全文获取类型
收费全文 | 2376篇 |
免费 | 133篇 |
国内免费 | 4篇 |
专业分类
林业 | 71篇 |
农学 | 61篇 |
基础科学 | 14篇 |
258篇 | |
综合类 | 439篇 |
农作物 | 70篇 |
水产渔业 | 88篇 |
畜牧兽医 | 1354篇 |
园艺 | 37篇 |
植物保护 | 121篇 |
出版年
2020年 | 28篇 |
2019年 | 30篇 |
2018年 | 36篇 |
2017年 | 35篇 |
2016年 | 41篇 |
2015年 | 24篇 |
2014年 | 46篇 |
2013年 | 95篇 |
2012年 | 94篇 |
2011年 | 84篇 |
2010年 | 61篇 |
2009年 | 64篇 |
2008年 | 101篇 |
2007年 | 76篇 |
2006年 | 82篇 |
2005年 | 80篇 |
2004年 | 81篇 |
2003年 | 92篇 |
2002年 | 70篇 |
2001年 | 79篇 |
2000年 | 65篇 |
1999年 | 60篇 |
1998年 | 23篇 |
1997年 | 18篇 |
1996年 | 18篇 |
1995年 | 18篇 |
1993年 | 24篇 |
1992年 | 59篇 |
1991年 | 57篇 |
1990年 | 52篇 |
1989年 | 28篇 |
1988年 | 52篇 |
1987年 | 42篇 |
1986年 | 54篇 |
1985年 | 53篇 |
1984年 | 33篇 |
1983年 | 29篇 |
1982年 | 17篇 |
1979年 | 34篇 |
1978年 | 17篇 |
1977年 | 19篇 |
1976年 | 24篇 |
1975年 | 22篇 |
1974年 | 17篇 |
1973年 | 31篇 |
1972年 | 22篇 |
1971年 | 20篇 |
1970年 | 17篇 |
1969年 | 24篇 |
1967年 | 17篇 |
排序方式: 共有2513条查询结果,搜索用时 31 毫秒
21.
C. W. Locuson P. Williams J. M. Adcock J. S. Daniels 《Journal of veterinary pharmacology and therapeutics》2016,39(2):122-130
The dog CYP1A2 enzyme is likely an important contributor to the metabolism of veterinary drugs. Dog CYP1A2 is expressed in liver, plus it is inducible and polymorphic, creating the potential for intersubject differences in pharmacokinetics. Hence, the ability to probe dog CYP1A2 activity and inhibition is relevant toward veterinary drug development and drug–drug interaction assessment. Previous studies have relied on human probes with questionable specificity for CYP1A2, so it was hypothesized that recombinant CYP1A2 could be used to find a specific CYP1A2 substrate. Intrinsic clearance experiments demonstrated that tizanidine was a substrate of CYP1A2. Profiling of tizanidine metabolites generated by CYP1A2 identified the imidazole metabolite that was detectable in dog plasma. The imidazole metabolite was subsequently used to evaluate tizanidine as a CYP1A2 probe. Co‐administration of the CYP1A inhibitor enrofloxacin with tizanidine significantly decreased (30%; n = 3) the formation of the imidazole metabolite vs. control experiments. As enrofloxacin is a weak inhibitor, further studies are required to confirm the sensitivity of tizanidine as an in vivo probe. However, tizanidine may be a more selective CYP1A2 probe than phenacetin when conducting in vitro studies due to the presence of other phenacetin‐metabolizing enzymes in dog liver microsomes. 相似文献
22.
23.
24.
Mechanical and Thermal Sensory Testing in Normal Chondrodystrophoid Dogs and Dogs with Spinal Cord Injury caused by Thoracolumbar Intervertebral Disc Herniations 下载免费PDF全文
25.
26.
27.
28.
29.
Molecular and serologic characterization, pathogenicity, and protection studies with infectious bronchitis virus field isolates from California 总被引:6,自引:0,他引:6
In this study, we characterized three variant infectious bronchitis virus (IBV) strains isolated in 2003 and 2004 from broiler chickens in California and compared them to previously isolated California variant viruses and to common vaccine serotypes used in the United States. We conducted genetic, serologic, and pathogenicity studies on all three isolates, then tested different vaccines against one of the viruses. Genetically the three variant IBV strains, designated CA557/03, CA706/03, and CA1737/04, were not related to each other. GenBank BLAST database search and phylogenetic analysis of the hypervariable region of the S1 subunit of the spike gene to determine the most closely related viruses to the three variants showed the CA557/03 variant to be 81.8% similar to the CAV/CA56b/91 whereas the CA706/03 and CA1737/04 variant viruses were only distantly related to Dutch/D1466/81 (72.2%), a vaccine strain used in Europe, and Korea/K142/02 (72.7%), a Korean field isolate, respectively. Cross virus-neutralization testing showed that none of the 2003-04 California IBV variant viruses were serologically related to each other or to Ark, Conn, or Mass vaccine strains. In addition the CA1737/04 isolate was also tested against DE072 and found not to be serologically related. All three variant viruses were pathogenic in 1-wk-old broilers and vaccination with Mass/Conn followed by Holland/Conn provided 80% protection against the CA1737/04 virus. The 2003-04 California variant viruses were not compared with variants isolated in California during 1970s and 1980s because, to our knowledge, no genetic information is available and those viruses are no longer obtainable. This study shows that the CA557/03 virus was distantly related to the CAV-type viruses isolated in California in the early 1990s, but that none of the 2003-04 viruses were similar genetically or serologically to the CAL99-type viruses, indicating that new IBV variants continue to emerge and cause disease in commercial chickens in California. 相似文献
30.
Williams DC Murison PJ Hill CL 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2007,54(4):199-202
A 9-year-old female Rothschild giraffe (Giraffa camelopardalis rothschildi), weighing approximately 900 kg, at Longleat Safari Park, Wiltshire, UK was presented with dystocia in September 2005. This paper details the surgical and anaesthetic procedures carried out performing a caesarean section to remove a dead male calf and the successful recovery of the giraffe. 相似文献