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排序方式: 共有108条查询结果,搜索用时 109 毫秒
1.
Josephine A. Dornbusch Laura E. Selmic Pin‐Chieh Huang Jonathan P. Samuelson Eric M. McLaughlin Vincent A. Wavreille Jessica A. Ogden Brittany Abrams Alex Kalamaras Eric Green Eric T. Hostnik Lincoln Every Jason A. Fuerst Ryan Jennings Christopher Premanandan Joshua N. Lorbach Sarah C. Linn Aneesh Alex Janet E. Sorrells Lingxiao Yang Stephen A. Boppart 《Veterinary surgery : VS》2021,50(1):111-120
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DNA vaccinations against fish viral diseases as IHNV at commercial level in Canada against VHSV at experimental level are both success stories. DNA vaccination strategies against many other viral diseases have, however, not yet yielded sufficient results in terms of protection. There is an obvious need to combat many other viral diseases within aquaculture where inactivated vaccines fail. There are many explanations to why DNA vaccine strategies against other viral diseases fail to induce protective immune responses in fish. These obstacles include: 1) too low immunogenicity of the transgene, 2) too low expression of the transgene that is supposed to induce protection, 3) suboptimal immune responses, and 4) too high degradation rate of the delivered plasmid DNA. There are also uncertainties with regard distribution and degradation of DNA vaccines that may have implications for safety and regulatory requirements that need to be clarified. By combining plasmid DNA with different kind of adjuvants one can increase the immunogenicity of the transgene antigen – and perhaps increase the vaccine efficacy. By using molecular adjuvants with or without in combination with targeting assemblies one may expect different responses compared with naked DNA. This includes targeting of DNA vaccines to antigen presenting cells as a central factor in improving their potencies and efficacies by means of encapsulating the DNA vaccine in certain carriers systems that may increase transgene and MHC expression. This review will focus on DNA vaccine delivery, by the use of biodegradable PLGA particles as vehicles for plasmid DNA mainly in fish. 相似文献
4.
G. Benckiser R. Eilts A. Linn H. -J. Lorch E. Sümer A. Weiske F. Wenzhöfer 《Biology and Fertility of Soils》1996,23(3):257-265
Nitrous oxide emissions, nitrate, water-soluble carbon and biological O2 demand (BOD5) were quantified in different cropping systems fertilized with varying amounts of nitrogen (clayey loam, October 1991 to May 1992), in an aerated tank (March 1993 to March 1994), and in the nitrification-denitrification unit (March to July 1994) of a municipal waste water treatment plant. In addition, the N2O present in the soil body at different depths was determined (February to July 1994). N2O was emitted by all cropping systems (mean releases 0.13–0.35 mg N2O m-2 h-1), and all the units of the domestic waste water treatment plant (aerated tank 0–6.2 mg N2O m-2 h-1, nitrification tank 0–204,3 mg N2O m-2, h-1, denitrifying unit 0–2.2 mg N2O m-2 h-1). During the N2O-sampling periods estimated amounts of 0.9, 1.5, 2.4 and 1.4 kg N2O–N ha-1, respectively, were released by the cropping systems. The aerated, nitrifying and denitrifying tanks of the municipal waste water treatment plant released mean amounts of 9.1, 71.6 and 1.8 g N2O–N m-2, respectively, during the sampling periods.The N2O emission were significantly positively correlated with nitrate concentrations in the field plots which received no N fertilizer and with the nitrogen content of the aerated sludge tank that received almost exclusively N in the form of NH
4
+
. Available carbon, in contrast, was significantly negatively correlated with the N2O emitted in the soil fertilized with 80 kg N ha-1 year. The significant negative correlation between the emitted N2O and the carbon to nitrate ratio indicates that the lower the carbon to nitrate ratio the higher the amount of N2O released. Increasing N2O emissions seem to occur at electron donorto-acceptor ratios (CH2O or BOD5-to-nitrate ratios) below 50 in the cropping systems and below 1200–1400 in the waste water treatment plant. The trapped N2O in the soil body down to a depth of 90 cm demonstrates that agricultural production systems seem to contain a considerable pool of N2O which may be reduced to N2 on its way to the atmosphere, which may be transported to other environments or which may be released at sometime in the future.Dedicated to Professor J.C.G. Ottow on the occasion of his 60th birthday 相似文献
5.
François Pimont Jean-Luc Dupuy Rodman R. Linn Sylvain Dupont 《Annals of Forest Science》2011,68(3):523-530
Introduction
Forest fuel management in the context of fire prevention generally induces heterogeneous spatial patterns of vegetation. However, the impact of the canopy structure on both wind flows and fire behavior is not well understood. 相似文献6.
Toxic DNA damage by hydrogen peroxide through the Fenton reaction in vivo and in vitro 总被引:49,自引:0,他引:49
Exposure of Escherichia coli to low concentrations of hydrogen peroxide results in DNA damage that causes mutagenesis and kills the bacteria, whereas higher concentrations of peroxide reduce the amount of such damage. Earlier studies indicated that the direct DNA oxidant is a derivative of hydrogen peroxide whose formation is dependent on cell metabolism. The generation of this oxidant depends on the availability of both reducing equivalents and an iron species, which together mediate a Fenton reaction in which ferrous iron reduces hydrogen peroxide to a reactive radical. An in vitro Fenton system was established that generates DNA strand breaks and inactivates bacteriophage and that also reproduces the suppression of DNA damage by high concentrations of peroxide. The direct DNA oxidant both in vivo and in this in vitro system exhibits reactivity unlike that of a free hydroxyl radical and may instead be a ferryl radical. 相似文献
7.
Sex pheromone of the winter moth, a geometrid with unusually low temperature precopulatory responses
Roelofs WL Hill AS Linn CE Meinwald J Jain SC Herbert HJ Smith RF 《Science (New York, N.Y.)》1982,217(4560):657-659
The sex pheromone for the winter moth, Operophtera brumata (L.), has been identified as the novel compound (Z,Z,Z)-1,3,6,9-nonadecatetraene. The male moths respond to the pheromone at low temperatures (4 degrees to 15 degrees C) and exhibit an upper response limit that coincides with the lower response limit for other reported moth sex pheromone systems. The pheromone attracted two other geometrid species, O. bruceata (Bruce spanworm) and O. occidentalis. 相似文献
8.
[目的] 筛选对板蓝根根腐病有较强拮抗作用的生防菌株。[方法] 采用平板对峙法对137个板蓝根根际土壤样本中分离到的201株拮抗细菌进行测试。[结果] 筛选出1个对板蓝根根腐病菌有强烈抑制作用的菌株Bs-0728。结合显微镜观察确定Bs-0728菌株对板蓝根根腐病的主要致病菌茄腐镰刀菌(Fusarium solani)菌丝生长有较强的抑制作用,导致菌丝生长畸形,弯曲,部分细胞膨大。田间试验结果表明,Bs-0728的发酵液田间防效达72.97%,且增产86.26%。经形态观察、生理生化反应及16S rDNA 序列分析,初步将此拮抗细菌鉴定为枯草芽胞杆菌Bacillus subtilis。[结论] 枯草芽孢杆菌Bs-0728菌株是一株很有应用前景的生防菌株。 相似文献
9.
Batch and upflow column leaching experiments were used to evaluate the nature and extent of Cu and Zn solubilization from contaminated soil by nitrilotriacetic acid (NTA) in 0.025 M NaClO4. In batch soil suspensions, NTA levels of 10?5 to 10?3 M substantially promoted Cu and Zn release from the metal-enriched soil. The ability of NTA to enhance Cu and Zn solubility decreased with increasing solution acidity probably due to competitive binding of NTA by protons and Fe released by hydrous oxide dissolution. However, in the pH range typically encountered in northeastern U.S. soils, soluble metal levels were nearly constant for a given NTA concentration. Leaching soil columns with NTA solutions enhanced Cu release more than Zn, as the enrichment ratio (cumulative metal leached by NTA compared to the 0.025 M NaClO4 control leachate) after 85 pore volumes displacements was 23.6 and 4.3 for Cu and Zn, respectively. While Cu release by 0.01 M CaCl2 differed little from the control, 0.01 M CaCl2 was substantially more effective than 10?5 M NTA in displacing bound Zn. The data reflect different retention mechanisms for Cu and Zn in this soil. 相似文献
10.
Rapid detection of Aujeszky's disease (pseudorabies) virus infection of pigs by direct filter hybridisation of nasal and tonsillar specimens 总被引:1,自引:0,他引:1
A direct filter hybridisation method has been developed to diagnose acute Aujeszky's disease in live pigs. The advantages of the method are easy, fast sample processing; no DNA-purification is needed, and the hybridisation itself is simplified. The direct filter hybridisation method has been tested on pseudorabies virus infected cultured cells, experimentally infected pigs and on specimens from an outbreak of Aujeszky's disease. Virus isolation and filter hybridisation gave comparable results, indicating that the direct filter hybridisation method is a good tool for rapid diagnosis. It is independent of cell culture facilities and the disease can be diagnosed in live animals within 15 hours. 相似文献