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   68篇
  免费   14篇
林业   2篇
基础科学   1篇
  3篇
综合类   9篇
农作物   1篇
畜牧兽医   61篇
园艺   1篇
植物保护   4篇
  2023年   1篇
  2020年   6篇
  2019年   1篇
  2018年   4篇
  2017年   2篇
  2016年   3篇
  2015年   9篇
  2014年   4篇
  2013年   7篇
  2012年   1篇
  2011年   3篇
  2010年   5篇
  2009年   3篇
  2008年   1篇
  2006年   1篇
  2005年   4篇
  2004年   1篇
  2002年   1篇
  2001年   1篇
  1999年   1篇
  1998年   3篇
  1997年   2篇
  1996年   3篇
  1995年   2篇
  1993年   4篇
  1991年   1篇
  1989年   1篇
  1985年   1篇
  1984年   1篇
  1979年   2篇
  1976年   1篇
  1972年   2篇
排序方式: 共有82条查询结果,搜索用时 15 毫秒
11.
12.
Objective To investigate the effect of a topical anaesthetic formulation on pain alleviation, wound healing and systemic levels of local anaesthetic actives in lambs undergoing castration and tail docking. Design Three placebo-controlled and/or randomised experiments were conducted using three groups of Merino lambs (n = 62, 68 and 19) undergoing routine castration and tail docking. Procedure Surgical castration, with either surgical or hot-iron tail docking, was performed with and without the application of topical anaesthetic (Tri-Solfen®) or placebo. The effects of this procedure were compared with those of rubber ring castration and tail docking, and of the handled but unmarked controls. Wound pain was assessed using calibrated Von-Frey monofilaments over a 4-h period, pain-related behaviour was assessed over 5 h, wound healing was assessed at 14 and 28 days, and the plasma levels of lignocaine and bupivacaine were determined. Results Rapid and up to 4 h primary hyperalgesia developed following surgical castration and tail docking in the untreated and placebo-treated lambs. It was absent in the castration wounds, and significantly reduced in the tail-docking wounds, of the treated lambs. Hot-iron docking was associated with mild and transient secondary hyperalgesia, which was abolished by the topical anaesthesia. There was a significant reduction in pain-related behaviours in treated lambs, which were not significantly different in their behaviour to the sham-operation handled controls. Plasma lignocaine and bupivacaine levels were below the toxic thresholds in all tested lambs. Conclusion Topical anaesthesia alleviates wound pain and significantly reduces pain-related behaviours in lambs undergoing surgical castration plus surgical or hot-iron tail docking, without a negative effect on wound healing or a risk of systemic toxicity.  相似文献   
13.
14.
15.
The concentrations of IgA, IgG and IgM were measured in plasma, lung lymph and lung lavage fluid from adult sheep. Immunoglobulin concentrations in lymph and lavage fluid should fall sequentially during diffusive flux from the vascular compartment as a result of molecular sieving at the capillary endothelium and the alveolar epithelium. This was seen only for the IgG class. High concentrations of IgA and IgM in the interstitial (lymph) and luminal (lavage) compartments of the lung (relative to plasma levels) suggest either local synthesis of these classes or the existence of class specific active transport.  相似文献   
16.
Classical swine fever virus (CSFV) compromises the host immune system, causing indirect leucopoenia and disruption of in vitro T cell stimulation capacity. In order to explore the potential role of dendritic cells (DC) in such phenomena, the activation of conventional DC (cDC) and plasmacytoid DC (pDC) in blood and secondary lymphoid organs of infected pigs was investigated in the early time course post-inoculation (pi), together with viral components dissemination and cytokine production in serum. Whereas CD11R1+CD172a+ cDC frequencies were markedly reduced in blood and spleen, analysis of CD4+CD172a+ pDC numbers revealed a rapid turn-over of this DC subset in tissues pi. Both subsets matured and were activated after infection, as demonstrated by down-regulation of CD1a, up-regulation of the co-stimulation molecule CD80/86 and expression of cytokines. cDC essentially expressed tumor necrosis factor alpha (TNF-alpha) and interleukin (IL)-10, whereas pDC produced alpha interferon (IFN-alpha) and IL-12. IFN-alpha and TNF-alpha productions revealed an enhancement of innate anti-viral immune responses. Detection of antigen activated B lymphocytes in tonsil T-cell areas at 72 h pi, subsequently to the transient translocation of the viral E2 protein within germinal centres at 48 h pi, indicates the initiation of humoral response. This response was also evidenced by an important IL-10 production in serum one week pi. IL-12 expression in organs, as well as transient detection of IL-18 and IFN-gamma in serum, reflected the initiation of cellular immune responses. However, the uncommonly high levels of TNF-alpha and IFN-alpha produced by DC and measured in serum early post-infection, together with IL-10 expression in spleen, could play a role in the disruption of immune system cells, either inducing apoptosis or impairing DC functionalities themselves.  相似文献   
17.
芽孢杆菌HSY-8-1对植物病原真菌的抑制及其抑菌产物特性   总被引:3,自引:1,他引:3  
为挖掘用于生物防治的微生物资源,自海南蚕豆枯萎病区土壤分离1株芽孢杆菌HSY-8-1,经抗菌试验分析表明,其代谢产生的拮抗物质对引发植物立枯病和根腐病的立枯丝核菌(Rhizoctonia solani)和镰刀菌(Fusariumspp.)抑菌作用较强,具有使病菌菌丝扭曲、缢缩等致畸效应,并抑制立枯丝核菌的菌核形成。研究表明,在NB液体培养基中发酵时,进入稳定生长期后开始产生抑菌物质,72 h时累积达到最大值。这种抑菌物质的特性为外泌型、水溶性,可透过0.22μm的微孔滤膜,对热、酸、碱、蛋白酶水解、紫外线照射等影响有较强的稳定性。  相似文献   
18.
奶花芸豆种植密度与施肥量优化组合模式的研究   总被引:1,自引:0,他引:1  
采用正交回归旋转组合设计,研究了密度、氮(N)、磷(P2O5)、钾(K2O)施用量对奶花芸豆产量的影响,通过田间试验测定参数,利用计算机技术对试验数据进行处理,建立了产量函数模型,经计算机模拟寻优,筛选出了产量的最佳农艺措施组合方案。在试验条件下,当奶花芸豆栽培密度为150000株/hm^2,施氮量300kg/hm^2,施磷量200kg/hm^2,施钾量45kg/hm^2组合时,产量可达到3833.4kg/hm^2。  相似文献   
19.
Climate Change During the Last Deglaciation in Antarctica   总被引:1,自引:0,他引:1  
Greenland ice core records provide clear evidence of rapid changes in climate in a variety of climate indicators. In this work, rapid climate change events in the Northern and Southern hemispheres are compared on the basis of an examination of changes in atmospheric circulation developed from two ice cores. High-resolution glaciochemical series, covering the period 10,000 to 16,000 years ago, from a central Greenland ice core and a new site in east Antarctica display similar variability. These findings suggest that rapid climate change events occur more frequently in Antarctica than previously demonstrated.  相似文献   
20.
分析了高校图书馆流通服务和赢利性企业的共性,论述了高校图书馆流通服务管理应用“关键时刻”管理理论的可行性和必要性。提出了通过对高校图书馆流通服务中的一系列“关键时刻”的强化管理.提高流通服务质量,最大限度地满足读者需求的策略。  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