全文获取类型
收费全文 | 91篇 |
免费 | 2篇 |
专业分类
农学 | 5篇 |
7篇 | |
综合类 | 4篇 |
农作物 | 1篇 |
畜牧兽医 | 76篇 |
出版年
2020年 | 1篇 |
2019年 | 1篇 |
2015年 | 1篇 |
2013年 | 2篇 |
2012年 | 5篇 |
2011年 | 9篇 |
2009年 | 3篇 |
2008年 | 5篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 7篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1981年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有93条查询结果,搜索用时 15 毫秒
1.
Hong Li Donal O'Toole Okjin Kim J Lindsay Oaks Timothy B Crawford 《Journal of veterinary diagnostic investigation》2005,17(2):171-175
A malignant catarrhal fever (MCF)-like disease was induced experimentally in 3 sheep after aerosol inoculation with ovine herpesvirus-2 (OvHV-2). Each of 3 OvHV-2-negative sheep was nebulized with 2 ml of nasal secretions containing approximately 3.07 X 10(9) OvHV-2 DNA copies from a sheep experiencing an intensive viral-shedding episode. Ovine herpesvirus-2 DNA became detectable by polymerase chain reaction in the peripheral blood leukocytes of all 3 sheep within 3 days, and all 3 seroconverted between 6 and 8 days postinfection (PI). The sheep developed clinical signs, with copious mucopurulent nasal discharge and fever around 14 days PI. One of the 3 clinically affected sheep was euthanized at 18 days PI. Major lesions at necropsy were multifocal linear erosions and ulcers in mucosa of the cheeks, tongue, pharynx, and proximal esophagus and mild disseminated pneumonia. Microscopically, there was extensive moderate superficial histiocytic-lymphocytic rhinitis with epithelial dissociation and degeneration. Moderate multifocal histiocytic bronchointerstitial pneumonia was associated with loss of terminal bronchiolar epithelium. Lymphocytic vasculitis was present only in the lung. The remaining 2 sheep recovered clinically, approximately 25 days PI. The study revealed that clinical signs and lesions resembling MCF can develop when uninfected sheep are exposed to a high dose of aerosolized OvHV-2. 相似文献
2.
Neospora caninum encephalomyelitis in a British dog 总被引:2,自引:0,他引:2
3.
4.
Evaluation of a simple technique for characterizing rice root systems in relation to drought resistance 总被引:1,自引:0,他引:1
Summary Drought is a constraint to rice yields in much of Asia's rainfed rice crop. Although genotypic variation for root system characteristics is well documented in this semiaquatic species, little improvement of rice for drought resistance has been attempted. No simple method to evaluate root systems exists. In this paper we report the development and testing of a simple device to measure the pulling force required to uproot rice seedlings. The force required to pull rice seedlings from the paddy soil was correlated with root weight, root branching and thick root number. The capability to separate rice cultivars by this technique and relationship of the root pulling force to other drought screening methods are illustrated. 相似文献
5.
Modulation of the affinity of integrin alpha IIb beta 3 (GPIIb-IIIa) by the cytoplasmic domain of alpha IIb 总被引:33,自引:0,他引:33
T E O'Toole D Mandelman J Forsyth S J Shattil E F Plow M H Ginsberg 《Science (New York, N.Y.)》1991,254(5033):845-847
Intracellular signaling alters integrin adhesive functions in inflammation, immune responses, hemostasis, thrombosis, and retinal development. By truncating the cytoplasmic domain of alpha IIb, the affinity of integrin alpha IIb beta 3 for ligand was increased. Reconstitution with the cytoplasmic domain from integrin alpha 5 did not reverse the increased affinity. Thus, the cytoplasmic domain of the alpha subunit of GPIIb-IIIa controls ligand binding affinity, which suggests mechanisms for inside-out transmembrane signaling through integrins. These findings imply the existence of hitherto unappreciated hereditary and acquired thrombotic disorders in humans. 相似文献
6.
A genetic, pathological and virological study of congenital hypotrichosis and incisor anodontia in cattle 总被引:2,自引:0,他引:2
Two Friesian cows, half-sibs by a common dam, produced four bull calves with severe congenital hypotrichosis and incisor anodontia and three normal heifers by six unrelated Holstein, Friesian, Devon and Hereford bulls. The two dams, and their dam, had coats of a short, stubbly nature and the pigmented areas appeared rusty grey rather than black. Pathological examination of skin samples taken from multiple standardised sites from two of the affected calves showed a reduction in the number of large first-formed hair follicles. Smaller calibre hair follicles were present but, unlike those of normal neonatal calves, all were in the telogen (inactive) phase. Although the herd was infected with bovine virus diarrhoea virus there was no convincing evidence that the virus was implicated in the pathogenesis of these cases of congenital hypotrichosis with incisor anodontia. The family breeding information on the few severely affected and normal progeny and mildly affected and normal parents may be explained by the genetic hypothesis of an X-linked incompletely dominant gene. 相似文献
7.
Congenital sporozoan encephalomyelitis in a calf 总被引:1,自引:0,他引:1
Protozoan encephalomyelitis was diagnosed post mortem in a five-day-old Friesian calf which had shown nervous signs from birth. The lesion was a subacute necrotising multifocal encephalomyelitis associated with protozoan bodies (6 X 6 microns to 16 X 30 microns). Ultrastructurally these bodies corresponded to apicomplexan meronts composed of eight to 89 merozoites which reproduced by internal budding to form paired daughter cells (endodyogeny). The merozoites were indistinguishable from Toxoplasma gondii; they reacted weakly with anti-Sarcocystis species serum and did not cross react with anti-T gondii serum. The generic identity of the sporozoan was not established, but it is unlikely to have been either Sarcocystis species or T gondii. 相似文献
8.
Two unrelated adult dogs developed idiopathic, acute-onset, bilateral total blindness. The ophthalmoscopic changes were minimal and no electroretinographic response could be detected in either dog. The retinas were examined ultrastructurally 10 days (dog 1) and two-and-a-half months (dog 2) after they became blind. There was widespread loss of the outer segments of rod and cone photoreceptors. Where the outer segments persisted, there was marked tubulovesicular change with loss of normal orientation in their lamellae. Second order neurons (bipolar cells) and ganglion cells were unaffected. The cause of this selective and massive disruption of rod and cone endings was not established, but acute toxicity is proposed as a possible mechanism. 相似文献
9.
Virus localisation and lesions were studied in 14-one-week-old piglets following combined intranasal-oral inoculation with a British isolate of 'pneumotropic' porcine coronavirus (PCV) and were compared with the effects of transmissible gastroenteritis virus (TGEV) infection in five piglets. Unlike TGEV-infected piglets, all PCV-inoculated piglets remained clinically healthy. Seroconversion was detected at seven days after inoculation. Mild bronchointerstitial pneumonia involving terminal airways was consistently present at two days after infection and thereafter. Both PCV and TGEV infected bronchiolar epithelium and alveolar macrophages but, unlike TGEV, replication by PCV in villous enterocytes was limited and did not cause villous atrophy. 相似文献
10.
Hemochromatosis is an inherited defect in Salers cattle, characterized by increased iron absorption and wasting in young animals. Loss of teeth and soft bones has been reported. This study details bone changes in a prospective study of an affected Salers heifer and an age-matched, half-sibling control. The heifer fell 2 weeks before euthanasia, developed non-weight bearing lameness, and then became recumbent. At necropsy, the heifer was smaller than the control and had fractures of the humerus, femur, and ribs. Distinctive circumferential laminations in the outer third of the cortex were seen radiographically as layers of variably decreased density. In midshaft cross sections, the cortex was wider in some long bones, and fluorescent labeling revealed irregular and intermittent mineralization in the outer cortical layers. Mineral apposition rates in osteons of the inner cortex were decreased as compared with the control, and longitudinal bone formation at the growth plate was markedly decreased. Histologically, there were buried layers of osteopenic, poorly mineralized plexiform bone in outer circumferential lamellae. There was stainable iron in woven bone cores of the matrix. Iron was found in occasional osteoclasts as well. The mandible was severely affected, with loss of cortical bone as well as trabecular bone around the teeth and resorption of dental roots. Bone analysis revealed iron levels in the affected calf that were 30-50 times greater than the control and decreased percent ash in the outer cortex. These results indicate that periosteal dysplasia and osteopenia are responsible for pathologic fractures and tooth loss. 相似文献