全文获取类型
收费全文 | 284篇 |
免费 | 38篇 |
国内免费 | 9篇 |
专业分类
林业 | 1篇 |
农学 | 2篇 |
综合类 | 53篇 |
农作物 | 3篇 |
畜牧兽医 | 269篇 |
园艺 | 3篇 |
出版年
2023年 | 5篇 |
2022年 | 9篇 |
2021年 | 18篇 |
2020年 | 27篇 |
2019年 | 13篇 |
2018年 | 7篇 |
2017年 | 11篇 |
2016年 | 15篇 |
2015年 | 12篇 |
2014年 | 23篇 |
2013年 | 26篇 |
2012年 | 17篇 |
2011年 | 13篇 |
2010年 | 11篇 |
2009年 | 7篇 |
2008年 | 14篇 |
2007年 | 5篇 |
2006年 | 8篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1982年 | 4篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有331条查询结果,搜索用时 15 毫秒
321.
322.
AIM: To investigate the effects of sphingosine-1-phosphate receptor 2 (S1PR2) on influenza A virus-induced viral pneumonia.METHODS: The animal model of influenza A virus pneumonia was established by infecting wild-type C57BL/6 mice and S1pr2-/- mice with influenza virus subtype FM1 mouse lung adaptable strain through nose drops. The pathological changes of the lung tissues of wild-type mice (model group), JTE-013 (S1PR2 effective antagonist)-challenged mice and S1pr2-/- mice were observed, and the protein concentration, total cell number, and interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) levels were determined in the bronchoalveolar lavage fluid (BALF) at 4 d and 6 d after virus infection. The phosphorylation levels of AKT and eNOS in the lung tissues were determined by Western blot. RESULTS: Compared with the wild-type mice of control group, the influenza A virus pneumonia in JTE treatment group and S1pr2-/- mice were more serious, and the protein concentration, total cell number and inflammatory cytokines in the BALF were remarkably increased. Moreover, the phosphorylation levels of AKT and eNOS, the downstream targets of PI3K, were significantly increased (P<0.01). CONCLUSION: S1PR2 mediates PI3K/AKT/eNOS signaling transduction pathway to regulate NO generation, and inhibit vascular permeability and inflammatory cytokine release, thus attenuating the viral pneumonia induced by influenza A virus. 相似文献
323.
324.
Marsupostrongylus spp. are the metastrongyloid nematodes most commonly associated with verminous pneumonia in Australian marsupials. Currently, there is a scarcity of information regarding this parasite in the common brushtail possum (Trichosurus vulpecula). Thirty-four free-living possums submitted to two wildlife hospitals in Sydney, Australia, between 2008 and 2015 were diagnosed with verminous pneumonia on postmortem examination. The majority of possums presented ill with multiple comorbidities. However, only five cases had clinical signs of respiratory disease. Necropsy and histopathology revealed extensive lung lesions characterised by diffuse, mixed interstitial infiltrates of macrophages, lymphocytes and plasma cells with mild to marked concentrations of eosinophils. Bronchopneumonia, pulmonary oedema, interstitial fibrosis, atelectasis and type II pneumocyte hyperplasia were also present in most cases. Adult nematodes, first-stage larvae and embryonating eggs were present in the large airways and alveolar spaces. The parasites were definitively identified as Marsupostrongylus spp. in eight cases with presumptive diagnoses based on histopathological characteristics reached in a further 26 cases. Twenty-nine of the 34 affected possums were adults with no sex predisposition. A review of the brushtail possum records at Taronga Wildlife Hospital from 1999 to 2015 revealed no lungworm infections were reported in the 45 possums examined before 2008. However, between 2008 and 2015, 30 of 47 possums (63.8%) examined were diagnosed with metastrongyloid lungworms. This case series is the first detailed report of Marsupostrongylus nematodes in common brushtail possums and highlights the clinical and pathological features, along with epidemiological findings. 相似文献
325.
犊牛肺炎是犊牛的一种常见病,以小叶性肺炎多见,多发于气温低、天气严寒的1-3月份出生的6~30日龄的犊牛。通过病因调查分析,该病可能发生的原因是阴天、雨天、风天和夜间低温、牛舍空气污浊、有烟雾、牛只拥挤、缺乏运动等。临床检查发现主要是呼吸道症状。患肺炎的犊牛,死亡率很高,患过肺炎的犊牛很容易发生呼吸道疾病。通过以抗菌素、磺胺类为主,配以强心补液的治疗措施获得良好疗效。因此笔者认为,应采用正确的饲养管理预防,并及时给予治疗病牛,才能避免造成更大经济损失。 相似文献
326.
327.
328.
329.
Audrey Charlebois Corinne Marois-Créhan Pierre Hélie Carl A. Gagnon Marcelo Gottschalk Marie Archambault 《Veterinary microbiology》2014,168(2-4):348-356
Mycoplasma hyopneumoniae, the causative agent of porcine enzootic pneumonia, is present in swine herds worldwide. However, there is little information on strains infecting herds in Canada. A total of 160 swine lungs with lesions suggestive of enzootic pneumonia originating from 48 different farms were recovered from two slaughterhouses and submitted for gross pathology. The pneumonic lesion scores ranged from 2% to 84%.Eighty nine percent of the lungs (143/160) were positive for M. hyopneumoniae by real-time PCR whereas 10% (16/160) and 8.8% (14/160) were positive by PCR for M. hyorhinis and M. flocculare, respectively. By culture, only 6% of the samples were positive for M. hyopneumoniae (10/160). Among the selected M. hyopneumoniae-positive lungs (n = 25), 9 lungs were co-infected with M. hyorhinis, 9 lungs with PCV2, 2 lungs with PRRSV, 12 lungs with S. suis and 10 lungs with P. multocida. MLVA and PCR-RFLP clustering of M. hyopneumoniae revealed that analyzed strains were distributed among three and five clusters respectively, regardless of severity of lesions, indicating that no cluster is associated with virulence. However, strains missing a specific MLVA locus showed significantly less severe lesions and lower numbers of bacteria. MLVA and PCR-RFLP analyses also showed a high diversity among field isolates of M. hyopneumoniae with a greater homogeneity within the same herd. Almost half of the field isolates presented less than 55% homology with selected vaccine and reference strains. 相似文献
330.