分子信标探针用于PCR检测对虾白斑杆状病毒

将对虾白斑杆状病毒的一段特异性DNA设计成分子信标探针 ,用于该病毒的PCR检测 .温度与荧光强度之间的关系表明 ,所设计探针的发夹既可以形成也可以打开 ,符合PCR对分子信标探针的要求 .结果表明 ,在PCR同时加入分子信标探针不影响PCR扩增 ,分子信标探针只能与目的DNA杂交 ,具有较高的特异性 .随着PCR循环数的增加以及含目的DNA的质粒拷贝数的增加 ,荧光强度都随之增

抗氧化剂Isoverbascoside对MGC80-3细胞抗氧化酶活性和癌基因表达的影响

以苔酚蓝拒染法、核黄素-NBT还原法、DTNB还原法及RNA斑点杂交分析法分别对经不同浓度Isoverbascoside(Isov)处理的MGC80-3 细胞的生长速率、II期抗氧化酶(超氧化物歧化酶、谷胱甘肽过氧化物酶和过氧化氢酶)活性和N-ras、C-m yc及p53 基因表达作了检测.结果显示:经Isov处理后,细胞生长明显受抑;II期抗氧化酶活性较处理前明显上升;癌基因N-ras、C-m yc的表达较处理前下降,而抑癌基因p53 表达上升. 表明Isov 的抑癌作用与诱导II期抗氧化酶活性升高和癌基因表达改变有

The Research of Hardware Test Platform for Protograph LDPC Codes based on FPGA

随着信息的高速增长，信息传输速率及传输容量需求越来越大，人们对信息传输的可靠性也有了更大的需求。信道纠错码作为数字通信系统中物理层关键技术的核心，其最大的作用就是保证信息传输的可靠性。相对于传统的大范围移动通信，一些对误码率要求更低的特定应用场合，比如：磁记录系统中、高清数字电视系统、医学中的无线人体网等，其信息传输的可靠性显得尤为重要。这些应用中通常要求BER达到，我们称之为极低误码率区，而优秀的信道纠错码为这些系统中信息传输的极低误码性能提供了可能。低密度奇偶校验（LDPC）码就是这些优秀码型中的一种，它是一种分组码，具有非常优异的性能。原模图LDPC码是低密度奇偶校验码（LDPC）码中的...With the rapid development of information and large demand of multimedia, the transmission reliability of information become more and more important. As the core technology of physical layer in digital communication system, the most important role of channel error correcting code is to ensure the reliability of information transmission. Compared with traditional wide range of mobile communication...学位：工程硕士院系专业：信息科学与技术学院_电子与通信工程学号：2332011115315

Construction of full-length cDNA expression library of hepatopancreas of Penaeus monodon

采用PolyATtract1000系统提取完整的斑节对虾肝胰腺mRNA,ZAPExpresscDNA合成试剂盒合成具有EcoRⅠ和XhoⅠ末端的双链cDNA.cDNA与经EcoRⅠ和XhoⅠ预消化的λZAPExpress载体连接,再经GigapackⅢGold蛋白体外包装和感染E.coli菌株XL1-BlueMRF′,成功构建了库容量为7 7×105,重组率高达99 1%的cDNA表达文库.将初级文库进行扩增,并在滴定扩增文库时随机挑取9个噬菌斑,在辅助噬菌体ExAssist的作用下通过体内切除形成phagemid,再用EcoRⅠ和XhoⅠ双酶切获得插入cDNA片段,其长度最长达1 6kb.我们还用PCR法从库中扩增出完整的肌动蛋白编码区cDNA(约1 2kb).以上结果说明此表达文库含有斑节对虾肝胰腺全长cDNA片段,因此本文库为对虾基因的克隆、表达及其结构和功能的研究奠定了基础.mRNA was isolated from the hepatopancrease of shrimp Penaeus monodon with a PolyATtract System1000 Kit. By using mRNA as template, double-strand cDNA with EcoRⅠ/XhoⅠends was synthesized by using a ZAP expression cDNA Synthesis Kit. The cDNA was inserted into the lambda ZAP expression vector predigested with EcoRⅠ/XhoⅠ, and the recombinant DNA was in vitro packaged into lambda phage with GigapackⅢ Gold packaging extracts. These recombinant phages were then used to transfect E. coli XL1-Blue MRF', and finally a cDNA expression library was constructed. The library is 7.2×10~5 pfu in capacity and its recombination ratio is higher than 99%. The size of the inserted cDNAs was determined by EcoRⅠ/XhoⅠ digestion of 9 phagemids prepared by in vivo excision of plaques selected randomly from amplified cDNA library. The longest inserted cDNA is about 1.6 kb in length. The complete sequence (about 1.2 kb) of actin cDNA amplified from the library by PCR reveals that this library contains full-length cDNAs of shrimp Penaeus monodon hepatopancreas and is available for screening and expression of shrimp genes.国家海洋"863"计划资助项目(2001AA621130);; 国家海洋局海洋科技研究资助项目

Sequence analysis and characterizations of two novel plasmids isolated from Thermus sp 4C

Two novel plasmids, named pS4C and pL4C, were isolated from the thermophilic bacterium Thermus sp. 4C. The pS4C with a length of 5015 by and 58.25% of G+C content, contains 9 putative open reading frames (ORFs). The larger plasmid, pL4C, consisting of 21,248 bp, has a G+C content of 68.60% and 34 putative ORFs. Both plasmids encode their own replication protein. The ORF 22 of pL4C and the ORF 4 of pS4C encode proteins with high sequence similarities to integrase (97%) and transposase (97%), respectively, which are both involved in DNA rearrangement and exchange. Furthermore, sequence analysis of pL4C also showed that several plasmid-encoded genes may be involved in DNA modification and repair, such as DNA G:T-mismatch repair endonuclease and micrococcal nuclease-like protein. These proteins may be involved in raising the repair efficiency and other minor editing needs. Interestingly, the elimination of plasmids significantly lowered the growth temperature of Thermos sp. 4C. Few reports dealing with the DNA repair enzymes on the plasmid from Thermus strains were published so far. (c) 2007 Elsevier Inc. All rights reserved

Mj-DWD, a double WAP domain-containing protein with antiviral relevance in Marsupenaeus japonicus

National Natural Science Foundation of China [30330470]; National Basic Science Research 973 program [2006CB101804]; The Main Science Foundation of Fujian [2006N0039]The Mj-DWD (Marsupenaeus japonicus' double-WAP domains) gene was originally found up-regulated in virus-resistant shrimp M. japonicus by suppression subtractive hybridization (SSH). The full-length cDNA of Mj-DWD encodes a novel protein containing a KGD (Lys-Gly-Asp) motif and double WAP domains. Performed by quantitative real-time PCR, the expression level of Mj-DWD gene was consistently maintained at a high level in the newly prepared virus-resistant shrimp compared to the normal one. In addition, the Mj-DWD gene was also found to be rapidly up-regulated by WSSV infection during the early phase. Furthermore, the recombinant Mj-DWD, expressed by Pichia pastoris, showed specific protease inhibitory activity on Bacillus subtilis. These findings suggest that Mj-DWD plays an important role in the host defence system against WSSV infection in M. japonicus, possibly through its protease inhibitory activity. (C) 2008 Elsevier Ltd. All rights reserved

An Early Time-course Study on the Infection and Proliferation of Shrimp White Spot Bacilliform Virus with Quantitative PCR

对虾白斑杆状病毒又称白斑综合症病毒,是对虾养殖业危害最严重的病原体,至今未找到有效的防治方法.充分了解病毒的分子生物学特性和分子致病机理,是病害防治的根本途径,了解病毒的动态增殖特征是该研究的基础.本文采用定量PCR技术,研究对虾白斑杆状病毒人工注射感染后,早期的增殖规律以及感染致死对虾的病毒累积.并对对虾感染病毒后存活时间与个体大小的关系进行了观察.研究发现初期感染病毒含量有短期下降,然后才呈现递增的过程.死亡对虾病毒累积量大于1011病毒粒子/毫克组织(P0.2).Shrimp white spot bacilliform virus (WSBV) was the heaviest pathogen for shrimp culture. No efficient medicament had been founded. The acquisition of molecular characteristics of WSBV and its pathogenesis was most important for WSBV prevention. The research on dynamic proliferation of WSBV was the foundation of the study work. Quantitative PCR was applied to study the proliferation at early infection stage and accumulation of WSBV in died infected prawns. The relation between survival time and weight of prawns was also observed. After infection, the quantity of WSBV was declined before 4 h and increased gradually thereafter. The accumulation of WSBV was more than 1011virions/mg tissue in dead infected prawns. There was no relativity between survival time and weight of prawns ranging from 4.6 g to 11.6 g.国家自然科学基金(30170728)资

A new approach to puriFy occlusion bodies of Penaeus monodon-type baculovirus

本文报道了一种纯化草虾杆状病毒（MbV）包涵体的方法。取出受MbV感染的虾肝胰组织，在TESP溶液中（50MMOl/dM3TrIS-HCIPH8.0，50MMOl/dM3EdTA，0.1MOl/dM3nACl，0.5MMOl/dM3PMSf）破碎，差迷离心，再经30%~70%蔗糖浓度梯度高速离心，可得到合包涵体的区带。电镜下观察到较纯的包涵体，经蛋白酶k降解后，PCr扩增，经琼脂糖凝胶电泳可见清晰的dnA区带。A new approach to puriFy occlusion bodies (OB) of Penaeus monodon-type baculovirus(MBV) is described.MBV-inFected hepatoancraFa were removed From the shrimps andhomogenized in a solution of TESP buFFer (50mmol/dm' Tris-HCl pH 8.0, 50mmol/dm3EDTA, 0.1mol/dm3 NaCl, 0.5mmol/dm3 PMSF).PMSF (phenylmethyl solFonyl Flouride) wasused as a proteinase inhibitor protecting OB From degradation.The suspension was clariFiedin diFFerential cantriFugation and the pellet was Further separted in a 30%-- 70% sucrosegradient by high speed centriFugation.Occlusion bodies corresponding to a speciFic band inthe gradient was collected and observed under an electron microscope.AFter digestion byproteinase K, the MBV DNA was ampliFied by PCR and visualized on an agarose gel.厦门市虾病攻关专项基

The structure and function of a gene encoding a basic peptide from prawn white spot syndrome virus

Prawn white spot syndrome virus (WSSV) is the major pathogen responsible for the high mortality of cultured prawns. A gene (termed as p6.8) encoding a basic peptide was found by screening the cDNA and DNA libraries of WSSV. The peptide was highly homologous with proteins rich in arginine and lysine. A fusion protein containing the p6.8 and green fluorescent protein (GFP) genes was cloned into pBV220 and expressed in E. coli. Gel mobility shift assay indicated that the peptide encoded by p6.8 had the capability of binding DNA and might be involved in DNA packaging. (C) 2001 Elsevier Science B.V. All rights reserved

轴承预紧对高速重载行星齿轮传动动态特性影响研究

为分析轴承预紧对高速重载行星齿轮传动系统动态特性的影响，建立高速重载行星齿轮传动动力学模型，考虑轴承预紧因素，分析行星销轴承预紧量对系统支撑刚度、固有频率、内外啮合副动态啮合力的影响。结果表明，行星销轴承预紧可以有效增加行星销支撑刚度；系统的固有频率随预紧先减小后增大，随游隙增大而增大；行星齿轮内外啮合副动态啮合力峰值随预紧增大而减小，随游隙增大而增大。研究结果可为优化高速重载行星齿轮传动的轴承预紧量提供支撑