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981.
活性Stat3能够抑制细胞凋亡和促进肿瘤细胞增殖,从而促进皮肤肿瘤的形成与发展,构建高特异性及高选择性的显性负相Stat3重组体是预防和治疗皮肤肿瘤的有效方法。 相似文献
982.
咽康片抗流感病毒的实验研究 总被引:1,自引:0,他引:1
目的:探讨咽康的抗病毒作用及疗效。方法:采用微量细胞培养法进行抗病毒疗效和病毒滴定。结果:咽康片对流感病毒的最小有效浓度为 :131.25μg/ml。咽康片对流感病毒的治疗指数(therapeuticindex,TI)等于4 ,经最小有效剂量咽康溶液作用后 ,流感病毒的滴度由104.5TCID50/0.1ml下降为101.7TCID50/0.1ml。结论:咽康在体外对流感病毒有一定的治疗作用 相似文献
983.
赵建平 《科技情报开发与经济》2004,14(5):181-182
病毒、黑客、计算机犯罪等网络安全事件的日益增多已严重阻碍了网络经济的正常发展,计算机信息产业面临着严峻的挑战,因此,必须采取切实可行的措施来保障网络信息系统的安全,首先应提高广大用户的信息安全管理意识,其次是要建立完善的安全防护体系。 相似文献
985.
草酸诱导甜瓜对南瓜花叶病毒的系统抗性 总被引:3,自引:0,他引:3
用草酸涂抹甜瓜叶片后,显提高了甜瓜对南瓜花叶病毒(SqMV)的系统抗性。最后处理的草酸浓度为30mmol·L^-1。挑战接种试验证明,草酸处理植株的感病症状显轻于对照植株,病毒的相对质量尝试仅为对照值株的4%,草酸处理植株的过氧化物酶活性为对照植株的6倍,且诱导出3种新的过氧化物酶同工酶;木质素相对质量浓度亦提高了82.9%。结果表明,草酸对提高甜瓜过氧化酶活性和木质素相对质量浓度与诱导甜瓜对 相似文献
986.
Southern rice black-streaked dwarf virus:A new proposed Fijivirus species in the family Reoviridae 总被引:3,自引:0,他引:3
《科学通报(英文版)》2008,(23)
For the past several years, a novel dwarf disease has been observed on rice (Oryza sativa) in some regions of Guangdong Province and Hainan Province, southern China. Infected plants showed stunting, dark leaf and small enations on stem and leaf back. Typical Fijivirus viroplasma containing crystalline arrayed spherical virons approximately 70―75 nm in diameter and tubular structures were detected in ultrathin sections by an electron microscope in parenchyma phloem cells of the infected plants. The virus was transmitted to rice seedlings by white-backed planthoppers, Sogatella furcifera (Hemiptera: Delphacidae), collected in the diseased fields. Analysis of dsRNA extracts from infected plants revealed ten linear segments, which were similar to the electrophoretic profile of Rice black-streaked dwarf virus (RBSDV). RT-PCR with a single primer which matched to a linker sequence ligated to both 3′ ends of the viral genomic dsRNAs resulted in amplification of genome segments 9 (S9) and 10 (S10) cDNA products. The complete nucleotide sequences of S9 and S10 were obtained from clones of the RT-PCR amplicon exhibited characteristic properties of Fijivirus including low GC content (34.5% and 35.6%), genus conserved 5′ and 3′ termini sequences and similar genome organization. Blast searches indicated that the sequences of S9 and S10 shared 68.8%―74.9% and 67.1%―77.4% nucleotide identities with those of viruses in the Fijivirus group 2, respectively. These values were similar to those among other viruses in the Fijivirus group 2 and considerably lower than those among RBSDV isolates. Phylogenetic trees based on S9 and S10 nucleotide sequences and their putative amino acid sequences showed that this virus represented a separate branch among other Fijiviruses. The virus was also detected by a nested RT-PCR assay in corn (Zea mays), barnyard grass (Echinochloa crusgalli), Juncellus serotinus and flaccidgrass (Pennisetum flaccidum) in and/or adjacent to the infected rice fields. It is proposed that this virus be considered as a new species, Southern rice black-streaked dwarf virus, in the group 2 of the genus Fijivirus in the family Reoviridae. 相似文献
987.
YuanQing Yan ShaoWei Li ChunYan Yang WenXin Luo MingQiao Wang YiXin Chen HaiFeng Luo Ting Wu Jun Zhang NingShao Xia 《科学通报(英文版)》2008,53(6):868-877
The H5N1 avian influenza virus (AIV) has widely spread in Asia, Europe and Africa, making a large amount of economic loss. Recently, our research group has screened a common neutralizing mono-clonal antibody named 8H5, which can neutralize almost all H5 subtype AIV ever isolated so far. Obviously, this monoclonal antibody would benefit for research and development of the universal AIV vac-cine and design of the drug against H5N1 AIV in high mutation rate. In this study, the homology modeling was applied to generate the 3D structure of 8H5 Fab fragment, and "canonical structure" method was used to define the specified loop conformation of CDR regions. The model was subjected to energy minimization in cvff force field with Discovery module in Insight II program. The resulting model has correct stereochemistry as gauged from the Ramachandran plot calculation and good 3D-structure compatibility as assessed by interaction energy analysis, solvent accessible surface (SAS) analysis, and Profiles-3D approach. Furthermore, the 8H5 Fab model was subjected to docking with three H5 subtype hemagglutinin (HA) structures deposited in PDB (ID No: ljsm, 2ibx and 2fk0) respectively. The result indicates that the three docked complexes share a common binding interface, but differ in binding angle related with HA structure similarity between viral subtypes. In the light of the three HA inter-faces with structural homology analysis, the common neutralizing epitope on HA recognized by 8H5 consists of 9 incontinuous amino acid residues: Asp^58, Asn^72, Glu^112, Lys^113, lie^114, Pro^118, Ser^120, Tyr^137, Tyr^252 (numbered as for ljsm sequence). The primary purpose of the present work is to provide some insight into structure and binding details of a common neutralizing epitope of H5N1 AIV, thereby aiding in the structure-based design of universal AIV vaccines and anti-virus therapeutic drugs. 相似文献
988.
LIU FuXiu ZHAO Qin RUAN XiaoLei HE YunWei LI HuaPing 《科学通报(英文版)》2008,53(3):362-369
Rice gall dwarf virus (RGDV) is an important rice pathogen in China and Southeast Asia. However, little is known about the molecular mechanisms of RGDV interactions with plant cells. Here, we have identified an RGDV protein, Pns11, which acts as a suppressor of RNA silencing in coinfiltration assays with the reporter, green fluorescent protein (GFP)in transgenic Nicotiana benthamiana line 16c carrying GFP. Pns11 suppressed local and systemic silencing induced by sense RNA. The spread of mobile RNA silencing signals was blocked or inactivated by Pns11. Expression of Pns11 also enhanced Potato virus X pathogenicity in IV. benthamiana. This suppressor could reduce, but not eliminate, siRNA in the local and systemic RNA silencing suppression assays, suggesting that Pns11 functions by interfering with initial stages of RNA silencing. 相似文献
989.
人Elongator是在转录中有功能的组蛋白乙酰转移酶(HAT)复合物,为研究其催化亚基Elp3功能,构建了酵母组蛋白H3/H4拷贝1的双元表达载体pRS316CFT,通过PCR介导的基因敲除,获酵母基因组H3/H4缺失由双元载体提供单拷贝H3/H4的elp3Δ菌株.敏感性实验表明该载体提供H3/H4可维持酵母正常生长.本工作为构建H3/H4乙酰化位点突变菌株,用功能互补在体内研究人Elp3 HAT活性功能奠定了基础. 相似文献
990.
西瓜花叶病毒外壳蛋白基因的克隆与原核表达 总被引:3,自引:1,他引:2
利用RT-PCR方法获得了西瓜花叶病毒(WMV)陕西分离物外壳蛋白(CP)基因,大小为843 bp.将CP基因克隆到pMD18-T Simple Vector,测序分析发现与各个国家CP核苷酸和氨基酸同源性分别为93.0%~95.0%和96.5%~98.6%.将CP基因定向插入EcoR I/SalI切开的pET30a中,构建了原核表达载体pET30-WCP,转化大肠杆菌BL21.经IPTG诱导2~8 h后,成功表达了分子量约为37 kD的CP蛋白.通过不同时间诱导发现,加入IPTG 4 h后蛋白开始表达,8 h后表达量比较大.以诱导的蛋白为抗原免疫家兔,制备了WMV CP抗血清,ELISA法测其效价为1/6 400,Western blot分析能与CP发生血清学反应. 相似文献