首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   65篇
  免费   4篇
  国内免费   1篇
林业   1篇
  1篇
综合类   3篇
农作物   3篇
水产渔业   3篇
畜牧兽医   54篇
园艺   1篇
植物保护   4篇
  2018年   1篇
  2017年   3篇
  2015年   1篇
  2014年   2篇
  2013年   2篇
  2012年   3篇
  2011年   1篇
  2010年   2篇
  2009年   1篇
  2007年   3篇
  2005年   2篇
  2004年   1篇
  2003年   3篇
  2002年   1篇
  2001年   1篇
  2000年   1篇
  1999年   2篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1993年   3篇
  1990年   1篇
  1989年   3篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1983年   4篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1972年   5篇
  1968年   1篇
  1961年   1篇
排序方式: 共有70条查询结果,搜索用时 15 毫秒
41.
A microplate enzyme immunoassay (EIA) is described for measuring IgG antibody to Babesia bovis in cattle serum. B. Bovis antibody status (whether positive or negative) and the amount of B. Bovis antibody (EIA score), were measured by comparison with reference serums. The EIA was shown to be specific for B. Bovis, and EIA score correlated well with EIA titre. Comparison of EIA with the Indirect Fluorescent Antibody Test (IFAT) showed more than 95% agreement between the methods and disagreement in only 1.6% of serum samples tested. The remaining 3.2% were positive by EIA and suspected positive by IFAT. The EIA was shown, by titrating positive serums, to be more sensitive than IFAT, which explained its tendency to detect more positive serums than IFAT. EIA detected B. bovis antibody in experimentally infected cattle by day 14 post infection (pi) and for at least 268 days pi. EIA score for B. bovis antibody in immune cattle increased significantly (p less than 0.05) following heterologous strain challenge.  相似文献   
42.
43.
Complex interactions between Chlamydia pecorum infection, the immune response and disease exist in the koala. We used quantitative polymerase chain reaction to investigate the relationship between C. pecorum infectious load and ocular and urogenital tract disease. Chlamydia pecorum shedding was generally higher in animals with chronic, active disease than in animals with inactive disease. The absence of ocular disease was generally associated with low levels of shedding, but relatively high levels of shedding in the urogenital tract were detected in some koalas without clinical disease signs. These results suggest a complex disease pathogenesis and clinical course in C. pecorum-infected koalas.  相似文献   
44.
As part of a survey of patterns of disease in relation to air pollution in various towns, atmospheric concentrations of metals were measured in Armadale, West Lothian. The first survey of metallic pollutants in the environment consisted of measuring selected metal concentrations in indigenous Hypnum cupressiforme throughout Armadale. As in other surveys using this moss, Hypnum proved to be most useful in collecting at least 9 metals from the atmosphere. Some values, such as Fe, were significantly lower in Armadale, than those levels found in a similar survey sited around a steelworks in Consett, England. However, other metals such as Cu were present in much higher concentrations. All metals measured (apart from Pb values, which showed the influence of traffic routes) revealed an increasing concentration from the periphery of the town towards the vicinity of Armadale's steel foundry.  相似文献   
45.
AIM: To validate the use of para-aminohippuric acid (PAH) as a marker for measuring blood flow in wethers consuming a mixed diet of locoweed and blue grama hay.

METHODS: Fourteen sheep, stratified by bodyweight (BW), were assigned to one of three treatments: 0.8 mg swainsonine (SW)/kg BW (HI), 0.2 mg SW/kg BW (LO), and no SW (Control). Sheep were fed various ratios of locoweed and blue grama hay to deliver SW treatments, for 28 days prior to infusion of PAH. Concentrations of SW and activities of alkaline phosphatase (Alk-P) and aspartate aminotransferase (AST) in serum were measured to confirm exposure to SW and subclinical intoxication. A single 20-ml injection of 5% PAH was delivered into the jugular vein after subclinical intoxication had been achieved. Blood samples were collected and serum analysed for PAH immediately prior to injection, then every 5 min from 5–30 min, and every 10 min from 30–60 min, following injection of PAH.

RESULTS: Effective delivery of SW was evident from the greater concentrations of SW measured in the serum of HI compared with LO animals (p<0.05). No significant differences were detected in the rate of elimination (range 0.097–0.108 L/min), elimination half-life (range 6.62–7.24 min), apparent volume of distribution for the central compartment (range 7.14–9.72 L), and clearance (range 0.73–0.92 L/min) of PAH, between treatments.

CONCLUSIONS: Subclinical intoxication with SW did not affect the pharmacokinetics of PAH. Thus, use of downstream dilution of PAH is a valid method to determine the rate of blood flow in nutrient flux experiments that involve consumption of locoweed.  相似文献   
46.
An experimental inactivated Salmonella enteritidis PT4 vaccine, containing 10(11) cfu/ml and 50 per cent oil adjuvant, was used in laboratory vaccination trials in chickens. A single subcutaneous vaccination at three weeks or two vaccinations at three and six weeks old provided good protection against challenge with 10(9) cfu or 10(8) cfu of virulent organisms administered intramuscularly or intravenously at five and eight weeks old, respectively. The degree of protection was assessed according to the severity of the clinical signs, the mortality, the post mortem lesions and the recovery of the challenge organisms from post mortem material.  相似文献   
47.
The incidence of leg abnormalities was studied in 216 male Ross I broilers, fed for 10 weeks on a diet containing 12.5 per cent extracted rapeseed. Regular serological examination showed that the birds remained free from Mycoplasma gallisepticum, Mycoplasma synoviae and avian reovirus throughout the period of investigation. Post mortem examination and radiographs were performed when birds were culled due to leg deformities or at the end of the experiment. Leg abnormalities were seen in 19.4 per cent of the birds which represents a very significant increase above that currently seen in commercial flocks. They consisted of a large range of skeletal deformities including valgus and varus deformities, dyschondroplasia, slipped gastrocnemius tendons, dislocated condyles, rotation and penetration of the distal tibiotarsus and fractured fibulas. Multiple forms of leg abnormality were often observed in individual birds and their association is briefly discussed.  相似文献   
48.
A combination of stationary culture and suspension culture was used to produce litre quantities of Babesia bovis parasites suitable for use as live vaccine. The Australian vaccine strain of B bovis, Ka, was maintained continuously in microaerophilus stationary phase (MASP) cultures, and for a short period in batch and flow-through spinner flask cultures. Although continuous culturing was not achieved in spinner flasks, the production of litre quantities of heavily parasitised erythrocytes was achieved more simply than by using MASP cultures. Ka strain parasites were maintained continuously in MASP culture for 174 days without altering their virulence or immunogenicity when compared to calf-derived parasites. Cultured parasites also survived storage at 4 degrees C for six days in basal medium, adding to their potential usefulness as a live vaccine in field situations.  相似文献   
49.
The purpose of this study was to evaluate the effect of cooling ovarian tissue on pig pre-antral follicles. Ovaries were maintained in saline solution (0.9%) at 4 or 20 degrees C for 6, 12 or 18 h. After storage, pre-antral follicles were morphologically evaluated. While primordial follicles were not affected by the storage, the percentage of morphologically normal growing follicles was significantly reduced in ovarian tissue stored at 20 degrees C for 12 or 18 h. To test the viability of stored follicles, growing follicles isolated from ovaries stored at 4 degrees C for 18 h and at 20 degrees C for 6 h were cultured for 3 days. Follicles stored in either condition presented the same growth pattern in vitro as fresh follicles. We conclude that storage of pig ovaries at 4 degrees C for up to 18 h or at 20 degrees C for up to 6 h does not affect the morphology of growing follicles or their ability to grow in vitro.  相似文献   
50.
The western barred bandicoot (Perameles bougainville) is an endangered species, free ranging on only two islands off the coast of Western Australia (Dorre and Bernier Islands). Conservation efforts are currently directed at reintroducing these marsupials into predator-proof enclosures and habitats in historical distribution ranges on the mainland in the southwest of Western Australia and in South Australia. In September 2000, 19 western barred bandicoots were captured on Bernier Island for translocation, and 11 of these had evidence of at least one of the following eye conditions: corneal opacity, conjunctivitis, ocular discharge, and blepharitis. Five bandicoots were examined, and conjunctival and cloacal swabs were collected. Polymerase chain reaction for Chlamydiales was positive in four bandicoots. Four Chlamydiales types were identified by gene sequencing, including a strain of Chlamydia pecorum different from strains previously found in koalas and several new Chlamydiales genotypes. The bandicoots responded excellently to treatment with oxytetracyline weekly for 6 wk, and topical oxytetracycline and neomycin were administered topically to both eyes s.i.d. for 4 mo.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号