不同载体对牛粪30℃厌氧处理性能的影响

在30℃条件下,观察尼龙纤维、聚丙烯网状球、玻璃纤维作为微生物载体对5.34%牛粪厌氧发酵沼气产量、总COD去除率、发酵产物微生物数量及辅酶F420活性的影响。结果表明,添加尼龙纤维和聚丙烯载体显著提高牛粪厌氧发酵的沼气产量(P<0.05)和总COD去除率(P<0.05),玻璃纤维对沼气产量和总COD去除率的影响未达到显著水平。尼龙纤维、聚丙烯球和玻璃纤维使随污泥排出而流失的细菌数量分别降低11.30%(P<0.05)、22.84%(P<0.01)及13.01%(P<0.05)。     

镉离子在三正辛胺为载体的支撑液膜中的传输

用三正辛胺为载体，聚丙烯微孔膜为支撑体的支撑液膜体系处理含镉料液，得出影响镉离子传输的参数。     

Investigation of wild caught whitefish, Coregonus lavaretus (L.), for infection with viral haemorrhagic septicaemia virus (VHSV) and experimental challenge of whitefish with VHSV

Abstract One hundred and forty-eight wild whitefish, Coregonus lavaretus (L.), were caught by electrofishing and sampled for virological examination in December 1999 and 2000, during migration from the brackish water feeding grounds to the freshwater spawning grounds, where the whitefish may come into contact with farmed rainbow trout. All samples were examined on cell cultures. No viruses were isolated. Three viral haemorrhagic septicaemia virus (VHSV) isolates of different origin were tested in infection trials by immersion and intraperitoneal (IP) injection, using 1.5 g farmed whitefish: an isolate from wild caught marine fish, a farmed rainbow trout isolate with a suspected marine origin and a classical freshwater isolate. The isolates were highly pathogenic by IP injection where 99-100% of the whitefish died. Using an immersion challenge the rainbow trout isolates were moderately pathogenic with approximately 20% mortality, whereas the marine isolate was virtually non-pathogenic. At the end of the experiment it was possible to isolate VHSV from survivors infected with the marine and suspected marine isolates. Because of the low infection rate in wild whitefish in Denmark, the role of whitefish in the spread of VHSV in Denmark is probably not significant. The experimental studies, however, showed that whitefish are potential carriers of VHSV as they suffer only low mortality after infection but continue to carry virus.     

A sensitive non-destructive method for detecting IPNV carrier Atlantic salmon, Salmo salar L., by culture of virus from plastic adherent blood leucocytes

In populations of Atlantic salmon in sea water, infectious pancreatic necrosis virus (IPNV) could be detected by standard virological culture methods in sonicated kidney homogenates and in mucus samples (gill, skin and rectum) from 14 and nine of 25 fish, respectively, but all fish were positive by virus culture from lysates of kidney macrophages and adherent blood leucocytes. In fish which tested negative for IPNV by the standard method of detection, the virus could be detected using adherent blood leucocytes isolated on a Percoll gradient from as little as 10 microL of blood. The blood sample could be stored for at least 3 days in a heparinized tube on ice before preparing the plastic adherent leucocytes. Furthermore, the latter could be prepared without prior fractionation on Percoll simply by incubating whole blood (33 microL) in cell culture medium (66 microL) in 96-well plates overnight and washing away the non-adherent cells before lysing the adherent cells and inoculation of the lysate onto CHSE-214 cells. This highly sensitive method for detecting IPNV-carriers is therefore very suitable for non-destructive sampling of fish in the field.     

基于产业融合视角的新型渔业经营主体发展研究

在国家实施乡村振兴战略的大背景下,推进渔业一二三产业融合是顺应渔业发展新形势的必然要求, 也是渔业转方式调结构实现转型升级的有效途径。新型经营主体是实现渔业产业融合的重要组织载体,已成为 促进渔业产业融合、提升渔业竞争力的重要力量。我国新型经营主体数量保持较快增长,2017 年,渔民专业合 作社增长率为 11.7%,渔业家庭农场增长率为 23.3%,且新型经营主体的产业融合特征更加凸显,辐射带动作用 也日趋增强,但总体数量占比仍然较小,区域差异发展较大。在阐述新型经营主体和渔业产业融合关系的基础上, 分析新型经营主体在推进产业融合过程中存在的主要问题,提出相应的对策建议,包括应完善产业融合中相关 主体利益联结机制,优化产业融合外部支撑环境,提升新型经营主体科技创新应用能力,充分发挥新型经营主 体带头作用,激发主体生机活力,推进渔业产业融合。     

Listeriosis in sheep. Isolation of Listeria monocytogenes from organs of slaughtered animals and dead animals submitted for post-mortem examination

The udders from 13 culled ewes and liver, spleen, kidney, lung and brain from 15 lambs, 11 months old, were examined for the presence of Listeria monocytogenes (Lm) at slaughter. Lm was isolated from 1 of 13 udders, from 6 of the 15 brains and from 0–4 of the other organs from each of the 15 lambs.Internal organs from 68 sheep submitted for post-mortem examination were examined in the same way. Lm was isolated from 25 of these animals. Lm was isolated from the brain of 7 of 9 animals with encephalitis, and from 0–3 of the other 4 organs examined. Lm was also isolated from 10–20 % of the organs from animals with other diagnoses. Altogether 9 of 10 animals with encephalitis and 16 of 58 with other diagnoses (28 %) were found to harbour this organism.     

Factor VIII activity in canine von Willebrand disease

This study was conducted to determine the relationship between factor VIII (FVIII) activity and von Willebrand factor antigen (vWf:Ag) concentration in canine von Willebrand Disease (vWD). In addition, the clinical utility of measuring FVIII activity in vWD was assessed. This was performed by the concurrent analysis of both FVIII activity and vWf:Ag concentration in three breeds of dogs, namely Dobermans (n=183), Scottish Terriers (n=169), and Labrador Retrievers (n=146). In the three breeds tested, linear regression analysis illustrated a positive relationship between FVIII activity and vWf:Ag concentration. This was reaffirmed in the Doberman and Scottish Terrier breeds, in which dogs with vWf:Ag concentrations < 50 CU/dL ("carriers") had lower median FVIII activities than dogs with vWf:Ag concentrations > 70 CU/dL ("normals"). The determination of various FVIII "cut-off" values was a poor test to separate Dobermans with and without clinical signs of hemorrhage attributable to vWD. In addition, the occurrence of hemorrhage in Dobermans with vWf:Ag concentrations < 50 CU/dL was not influenced by the FVIII activity. Various tests were performed to determine if the measurement of FVIII activity aided in the identification of "carriers" of the vWD gene in the Doberman and Scottish Terrier breeds. These included the use of optimal FVIII "cut-off" values for each breed and a FVIII "cut-off" value of 55 CU/dL; FVIII/vWf:Ag ratios and FVIII/vWf:Ag ratio "cut-off" values; and linear regression analysis of vWf:Ag concentration against FVIII activity. Of all these tests, only the determination of FVIII/vWf:Ag ratios appeared to have promise for "carrier" detection. The data in the present study indicated that routine FVIII assessment in vWD is not warranted; however, measurement of FVIII activity may be of use in confirming the "carrier" status of vWD.     

水溶性壳聚糖纳米载体蛋白药物的体外释放模型

[目的]探讨水溶性壳聚糖（WSC）纳米蛋白药物载体的体外释放规律。[方法]以牛血清蛋白（BSA）为模型药物,分别采用动力学模型、Weibull模型、Gompertz模型、Logistic模型、Higuchi模型对纳米粒子的蛋白释放进行拟合试验。[结果]供试7个模型中,除Higuchi和Logistic模型外,其余模型均能较好地拟合BSA的释放情况。[结论]Gompertz二级模型能很好地拟合WSC纳米载体体系BSA的释放规律,且模型参数具备实际的物理意义。     

β—1,3—葡聚糖酶基因植物表达载体的构建

采用ＰＣＲ的方法,对严自大麦ｃＤＮＡ克隆的β－１,３－葡聚糖酶基因进行了扩增,在此基因的５’及３’端分别加入了克隆所需的ＸｂａＩ和ＳｓｔＩ限性酶切位点,定向克隆到经改造的质粒载体ｐＢｉｎｈ中,获得了含有β－１,３－葡聚糖酶基因的植物表达载体ｐＢｉｎｈ－Ｇｌｕ。     

Establishment of Azorhizobium caulinodans in the rhizosphere of wetland rice (Oryza sativa L.)

 Azorhizobium caulinodans strongly colonized the rhizosphere of rice plants after incorporation of Sesbania rostrata in a field trial throughout the growing season and during the fallow period until 19 weeks after incorporation of S. rostrata. A. caulinodans became well established in the rhizosphere (7.17 log cfu g^–1 dry rice root) and colonized subsequent S. rostrata test plants. Three traditional and three improved high-yielding rice varieties were inoculated with A. caulinodans under gnotobiotic conditions. In none of the combinations did acetylene reduction activity significantly increase. Ethylene production on colonized rice roots only started after the growth medium had been supplemented with an extra C source (0.1 to 0.25% Na-lactate). This indicates that the bacterial nitrogenase activity is limited by energy supply. Four possible inoculant-carriers (peat, coir dust, bagasse, rice straw) were compared for long-term survival of the bacterial strain. Independent of the storage temperature (26  °C or 4  °C), the survival of A. caulinodans in peat and coir dust was very high during a 12-month period (>8 log cfu g^–1 dry carrier), whereas the bagasse and rice straw carriers showed a serious decline from 3 months onwards. Received: 6 April 1999