全文获取类型
收费全文 | 524篇 |
免费 | 39篇 |
专业分类
林业 | 11篇 |
农学 | 3篇 |
基础科学 | 3篇 |
25篇 | |
综合类 | 124篇 |
农作物 | 65篇 |
水产渔业 | 31篇 |
畜牧兽医 | 275篇 |
园艺 | 4篇 |
植物保护 | 22篇 |
出版年
2020年 | 7篇 |
2016年 | 11篇 |
2015年 | 10篇 |
2014年 | 11篇 |
2013年 | 21篇 |
2012年 | 14篇 |
2011年 | 9篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 16篇 |
2007年 | 9篇 |
2006年 | 10篇 |
2005年 | 13篇 |
2004年 | 11篇 |
2003年 | 14篇 |
2001年 | 13篇 |
2000年 | 19篇 |
1999年 | 16篇 |
1998年 | 11篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 10篇 |
1991年 | 7篇 |
1990年 | 17篇 |
1989年 | 11篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1978年 | 5篇 |
1975年 | 6篇 |
1974年 | 7篇 |
1971年 | 8篇 |
1970年 | 12篇 |
1969年 | 6篇 |
1966年 | 7篇 |
1950年 | 4篇 |
1949年 | 7篇 |
1948年 | 7篇 |
1946年 | 9篇 |
1945年 | 7篇 |
1944年 | 6篇 |
1943年 | 13篇 |
1941年 | 6篇 |
1940年 | 5篇 |
1939年 | 4篇 |
排序方式: 共有563条查询结果,搜索用时 531 毫秒
131.
Climate. Caving in to new chronologies 总被引:1,自引:0,他引:1
Henderson GM 《Science (New York, N.Y.)》2006,313(5787):620-622
132.
OBJECTIVES: To compare suture patterns (simple interrupted, modified pulley, horizontal mattress, double butterfly) by use of a novel in vitro model that quantifies force required for closure against tension. STUDY DESIGN: In vitro study. SAMPLE POPULATION: Suture constructs. METHODS: An in vitro suturing frame was constructed with extension springs to provide a standard resistance against movement of 2 panels of loops toward each other. Four different suture patterns were applied to the frame in randomized trials. The frame was affixed to a tensiometer that measured the force required for each suture pattern to close a fixed distance (3.81 cm) at a constant rate (5.08 cm/min) against the tension (0.6 kg/cm) of the extension springs. The closure distance and tension were selected subjectively to mimic tension encountered clinically during wound reconstruction oncologic surgical procedures. RESULTS: The modified pulley suture required the least force to close, followed by the double butterfly, simple interrupted, and horizontal mattress patterns. CONCLUSIONS: The modified pulley suture and double butterfly suture patterns require less force to close a given distance under tension than either simple interrupted or horizontal mattress suture patterns. CLINICAL RELEVANCE: Application of tension relieving suture techniques for fascia, subcutaneous, and buried-knot subdermal suturing should be considered to facilitate direct closure of wounds under tension. Modified pulley and double butterfly suture patterns offer some mechanical advantage by requiring less force to achieve closure compared with other suture patterns that might be used in reconstructive surgery. 相似文献
133.
Henderson P 《Journal of the American Veterinary Medical Association》2012,240(3):260; author reply 261
134.
135.
Waldner CL Janzen ED Henderson J Haines DM 《Journal of the American Veterinary Medical Association》1999,215(10):1485-90, 1448-9
Abortion outbreaks caused by infection with Neospora caninum in beef cattle have not been well documented. Neospora caninum infection was confirmed in 4 fetuses that were aborted by cattle in a 350-head beef herd; an additional 58 cattle aborted during the next 2.5 months. Overall, 44.4% (157/354) of the cattle in the herd did not become pregnant or experienced fetal loss during this period. Initially, 81.3% (282/347) of the herd was seropositive for antibodies to N caninum, and seropositive cows were 6.2 times as likely to not be pregnant as were seronegative cows. Other potential causes of abortion were not identified in this herd. Following the outbreak, few cattle in the herd or in a second exposed herd seroconverted, but high antibody titers persisted in most seropositive cattle through the end of the calving season. Evidence of cow-to-fetus transmission of the organism was detected in > 82% of seropositive cows. 相似文献
136.
Hostutler RA Chew DJ Jaeger JQ Klein S Henderson D DiBartola SP 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2005,19(1):29-33
Uncorrected hypercalcemia can cause clinical signs such as polyuria, polydipsia, vomiting, diarrhea, lethargy, and depression and contributes to the development of primary renal failure and soft tissue mineralization. Treatment of hypercalcemia includes diagnosis and treatment of the underlying disease process and some combination of excracellular fluid volume expansion by administration of fluids intravenously and administration of glococorticosteroids, salmon calcitonin, and furosemide. Bisphosphonates such as pamidronate disodium also may be safe and effective in the treatment of hypercalcemia. The purpose of our study was to characterize the efficacy and safety of pamidronate in the treatment of hypercalcemia attritutable to several different disease processes in the dog and cat. Seven dogs and 2 cats were administered pamidronate at a dose of 1.05-2.0 mg/kg IV for a variety of disease processes, including neoplasia (n = 4), calcipotriene toxicity (n = 3), nocardiosis (n = 1), and idiopathic hypercalcemia with chronic renal failure (n = 1). In all the animals, IV pamidronate administration rapidly decreased serum calcium concentrations without evident toxicosis. Two animals received pamidronate several times without obvious toxicosis. On the basis of the findings in our retrospective study, pamidronate may be a safe and effective drug with which to lower both serum total and ionized calcium concentrations in patients with hypercalcemia arising from a wide variety of underlying disease processes. 相似文献
137.
138.
139.
Stear MJ Bishop SC Henderson NG Scott I 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2003,4(1):45-52
Infection of sheep with the abomasal nematode Teladorsagia circumcincta can cause a relative protein deficiency and reduce growth rate in growing lambs. A key event appears to be the destruction of junctions between epithelial cells. If the infection is heavy or prolonged, this leads to increased mucus production, hyperplasia, decreased acid production, gastrinemia, inappetance and pepsinogenemia. The severity of the infection depends upon the extent of concurrent infection, the nutritional status of the host and genetically controlled variation in the ability to mount protective immune responses. 相似文献
140.