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   224篇
  免费   16篇
林业   6篇
农学   1篇
  13篇
综合类   35篇
农作物   2篇
水产渔业   13篇
畜牧兽医   161篇
植物保护   9篇
  2021年   2篇
  2019年   2篇
  2018年   6篇
  2017年   5篇
  2016年   8篇
  2014年   10篇
  2013年   35篇
  2012年   8篇
  2011年   6篇
  2010年   13篇
  2009年   6篇
  2008年   6篇
  2007年   6篇
  2006年   6篇
  2005年   9篇
  2004年   4篇
  2003年   3篇
  2002年   4篇
  2001年   2篇
  2000年   4篇
  1999年   2篇
  1998年   8篇
  1997年   4篇
  1996年   4篇
  1995年   7篇
  1994年   2篇
  1993年   10篇
  1992年   2篇
  1991年   3篇
  1990年   3篇
  1988年   2篇
  1986年   2篇
  1984年   2篇
  1983年   2篇
  1979年   2篇
  1976年   2篇
  1974年   3篇
  1973年   2篇
  1971年   2篇
  1970年   3篇
  1967年   2篇
  1945年   2篇
  1942年   2篇
  1929年   2篇
  1912年   1篇
  1911年   1篇
  1910年   2篇
  1909年   1篇
  1908年   2篇
  1904年   1篇
排序方式: 共有240条查询结果,搜索用时 31 毫秒
161.
AIM: To describe the pathology and inheritance of a congenital polycystic kidney disease (PKD) of sheep.

METHODS: Mode of inheritance of PKD was investigated by evaluation of results of the disorder from planned matings in two consecutive years within subsets of a flock that had a high prevalence of PKD in lambs. Gross pathological and histopath- ological studies were based on tissues derived from this study. Haematoxylin and eosin (H&E)-stained paraffin sections of kidney, liver, extrahepatic biliary and pancreatic ducts, pancreas and epididymis were used to describe the lesions.

RESULTS: Twenty-five lambs affected by PKD, of both sexes, were born, numbers in accord with those expected for an autosomal recessive disorder in the population studied. In all cases for which tissues were available, the renal, bile ductal (intrahepatic and extrahepatic), pancreatic and epididymal tissues had widespread dysplastic changes and associated cyst formation.

CONCLUSIONS: The findings of renal cysts in conjunction with cysts in other organs are unifying features in many of the human and animal forms of PKD and suggest a related pathogenic and genetic base consistent with an autosomal recessive disorder.  相似文献   
162.
163.
Twenty-nine euphausiid species were collected during the three cruises of the S.A.S. Natal in 1958. Of these only Stylocheiron microphthalmia had not previously been taken in South African waters. The commonest euphausiid represented in the collection is a larval series which is provisionally linked with Euphausia recurva or E. mutica. The vertical and horizontal distribution of each species is re-corded and seasonal and latitudinal variation discussed. Stylocheiron suhmii, S. microphthalma and Thysanopoda tricuspidata are proposed as indicators of Agulhas Current water and Nyctiphanes capensis and Euphausia lucens as indicators of water not of Agulhas Current origin. The largest number of euphausiids was found off Port Elizabeth during both summer and winter.  相似文献   
164.
165.
Staphylococcus aureus intramammary colonization of the mouse mammary gland induces migration of polymorphonuclear neutrophils (PMNs) similar to that observed during bovine mastitis. In the present study, a method combining acridine orange staining, fluorescence microscopy and computer-assisted image analysis has been developed to quantitate PMN infiltration in a mouse model of mastitis. This was carried out using paraffin embedded sections, and using this method, we showed that the presence of PMNs increased with the number of bacteria present in tissues. Nearly 400 and 1100 times more PMNs were counted in the mammary gland tissue after 12 and 24 h of infection, respectively, compared to mice infected for 6 h. Treatment with the antibiotic cephapirin at 10 or 25 mg/kg reduced PMN infiltration by 71 and 85%, respectively. In conclusion, this method can be used to quantitate PMN infiltration as a marker of inflammation and bacterial burden in infected tissue sections.  相似文献   
166.
167.
168.
To characterize further the chemical and biological properties of bovine soluble (bos) CD14, a panel of ten murine monoclonal antibodies (mAb) reactive with recombinant (r) bosCD14 were produced. A sandwich ELISA, using murine mAb and rabbit polyclonal antibodies reactive with rbosCD14 was developed. All the mAb were reactive by ELISA with baculovirus-derived rbosCD14 and they recognized rbosCD14 (40 kDa) by western blot analysis. The mAb also identified by western blot sCD14 (53 and 58 kDa) in milk and blood and sCD14 (47 kDa) in a lysate of macrophages obtained from involuted bovine mammary gland secretions. Analysis by ELISA of whey samples after intramammary injection of lipopolysaccharide (LPS) (10 micro g) revealed increased sCD14 levels between 8 to 48 h after injection. Flow cytometric analysis showed that the mAb bound to macrophages isolated from involuted mammary gland secretions and mouse macrophages but not to swine or horse monocytes. Addition of anti-rbosCD14 mAb to monocytes stimulated with LPS reduced in vitro production of TNF-alpha. The anti-rbosCD14 antibodies generated in this study will be useful in studying CD14, an accessory molecule that contributes to host innate recognition of bacterial cell wall components in mammary secretions produced during mastitis.  相似文献   
169.
Chondrodysplasia in Australian Dexter cattle   总被引:1,自引:0,他引:1  
Objective To describe the occurrence of chondrodysplasia in Australian Dexter cattle.
Design A pathological and genetic case report.
Procedure Congenital lethal chondrodysplasia was studied in two female Dexter foetuses aborted mid to late gestation. Clinicopathological findings including histological changes in limb bones, and analysis of pedigree information were evaluated.
Results Characteristic features of congenital lethal chon-drodysplasia (Dexter bulldog) include abortion, disproportionate dwarfism, a short vertebral column, marked micromelia, a relatively large head with retruded muzzle, cleft palate and protruding tongue and a large abdominal hernia. Histological changes in limb bones are consistent with failure of endochondral ossification. Dexter chondrodysplasia is considered to be inherited in an incompletely dominant manner with the homozygous form producing the congenital lethal condition. A preliminary minimum estimate of heterozy-gote frequency is 19% within the registered Australian Dexter herd, based on analysis of the contribution of three obligate heterozygotes whose semen has been widely used by artificial insemination in Australia.
Conclusion Dexter chondrodysplasia is present in Australian cattle and further cases of the homozygous form, congenital lethal chondrodysplasia, are likely to occur.
Recommendation It is requested that spleen and liver tissue from bulldog foetuses and blood from their parents be collected to assist research into Dexter chondrodysplasia.  相似文献   
170.
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