全文获取类型
收费全文 | 3140篇 |
免费 | 235篇 |
国内免费 | 1篇 |
专业分类
林业 | 351篇 |
农学 | 112篇 |
基础科学 | 11篇 |
688篇 | |
综合类 | 284篇 |
农作物 | 146篇 |
水产渔业 | 169篇 |
畜牧兽医 | 1199篇 |
园艺 | 69篇 |
植物保护 | 347篇 |
出版年
2023年 | 22篇 |
2022年 | 39篇 |
2021年 | 55篇 |
2020年 | 73篇 |
2019年 | 54篇 |
2018年 | 98篇 |
2017年 | 115篇 |
2016年 | 113篇 |
2015年 | 92篇 |
2014年 | 110篇 |
2013年 | 169篇 |
2012年 | 219篇 |
2011年 | 253篇 |
2010年 | 134篇 |
2009年 | 134篇 |
2008年 | 219篇 |
2007年 | 194篇 |
2006年 | 157篇 |
2005年 | 167篇 |
2004年 | 140篇 |
2003年 | 127篇 |
2002年 | 123篇 |
2001年 | 55篇 |
2000年 | 47篇 |
1999年 | 48篇 |
1998年 | 30篇 |
1997年 | 18篇 |
1996年 | 16篇 |
1995年 | 24篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 25篇 |
1991年 | 15篇 |
1990年 | 19篇 |
1989年 | 19篇 |
1988年 | 16篇 |
1987年 | 20篇 |
1986年 | 8篇 |
1985年 | 16篇 |
1983年 | 10篇 |
1979年 | 12篇 |
1978年 | 7篇 |
1976年 | 10篇 |
1974年 | 7篇 |
1973年 | 10篇 |
1972年 | 7篇 |
1970年 | 8篇 |
1969年 | 12篇 |
1968年 | 7篇 |
1958年 | 7篇 |
排序方式: 共有3376条查询结果,搜索用时 18 毫秒
31.
Josée Roy Christian Bédard Maxim Moreau Frédéric Sauvé 《The Canadian veterinary journal. La revue veterinaire canadienne》2012,53(7):762-766
The efficacy of Oridermyl® (acaricidal/antibiotic/antifungal/anti-inflammatory ointment) and Revolution® (selamectin spot-on) was compared in a blinded randomized study on 24 adult cats with otoacariasis. Twelve cats were treated once daily for 10 d with Oridermyl® and 12 cats were treated on Day 0 with Revolution®. Otitis was assessed with cytological counts of mean number of bacteria and yeast on Days 0 and 10, and scored clinically every other day. All auricular secretions were removed for mite count on Day 10. On Day 0, cytological examination confirmed the presence of secondary bacterial (24/24) and fungal (21/24) infections. No live mites were observed otoscopically after Day 4 and in auricular secretions at Day 10 in both groups. On Day 10, secondary infections were resolved for all cats treated with Oridermyl® but were present in all cats treated with Revolution®. Improvement in clinical signs of otitis over time was superior in the Oridermyl® group (P < 0.001). 相似文献
32.
Susanne M. Stieger Christian Wenker Daniela Ziegler-Gohm Mark Flückiger PHD 《Veterinary radiology & ultrasound》2003,44(3):326-329
A 5-year-old guinea pig with suspected urolithiasis was presented for radiology and ultrasound examinations of the abdomen. Radiographically, an irregular-shaped mineral opacity was detected in the area of the urinary bladder. Ultrasonographically, pyelectasia of the right kidney, hydroureter with an ureterolith cranial to a thickened ureter wall close to the ureterovesical junction, and a thickened urinary bladder wall were detected. Histopathologically, the thickened ureter wall was found to be a papilloma. The ureter calculus consisted of 100% calcite. 相似文献
33.
Pressler BM Hardie EM Pitulle C Hopwood RM Sontakke S Breitschwerdt EB 《Journal of the American Veterinary Medical Association》2002,220(9):1336-40, 1313-4
A 3-year-old spayed female Whippet was examined for cough and respiratory distress. Lung lobe torsion with pleural effusion was diagnosed, and lung lobectomy was performed. Pleural effusion recurred during the following 27 months; conventional bacteriologic cultures of pleural effusion did not result in bacterial growth. A second lung lobectomy, pleuroperitoneal shunt placement. and pericardectomy were subsequently performed. Mycobacterium kansasii was eventually isolated from pleural fluid and identified by polymerase chain reaction amplification and DNA sequencing. The dog was euthanatized before therapeutic response could be evaluated. To our knowledge, this is the first report of M. kansasii infection in a dog. Additionally, this is the first report of mycobacterial isolation from pleural fluid, and one of few reports of antemortem mycobacterial isolation from a body fluid, as opposed to identification in specimens during histologic examination. Routine bacteriologic culture methods are insufficient to isolate mycobacterial agents, and special methods are indicated in dogs with persistent pleural effusion. 相似文献
34.
Giguère S Gaskin JM Miller C Bowman JL 《Journal of the American Veterinary Medical Association》2002,220(1):59-63
OBJECTIVE: To determine efficacy of a commercially available hyperimmune plasma product for prevention of naturally acquired pneumonia caused by Rhodococcus equi in foals. DESIGN: Randomized clinical trial. ANIMALS: 165 foals. PROCEDURE: Foals were randomly assigned to 1 of 2 groups (hyperimmune plasma or nontreated controls). Foals with failure of passive transfer (FPT) of immunity were treated with hyperimmune plasma and evaluated as a third group. Foals that received plasma were given 950 ml between 1 and 10 days of age and between 30 and 50 days of age. A tracheobronchial aspirate was obtained from foals with clinical signs of respiratory tract disease for bacteriologic culture. RESULTS: A significant difference in incidence of pneumonia caused by R equi in foals with adequate passive transfer was not detected between foals that received plasma (19.1%) and nontreated foals (30%). Of 13 foals without FPT that received plasma and developed pneumonia caused by R equi, 12 developed disease prior to administration of the second dose of hyperimmune plasma. Incidence of undifferentiated pneumonia of all causes was not different between groups. CONCLUSION AND CLINICAL RELEVANCE: Intravenous administration of the commercially available hyperimmune plasma was safe, and the product contained high concentrations of anti-R equi antibodies. However, within this limited foal population, the difference in incidence of pneumonia caused by R equi observed between foals that received plasma and control foals was not significant. 相似文献
35.
The canine veterinary medicine in the Middle Ages according to the Livre de chasse by Gaston Phoebus
Boor-van der Putten I 《Historia medicinae veterinariae》2003,28(1):1-11
Gaston Phoebus (1331-1391) of Foix-Béarn was a mighty vassal of the king of France as well as of the king of England. His book, the Livre de Chasse was the first technical treaty of this scope. It was fundamental for the regulation of hunting in Europe, as it was copied and plagiarized later on by a number of authors. Chapter 16 is about diseases of the dog and their treatment. In this article Phoebus views about pathology, etiology and therapy are discussed. The absence of superstition, magic and preconceived notions is remarkable. His writings are based on personal observations which are detailed. His therapy is generally rational and probably often effective, never harmful. His love of hounds is evident. It is regrettable that this highly rational approach didn't have a longer lasting effect on the development of canine medicine. 相似文献
36.
37.
de la Fuente J Ruybal P Mtshali MS Naranjo V Shuqing L Mangold AJ Rodríguez SD Jiménez R Vicente J Moretta R Torina A Almazán C Mbati PM de Echaide ST Farber M Rosario-Cruz R Gortazar C Kocan KM 《Veterinary microbiology》2007,119(2-4):382-390
Anaplasma marginale is a tick-borne pathogen of cattle that causes the disease bovine anaplasmosis worldwide. Major surface proteins (MSPs) are involved in host-pathogen and tick-pathogen interactions and have been used as markers for the genetic characterization of A. marginale strains and phylogenetic studies. MSP1a is involved in the adhesion and transmission of A. marginale by ticks and varies among geographic strains in the number and sequence of amino-terminal tandem repeats. The aim of this study was to characterize the genetic diversity of A. marginale strains collected from countries in North and South America, Europe, Asia, Africa and Australia, inclusive of all continents. In this study, we characterized 131 strains of A. marginale using 79 MSP1a repeat sequences. These results corroborated the genetic heterogeneity of A. marginale strains in endemic regions worldwide. The phylogenetic analyses of MSP1a repeat sequences did not result in clusters according to the geographic origin of A. marginale strains but provided phylogeographic information. Seventy-eight percent of the MSP1a repeat sequences were present in strains from a single geographic region. Strong (> or =80%) support was found for clusters containing sequences from Italian, Spanish, Chinese, Argentinean and South American strains. The phylogenetic analyses of MSP1a repeat sequences suggested tick-pathogen co-evolution and provided evidence of multiple introductions of A. marginale strains from various geographic locations worldwide. These results contribute to the understanding of the genetic diversity and evolution of A. marginale and tick-pathogen interactions. 相似文献
38.
Riggs LM Franck T Moore JN Krunkosky TM Hurley DJ Peroni JF de la Rebière G Serteyn DA 《American journal of veterinary research》2007,68(1):81-86
OBJECTIVE: To compare measurements of myeloperoxidase (MPO) in plasma, laminar tissues, and skin obtained from control horses and horses given black walnut heartwood extract (BWHE). ANIMALS: 22 healthy 5- to 15-year-old horses. PROCEDURES: Horses were randomly assigned to 4 groups as follows: a control group given water (n = 5) and 3 experimental groups given BWHE (17) via nasogastric intubation. Experimental groups consisted of 5, 6, and 6 horses that received BWHE and were euthanatized at 1.5, 3, and 12 hours after intubation, respectively. Control horses were euthanatized at 12 hours after intubation. Plasma samples were obtained hourly for all horses. Laminar tissue and skin from the middle region of the neck were harvested at the time of euthanasia. Plasma and tissue MPO concentrations were determined via an ELISA; tissue MPO activity was measured by use of specific immunologic extraction followed by enzymatic detection. RESULTS: Tissues and plasma of horses receiving BWHE contained significantly higher concentrations of MPO beginning at hour 3. Laminar tissue and skin from horses in experimental groups contained significantly higher MPO activity than tissues from control horses. Concentrations and activities of MPO in skin and laminar tissues were similar over time. CONCLUSIONS AND CLINICAL RELEVANCE: In horses, BWHE administration causes increases in MPO concentration and activity in laminar tissue and skin and the time of increased MPO concentration correlates with emigration of WBCs from the vasculature. These findings support the hypothesis that activation of peripheral WBCs is an early step in the pathogenesis of acute laminitis. 相似文献
39.
40.