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   51篇
  免费   0篇
林业   3篇
农学   1篇
  2篇
水产渔业   6篇
畜牧兽医   34篇
园艺   4篇
植物保护   1篇
  2021年   2篇
  2019年   1篇
  2017年   1篇
  2013年   3篇
  2008年   1篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2004年   5篇
  2003年   5篇
  2001年   6篇
  2000年   1篇
  1997年   1篇
  1992年   2篇
  1990年   2篇
  1989年   4篇
  1988年   3篇
  1987年   2篇
  1986年   1篇
  1983年   2篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1972年   1篇
排序方式: 共有51条查询结果,搜索用时 15 毫秒
1.
2.
Ninety-seven pure-bred Akitas were examined clinically and histologically for sebaceous adenitis. The diagnosis was established histologically in 23 Akitas by demonstrating an inflammatory reaction targeted against the sebaceous glands or a reduction in the number of glands. The clinical course of sebaceous adenitis in the Akita was similar to that seen in other breeds. The first skin lesions occurred mainly on the dorsal midline and ears. Compared with the Poodle, the age at first onset of the disease was more variable and the hair loss affected mainly the undercoat. The progression of sebaceous gland destruction varied between dogs and was not seen in all cases. Because bud-like sebaceous gland proliferation could be identified, it seems that regeneration of the sebaceous glands may occur. An autosomal recessive inheritance appears to be possible. Apart from a genetic background, immune-mediated factors possibly influence the onset and course of sebaceous adenitis.  相似文献   
3.
4.
Papillomaviruses (PVs) are highly species- and site-specific pathogens of stratified squamous epithelium. Although PV infections in the various Felidae are rarely reported, we identified productive infections in six cat species. PV-induced proliferative skin or mucous membrane lesions were confirmed by immunohistochemical screening for papillomavirus-specific capsid antigens. Seven monoclonal antibodies, each of which reacts with an immunodominant antigenic determinant of the bovine papillomavirus L1 gene product, revealed that feline PV capsid epitopes were conserved to various degrees. This battery of monoclonal antibodies established differential expression patterns among cutaneous and oral PVs of snow leopards and domestic cats, suggesting that they represent distinct viruses. Clinically, the lesions in all species and anatomic sites were locally extensive and frequently multiple. Histologically, the areas of epidermal hyperplasia were flat with a similarity to benign tumors induced by cutaneotropic, carcinogenic PVs in immunosuppressed human patients. Limited restriction endonuclease analyses of viral genomic DNA confirmed the variability among three viral genomes recovered from available frozen tissue. Because most previous PV isolates have been species specific, these studies suggest that at least eight different cat papillomaviruses infect the oral cavity (tentative designations: Asian lion, Panthera leo, P1PV; snow leopard, Panthera uncia, PuPV-1; bobcat, Felis rufus, FrPV; Florida panther, Felis concolor, FcPV; clouded leopard, Neofelis nebulosa, NnPV; and domestic cat, Felis domesticus, FdPV-2) or skin (domestic cat, F. domesticus, FdPV-1; and snow leopard, P. uncia, PuPV-2).  相似文献   
5.
Performance of phyllosoma of thesouthern rock lobster (Jasus edwardsii)was examined after feeding Artemia-baseddiets. Survival and growth of newly-hatchedlarvae cultured to Stage III were lower(p < 0.05) when fed 0.8 mm Artemia than1.5 mm or 2.5 mm Artemia alone or 1.5 mmArtemia in combination with pieces ofmussel (Mytilus edulis planulatus) gonad.This could not be attributed to deficiencies inthe composition of fatty acids but appeared tobe due to the inability of larvae to capturesufficient appropriate-sized, enrichedArtemia for their nutritional requirements.There was an indication that survival andgrowth were higher between Stages III and Vwhen fed 2.5 mm Artemia than 1.5 mmArtemia alone or in combination with musselpieces. However, Stage VI larvae grew to asimilar size at Stage VIII when fed 1.5 mm or2.5 mm Artemia. Unexpectedly, larvae fedthe combination of 1.5 mm Artemia plusmussel supplement had lower survival than foundpreviously, and generally lower than when fed 1.5 mm Artemia alone. This was despitean apparent nutritional profile (lipid contentand fatty acid composition) of mussel more akinto that of newly-hatched phyllosoma thanenriched Artemia. On the other hand,survival and growth to Stage VIII were higherwhen larvae were fed alginate pelletscontaining Artemia than when fed 1.5 mmor 2.5 mm Artemia alone.  相似文献   
6.
Large numbers of shoots have been obtained from the excised basal regions of leek plants, cultured on BDS medium. Shoots could be induced optimally upon media within the range of 6.0–8.0 mg 1?1 6-(3-methyl-2-buten-1-ylamino)-purine (2iP) and 1.0–2.0 mg 1?1 napthaleneacetic acid (NAA). Sub-culture of induced shoots onto fresh media, from the above hormone ranges, resulted in further multiplication. Sub-culture, onto fresh medium from the above hormone ranges, of the callus-like region around the bases of induced shoots and adjacent tissue, could also result in shoot production. Internally developing shoot primordia occurred in close proximity to meristematic regions, whereas superficially developing primordia did not show distinct affinities, although there was evidence of localised pockets of meristematic cells amidst senescing explant material at the surface of the culture. Such regions may represent early stages in the formation of the superficial primordia. The production of large numbers of leek shoots in vitro is mentioned in relation to present techniques of micro-propagation and cryopreservation.  相似文献   
7.
Synovial chondrometaplasia was diagnosed in 5 dogs. Four dogs improved dramatically after surgical removal of subsynovial nodules, but the fifth improved only slightly. This potentially treatable condition is recognized in human beings, and has been described in dogs in the German scientific literature. Synovial chondrometaplasia should be suspected if numerous joint mice are visualized radiographically, without an obvious inciting cause. It also should be suspected when periarticular osteophytes are found radiographically in unusual locations.  相似文献   
8.
Shoots have been produced on callus derived from onion set and from seedling radicle tissue. Whilst callus of set origin responded optimally to medium containing the cytokinin 6-(3-methyl-2-buten-1-ylamino)-purine (2iP) at 2.00 mg l?1 and naphthaleneacetic acid (NAA) at 0.06 mg l?1, seedling radicle callus showed a range of response. The medium used for callus initiation, the age of callus, and the provision of a dark period following inoculation on to the organogenesis medium have been shown to be critical for shoot formation. A limited number of embryoids have been produced from cultures; their occurrence was usually associated with an increase in shoot numbers for the generative callus tissue. Meristemoid areas have been observed in light micrographs of callus cultured upon organogenesis media.  相似文献   
9.
10.
Salmonella: immune responses and vaccines   总被引:2,自引:0,他引:2  
Salmonella infections are a serious medical and veterinary problem world-wide and cause concern in the food industry. Vaccination is an effective tool for the prevention of Salmonella infections. Host resistance to Salmonella relies initially on the production of inflammatory cytokines leading to the infiltration of activated inflammatory cells in the tissues. Thereafter T- and B-cell dependent specific immunity develops allowing the clearance of Salmonella microorganisms from the tissues and the establishment of long-lasting acquired immunity to re-infection. The increased resistance that develops after primary infection/ vaccination requires T-cells cytokines such as IFNgamma TNFalpha and IL12 in addition to opsonising antibody. However for reasons that are not fully understood seroconversion and/or the presence of detectable T-cell memory do not always correlate with the development of acquired resistance to infection.Whole-cell killed vaccines and subunit vaccines are used in the prevention of Salmonella infection in animals and in humans with variable results. A number of early live Salmonella vaccines derived empirically by chemical or u.v. mutagenesis proved to be immunogenic and protective and are still in use despite the need for repeated parenteral administration. Recent progress in the knowledge of the genetics of Salmonella virulence and modern recombinant DNA technology offers the possibility to introduce multiple defined attenuating and irreversible mutations into the bacterial genome. This has recently allowed the development of Salmonella strains devoid of significant side effects but still capable of inducing solid immunity after single oral administration. Live attenuated Salmonella vaccines have been used for the expression of heterologous antigens/proteins that can be successfully delivered to the immune system. Furthermore Salmonella can transfer plasmids encoding foreign antigens under the control of eukaryotic promoters (DNA vaccines) to antigen-presenting cells resulting in targeted delivery of DNA vaccines to these cells. Despite the great recent advances in the development of Salmonella vaccines a large proportion of the work has been conducted in laboratory rodents and more research in other animal species is required.  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