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   913篇
  免费   80篇
林业   24篇
农学   4篇
基础科学   1篇
  65篇
综合类   62篇
农作物   20篇
水产渔业   31篇
畜牧兽医   748篇
园艺   17篇
植物保护   21篇
  2023年   18篇
  2022年   14篇
  2021年   30篇
  2020年   43篇
  2019年   30篇
  2018年   33篇
  2017年   26篇
  2016年   19篇
  2015年   25篇
  2014年   34篇
  2013年   40篇
  2012年   54篇
  2011年   70篇
  2010年   48篇
  2009年   30篇
  2008年   58篇
  2007年   40篇
  2006年   44篇
  2005年   42篇
  2004年   37篇
  2003年   34篇
  2002年   35篇
  2001年   10篇
  2000年   10篇
  1999年   7篇
  1998年   15篇
  1997年   12篇
  1996年   14篇
  1995年   5篇
  1994年   5篇
  1993年   12篇
  1992年   12篇
  1991年   16篇
  1990年   16篇
  1989年   17篇
  1988年   9篇
  1987年   8篇
  1986年   4篇
  1985年   3篇
  1984年   3篇
  1983年   7篇
  1982年   2篇
  1980年   1篇
  1978年   1篇
排序方式: 共有993条查询结果,搜索用时 46 毫秒
21.
22.
23.
24.
Currently, a histological diagnosis of highly vascularized canine (c) thyroid carcinoma (TC) is primarily obtained following excisional biopsy (EB) through thyroidectomy. Non-EBs are contraindicated in unresectable invasive cTCs due to their highly vascularized nature, which subsequently, lack histological diagnosis. We hypothesised ultrasound-guided core needle biopsy (UGCNB) to be a safe biopsy technique to obtain an accurate histological diagnosis in unresectable TCs. Nine client-owned dogs with suspected naturally occurring TC, presented for surgical excision, were included. First, a UGCNB was taken from the cervical tumour, followed by EB. Haemorrhage following UGCNB was evaluated preoperatively and once the tumour was surgically exposed by visual inspection and ultrasonography. Histological analysis, including cell organisation, tumour capsular and vascular invasion, and immunohistochemistry were performed and compared between both biopsy specimens (i.e., UGCNB and EB) of the same dog. Pre- and peroperative visual inspection revealed minor, localised haemorrhage, subsequent to the UGCNB, in 7/9 dogs. Histology of the EBs confirmed TC in 8/9 dogs and was inconclusive in 1/9 dogs. Histology of the UGCNBs revealed neoplastic thyroid tissue in 7/9 UGCNBs and was inconclusive in 1/9 UGCNBs. The remaining UGCNB contained no mass related tissue and was, therefore, excluded. Histological parameters (i.e., cell organisation, tumour capsular and vascular invasion) were not concordant between 6/8 included UGCNBs and their respective EB. Immunolabelling for thyroglobulin and calcitonin was concordant between all eight included UGCNBs and their respective EB. The remaining evaluated immunohistochemical markers (i.e., cyclooxygenase-2 [COX-2], P-glycoprotein and vascular endothelial growth factor [VEGF]) were concordant between the included UGCNBs and the EBs in 6/8 dogs. To conclude, UGCNBs can be safely obtained in suspected cTCs and enable a reliable diagnosis of the thyroid origin, thyroid cell origin and potential therapeutic markers such as COX-2, P-glycoprotein and VEGF. Subsequently, UGCNB enables clinicians to establish an individually tailored treatment plan in dogs with unresectable TC.  相似文献   
25.
26.
27.
28.
Plant Foods for Human Nutrition - Chickpea is one of the most consumed legumes worldwide. Among their benefits are the high protein concentration that reflects not only at the nutritional level but...  相似文献   
29.
Succinate dehydrogenase inhibitors (SDHIs) have played a crucial role in disease control to protect cereals as well as fruit and vegetables for more than a decade. Isoflucypram, the first representative of a newly installed subclass of SDHIs inside the Fungicide Resistance Action Committee (FRAC) family of complex II inhibitors, offers unparalleled long‐lasting efficacy against major foliar diseases in cereals. Herein we report the chemical optimization from early discovery towards isoflucypram and the first hypothesis of its altered binding mode in the ubiquinone binding site of succinate dehydrogenase. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   
30.
Adult male German cockroaches were exposed to surface deposits of insecticides for 5 min in the central compartment of a three-compartment choice chamber illuminated at one end. They were then allowed access to the escape compartments and their distribution recorded over the subsequent 60 min. Cockroaches exposed to pyrethroid insecticides rapidly accumulated in the escape compartment closest to the light source; the same effect was observed to a lesser extent following exposure to propoxur. Boric acid and bendiocarb deposits inhibited the movement of the cockroaches away from the light source, and fenitrothion deposits delayed it. Dieldrin had no effect on the distribution of cockroaches within the choice chamber. The reversal of the normal tendency of German cockroaches to move from a light area to a dark harbourage following exposure to pyrethroids may contribute to the flushing action observed when these chemicals are used for control of B. germanica populations.  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