全文获取类型
收费全文 | 980篇 |
免费 | 74篇 |
国内免费 | 32篇 |
专业分类
林业 | 71篇 |
农学 | 70篇 |
基础科学 | 21篇 |
162篇 | |
综合类 | 197篇 |
农作物 | 76篇 |
水产渔业 | 105篇 |
畜牧兽医 | 251篇 |
园艺 | 44篇 |
植物保护 | 89篇 |
出版年
2024年 | 2篇 |
2023年 | 12篇 |
2022年 | 30篇 |
2021年 | 32篇 |
2020年 | 39篇 |
2019年 | 38篇 |
2018年 | 45篇 |
2017年 | 35篇 |
2016年 | 35篇 |
2015年 | 41篇 |
2014年 | 37篇 |
2013年 | 58篇 |
2012年 | 68篇 |
2011年 | 83篇 |
2010年 | 39篇 |
2009年 | 45篇 |
2008年 | 73篇 |
2007年 | 49篇 |
2006年 | 36篇 |
2005年 | 34篇 |
2004年 | 35篇 |
2003年 | 36篇 |
2002年 | 46篇 |
2001年 | 32篇 |
2000年 | 20篇 |
1999年 | 13篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 8篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1980年 | 3篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1963年 | 1篇 |
1961年 | 1篇 |
1955年 | 1篇 |
1949年 | 3篇 |
1945年 | 1篇 |
1930年 | 1篇 |
排序方式: 共有1086条查询结果,搜索用时 15 毫秒
11.
Charles O Thoen Jerald L Jarnagin Charles C Muscoplat L.S Cram Donald W Johnson Rube Harrington 《Comparative immunology, microbiology and infectious diseases》1980,3(3):355-361
A comparison of in vitro lymphocyte responses and delayed type tuberculin skin test responses was made in an animal experimentally exposed to a Mycobacterium bovis-infected animal and in cattle naturally infected with M. bovis. Tuberculin skin tests did not suppress in vitro lymphocyte responses to M. bovis PPD and to M. avium PPD tuberculin. The whole blood test used in these studies provided for considerable savings in time as compared to use of purified lymphocytes for evaluating in vitro cellular responses. Variations in the responsiveness of lymphocytes to specific mycobacterial antigens was observed, therefore, it is recommended that profiles be established using three or more tests conducted at 14-day intervals. 相似文献
12.
Ragnhild J Bager Egle Kudirkiene Isabelle da Piedade Torsten Seemann Tine K Nielsen Susanne E Pors Andreas H Mattsson John D Boyce Ben Adler Anders M Bojesen 《Veterinary research》2014,45(1)
The Gram-negative bacterium Gallibacterium anatis is a major cause of salpingitis and peritonitis in commercial egg-layers, leading to reduced egg production and increased mortality. Unfortunately, widespread multidrug resistance and antigenic diversity makes it difficult to control infections and novel prevention strategies are urgently needed. In this study, a pan-genomic reverse vaccinology (RV) approach was used to identify potential vaccine candidates. Firstly, the genomes of 10 selected Gallibacterium strains were analyzed and proteins selected on the following criteria; predicted surface-exposure or secretion, none or one transmembrane helix (TMH), and presence in six or more of the 10 genomes. In total, 42 proteins were selected. The genes encoding 27 of these proteins were successfully cloned in Escherichia coli and the proteins expressed and purified. To reduce the number of vaccine candidates for in vivo testing, each of the purified recombinant proteins was screened by ELISA for their ability to elicit a significant serological response with serum from chickens that had been infected with G. anatis. Additionally, an in silico prediction of the protective potential was carried out based on a protein property prediction method. Of the 27 proteins, two novel putative immunogens were identified; Gab_1309 and Gab_2312. Moreover, three previously characterized virulence factors; GtxA, FlfA and Gab_2156, were identified. Thus, by combining the pan-genomic RV approach with subsequent in vitro and in silico screening, we have narrowed down the pan-proteome of G. anatis to five vaccine candidates. Importantly, preliminary immunization trials indicated an in vivo protective potential of GtxA-N, FlfA and Gab_1309.
Electronic supplementary material
The online version of this article (doi:10.1186/s13567-014-0080-0) contains supplementary material, which is available to authorized users. 相似文献13.
S. Kennou Sebei R. Bergaoui M. Ben Hamouda R. G. Cooper 《Tropical animal health and production》2009,41(7):1427-1438
The aim of the current investigation was to determine wild ostrich reproductive behaviour in Orbata Nature Reserve by observing
16 hens and 28 cocks over a seven-year period. Intense laying commenced in January, one month after the cessation of the rainy
season, and 92% of the eggs were produced during the dry season (January to May, peaking in March). Over the seven years,
1,322 eggs were laid in 69 nests, which corresponded to an annual average production of 19.2 ± 9.1 eggs/nest and 11.8 eggs/hen.
24 nests (34.78%) were non-brooded, 17 nests (24.64%) were deserted in the course of incubation, and 28 nests (40.58%) possessed
hatched eggs. All the non-incubated nests had egg losses equivalent to 46.6 ± 12.6%. Hatchability success of incubated eggs
was 41.9 ± 12.0%. Ostriches tended to dig their nests adjacent to the reserve enclosure which had direct access by road and
track, the latter subjecting them to human disturbance and predation. The systematic obstruction of these nests stimulated
ostriches to build additional nests within the reserve perimeter. The authors discussed the results recorded in an ostrich
flock in relation to the environmental factors (climatic factors, food disponibility and predation) and suggested possibilities
for improved wildlife management. 相似文献
14.
15.
16.
动物园动物体内寄生虫的调查 总被引:5,自引:0,他引:5
为了摸清我市龙沙公园内展出的野生观赏动物寄生虫的感染情况 ,1991年以来随机对齐齐哈尔市龙沙公园的 33种 2 2 5头 (只 )的不同动物进行了以肠道寄生虫为主的 (不包括皮肤寄生虫 )调查 ,基本查清了感染情况 ,对临床治疗、动物管理和人员防护将起到协助作用。报告如下。1 普查方法1.1 蠕虫学常规粪检法收集虫卵。饱和食盐浮集法、反复洗涤沉淀法等 ,对肠道寄生原虫除直接涂片碘着色观察外 ,并用铁苏木素染色法 ,制成标本保存 ,以便鉴定虫体。1.2 用蠕虫学剖检对尸体进行虫体收集。1.3 对临床检查寄生虫阳性的动物进行驱虫 ,对驱出的虫… 相似文献
17.
Ben J. Schlegel Tony Van Dreumel Durda Slavi? John F. Prescott 《The Canadian veterinary journal. La revue veterinaire canadienne》2012,53(5):555-557
The morning after participating in a dog show, a 2-year-old Pomeranian dog was found dead in a pool of bloody feces. Necropsy revealed hemorrhagic gastroenteritis of the entire gastrointestinal tract, with many Gram-positive bacilli on the surface and in the lumen and crypts of the intestine. Enterotoxin-positive type A Clostridium perfringens were isolated in large numbers. This dramatic case of fatal C. perfringens gastroenteritis highlights the need to better understand the role of this bacterium in enteric disease of dogs. 相似文献
18.
John M Sykes Michael M Garner Leah L Greer Nancy P Lung Rob L Coke Frank Ridgley Mitch Bush Richard J Montali Ben Okimoto Robert Schmidt Jack L Allen Bruce A Rideout Patricia A Pesavento Edward C Ramsay 《Journal of zoo and wildlife medicine》2007,38(2):300-308
Oral eosinophilic granulomas were diagnosed in 16 tigers (Panthera tigris). All lesions were located on the hard or soft palate and typically consisted of flat or slightly raised circular ulcers. Histologic features of these lesions were essentially identical to those seen in oral eosinophilic granulomas of domestic cats and dogs. No clinical signs were noted in eight cases, though various degrees of inappetence, excessive salivation, and dysphagia were noted in the other eight tigers. Six cases were not treated. Treatment for the remaining 10 cases centered on corticosteroids and additional treatments included surgical removal, cryotherapy, antibiotics, and chlorpheniramine. Treatment with corticosteroids did appear to be effective in some cases, though lesions would worsen after cessation of therapy and no cases were cured. In addition, three cases developed complications possibly related to this corticosteroid therapy. The etiology of these lesions remains unknown, though an underlying allergic condition is likely. 相似文献
19.
为探讨不同细胞因子对水牛原始生殖细胞(PGCs)传代培养的影响,将PGCs分别采用A、B、C、D、E、F和G共7种培养基进行培养,即A组:基础液+10ng/mL白血病抑制因子(LIF)+10ng/mL碱性成纤维细胞生长因子(bFGF);B组:基础液+20ng/mL LIF+20ng/mL bFGF;C组:基础液+20ng/mL LIF+10ng/mL bFGF;D组:基础液+20ng/mL LIF;E组:基础液+20ng/mL LIF+20ng/mL bFGF+20ng/mL干细胞因子(SCF);F组:基础液+20ng/mL LIF+40ng/mL bFGF+40ng/mL SCF;G组(对照组):基础液。将机械法分离的PGCs小集落接种到水牛胎儿成纤维细胞(BEF)饲养层上进行传代培养。结果,原代时,A、B、C、D、E和F组的克隆数目都显著高于对照组(P%0.05),其中E和F组的克隆数目显著高于A组(P〈0.05),而与B、C、D组差异均不显著(P〉0.05);1~8代时,B、C、D、E、F组的克隆数目显著高于A组(P〈0.05);对照组传代数仅为2代,A组为5代,而B、C、D、E和F组均为8代以上。结果表明,在传代过程中,LIF起主要作用,20ng/mL的LIF浓度可以满足水牛PGCs传代培养的需要。 相似文献
20.
Gómez-Villamandos RJ Palacios C Benítez A Granados MM Domínguez JM López I Ruiz I Aguilera E Santisteban JM 《Journal of veterinary pharmacology and therapeutics》2006,29(3):157-163
The objective of this study was to evaluate dexmedetomidine as a premedicant in dogs prior to propofol-desflurane anaesthesia, and to compare it with medetomidine. Six healthy dogs were anaesthetized. Each dog received intravenously (i.v.) five preanaesthetic protocols: D1 (dexmedetomidine, 1 microg/kg, i.v.), D2 (dexmedetomidine, 2 microg/kg, i.v.), M1 (medetomidine, 1 microg/kg, i.v.), M2 (medetomidine, 2 microg/kg, i.v.), or M4 (medetomidine, 4 microg/kg, i.v.). Anaesthesia was induced with propofol (2.3-3.3 mg/kg) and maintained with desflurane. The following variables were studied: heart rate (HR), mean arterial pressure, systolic arterial pressure, diastolic arterial pressure, respiratory rate (RR), arterial oxygen saturation, end-tidal CO2, end-tidal concentration of desflurane (EtDES) required for maintenance of anaesthesia and tidal volume. Arterial blood pH (pHa) and arterial blood gas tensions (PaO2, PaCO2) were measured during anaesthesia. Time to extubation, time to sternal recumbency and time to standing were also recorded. HR and RR decreased significantly during sedation in all protocols. Cardiorespiratory variables during anaesthesia were statistically similar for all protocols. EtDES was significantly different between D1 (8.1%) and D2 (7.5%), and between all doses of medetomidine. Desflurane requirements were similar for D1 and M2, and for D2 and M4 protocols. No statistical differences were observed in recovery times. The combination of dexmedetomidine, propofol and desflurane appears to be effective for induction and maintenance of general anaesthesia in healthy dogs. 相似文献