全文获取类型
收费全文 | 1676篇 |
免费 | 114篇 |
国内免费 | 1篇 |
专业分类
林业 | 118篇 |
农学 | 61篇 |
基础科学 | 12篇 |
236篇 | |
综合类 | 311篇 |
农作物 | 64篇 |
水产渔业 | 212篇 |
畜牧兽医 | 603篇 |
园艺 | 58篇 |
植物保护 | 116篇 |
出版年
2023年 | 16篇 |
2022年 | 10篇 |
2021年 | 35篇 |
2020年 | 52篇 |
2019年 | 49篇 |
2018年 | 58篇 |
2017年 | 50篇 |
2016年 | 40篇 |
2015年 | 40篇 |
2014年 | 59篇 |
2013年 | 75篇 |
2012年 | 100篇 |
2011年 | 139篇 |
2010年 | 70篇 |
2009年 | 57篇 |
2008年 | 107篇 |
2007年 | 99篇 |
2006年 | 89篇 |
2005年 | 92篇 |
2004年 | 104篇 |
2003年 | 111篇 |
2002年 | 85篇 |
2001年 | 38篇 |
2000年 | 24篇 |
1999年 | 12篇 |
1998年 | 12篇 |
1997年 | 15篇 |
1996年 | 7篇 |
1995年 | 14篇 |
1994年 | 10篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 10篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1978年 | 7篇 |
1977年 | 8篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1973年 | 6篇 |
1972年 | 3篇 |
1970年 | 3篇 |
排序方式: 共有1791条查询结果,搜索用时 0 毫秒
991.
992.
Over the past 20 years, there have been significant inroads into understanding the roles of antimicrobial peptides in homeostatic functions and their involvement in disease pathogenesis. In addition to direct antimicrobial activity, these peptides participate in many cellular functions, including chemotaxis, wound healing and even determination of canine coat colour. Various biological and genetic approaches have helped to elucidate the role of antimicrobial peptides with respect to innate immunity and host defense. Associations of antimicrobial peptides with various skin diseases, including psoriasis, rosacea and atopic dermatitis, have been documented in humans. In the longer term, therapeutic modulation of antimicrobial peptide expression may provide effective new treatments for disease. This review highlights current knowledge about antimicrobial peptides of the skin and circulating leukocytes, with particular focus on relevance to physiology and disease in companion animals. 相似文献
993.
A 9 yr old spayed female German shepherd dog was referred for MRI of the thoracic and lumbar spine because she had clinical signs of chronic neurogenic bladder dysfunction of an unknown cause. Transverse T2-weighted images identified a type II split cord malformation (i.e., diastematomyelia) in the thoracic spine. Split cord malformations are forms of spinal dysraphism where the abnormal development of spinal cord results in sagittal splitting of a portion of the cord into two hemicords. The location of the lesion in the thoracic spine was consistent with the dog's clinical signs of an upper motor neuron bladder. Split cord malformations that occur in humans have similar MRI characteristics and can result in similar clinical signs as those identified in the dog described in this report. 相似文献
994.
995.
Beutlich J Guerra B Schroeter A Arvand M Szabo I Helmuth R 《Berliner und Münchener tier?rztliche Wochenschrift》2012,125(3-4):89-95
In recent years in France, England, Wales, Denmark and the USA about 500 human infections occurred, which were caused by multidrug-resistant Salmonella enterica Serovar (S.) Kentucky isolates displaying high-level resistance to fluoroquinolones (ciprofloxacin, MIC > or = 4 mg/l). The responsible clone was referred to as ST198-X1.To determine whether this clone is also present in German S. Kentucky isolates, the National Reference Laboratory for Salmonella (NRL-Salm) at the BfR analyzed the trend of S. Kentucky isolates received over the past years. Since 2010 the first entries of highly ciprofloxacin resistant S. Kentucky isolates, especially from turkey meat products, were recorded. 15 isolates originating from animal or food as well as one human isolate displayed MIC values of > or = 8 mg/l to ciprofloxacin. Molecular biological typing methods showed the in Germany isolated S. Kentucky isolates to be identical to the clone described by Le Hello et al. (2011) and to carry a multidrug resistance conferring region (SGI1). Since fluoroquinolones are considered by the WHO in human and veterinary medicine as drugs of critical importance, this trend demands attention. The implementation of mitigation strategies for this highly resistant clone seems to be required. 相似文献
996.
997.
Brian Wilcock Anne Wilcock Katherine Bottoms 《The Canadian veterinary journal. La revue veterinaire canadienne》2012,53(4):430-434
Comparison of the annual prevalence of feline postvaccinal sarcomas among 11 609 feline skin mass submissions from 1992 to 2010 revealed no decrease in disease prevalence or increase in the age of affected cats in response to changes in vaccine formulation or recommended changes in feline vaccination protocols. 相似文献
998.
Abutarbush SM Schunicht OC Wildman BK Hannon SJ Jim GK Ward TI Booker CW 《The Canadian veterinary journal. La revue veterinaire canadienne》2012,53(1):57-62
This commercial field trial compared the efficacy of enrofloxacin and ceftiofur sodium in beef cattle at high risk of developing undifferentiated fever (UF), also known as bovine respiratory disease (BRD) that received tilmicosin at feedlot arrival, were diagnosed and initially treated for UF with tilmicosin, and subsequently required a second UF treatment (first relapse). Feedlot cattle (n = 463) were randomly assigned to 2 experimental groups: ENRO or CEF. Second UF relapse, 3rd UF relapse, overall case fatality and BRD case fatality rates were lower in the ENRO group than in the CEF group (P < 0.05). There were no differences in average daily gain (allocation to re-implant date), chronicity, histophilosis case fatality or miscellaneous case fatality rates between the groups (P ≥ 0.05). A per-animal economic advantage of Can$57.08 was calculated for the ENRO group versus the CEF group. In feedlot cattle in western Canada at high risk of developing UF, it was more cost effective to administer enrofloxacin than ceftiofur sodium for treatment of UF relapse. 相似文献
999.
Vordermeier M Ameni G Berg S Bishop R Robertson BD Aseffa A Hewinson RG Young DB 《Comparative immunology, microbiology and infectious diseases》2012,35(3):227-232
Bovine tuberculosis in domestic livestock such as cattle is an economically important disease with zoonotic potential, particularly in countries with emerging economies. We discuss the findings of recent epidemiological and immunological studies conducted in Ethiopia on host susceptibility differences between native zebu and the exotic Holstein-Friesian cattle that are increasingly part of the Ethiopian National herd, due to the drive to increase milk yields. These findings support the hypothesis that native Zebu cattle are more resistant to bovine tuberculosis. We also summarise the results of experimental infections that support the epidemiological data, and of laboratory experiments that suggest a role for the innate immune response, and in particular interleukin-6, in the outcome of bovine tuberculosis infection. 相似文献
1000.