全文获取类型
收费全文 | 525篇 |
免费 | 37篇 |
国内免费 | 2篇 |
专业分类
林业 | 33篇 |
农学 | 16篇 |
基础科学 | 3篇 |
163篇 | |
综合类 | 33篇 |
农作物 | 36篇 |
水产渔业 | 43篇 |
畜牧兽医 | 181篇 |
园艺 | 18篇 |
植物保护 | 38篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 10篇 |
2021年 | 13篇 |
2020年 | 17篇 |
2019年 | 11篇 |
2018年 | 26篇 |
2017年 | 21篇 |
2016年 | 24篇 |
2015年 | 11篇 |
2014年 | 20篇 |
2013年 | 39篇 |
2012年 | 36篇 |
2011年 | 58篇 |
2010年 | 42篇 |
2009年 | 23篇 |
2008年 | 34篇 |
2007年 | 31篇 |
2006年 | 32篇 |
2005年 | 28篇 |
2004年 | 25篇 |
2003年 | 15篇 |
2002年 | 16篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有564条查询结果,搜索用时 0 毫秒
71.
72.
Swan Specchi Giuseppe Lacava Marc-André d’Anjou Eric Zini Edoardo Auriemma 《The Canadian veterinary journal. La revue veterinaire canadienne》2012,53(11):1187-1190
A 10-year-old spayed female dalmatian dog developed acute vomiting and abdominal pain. Ultrasound examination of the abdomen showed right hydronephrosis and proximal ureter dilation with mild retroperitoneal free fluid. Computed tomography (CT) of the abdomen confirmed the ultrasonographic findings and revealed, additionally, a right ureteral stone. Spontaneus rupture of the right ureter was confirmed with CT post ultrasound-guided percutaneous antegrade pyelography. Pyeloureteral rupture and the presence of a ureteral stone were confirmed at surgery. 相似文献
73.
Follicular dendritic cells (FDCs) residing within ileal Peyer's patches (PPs) are of crucial relevance for sheep scrapie early pathogenesis and subsequent scrapie prion neuroinvasion. In this study, ileal PP follicles were significantly more numerous in lambs than in adult Sarda breed sheep, with significant differences being also found in lymphoid follicle area, perimeter and FDC density. Furthermore, PrPd deposition within ileal PPs and host's PrP genotype did not significantly influence these parameters. We conclude that age significantly affects FDC density in ileal PPs from Sarda breed ovines, independently from host's scrapie status and PrP genotype. 相似文献
74.
75.
Lynen G Yrjö-Koskinen AE Bakuname C Di Giulio G Mlinga N Khama I Hanks J Taylor NM James AD McKeever D Peters AR Rushton J 《Tropical animal health and production》2012,44(3):567-572
East Coast fever (ECF) causes considerable mortality and production losses in the Tanzania smallholder dairy sector and limits the introduction of improved dairy breeds in areas where the disease is present. The infection and treatment method (ITM) was adopted by smallholder dairy farms for ECF immunisation in Hanang and Handeni districts of Tanzania. This study recorded incidence rates for ECF and other tick-borne diseases (TBDs) for ECF-immunised and non-immunised cattle between 1997 and 2000. Approximately 80% of smallholder households from both sites (n?=?167) participated in this longitudinal study, with immunisations carried out at the request of the livestock owners. Efficacy of ITM for preventing ECF cases in these crossbred dairy cattle was estimated at 97.6%, while that for preventing ECF deaths was 97.9%. One percent of the cattle developed clinical ECF as a result of immunisation. Since ECF immunisation permits a reduction in acaricide use, an increase in other TBDs is a potential concern. Sixty-three percent of farmers continued to use the same acaricide after immunisation, with 80% of these reducing the frequency of applications. Overall, 78% of farmers increased the acaricide application interval after immunisation beyond that recommended by the manufacturer, resulting in annual savings in the region of USD 4.77 per animal. No statistical difference was observed between the immunised and non-immunised animals in the incidence of non-ECF TBDs. However, immunised animals that succumbed to these diseases showed fewer case fatalities. ITM would therefore appear to be a suitable method for ECF control in Tanzania's smallholder dairy sector. 相似文献
76.
Traversa D Castagna G von Samson-Himmelstjerna G Meloni S Bartolini R Geurden T Pearce MC Woringer E Besognet B Milillo P D'Espois M 《Veterinary parasitology》2012,188(3-4):294-300
This paper reports a survey conducted in France during 2011 to evaluate the efficacy of commonly used anthelmintics against horse cyathostomins. A total of 40 farms and 1089 horses were screened for the presence of cyathostomins. All farms but one were positive, with an overall animal infection rate of 53.7%, ranging from 9% to 83% on individual farms. On 445 horses from 30 of these farms, a faecal egg count reduction test (FECRT) was performed to evaluate the efficacy of oral formulations of fenbendazole (FBZ), pyrantel embonate (PYR), ivermectin (IVM) and moxidectin (MOX). Calculation of the mean FECR and 95% confidence intervals (95% CI) around the mean was performed using bootstrap analysis. Resistance to FBZ was found on 17 of 18 farms investigated, with a mean reduction of 57% (95% CI: 38.5-71.2%). Suspected resistance for PYR was found on 6 of 30 farms, and confirmed on another 3 of 30 farms, with a mean reduction for PYR of 94.7% (95% CI: 88.9-98.5%). Reduced efficacy simultaneously of FBZ and PYR was found in 7 farms. Reduced efficacy of IVM was found in one animal on one farm and of MOX in one animal on another farm, and was combined with resistance against FBZ and/or PYR. These results indicate that single and multiple drug resistance and reduced efficacy in equine cyathostomins is present in France. Macrocylic lactones proved to be highly effective compounds against cyathostomins, with reduced efficacy for IVM and MOX in two farms only. These results extend present knowledge on the occurrence of drug resistant cyathostomins in Europe, and illustrate the necessity to use anthelmintics in appropriate worm control programmes. 相似文献
77.
Bertolini S Maurella C Bona C Ingravalle F Desiato R Baioni E Chiavacci L Caramelli M Ru G 《Veterinary research》2012,43(1):63
ABSTRACT: A sudden increase in the incidence of scrapie in Italy in 1997 was subsequently linked to theuse of a potentially infected vaccine against contagious agalactia. The relative risk for theexposed farms ranged between 6 and 40. The aim of this study was to assess the long-termimpact of exposure to the potentially scrapie-contaminated vaccine on the Italian classicalscrapie epidemic. We carried out a retrospective cohort study, fitting mixed-effects Poissonregression models, dividing national geographic areas into exposure categories on the basis ofthe vaccine circulation levels. We took into account the sensitivity of the surveillance systemapplied in the different areas. The population attributable fraction (PAF) was used to assessthe impact on the total population of farms associated with the effect of circulation of thevaccine. The provinces where the vaccine was more often sold were noted to have a higherlevel of disease when compared to those provinces where the vaccine was sold less often(incidence rate ratio [IRR]: 2.7; 95% confidence interval [CI]: 1.1-6.5). The populationattributable fraction was high (68.4%). Standardization techniques allowed to account for thepotential of geographical variability in the sensitivity of the Italian surveillance system.Although the number of the directly exposed farms was limited, an important long-termimpact of the vaccine circulation could be quantified in terms of secondary outbreaks likelydue to the exchange of animals from directly exposed flocks. 相似文献
78.
The pharmacokinetic (PK) parameters of artesunate, artemether and their metabolites dihydroartemisinin (DHA) and dihydroartemisinin-glucuronide (DHA-glucuronide) were determined in sheep naturally infected with Fasciola hepatica. Sheep were treated either with artesunate (intramuscular (i.m.): 40 and 60 mg/kg) or artemether (i.m.: 40 and 160 mg/kg; oral: 80 mg/kg). Blood samples were withdrawn at selected time points post treatment and the artemisinins were quantified in plasma by liquid chromatography and tandem mass spectrometry (LC-MS/MS). The in vitro effect of the metabolites against F. hepatica was investigated using a phenotype-based assay and scanning electron microscopy (SEM). Following artesunate applications (40 and 60 mg/kg), comparable C(max) (maximal plasma concentration) and AUCs (area under the plasma concentration-time curve) were observed for artesunate (C(max): 8.4×10(3) and 9.4×10(3)ng/ml; AUC: 6.9×10(5) and 9.7×10(5) ng min/ml), DHA (C(max): both 2.4×10(3)ng/ml; AUC: 3.7×10(5) and 5.0×10(5) ng min/ml), and DHA-glucuronide (C(max): 1.7×10(4) and 1.6×10(4)ng/ml; AUC: 2.6×10(6) and 3.3×10(6) ng min/ml). Mean elimination half-lifes (t(1/2)) of artesunate, DHA and DHA-glucuronide ranged between 58 and 63 min, 94 and 113min, and 89 and 98 min, respectively. The i.m. oil-based drug formulation liberated artemether slowly and constant levels of artemether and its metabolites were observed during the entire sampling period (24 h). The AUCs of all analytes were significantly higher for the i.m. 160 mg/kg dose compared to i.m. 40 and oral 80 mg/kg doses (P=0.018). Mean C(max) of artemether (2126 and 426 ng/ml) and DHA-glucuronide (3477 and 1587 ng/ml) were higher following oral compared to i.m. (160 mg/kg) treatments (P>0.068), whereas C(max) of DHA was significantly higher following i.m. applications (P=0.0062). DHA rapidly reduced the viability of F. hepatica in vitro, whereas DHA-glucuronide showed no activity. SEM observations revealed only minor and focal tegumental alterations in few of the DHA treated worms. The calculated PK parameters reflect the anthelmintic activity of artesunate and artemether following different routes of application and will aid in the design of future studies with these drugs. 相似文献
79.
80.
Marrubium vulgare (Lamiaceae) is a plant traditionally used for the treatment of diabetes in Algeria. Compositional analysis of the aqueous infusion revealed the presence of fifteen metabolites, all belonging to the class of polyphenols. Particularly, seven flavonoids have been detected, together with 5-caffeoylquinic (chlorogenic) acid in small amounts; the extract is dominated by the presence of a series of complex molecules, characterized as verbascoside (acteoside) derivatives. Concerning the anti-diabetic effectiveness a series of in vivo experiments were carried out on albinos Wistar rats. Diabetes was induced in the animals by intra-peritoneal injection of alloxane; they were treated twice a day with aqueous extract from aerial part infusion (100, 200 and 300 mg/kg body weight) and glibenclamide (5mg/kg body weight) for 15 days. Oral administration of 200 and 300 mg/kg body weight of aqueous extract the Marrubium vulgare induced an significant effect antidiabetic and antihyperlipidemic (dose-dependent effect). A decrease in blood glucose by 50% for the dose 100 mg/kg and more than 60% for doses 200 and 300 mg/kg, as well as a significant lowering of total lipids, triglycerides, and total cholesterol levels in treated animals, compared with diabetic controls group (p<0.001), have been observed. Glibenclamide was used as reference and showed similar effects. 相似文献