全文获取类型
收费全文 | 882篇 |
免费 | 43篇 |
专业分类
林业 | 48篇 |
农学 | 25篇 |
130篇 | |
综合类 | 77篇 |
农作物 | 25篇 |
水产渔业 | 39篇 |
畜牧兽医 | 492篇 |
园艺 | 11篇 |
植物保护 | 78篇 |
出版年
2023年 | 6篇 |
2022年 | 5篇 |
2021年 | 13篇 |
2020年 | 19篇 |
2019年 | 21篇 |
2018年 | 13篇 |
2017年 | 19篇 |
2016年 | 19篇 |
2015年 | 17篇 |
2014年 | 25篇 |
2013年 | 49篇 |
2012年 | 60篇 |
2011年 | 60篇 |
2010年 | 33篇 |
2009年 | 27篇 |
2008年 | 60篇 |
2007年 | 61篇 |
2006年 | 53篇 |
2005年 | 50篇 |
2004年 | 69篇 |
2003年 | 60篇 |
2002年 | 61篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 9篇 |
1998年 | 9篇 |
1997年 | 11篇 |
1996年 | 6篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 9篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1955年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有925条查询结果,搜索用时 328 毫秒
31.
32.
Williamson NL Frank LA Hnilica KA 《Journal of the American Veterinary Medical Association》2002,221(6):802-806
OBJECTIVE: To determine how rapidly trimethoprim-sulfamethoxazole affects serum total thyroxine (T4) and thyroid-stimulating hormone (TSH) concentrations in euthyroid dogs and how quickly hormone concentrations return to reference values following discontinuation of administration. DESIGN: Prospective study. ANIMALS: 7 healthy euthyroid dogs. PROCEDURE: Dogs were given trimethoprim-sulfamethoxazole (26.5 to 31.3 mg/kg [12 to 14.2 mg/lb], PO, q 12 h) for a maximum of 6 weeks. A CBC and Schirmer tear test were performed and serum total T4 and TSH concentrations were measured weekly. Administration of trimethoprim-sulfamethoxazole was discontinued if total T4 concentration was less than the lower reference limit and TSH concentration was greater than the upper reference limit or if persistent neutropenia developed. RESULTS: Six dogs had total T4 concentrations less than the lower reference limit within 3 weeks; T4 concentration was decreased after 1 week in 3 of these 6 dogs. In these 6 dogs, TSH concentration was greater than the upper reference limit within 4 weeks. In 1 dog, T4 and TSH concentrations were not affected, despite administration of trimethoprim-sulfamethoxazole for 6 weeks. Neutropenia developed in 4 dogs. In 1 dog, the neutropenia resolved while trimethoprim-sulfamethoxazole was still being administered. In the other 3, neutrophil counts returned to reference values 1 week after drug administration was discontinued. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of trimethoprim-sulfamethoxazole at a dosage of 26.5 to 31.3 mg/kg, PO, every 12 hours can substantially alter serum total T4 and TSH concentrations and neutrophil counts in dogs within as short a time as a few weeks. 相似文献
33.
Watson ZE Steffey EP VanHoogmoed LM Snyder JR 《American journal of veterinary research》2002,63(7):1061-1065
OBJECTIVE: To characterize the effect of general anesthesia and minor surgery on renal function in horses. ANIMALS: 9 mares with a mean (+/- SE) age and body weight of 9+/-2 years and 492+/-17 kg, respectively. PROCEDURE: The day before anesthesia, urine was collected (catheterization) for 3 hours to quantitate baseline values, and serum biochemical analysis was performed. The following day, xylazine (1.1 mg/kg, IV) was administered, and general anesthesia was induced 5 minutes later with diazepam (0.04 mg/kg, IV) and ketamine (2.2 mg/kg, IV). During 2 hours of anesthesia with isoflurane, Paco2 was maintained between 48 and 52 mm Hg, and mean arterial blood pressure was between 70 and 80 mm Hg. Blood and urine were collected at 30, 60, and 120 minutes during and at 1 hour after anesthesia. RESULTS: Baseline urine flow was 0.92+/-0.17 ml/kg/h and significantly increased at 30 and 60 minutes after xylazine administration (2.14+/-0.59 and 2.86+/-0.97 ml/kg/h respectively) but returned to baseline values by the end of anesthesia. Serum glucose concentration increased from 12+/-4 to 167+/-8 mg/dl at 30 minutes. Glucosuria was not observed. CONCLUSIONS AND CLINICAL RELEVANCE: Transient hyperglycemia and an increase in rine production accompanies a commonly used anesthetic technique for horses. The increase in urine flow is not trivial and should be considered in anesthetic management decisions. With the exception of serum glucose concentration and urine production, the effect of general anesthesia on indices of renal function in clinically normal horses is likely of little consequence in most horses admitted for elective surgical procedures. 相似文献
34.
35.
Cat teeth with resorptive lesions and periodontitis may have a distinctly different clinical and radiographic appearance compared with teeth that have focal, lesion-associated gingivitis. A retrospective, case-controlled study was performed to determine the occurrence of root replacement in cats with resorptive lesions and associated periodontitis. Of 543 teeth evaluated with resorptive lesions, radiographic and/or clinical signs of periodontitis were identified in 236 (43.5%) teeth. Periodontitis was present in 43 of 275 (15.6%) teeth with root replacement and 193 of 268 (72.0%) teeth that had normal radiodensity and maintenance of the periodontal ligament. There was a significantly lower occurrence of root replacement in cat teeth with resorptive lesions and periodontitis. 相似文献
36.
37.
38.
Multiple, dermal and subcutaneous nodules developed in a young female Manchester Terrier dog that had a chronic history of superficial dermatophytosis. Skin biopsy specimens of the nodules revealed granulomatous inflammation in the deep dermis and subcutis with branching fungal organisms. Cultures of multiple biopsy specimens from the nodules all yielded Trichophyton mentagrophytes. The lesions in this dog were similar to granulomatous dermatophytosis, a skin disease that has been reported in Persian cats and one Yorkshire Terrier dog. 相似文献
39.
Thermography is a non-contact, non-invasive technique that detects surface heat emitted as infrared radiation. Because skin temperature reflects the status of underlying tissue metabolism and blood circulation, abnormal thermal patterns can signify areas of superficial inflammation. The objective of this study was to determine if thermography could detect the injection of analgesic and neurolytic agents and surgical palmar digital neurectomy. Procedures evaluated include injection of the lumbar region, suspensory ligaments, tibial nerve, palmar digital nerves, and palmar digital neurectomy. Thermographic images were obtained before and after the procedures until a significant difference was no longer detected. Local injection of the lumbar region and the suspensory ligament produced detectable thermal patterns for two days, and tibial nerve infiltration with a neurolytic agent was significant for two days. Analgesia of the palmar nerves was significant for 24h with bupivicaine, compared to five days for ammonium chloride. Palmar digital neurectomy produced more variable thermal patterns. While sensitive enough to detect changes in heat patterns from control regions, thermography is not specific enough to discriminate between procedures and injury inducing an inflammatory response. 相似文献
40.
Assessment of melamine and cyanuric acid toxicity in cats. 总被引:30,自引:0,他引:30
Birgit Puschner Robert H Poppenga Linda J Lowenstine Michael S Filigenzi Patricia A Pesavento 《Journal of veterinary diagnostic investigation》2007,19(6):616-624
The major pet food recall associated with acute renal failure in dogs and cats focused initially on melamine as the suspect toxicant. In the course of the investigation, cyanuric acid was identified in addition to melamine in the offending food. The purpose of this study was to characterize the toxicity potential of melamine, cyanuric acid, and a combination of melamine and cyanuric acid in cats. In this pilot study, melamine was added to the diet of 2 cats at 0.5% and 1%, respectively. Cyanuric acid was added to the diet of 1 cat at increasing doses of 0.2%, 0.5%, and 1% over the course of 10 days. Melamine and cyanuric acid were administered together at 0%, 0.2%, 0.5%, and 1% to 1 cat per dose group. No effect on renal function was observed in cats fed with melamine or cyanuric acid alone. Cats dosed with a combination were euthanized at 48 hours after dosing because of acute renal failure. Urine and touch impressions of kidneys from all cats dosed with the combination revealed the presence of fan-shaped, birefringent crystals. Histopathologic findings were limited to the kidneys and included crystals primarily within tubules of the distal nephron, severe renal interstitial edema, and hemorrhage at the corticomedullary junction. The kidneys contained estimated melamine concentrations of 496 to 734 mg/kg wet weight and estimated cyanuric acid concentrations of 487 to 690 mg/kg wet weight. The results demonstrate that the combination of melamine and cyanuric acid is responsible for acute renal failure in cats. 相似文献