全文获取类型
收费全文 | 249篇 |
免费 | 27篇 |
国内免费 | 1篇 |
专业分类
林业 | 2篇 |
农学 | 5篇 |
基础科学 | 1篇 |
9篇 | |
综合类 | 54篇 |
农作物 | 15篇 |
水产渔业 | 6篇 |
畜牧兽医 | 160篇 |
园艺 | 2篇 |
植物保护 | 23篇 |
出版年
2023年 | 2篇 |
2021年 | 2篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 8篇 |
2013年 | 19篇 |
2012年 | 10篇 |
2011年 | 12篇 |
2009年 | 12篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 12篇 |
2004年 | 10篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 7篇 |
1988年 | 8篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1980年 | 5篇 |
1973年 | 2篇 |
1967年 | 3篇 |
1966年 | 4篇 |
1954年 | 2篇 |
1953年 | 2篇 |
1952年 | 3篇 |
1946年 | 1篇 |
1932年 | 1篇 |
1931年 | 1篇 |
1902年 | 1篇 |
排序方式: 共有277条查询结果,搜索用时 31 毫秒
101.
Eggleston RB Mueller PO Chambers JN Bentley A 《Journal of the American Veterinary Medical Association》2000,217(8):1186-1190
Numerous techniques for surgical correction of angular limb deformities in horses involving an osteotomy of the affected bone and stabilization with an internal fixation device have been described. However, because the osteotomy typically has to be performed at the level of the physis, leaving little bone between the physis and the nearest joint, stabilizing the osteotomy by use of internal fixation devices may be difficult. In horses with severe chronic angular limb deformities, the amount of soft-tissue contracture may make it impossible to correct the deformity during a single procedure without causing stretch injuries to the adjacent tendons and neurovascular structures. Adjustable external ring fixators incorporating hinged rods on 1 side of the limb and an angular motor assembly on the other may be useful for treatment of severe chronic angular limb deformities in younger equids, because they allow for gradual correction of the deformity. 相似文献
102.
103.
Croucher NJ Harris SR Fraser C Quail MA Burton J van der Linden M McGee L von Gottberg A Song JH Ko KS Pichon B Baker S Parry CM Lambertsen LM Shahinas D Pillai DR Mitchell TJ Dougan G Tomasz A Klugman KP Parkhill J Hanage WP Bentley SD 《Science (New York, N.Y.)》2011,331(6016):430-434
Epidemiological studies of the naturally transformable bacterial pathogen Streptococcus pneumoniae have previously been confounded by high rates of recombination. Sequencing 240 isolates of the PMEN1 (Spain(23F)-1) multidrug-resistant lineage enabled base substitutions to be distinguished from polymorphisms arising through horizontal sequence transfer. More than 700 recombinations were detected, with genes encoding major antigens frequently affected. Among these were 10 capsule-switching events, one of which accompanied a population shift as vaccine-escape serotype 19A isolates emerged in the USA after the introduction of the conjugate polysaccharide vaccine. The evolution of resistance to fluoroquinolones, rifampicin, and macrolides was observed to occur on multiple occasions. This study details how genomic plasticity within lineages of recombinogenic bacteria can permit adaptation to clinical interventions over remarkably short time scales. 相似文献
104.
105.
106.
107.
108.
Objective To determine the effects of topical 0.5% tropicamide on anterior segment morphology (ASM) and intraocular pressure (IOP) in normal and glaucomatous cats. Animals used Normal cats and cats with inherited primary congenital glaucoma (PCG). Procedures Control IOP curves were performed in untreated normal and PCG cats. In the first experiment, tropicamide was applied OD in eight normal and nine PCG cats. IOP and pupillary diameter (PD) were measured at 0, 30, and 60 min, then hourly until 8 h post‐treatment. In a second experiment, six normal and seven PCG cats received tropicamide OD. High‐resolution ultrasound images were obtained at 0, 1, 5, and 10 h post‐treatment to measure ASM changes. IOP and PD were measured OD at 0, 1, 2, 3, 5, 7, and 9 h. Results In untreated normal cats IOP OU decreased throughout the day. In PCG cats IOP OU had wide fluctuations over time. In normal cats IOP response varied in the treated eye but did not change significantly in untreated eyes. IOP significantly increased from baseline in both eyes of all treated PCG cats. Increases in IOP were associated with some ASM changes. Cats with PCG had a significantly smaller angle recess areas, diminished ciliary clefts and decreased iris‐lens contact. ASM changes were not strongly correlated with IOP in all cats. Conclusions The ASM of PCG cats is markedly different from normal cats, and clinically significant increases in IOP OU occur in cats with PCG after tropicamide treatment. The mechanism for this increase remains unclear. 相似文献
109.
Krista B. Halling DVM John P. Graham MVB MSc Susan P. Newell DVM MS Gary W. Ellison DVM MS Carol J. Detrisac DVM PhD Frank G. Martin PhD James M. Vangilder BS Daniel Grossman DVM 《Veterinary radiology & ultrasound》2003,44(6):707-713
The sonographic features of acute renal allograft rejection in humans and dogs are manifested by increase in renal cross-sectional area and reduction in renal cortical blood flow. These changes have not been investigated in cats. The objectives of this study were to evaluate sonographic and scintigraphic changes during acute renal allograft rejection in cats. Eight SPF, intact, adult, male cats received heterotopic renal allotransplantations. Immunosuppressive doses of cyclosporine and prednisolone were administered for 14 days and then discontinued to allow acute allograft rejection to occur. Serial measurements of renal cross-sectional area, resistive index (RI), echogenicity, and glomerular filtration rate (GFR) were performed to evaluate changes during acute rejection. Upon sonographic confirmation of absent diastolic blood flow or a 20% increase in cross-sectional area of the allograft, a nephrectomy and histopathologic evaluation were performed. Acute allograft rejection was confirmed histologically in all cats. Significant increases in renal cross-sectional area (P < 0.001) occurred postoperatively and during rejection. There were no significant changes in RI (P = 0.43) at any time. A subjective increase in medullary echogenicity and a decrease in corticomedullary demarcation were observed in the rejection period. While GFR decreased significantly in the immediate postoperative period (P < 0.001), no further change occurred during rejection (P = 0.42). Changes in RI and GFR do not appear to be sensitive indicators of acute renal allograft rejection in cats. Serial measurements of renal cross-sectional area appear to be a sensitive method for the early diagnosis of allograft rejection in feline renal transplant recipients. 相似文献
110.
J P Thompson M M Christopher G W Ellison B L Homer B A Buchanan 《Journal of the American Veterinary Medical Association》1992,201(5):737-738
A dog with a rectal adenomatous polyp had extreme neutrophilic leukocytosis, monocytosis, and eosinophilia consistent with a paraneoplastic syndrome. Resolution of the leukogram abnormalities after tumor excision supported this belief. Except for a lack of circulating myeloblasts, the dog had leukogram findings consistent with a neutrophilic leukemoid reaction. 相似文献