全文获取类型
收费全文 | 13371篇 |
免费 | 995篇 |
国内免费 | 804篇 |
专业分类
林业 | 641篇 |
农学 | 831篇 |
基础科学 | 145篇 |
355篇 | |
综合类 | 4351篇 |
农作物 | 776篇 |
水产渔业 | 900篇 |
畜牧兽医 | 4742篇 |
园艺 | 640篇 |
植物保护 | 1789篇 |
出版年
2024年 | 80篇 |
2023年 | 256篇 |
2022年 | 436篇 |
2021年 | 539篇 |
2020年 | 535篇 |
2019年 | 603篇 |
2018年 | 392篇 |
2017年 | 506篇 |
2016年 | 533篇 |
2015年 | 527篇 |
2014年 | 717篇 |
2013年 | 720篇 |
2012年 | 869篇 |
2011年 | 849篇 |
2010年 | 731篇 |
2009年 | 725篇 |
2008年 | 659篇 |
2007年 | 670篇 |
2006年 | 628篇 |
2005年 | 494篇 |
2004年 | 466篇 |
2003年 | 368篇 |
2002年 | 298篇 |
2001年 | 346篇 |
2000年 | 350篇 |
1999年 | 292篇 |
1998年 | 201篇 |
1997年 | 162篇 |
1996年 | 151篇 |
1995年 | 162篇 |
1994年 | 133篇 |
1993年 | 126篇 |
1992年 | 147篇 |
1991年 | 97篇 |
1990年 | 79篇 |
1989年 | 73篇 |
1988年 | 45篇 |
1987年 | 44篇 |
1986年 | 23篇 |
1985年 | 16篇 |
1984年 | 10篇 |
1983年 | 14篇 |
1982年 | 18篇 |
1981年 | 10篇 |
1980年 | 20篇 |
1979年 | 17篇 |
1978年 | 7篇 |
1976年 | 8篇 |
1956年 | 5篇 |
1955年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Plasma N‐terminal pro‐B‐type natriuretic peptide concentration in healthy retired racing Greyhounds
下载免费PDF全文
![点击此处可从《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
992.
993.
994.
995.
996.
Cortisol Concentrations in Well‐Regulated Dogs with Hyperadrenocorticism Treated with Trilostane
下载免费PDF全文
![点击此处可从《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J.N. Midence K.J. Drobatz R.S. Hess 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(6):1529-1533
Background
There are no clear treatment guidelines for dogs with clinically well‐regulated hyperadrenocorticism in which serum cortisol concentrations before and after an ACTH stimulation test performed 3–6 hours after trilostane administration are < 2.0 μg/dL.Objective
To determine if serum cortisol concentrations measured before (Pre1) and after (Post1) ACTH stimulation at 3–6 hours after trilostane administration are significantly lower than cortisol concentrations measured before (Pre2) and after (Post2) ACTH stimulation 9–12 hours after trilostane administration, in a specific population of dogs with clinically well‐regulated hyperadrenocorticism and Pre1 and Post1 <2 μg/dL.Animals
Thirteen client‐owned dogs with clinically well‐regulated hyperadrenocorticism and Pre1 and Post1 serum cortisol concentrations <2.0 μg/dL 3–6 hours after trilostane administration.Methods
Prospective study. Dogs had a second ACTH stimulation test performed 9–12 hours after trilostane administration, on the same day of the first ACTH stimulation test. Cortisol concentrations before and after ACTH stimulation were compared using a paired t‐test.Results
Cortisol concentrations before (1.4 ± 0.3 μg/dL) and after the first stimulation (1.5 ± 0.3 μg/dL, mean ± SD) were significantly lower than cortisol concentration before the second stimulation (3.3 ± 1.6 μg/dL, P = .0012 each). Cortisol concentration before the first stimulation was also significantly lower than cortisol concentration after the second stimulation (5.3 ± 2.4 μg/dL, P = .0001).Conclusions and clinical importance
In dogs with clinically well‐regulated, trilostane‐treated, hyperadrenocorticism, and cortisol concentrations <2 μg/dL before and after the first stimulation, a second ACTH stimulation test performed 9–12 hours after treatment can result in higher cortisol concentrations that could support continued trilostane treatment. 相似文献997.
H. Titmarsh A.G. Gow S. Kilpatrick J. Sinclair T. Hill E. Milne A. Philbey J. Berry I. Handel R.J. Mellanby 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(6):1473-1478
Background
Dogs with a chronic enteropathy (CE) have a lower vitamin D status, than do healthy dogs. Vitamin D status has been associated with a negative clinical outcome in humans with inflammatory bowel disease.Objectives
To examine the relationship between serum 25 hydroxyvitamin D (25(OH)D) concentrations at diagnosis and clinical outcome in dogs with a CE.Animals
Forty‐one dogs diagnosed with CE admitted to the Royal Dick School of Veterinary Studies, Hospital for Small Animals between 2007 and 2013.Methods
Retrospective review. Serum 25(OH)D concentrations were compared between dogs which were alive at follow up or had died because of non‐CE‐related reasons (survivors) and dogs which died or were euthanized due to their CE (non‐survivors). A binary logistic regression analysis was performed to determine significant predictors of death in dogs with CE.Results
Serum concentrations of 25(OH)D at the time a CE was diagnosed were significantly lower in nonsurvivors (n = 15) (median nonsurvivors 4.36 ng/mL, interquartile range 1.6–17.0 ng/mL), median survivors (n = 26) (24.9 ng/mL interquartile range 15.63–39.45 ng/mL, P < .001). Serum 25(OH)D concentration was a significant predictor of death in dogs with CE (odds ratio 1.08 [95% CI 1.02–1.18)]).Conclusions
Serum 25(OH)D concentrations at diagnosis are predictive of outcome in dogs with CE. The role of vitamin D in the initiation and outcome of chronic enteropathies in dogs is deserving of further study. 相似文献998.
Secretoglobin and Transferrin Expression in Bronchoalveolar Lavage Fluid of Horses with Chronic Respiratory Disease
下载免费PDF全文
![点击此处可从《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M. Miskovic Feutz L.L. Couetil C.P. Riley X. Zhang J. Adamec R.E. Raskin 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(6):1692-1699
Background
Lower expression of secretoglobin and transferrin has been found in the bronchoalveolar lavage fluid (BALF) of a small number of horses with experimentally induced signs of recurrent airway obstruction (RAO) compared to healthy controls.Hypothesis/Objectives
Secretoglobin and transferrin BALF expression will be similarly decreased in horses with naturally occurring clinical signs of RAO and in horses with experimentally induced clinical signs of RAO as compared to healthy controls and intermediate in horses with inflammatory airway disease (IAD).Animals
Recurrent airway obstruction‐affected and control horses were subjected to an experimental hay exposure trial to induce signs of RAO. Client‐owned horses with a presumptive diagnosis of RAO and controls from the same stable environments were recruited.Methods
Pulmonary function and BALF were evaluated from control and RAO‐affected research horses during an experimental hay exposure trial (n = 5 in each group) and from client‐owned horses (RAO‐affected horses, n = 17; IAD‐affected horses, n = 19; healthy controls, n = 5). The concentrations of secretoglobin and transferrin in BALF were assessed using Western blots.Results
Naturally occurring and experimentally induced RAO horses had similar decreases in BALF transferrin expression, but secretoglobin expression was most decreased in naturally occurring RAO. Secretoglobin and transferrin expression were both lower in BALF of RAO‐affected horses than in IAD‐affected and control horses.Conclusions and Clinical Importance
Secretoglobin and transferrin expression is decreased in BALF of RAO‐affected horses after both experimental and natural exposure. Secretoglobin and transferrin likely play clinically relevant roles in the pathophysiology of RAO, and may thus be used as biomarkers of the disease. 相似文献999.
1000.
Omega‐3 Fatty Acid Supplementation Provides an Additional Benefit to a Low‐Dust Diet in the Management of Horses with Chronic Lower Airway Inflammatory Disease
下载免费PDF全文
![点击此处可从《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
N. Nogradi L.L. Couetil J. Messick M.A. Stochelski J.R. Burgess 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(1):299-306