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1.
 通过对斜纹夜蛾核多角体病毒(SpltNPV)在其不同龄期宿主体内增殖情况的研究,探索保幼激素类似物(JHA)methoprene促进SpltNPV在其宿主体内增殖的途径,为今后广泛利用methoprene进行高效率、低成本增殖昆虫杆状病毒杀虫剂提供理论依据和方法.运用正交组合的方法筛选3种主要因子(病毒感染浓度、methoprene用量和methoprene施用时间)对提高病毒增殖产量进行最佳组合实验.实验确立了以1×107PIBs/mL感染6龄刚蜕皮的斜纹夜蛾幼虫,并于感染第1天滴加10μL methoprene的最佳组合方法,病毒总产量和平均病毒产量分别可达1 856.0×108PIBs和62.2×108PIBs.并测定了methoprene处理对SpltNPV病毒LC50的影响.经methoprene处理后,病毒的LC50由1.578×107PIBs/mL增加至9.151×107PIBs/mL.  相似文献   

2.
本文对鳜鱼的食性驯化进行了较为详细的研究。在网箱养殖条件下.采用抛投活饵建立鳜鱼上水面摄食的条件反射,再改投死鱼、鱼块和配合饲料的方法,对鳜鱼进行驯化,经15d的驯化,5~7.5g、110~145g、205~245g的鳜鱼苗种驯化率分别达74%、71.5%、和70.5%。试验鱼的规格和饥饿时间对驯化率没有明显的影响。不用活饵建立摄食反射的鳜鱼.直接投喂鱼块和配合饲料,驯化率为零:直接投喂整尾死鱼.驯化率为13%。  相似文献   

3.
4.
生物成因的碳酸钙在自然界普遍存在。已有研究表明,鳜鱼耳石的主要无机矿物组成是碳酸钙,研究鳜鱼耳石中的碳酸钙物相组成有助于推理这些生物成因碳酸钙的矿化过程,为合成具有特定结构和功能的钙盐类材料提供有益的思考和实践途径。本文从鳜鱼中提取微耳石进行红外光谱和 XRD 分析,结果表明鳜鱼的微耳石为文石矿物相,扫描电镜观察发现其有着片层状的纤维结构。  相似文献   

5.
High-quality type-Ib tower-shape diamond single crystals were synthesized in cubic anvil high pressure apparatus (SPD-6×1200) at 5.4 GPa and 1250-1450°C. The (100) face of seed crystal was used as the growth face, and FeNiMnCo alloy was used as the solvent/catalyst. Two kinds of carbon diffusing fields (type-B and type-G) were simulated by finite element method (FEM). Using the two kinds of carbon diffusing fields, many diamond single crystals were synthesized. The effects of carbon diffusing fields on the ...  相似文献   

6.
斑鳜池塘高效养殖技术   总被引:1,自引:0,他引:1  
针对斑鳜养殖产量低的问题,通过从池塘选择、苗种培育、养殖管理等一系列技术措施入手,将养殖成活率提高到90%,平均尾质量0.42 kg,为斑鳜的高效养殖提供一种新模式.  相似文献   

7.
The feasibility of in vivo gene therapy for hemophilia B by VSV-G pseudotyped retroviral vector was introduced. The novel packaging cell line 293GPG was used to produce VSV-G/G1NaBAIX pseudotyped virus with the highest titers up to 8.5×108 cfu·mL-1. In contrast to the conventional retrovirus, VSV-G pseudotyped virus was more resistant to inactivation by serum complements (P<0.001). Our results also demonstrated that VSV-G pseudotyped virus was more stable in neonatal mice serum than in adult mice serum (P<0.01). After intraperitoneal injection of different doses of virus, hFIX antigen was detected and lasted for more than 120 d, the highest level reached (72.5±6.1) ng·mL-1. Moreover, the functional activity was improved to some extent in all hFIX-treated mice, the most remarkable improvement was observed in the mice treated with higher dose of virus whose clotting activity increased to (3.4±1.5)% and APTT (activated partial thromboplastin time) reduced to (43.2±7.2) s. The anti-hFIX antibody was not detected by the method of Bethesda, no germ line transmission and any side effects associated with gene transfer were found. Our results indicated that neonatal gene therapy for hemophilia B mice by VSV-G pseudotyped retrovirus is promising.  相似文献   

8.
The virophage as a unique parasite of the giant mimivirus   总被引:1,自引:0,他引:1  
Viruses are obligate parasites of Eukarya, Archaea and Bacteria. Acanthamoeba polyphaga mimivirus (APMV) is the largest known virus; it grows only in amoeba and is visible under the optical microscope. Mimivirus possesses a 1,185-kilobase double-stranded linear chromosome whose coding capacity is greater than that of numerous bacteria and archaea1, 2, 3. Here we describe an icosahedral small virus, Sputnik, 50 nm in size, found associated with a new strain of APMV. Sputnik cannot multiply in Acanthamoeba castellanii but grows rapidly, after an eclipse phase, in the giant virus factory found in amoebae co-infected with APMV4. Sputnik growth is deleterious to APMV and results in the production of abortive forms and abnormal capsid assembly of the host virus. The Sputnik genome is an 18.343-kilobase circular double-stranded DNA and contains genes that are linked to viruses infecting each of the three domains of life Eukarya, Archaea and Bacteria. Of the 21 predicted protein-coding genes, eight encode proteins with detectable homologues, including three proteins apparently derived from APMV, a homologue of an archaeal virus integrase, a predicted primase-helicase, a packaging ATPase with homologues in bacteriophages and eukaryotic viruses, a distant homologue of bacterial insertion sequence transposase DNA-binding subunit, and a Zn-ribbon protein. The closest homologues of the last four of these proteins were detected in the Global Ocean Survey environmental data set5, suggesting that Sputnik represents a currently unknown family of viruses. Considering its functional analogy with bacteriophages, we classify this virus as a virophage. The virophage could be a vehicle mediating lateral gene transfer between giant viruses.  相似文献   

9.
从波斯毛莨花卉上分离到一株病毒分离物R89—1,浸染波斯毛莨叶片表现为不规则的黄斑和坏死斑,易经汁液摩擦接种.可经桃蚜以非持久性方式传播.能侵染测试的11科40种植物中的7科23种.病毒粒体为正20面体,直径约25nm.在琼脂双扩散试验中与蚕豆萎蔫病毒(B—BWV)的抗血清发生沉淀反应.根据上述特征,K89—1分离物鉴定为蚕豆萎蔫病毒.蚕豆萎蔫病毒用感染的昆诺阿藜叶片通过丁醇澄清及聚乙二醇沉淀容易提纯,每100g叶组织可获22mg病毒.提纯的病毒制剂具有典型的核蛋白紫外吸收曲线,最大吸收波长为259nm,最小吸收波长为241nm,A260/A280为1.67.在蔗糖密度梯度离心中含有上、中、下三条沉淀带.利用提纯的病毒制备的抗血清经微量沉淀试验效价达1/2048.  相似文献   

10.
目的 了解吉林地区产常见野菜中粗纤维含量及与普通叶菜类含量的区别,为本地区野菜产品开发与居民食用提供依据.方法 根据国家标准对吉林地区山野菜中的粗纤维含量进行测定(酸碱消煮法).采集吉林地区野生野菜7种,人工养殖野菜4种,人工养殖菠菜1种(对照组),进行测定.结果 野生野菜组粗纤维含量最低为柳蒿[(2.74±0.47)×10-2g/g],最高为刺五加[(5.01±0.30)×10-2g/g].人工养殖组粗纤维含量最低为人工养殖刺老芽[(1.58±0.23)×10-2g/g],最高为养殖蒲公英[(2.27±0.20)×10-2g/g],人工养殖菠菜[(2.04±0.16)×10-2g/g].结论 不同种类野菜其粗纤维含量不同,同一区域的同种类野生野菜粗纤维平均含量明显高于人工养殖野菜;人工养殖野菜粗纤维含量与菠菜粗纤维含量并无明显差异.  相似文献   

11.
以邻苯二胺、谷氨酸及硼酸为前驱体,通过简单的一步水热法成功制备水溶性极好的硼氮共掺杂荧光碳点(B,N-CDs)。该B,N-CDs粒径约为20 nm,在吡罗昔康(PRX)的存在下,由于B,N-CDs和PRX之间存在强烈的电子或能量转移导致发生了强烈的荧光淬灭效应。据此,应用荧光碳点B,N-CDs作为荧光探针成功构建了高选择性、高灵敏性的PRX检测荧光传感器。实验数据显示,该传感器具有响应速度快、线性范围宽和检测限低等优点。检测PRX的线性范围为2×10~(-5)~1.5×10~(-4) mol/L,LOD为5.7×10~(-8) mol/L。该传感器用于实际样品检测得到了较好的回收率(94.3%~103.3%),充分说明B,N-CDs在药物检测领域具有很好的潜在应用价值。  相似文献   

12.
翘嘴鳜髓过氧化物酶基因克隆及重链序列的原核表达   总被引:1,自引:0,他引:1  
利用RT PCR和RACE PCR方法,从翘嘴鳜中克隆出髓过氧化物酶(myeloperoxidase, MPO)cDNA全长。其开放阅读框有2?292个核苷酸,编码763个氨基酸的蛋白。虽然序列相似性分析发现该蛋白与哺乳动物MPO相似性为64%~65%,但分子质量大小相近。翘嘴鳜含有1个与人MPO相似的血红素基,1个保守的Ca2+结合位点,6个分子内二硫键,以及6个糖基化位点。由此推测翘嘴鳜MPO蛋白的空间结构及催化机制可能与哺乳动物的相似。将翘嘴鳜MPO的部分DNA序列连接到pET 32a c(+)载体上,成功构建了1个重组表达质粒pET MPO,该质粒在大肠杆菌(DE3)中获得了高效表达。另外,利用重组蛋白N末端带有的6×His标签,通过Ni2 NTA柱纯化获得了翘嘴鳜MPO重组蛋白。  相似文献   

13.
以达旦黄为探针,应用荧光及紫外光谱法研究达旦黄(TY)与牛血清白蛋白(BSA)分子间的结合反应,测定了不同温度下的结合常数和结合位点数.实验表明:TY对BSA内源荧光的猝灭机理为静态猝灭,作用力类型为疏水作用.根据Frster能量转移理论,求得不同温度(16 ,30 ,40 ℃)下的能量转移效率E分别为0.419 6,0.401 9,0.386 5,作用距离r分别为3.05,3.04,3.10 nm.BSA存在猝灭TY的荧光,以此为基础建立了测定BSA的方法,线性范围:3×10-7~2×10-5 mol/L,检出限:9.07×10-7 mol/L,相对标准偏差:RSD=1.7%.  相似文献   

14.
为了提高马铃薯脱毒种薯的质量,使其从根本上不含有马铃薯主要病毒,对马铃薯脱毒苗的质量检测尤为重要。本文应用国际通用的双抗体夹心酶联免疫吸附试验方法,对6个品种的96份脱毒苗进行了6种病毒检测。检测结果表明共有20份材料不含有6种主要病毒,能够应用于马铃薯的脱毒种薯生产。检测结果还表明在脱毒苗中PVS的含有率最高,应提高脱除马铃薯S病毒的技术水平。  相似文献   

15.
Subtypes of H1N1 influenza virus can be found in humans in North America, while they are also associated with the infection of swine. Characterization of the genotypes of viral strains in human populations is important to understand the source and distribution of viral strains. Genomic and protein sequences of 10 isolates of the 2009 outbreak of influenza A (H1N1) virus in North America were obtained from GenBank database. To characterize the genotypes of these viruses, phylogenetic trees of genes PB2, PB1, PA, HA, NP, NA, NS and M were constructed by Phylip3.67 program and N-Linked glycosylation sites of HA, NA, PB2, NS1 and M2 proteins were analyzed online by NetNGlyc1.0 program. Phylogenetic analysis indicated that these isolates are virtually identical but may be recombinant viruses because their genomic fragments come from different viruses. The isolates also contain a characteristic lowly pathogenic amino acid motif at their HA cleavage sites (IPSIQSR↓GL), and an E residue at position 627 of the PB2 protein which shows its high affinity to humans. The homologous model of M proteins showed that the viruses had obtained the ability of anti-amantadine due to the mutation at the drug-sensitive site, while sequence analysis of NA proteins indicated that the viruses are still susceptible to the neuraminidase inhibitor drug (i.e. oseltamivir and zanamivir) because no mutations have been observed. Our results strongly suggested that the viruses responsible for the 2009 outbreaks of influenza A (H1N1) virus have the ability to cross species barriers to infect human and mammalian animals based on molecular analysis. These findings may further facilitate the therapy and prevention of possible transmission from North America to other countries.  相似文献   

16.
The acetone-sensing properties of the undoped and Pd doped perovskite-type oxides NdFeO3 were investigated from room temperature to 400°C. The perovskite-type NdFeO3 was synthesized by a sol-gel method, and the dopants Pd with the content from 1wt% to 5wt% were implanted into NdFeO3 nanoparticles by thermal diffusion. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques show that NdFeO3 is an orthorhombic structure with the average particle size of about 40 nm. A giant acetone-sensing response of 675.7 is observed when the Pd content in NdFeO3 powders is about 3wt%. The response and recovery time of the sensor to the 5×10−4 acetone gas are 16 and 1 s, respectively. At the same time, it performs a good selectivity to acetone gas and may be a new promising material candidate for the acetone-sensor development.  相似文献   

17.
Two-photon absorption (TPA) and frequencyupconversion properties of a new upconversion laser dyetrans-4-[p-(N-hydroxyethyl-N-methyl-amino)styryl]-N-methylpyridinium toluene-p-sulfonate (abbreviated to HMASPS) were reported in this note. The linear absorption, TPA, single-photon induced fluorescence, TPA induced fluorescence and TPA induced upconverted lasing spectra of HMASPS solution in dimethyl formamide (abbreviated to DMF) were measured at room temperature. The red shift for the central wavelength of TPA induced fluorescence peak, which was compared with that of the single-photon induced fluorescence peak, and the blue shift for that of TPA induced upconverted lasing compared with that of TPA induced fluorescence, were explained by using re-absorption effect. TPA peak was at 930 nm. There is an 11 nm blue shift for two-photon energy of TPA peak compared with the linear absorption peak. The molecular TPA cross-section σ2 9′ at 1064 nm was measured to be 6.0×10−48 cm4 · s/photon by using the open aperture Z-scanning system. The highest upconversion efficiency was measured to be 8.4% at 1064 nm.  相似文献   

18.
The vegetation spatial heterogeneity and ecological characteristics in different soil regions were analyzed by surveying the vegetation in 12 different soil regions of Inner Mongolia, China, including conifer- ous-broadleaf deciduous forests, shrub, grassland, and desert regions with 1122 large 2 cm × 2 cm quad- rats (actual size 30 km × 30 km, referred to as L-quadrat hereafter) in about 1.18 million km2. Each L- quadrat was divided into four small 1 cm × 1 cm quadrats (actual size 15 km × 15 km, S-quadrat). The vegetation was analyzed based on the beta-binomial distribution to describe the frequency of occurrence and spatial heterogeneity for each kind of vegetation. The weighted average of the heterogeneity of all vegeta- tion in the same soil region provides a measure of the soil regional landscape level heterogeneity which de- scribes the spatial complexity of the regional landscape composition of the existing vegetation. Comparison of the vegetation characteristics in the 12 soil regions shows that, the calcic gray soil has the highest average vegetation type per quadrat. The largest soil region is calcic chestnut soil and has the most vegetation types. Every soil region has its own dominant vegetation sequence which dominates in occurrence and dominant vegetation types which dominates in spatial heterogeneity. For the Inner Mongolian vegetation, the weighted average of the heterogeneity is 0.60 and the vegetation diversity index is 4.47.  相似文献   

19.
The characterization of the algaeAnabaena cylindrica solution with Fe (III) was investigated using fluorescence emission and synchronous-scan spectroscopy. The ranges of concentrations of algae and Fe (III) in aqueous solutions were 5.0×108 2.5×108 cell/L and 1060 μmol/L. respectively. The effective characterization method used was synchronous-scan fluorescence spectroscopy (SFS). The wavelength difference (Δλ) of 90 nm, was maintained between excitation wavelength (λen) and emission wavelength (λen). The peak was observed at about (λex) (λem) 326 nm for synchronous scan fluorescence spectroscopy. The fluorescence quenching in system of algae Fe(III)-HA was studied using synchronous-scan spectroscopy for the first time, Fe(III) was clearly the effective quencher. The relationship betweenI I (quenching efficiency) andc (concentration of Fe (III) added) was, a linear correlation for the algae solution with Fe(III). Also, Aldrich humie acid (HA) was found to be an effective quencher. Foundation item: Supported by the National Natural Science Foundation of China (20177017) and the Scientific Research Foundation of Wuhan Environmental Protection Bureau Biography: LIU Xian li(1965), male. Ph.D. Associate professor, research direction: environmental chemistry.  相似文献   

20.
Two recombinant baculoviruses, dciAcMNPV and dcdAcMNPV in which another copy of the v-cath gene controlled by ie1 promoter and polh promoter was inserted, were respectively constructed by the Bac-to-Bac system. The expression of the v-cath gene of the recombinant baculoviruses in Sf9 cells at different phases was investigated by SDSPAGE and Western blot. The results showed that only recombinant virus dciAcMNPV containing late gene v-cath driven by early gene promoter could express V-CATH protein, cathepsin encoded by virus genome, 12 h post-infection and dcdAcMNPV containing late gene v-cath driven by late and very late gene promoters could express more V-CATH protein. Negative control ncAcMNPV, a mutant deleted vcath gene, could not express V-CATH protein at all. The Spodopera exigua larvae were infected with viruses respectively and the results showed that the toxicity was as follows: dcdAcMNPV>dciAcMNPV>wtAcMNPV>ncAcMNPV. The toxicity of recombinant viruses and the characters of dead larvae showed that the v -cath gene was relative to viral toxicity and host liquefaction. Recombinant baculovirus dcdAcMNPV might be used as a new kind of safe viral-pesticide, because of its high toxicity obtained by adding another gene copy and changing the expression level of its own gene relative to virulence.  相似文献   

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