-glycerol was chosen as adjuvant and mixed with the plasmids to form DNA vaccine. Nine groups of mice were immunized with a dosage of 100 #mu#L(0.5g/L) of plasmids pIRES1neo, pIG-neo, pIN-neo, pIGN, pIG+pIN, pVAX1, pVG, pVN and pVGN, respectively, for 3 times at 14 days intervals. Indirect ELISA and neutralization were employed to determine the immunological response. Results showed that: (1) After 3 times of immunization, seroconversion occurred in all groups excepting negative controls. (2)Antibody level went up swiftly 14 days after the third injection of DNA vaccine. (3)The immunological effect of DNA vaccines based on the pIRES1neo was overally better than those based on the pVAX1. Of all the vaccines, the double gene expression vector pIGN haboring both the glycoprotein and the nucleoprotein cDNAs was the best. The antibody level it stimulated was significantly higher than the others. (4)The protective rate against the challenge of 7.5 LD_(50) CVS was 89%. It indicated that it was worthy being assayed in dogs.

目的观察国际流行株HIV-1gag与IFNα-2b基因共表达颗粒化抗原疫苗与质粒DNA核酸疫苗免疫程序优化的效果.方法将质粒pJ38gag/IFNα-2b经脂质体介导转染RK细胞,并在痘苗病毒中共表达HIV-1gag与IFNα-2b基因,以间接免疫荧光与斑点酶联免疫法鉴定其表达产物.以表达产物与质粒DNA联合免疫小鼠实验,检测淋巴细胞转化率、细胞毒性T细胞杀伤活性、CD+4、CD+8细胞计数与体液免疫水平.结果 pJ38gag/IFNα-2b基因表达的颗粒化抗原疫苗具有良好的免疫原性,3vJ38gag/IFNα-2b+pJ38gag/IFNα-2b联合免疫效果优于vJ38gag/IFNα-2b单独免疫.结论 pJ38gag/IFNα-2b基因表达的颗粒化抗原疫苗能诱导机体产生细胞免疫与体液免疫.

目的:将艾滋病病毒核心蛋白(gag)与干扰素(IFNα-2b)融合基因表达的融合蛋白作为免疫原免疫小鼠,动态观察小鼠的体液免疫、细胞免疫与CTL应答.方法:将IFNα-2b基因片段插入到gag基因的nt531位点,经脂质体转染与血凝素阴性蚀斑筛选,挑出重组痘苗病毒.经SDS-PAGE和Western blot鉴定表达产物.以小鼠为实验对象,用重组痘苗病毒vJ38gag/IFNα-2b免疫小鼠,用ELISA方法检测血清IgG抗体含量.用流式细胞仪测定小鼠外周血CD+4、CD+8T淋巴细胞计数.3H-TdR掺入法检测细胞毒性T淋巴细胞杀伤活性.结果:血清IgG抗体含量逐渐增高,实验组与对照组比较差异有显著性意义(p＜0.05).CD+4、CD+8T淋巴细胞计数、CTL检测实验组与对照组比较差异均有显著性意义(p＜0.05).结论:重组痘苗病毒vJ38gag/IFNα-2b能增强小鼠的体液免疫、细胞免疫和CTL应答.IFNα-2b可以作为免疫佐剂增强机体的免疫状态.

目的:探讨猪瘟基因疫苗免疫小鼠后机体产生体液和细胞免疫发生规律,为猪瘟基因疫苗推广应用提供科学依据.方法:应用FACS、MTT法及间接ELISA试验对猪瘟基因疫苗免疫小鼠脾脏及外周血中CD+4和CD+8淋巴细胞数、淋巴细胞的转化功能及特异的抗猪瘟病毒血清IgG抗体水平等动态变化进行了观察.结果:猪瘟基因疫苗免疫小鼠后脾细胞及外周血淋巴细胞对ConA和LPS均有明显的反应性.CD+4和CD+8细胞数量在免疫后20天开始反应,32天达到高峰后开始下降.鼠血清特异性猪瘟病毒血清抗体IgG随免疫时间延长而增加.结论:猪瘟基因疫苗免疫动物可诱导机体体液及细胞免疫.

Musca domestica yolk protein (mdyp) genes encode the major nutritional polypeptides deposited in developing oocytes for subsequent utilization during embryogenesis. About a 4 0 kb genomic gene encoding Musca domestica yolk protein 1(mdyp1) was cloned by screening Musca domestica genomic library constructed in EMBL3 vector with a mdyp1 DNA fragment obtained by PCR as probe labeling with Digoxigen. Sequence analysis revealed that it contained about 1 6 kb 5′ upstream region and about1 0 kb 3′ downstream region. Encoding region was composed of a 61 bp intron, a 222 bp exon 1 and a 1028 bp exon 2. 5′ upstream region possesses typical CAAT/TATA boxes.

The canine adenovirus-2(CAV-2) is associated with upper respiratory infection and intestinal syndroms.Adenovirus fiber protein(Fip) plays a crucial role in infection by attaching the virus to a specific cell-surface receptor.I n order to further explain the mechanism of difference in cell tropism and virul ence at molecular level,we designed 2 pairs of primers according to the publishe d CAV-2 Fip gene to amplify the Fip genes with PCR method.The Fip genes of the CAV-2 virulent strain SY-V5,attenuated SY-V60,SY-CP5(derived from SY-V60 pa ssed in susceptible dogs for 5 passages) and USA vaccine strain(US-V20) had bee n sequenced and compared with one another and with that of the standard CAV-2 T oronto virulent strain.Complete Fip gene of all CAV-2 strains were 1 629 nt and 542 amino acids.The deduced amino acid sequences of the Fip of the CAV-2 s trains were compared one another and with that of Toronto strain.Comparing with SY-V5 and Toronto strains,there are point mutation(transversion) occurring in S Y-V60 and SY-CP5 which changes the potential site for asparagine-linked glyco sylation.

This paper presents A/E/C industry needs, emerging information technologies, and applications for knowledge capture, sharing, and re-use that can enable corporations to turn knowledge into working knowledge. Innovative multimedia and multimodal digital communication channels, visualization and navigation techniques of large repositories, and information retrieval algorithms can assist in building effective and efficient next generation digital knowledge management environments. This paper presents four scenarios and technologies that support knowledge capture, sharing and re-use and discuss them in the larger perspective of industry practice today and beyond.

从孵化36 h的蝇蛆中提取基因组DNA,用限制性内切酶BclⅠ随机酶切,回收10～23kb的酶切DNA片段,通过匹配粘性末端与磷酸化的EMBL3BamH Ⅰ酶切载体臂连接,在体外经包装系统包装成活的重组噬菌体,成功地构建了家蝇基因组文库.重组噬菌体转染KW251宿主菌,测定文库效价为5×104pfu/mL.

S10 gene sequences of 1 attenuated vaccine strain and 31 Chinese field isolates & 1 South Africa strain of BTV were determined. The results revealed that all 33 S10 gene segments have 822 nucleotides in length with two in-frame initiation codons (nucleotides 20 to 22 and 59 to 61) and a common termination codon (nucleotides 707 to 709), which encodes two proteins (NS3 and NS3A). Nucleotide difference in the sequence of all S10 gene were from zero to 107 bp (86.4% - 100% identity). NS3/NS3A protein showed a light difference from zero to 10 amino acid (95.6% - 100% identity). Phylogenetic analysis of the S10 gene of above strains sequenced and 9 other strains from GenBank, segregated the Chinese viruses into a monophyletic group distinct from US viruses; Nucleotide identity was 85% between China Group and US group. The various Chinese isolates segregated into two phyletic subgroups based on S10 gene sequences. The clustering of viruses was dependent of geographical origin, and independent of host species of isolation, serotype & year of isolation.

The present study examined if injection of DNA into the testis tabular could generate transgenic mice via transfecting spermatogonia. The 0.9 kb Bcl-2 cDNA was fused to the promoter region of mouse whey acid protein gene and the SV40 polyA. A 3.0 kb fragment of WAP-Bcl-2-SV40 was mixed with cationic liposome and one side tabular of 3 mice testis was injected with the fragment, the other side was ligatured. Two out of the 3 males were used to mate with the female 4 days later. Twenty pups were produced and 3 of which were proven to be gene integration positive by PCR detection. Two, 1 male and 1 female, were further confirmed to carry the transgene by Southern blot analysis. The male died by accident during its feeding. The female was demonstrated to express Bcl-2 protein in its mammary glands by Western blot assay. Seven out of 45 F1 mice were proven to be transgenic by PCR. It is concluded that transfecting spermatogonia in vivo can produce transgenic mice.

CRFK cell line cultures of CCV YS1 and CCV CI1 strains isolated from dogs in China were inoculated to dogs which CCV SN titers were lower than 1∶4 at the age of 2 months.Clinical symptoms,body temperature and pathogenic changes were observed.Results shows that the virulence of CCV YS1 strain is stronger than that of CCV CI1.S gene of 2 strains were amplified by RT-PCR,cloned into Sma I point of pUC19 or pGEM-T vector and sequenced with the method of the Sanger's.Amino acid sequences were deduced and compared with that of CCV,FIPV,TGEV.According to the results of the comparison,amino acid of antigenic sites were analyzed and suggested that the amino acid of Ac antigenic site in the S protein may play an important role on the virulence of CCV.

Tissue-type plasminogen activator cDNA was cloned on downstream of the bovine beta-lactoglobulin promoter to form a expression vector pBTA. A 5.45kb fragment containing the tPA expression cassette was recovered and purified for microinjection. The microinjected ova were transferred to 50 pseudopregnant mouse recipients. 79 offspring were born. 19 of them were proved to be positive of gene integration by PCR, 4 mice were further confirmed to be transgenic by Southern hybridization.

A fusion expression plasmid was constructed by inserting the ovine IL-2 gene into PME290-Pili in the Pili gene at downstream 619 bp.The plasmid harbouring ovine IL-2 sequence was designated pmPili IL-2.The fusion protein was expressed by transforming the pmPili IL-2 into the competent host cell BL-21(DE3).Specific reaction between PiliIL-2 fusion protein and the antiserum of D.nodosus serotype E Pili was observed by cross electrophoresis.The molecular weight of the recombinant fusion protein was about 33 000 by SDS-PAGE and analyzed with thin layer.The recombinant Pili IL-2 fusion gene was expressed at higher level with about 5.49% of the total proteins of the transformant host cell BL-21(DE3).

对MDCK细胞上驯化克隆产毒量高的大斑株(LP)的第50代毒和75代毒进行了实验免疫研究,结果表明该毒株具有安全性好,通过静脉和口鼻接种CAV易感犬,无任何致病反应;用104.0TCID50以上的该毒免疫CAV易感犬,即获得97.5%以上的免疫保护;将其在CAV易感犬连续传5代,其安全性与原毒相同,表明该毒株在50～75代之间遗传性稳定,免疫原性良好;与CPV和CDV弱毒联合免疫,结果与各弱毒单独免疫所产生的抗体无差异,说明该毒株不但可以单独用于免疫,也可与其他弱毒联合免疫.是一株较好的疫苗候选株,具有开发应用价值.

Three mammary-specific expression vectors of pCBEA,pWE3′ and pCWEA were constructed with 1.1 kb bovine BLG gene promoter,0.949 kb WAP gene promoter and 2.4 kb erythropoietin genomic DNA minigene.The difference among the three vectors was that WAP3′ UTR was used as termination signal in pWE3′ and bGH polyA in pCBEA,pCWEA and the CMV enhancer element was cloned into the upstream of BLG,WAP gene promoter in pCBEA,pCWEA.The vectors mixed with liposome were injected into mammary glands of late stage pregnant rabbits through mammary gland teat canal respectively.Milk was collected on 1-25 d from rabbits after parturition.The results of ELISA assays showed that the expression level of pCBEA,pWE3′ and pCWEA was at the range of 0.335-0.680 μg/L,0.051-0.516 μg/L and 0.201-0.753 μg/L in the rabbit milk respectively.