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   416篇
  免费   43篇
林业   14篇
农学   6篇
基础科学   1篇
  47篇
综合类   77篇
农作物   14篇
水产渔业   34篇
畜牧兽医   246篇
园艺   5篇
植物保护   15篇
  2022年   3篇
  2021年   4篇
  2020年   7篇
  2019年   10篇
  2018年   7篇
  2017年   15篇
  2016年   13篇
  2015年   15篇
  2014年   8篇
  2013年   21篇
  2012年   15篇
  2011年   22篇
  2010年   14篇
  2009年   11篇
  2008年   13篇
  2007年   21篇
  2006年   30篇
  2005年   22篇
  2004年   11篇
  2003年   26篇
  2002年   21篇
  2000年   7篇
  1999年   3篇
  1998年   12篇
  1997年   12篇
  1996年   5篇
  1995年   3篇
  1994年   4篇
  1993年   12篇
  1992年   4篇
  1991年   7篇
  1990年   3篇
  1989年   5篇
  1988年   4篇
  1987年   5篇
  1986年   5篇
  1985年   7篇
  1984年   3篇
  1982年   3篇
  1979年   3篇
  1977年   4篇
  1973年   3篇
  1972年   4篇
  1971年   2篇
  1970年   2篇
  1969年   2篇
  1945年   3篇
  1944年   2篇
  1941年   2篇
  1910年   2篇
排序方式: 共有459条查询结果,搜索用时 834 毫秒
91.
Waste milk samples from 103 farms in England and Wales were examined for the presence of β-lactam antibiotics and ESBL-producing Enterobacteriaceae. Approximately 10 months after the initial sampling, further waste milk, environmental and faecal samples from farms shown to be positive for CTX-M Escherichia coli were investigated further. Isolates with an ESBL phenotype were tested by PCR for the presence of blaCTX-M, blaOXA, blaSHV and blaTEM genes. Isolates positive for blaCTX-M were sequenced to determine CTX-M type. Representative isolates were further examined by PFGE, plasmid replicon typing and serotyping. Of particular interest, 21.4% of waste milk samples contained residues of the cephalosporin cefquinome, which was significantly associated with CTX-M bacteria. Such bacteria occurred in 5.8% of the waste milk samples (including 3.9% CTX-M E. coli). CTX-M types identified were 1, 14, 14b and 15, but none of the E. coli were serotype O25, the serotype of the human pandemic strain.  相似文献   
92.
For the response to a zoonotic disease outbreak to be effective, animal health authorities and disease specialists must be involved. Animal health measures are commonly directed at known diseases that threaten the health of animals and impact owners. The measures have long been applied to zoonotic diseases, including tuberculosis and brucellosis, and can be applied to emerging diseases. One Health (veterinary, public, wildlife and environmental health) and all-hazards preparedness work have done much to aid interdisciplinary understanding and planning for zoonotic diseases, although further improvements are needed. Actions along the prevention, preparedness, response and recovery continuum should be considered. Prevention of outbreaks consists largely of import controls on animals and animal products and biosecurity. Preparedness includes situational awareness, research, tool acquisition, modelling, training and exercises, animal movement traceability and policy development. Response would include detection systems and specialized personnel, institutions, authorities, strategies, methods and tools, including movement control, depopulation and vaccination if available and appropriate. The specialized elements would be applied within a general (nationally standardized) system of response. Recovery steps begin with continuity of business measures during the response and are intended to restore pre-event conditions. The surveillance for novel influenza A viruses in swine and humans and the preparedness for and response to the recent influenza pandemic illustrate the cooperation possible between the animal and public health communities.  相似文献   
93.
94.
95.
Tendon lesions have been studied in 35 broiler or broiler breeder fowls. Tendon rupture most commonly affected the gastrocnemius and flexor muscles but was also seen in cranial tibial muscles (four cases) and the patellar tendon (one case). In nine birds tenosynovitis, characterised by a marked inflammatory response, was identified. In others, however, rupture occurred without appreciable inflammation and these cases were concluded to be comparable to spontaneous tendon rupture in other species. A traumatic aetiology is suggested in these cases, as other pelvic limb tendons or ligament rupture was a frequent concomitant finding. Degenerative tendon lesions were present but it is uncertain whether such changes are primary or secondary to rupture.  相似文献   
96.
97.
98.
99.
100.
Background: Canine distemper virus (CDV) infects families in the order Carnivora. As a preventive measure, vaccinations against CDV are frequently given to mustelids in captive environments.

Objectives: Our objectives were to compare the utility between two modified-live virus canine distemper vaccines (MLV CDV's), Fervac-D® (no longer manufactured) and Galaxy-D® (now manufactured by MSD Animal Health as part of a multivalent vaccine), in developing an immune response in wild-caught fishers.

Animals and methods: The Pennsylvania Fisher Reintroduction Project (PFRP) used 14 wild-caught fishers during one year of the project to evaluate the utility of vaccinations against CDV as part of any reintroduction project. Fishers were injected subcutaneously in the nape of the neck with their designated vaccine.

Results: Fervac-D® did not effectively stimulate development of a serologic antibody response, whereas Galaxy-D® had adequate seroconversion or rise of titer levels to suggest that the general use of MLV CDV may be suitable in fishers pending further studies.

Conclusion: We recommend that future studies be conducted, evaluating the use of currently produced vaccines in fishers. Future research should also focus on the length of days required between administration of primary and booster vaccines to achieve sufficient immune response.

Clinical importance: If only primary doses are required, then hard-release reintroduction projects for fishers could be recommended. If primary and booster vaccines are required then soft-release reintroduction projects should be recommended that include captive management periods, allowing for appropriate vaccination intervals needed to maximize the probability of protection against CDV.  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