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   491篇
  免费   17篇
  国内免费   2篇
林业   76篇
农学   25篇
基础科学   1篇
  24篇
综合类   8篇
农作物   10篇
水产渔业   50篇
畜牧兽医   254篇
园艺   9篇
植物保护   53篇
  2023年   1篇
  2022年   3篇
  2021年   25篇
  2020年   6篇
  2019年   6篇
  2018年   10篇
  2017年   9篇
  2016年   9篇
  2015年   26篇
  2014年   18篇
  2013年   21篇
  2012年   19篇
  2011年   27篇
  2010年   22篇
  2009年   21篇
  2008年   40篇
  2007年   37篇
  2006年   47篇
  2005年   35篇
  2004年   22篇
  2003年   30篇
  2002年   17篇
  2001年   10篇
  2000年   12篇
  1999年   4篇
  1998年   6篇
  1997年   3篇
  1996年   4篇
  1994年   1篇
  1992年   3篇
  1991年   1篇
  1990年   1篇
  1989年   7篇
  1988年   1篇
  1987年   1篇
  1984年   1篇
  1979年   1篇
  1978年   1篇
  1973年   1篇
  1972年   1篇
排序方式: 共有510条查询结果,搜索用时 0 毫秒
1.
2.
An apocrine adenocarcinoma was observed in the subcutis of the abdomen of golden hamster. Histologically, the tumor cells irregularly formed multiple layers of cysts and some detached cells were presented in the cystic space. PAS stain with alpha-amylase digestion revealed PAS-positive alpha-amylase-resistant granules in the cytoplasm. Immunohistochemically, cytokeratin was demonstrated in the tumor cells. By electron microscopy, the tumor cells had an oval nucleus with invagination, abundant cytoplasmic organelles and microvilli protruding into the intercellular spaces.  相似文献   
3.
4.
The dog of this case was a 10-year-old Shih Tzu with refractory vomiting, diarrhea and anorexia. Endoscopy revealed an unclear at gastric angle, a stenosis at pyloric antrum and congestion in duodenal mucosa. Since abnormal shadows of irregular echo-levels were disclosed by pancreas ultrasonography, serum gastrin level was determined with a suspect of gastrinoma. And an increase of serum gastrin was demonstrated. In addition, postmortem histological examination revealed that the pancreatic cells were positive for gastrin. Based on these findings, the dog was diagnosed as pancreatic gastrinoma.  相似文献   
5.
We investigated the concentration of the bacterial endotoxin lipopolysaccharide (LPS) in the blood, ovarian follicular fluid and uterine fluid of a clinical case of bovine metritis. A 2-year-old lactating Holstein cow exhibited continuous fever >39.5°C for more than 2 weeks after normal calving. The cow produced a fetid, watery, red-brown uterine discharge from the vagina and was diagnosed with metritis. The LPS concentrations in plasma and uterine fluid were 0.94 and 6.34 endotoxin units (EU)/ml, respectively. One of seven follicles showed an extremely high level of LPS (12.40 EU/ml) compared to the other follicles (0.62–0.97 EU/ml). These results might suggest the presence of high concentration of LPS in follicles in cows with postpartum metritis.  相似文献   
6.
Ehrlichia muris DNA was detected in the blood of sika deer (Cervus nippon yesoensis) by species-specific PCR based on the citrate synthase gene, which was shown to be more sensitive than species-specific PCR based on the 16S rRNA gene. Among 102 deer examined, one deer was positive. Deer may be a possible mammalian reservoir of E. muris.  相似文献   
7.
DNA from 111 ticks collected by flagging in Tokachi district, Eastern Hokkaido, Japan were examined for infection with Rickettsia and Ehrlichia, by PCR and sequencing methodology. For Rickettsia, analysis of the partial sequence of the citrate synthase gene was successfully performed on 11 DNA samples from I. persulcatus, and 7 of them showed 99.8% identical with Rickettsia helvetica while the other 4 showed 99.8% identical with ;Candidatus Rickettsia tarasevichiae'. For Ehrlichia, a partial sequence of the 16S rRNA gene detected from I. persulcatus was 100% identical with that from Ehrlichia muris, and another DNA sample from I. ovatus showed 99.8% identical with Ehrlichia species detected from I. ovatus. The results suggest that the pathogens detected here might be distributed in this area.  相似文献   
8.
The incidence of DIC in 208 dogs with a malignant tumor was evaluated. The incidence of DIC was 9.6% in dogs with a malignant tumor which was a solid tumor in all. In 164 dogs with a malignant solid tumor, the incidence of DIC was 12.2%. The incidence of DIC in dogs with hemangiosarcoma, mammary gland carcinoma and adenocarcinoma of the lung was significantly higher than that in dogs with other malignant tumors. These results suggested that special care in looking for DIC should be taken in dogs with a malignant solid tumor.  相似文献   
9.
10.
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