全文获取类型
收费全文 | 166篇 |
免费 | 19篇 |
专业分类
林业 | 7篇 |
5篇 | |
综合类 | 27篇 |
农作物 | 6篇 |
水产渔业 | 4篇 |
畜牧兽医 | 128篇 |
园艺 | 1篇 |
植物保护 | 7篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 3篇 |
2015年 | 7篇 |
2014年 | 2篇 |
2013年 | 14篇 |
2012年 | 9篇 |
2011年 | 5篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 7篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 8篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1926年 | 1篇 |
排序方式: 共有185条查询结果,搜索用时 0 毫秒
181.
182.
183.
B. D. Young J. M. Levine G. T. Fosgate A. de Lahunta T. Flegel K. Matiasek A. Miller G. Silver N. Sharp K. Greer S. J. Schatzberg 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2009,23(3):527-535
Background: The magnetic resonance imaging (MRI) characteristics of necrotizing meningoencephalitis (NME) are not well documented.
Objectives: To describe common MRI features of NME, to compare the MRI features to histopathologic findings, and to determine whether or not MRI lesions are predictive of survival time.
Animals: Eighteen Pugs with NME.
Methods: Retrospective MRI case study of Pugs identified by a search of medical records at 6 veterinary institutions. Eighteen dogs met inclusion criteria of histopathologically confirmed NME and antemortem MRI exam. MRI lesions were characterized and compared with histopathology with the kappa statistic. Survival times were compared with MRI findings by use of Mann-Whitney U -tests and Spearman's ρ.
Results: Twelve of 18 lesions were indistinctly marginated with mild parenchymal contrast enhancement. Prosencephalic (17/18) lesion distribution included the parietal (16/18), temporal (16/18), and occipital (16/18) lobes. There were cerebellar (4/18) and brainstem (3/18) lesions. Asymmetric lesions were present in both gray and white matter in all dogs. Falx cerebri shift was common (11/18), and 6 dogs had brain herniation. Leptomeningeal enhancement was present in 9/18 dogs. A moderate positive association was found between parenchymal contrast enhancement and both necrosis (κ= 0.45; P = .045) and monocytic inflammation (κ= 0.48; P = .025). Higher MRI lesion burden was correlated with longer time from disease onset to MRI ( P = .045). MRI lesion burden did not correlate to survival time.
Conclusions and Clinical Importance: Asymmetric prosencephalic grey and white matter lesions with variable contrast enhancement were consistent MRI changes in Pugs with confirmed NME. While not pathognomonic for NME, these MRI characteristics should increase confidence in a presumptive diagnosis of NME in young Pugs with acute signs of neurologic disease. 相似文献
Objectives: To describe common MRI features of NME, to compare the MRI features to histopathologic findings, and to determine whether or not MRI lesions are predictive of survival time.
Animals: Eighteen Pugs with NME.
Methods: Retrospective MRI case study of Pugs identified by a search of medical records at 6 veterinary institutions. Eighteen dogs met inclusion criteria of histopathologically confirmed NME and antemortem MRI exam. MRI lesions were characterized and compared with histopathology with the kappa statistic. Survival times were compared with MRI findings by use of Mann-Whitney U -tests and Spearman's ρ.
Results: Twelve of 18 lesions were indistinctly marginated with mild parenchymal contrast enhancement. Prosencephalic (17/18) lesion distribution included the parietal (16/18), temporal (16/18), and occipital (16/18) lobes. There were cerebellar (4/18) and brainstem (3/18) lesions. Asymmetric lesions were present in both gray and white matter in all dogs. Falx cerebri shift was common (11/18), and 6 dogs had brain herniation. Leptomeningeal enhancement was present in 9/18 dogs. A moderate positive association was found between parenchymal contrast enhancement and both necrosis (κ= 0.45; P = .045) and monocytic inflammation (κ= 0.48; P = .025). Higher MRI lesion burden was correlated with longer time from disease onset to MRI ( P = .045). MRI lesion burden did not correlate to survival time.
Conclusions and Clinical Importance: Asymmetric prosencephalic grey and white matter lesions with variable contrast enhancement were consistent MRI changes in Pugs with confirmed NME. While not pathognomonic for NME, these MRI characteristics should increase confidence in a presumptive diagnosis of NME in young Pugs with acute signs of neurologic disease. 相似文献
184.
LFC Brito JB Engiles RM Turner LM Getman A Ebling 《Reproduction in domestic animals》2009,44(5):846-851
An 18-year-old Friesian stallion was examined approximately one week after reportedly presenting scrotal swelling due to torsion of the spermatic cords. Upon presentation no scrotal swelling was noted, the testes were normally oriented, and no abnormalities of the spermatic cords were noted. However, both testes were smaller than expected for a mature stallion and deep palpation revealed that the consistency of the testes was nodular. Ultrasonographic evaluation of the testes revealed diffuse heterogeneous parenchyma with multiple hypoechoic nodular areas. Grossly, the testicular parenchyma was effaced by multiple gray-tan nodules of varying consistency interspersed with gray-white bands of tissue. Microscopic analysis revealed multiple pleomorphic neoplastic foci disseminated throughout both testes. Histological and immunohistochemical features were atypical and consistent with the diagnosis of bilateral testicular mixed germ cell-sex cord stromal tumours. Bilateral testicular tumours and testicular mixed cell tumours are extremely rare in stallions and this is the first report of bilateral testicular mixed germ cell-sex cord-stromal tumours in a stallion. Our findings indicate that certain ultrasonographic characteristics are suggestive of testicular tumour and that immunohistochemistry markers can be used to better characterize testicular neoplasms in stallions. 相似文献
185.
Distribution of thiobacillus ferrooxidans and leptospirillum ferrooxidans: implications for generation of acid mine drainage 总被引:1,自引:0,他引:1
MO Schrenk KJ Edwards RM Goodman RJ Hamers JF Banfield 《Science (New York, N.Y.)》1998,279(5356):1519-1522
Although Thiobacillus ferrooxidans and Leptospirillum ferrooxidans are widely considered to be the microorganisms that control the rate of generation of acid mine drainage, little is known about their natural distribution and abundance. Fluorescence in situ hybridization studies showed that at Iron Mountain, California, T. ferrooxidans occurs in peripheral slime-based communities (at pH over 1.3 and temperature under 30 degreesC) but not in important subsurface acid-forming environments (pH 0.3 to 0.7, temperature 30 degrees to 50 degreesC). Leptospirillum ferrooxidans is abundant in slimes and as a planktonic organism in environments with lower pH. Thiobacillus ferrooxidans affects the precipitation of ferric iron solids but plays a limited role in acid generation, and neither species controls direct catalysis at low pH at this site. 相似文献