全文获取类型
收费全文 | 294篇 |
免费 | 15篇 |
专业分类
林业 | 30篇 |
农学 | 8篇 |
基础科学 | 1篇 |
71篇 | |
综合类 | 13篇 |
农作物 | 21篇 |
水产渔业 | 24篇 |
畜牧兽医 | 95篇 |
园艺 | 17篇 |
植物保护 | 29篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 1篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 13篇 |
2015年 | 4篇 |
2014年 | 15篇 |
2013年 | 12篇 |
2012年 | 25篇 |
2011年 | 31篇 |
2010年 | 13篇 |
2009年 | 15篇 |
2008年 | 26篇 |
2007年 | 25篇 |
2006年 | 11篇 |
2005年 | 15篇 |
2004年 | 8篇 |
2003年 | 17篇 |
2002年 | 18篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1993年 | 4篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有309条查询结果,搜索用时 15 毫秒
81.
Single-step purification and evaluation of recombinant BP26 protein for serological diagnosis of Brucella ovis infection in rams 总被引:1,自引:0,他引:1
Zygmunt MS Baucheron S Vizcaino N Bowden RA Cloeckaert A 《Veterinary microbiology》2002,87(3):213-220
To investigate the value of the BP26 protein in the serological diagnosis of ovine brucellosis caused by Brucella ovis, recombinant BP26 protein was produced in Echerichia coli and purified for use in an indirect enzyme-linked immunosorbent assay (I-ELISA). The majority of the recombinant protein was recovered from the supernatant of sonicated recombinant E. coli cells in a soluble form. This facilitated the purification of the recombinant BP26 protein which was achieved by using ion-exchange chromatography. After one step of purification, the purity of the recombinant BP26 protein was analyzed by using SDS-PAGE, Coomassie blue staining, and Western blot with a monoclonal antibody (MAb) directed against the BP26 protein. The degree of purity appeared satisfactory so that it could be directly used in I-ELISA. Although the recombinant BP26-ELISA appeared less useful than I-ELISA using the B. ovis hot saline (HS) extract as antigen, the high number of sera from B. ovis infected rams found positive (90%) in the recombinant BP26-I-ELISA indicated that the BP26 protein may be an additional suitable antigen for serological diagnosis of B. ovis infection in rams. 相似文献
82.
83.
Van de Maele I Savary-Bataille K Gielen I Daminet S 《The Canadian veterinary journal. La revue veterinaire canadienne》2008,49(3):283-286
An Akita Inu, living in Belgium, was presented with unusual clinical manifestations of acute babesiosis that included neurological signs and pancytopenia. Diagnosis was made by identifying Babesia canis in the blood smear. Neurological signs resolved after treatment with imidocarb diproprionate. Normalization of hematological abnormalities was gradual over 5 months. 相似文献
84.
Lecollinet S Richardson J 《Comparative immunology, microbiology and infectious diseases》2008,31(2-3):167-190
Natural infection of domestic cats by the feline immunodeficiency virus (FIV) causes acquired immunodeficiency syndrome (AIDS). FIV is genetically related to human immunodeficiency virus (HIV), and the clinical and biological features of infections caused by feline and human viruses in their respective hosts are highly analogous. Although the obstacles to vaccinating against FIV and HIV would seem to be of comparable difficulty, a licensed vaccine against feline AIDS is already in widespread use in several countries. While this seemingly major advance in prevention of AIDS would appear to be highly instructive for HIV vaccine development, its message has not been heeded by investigators in the HIV field. This review endeavours to relate what has been learned about vaccination against feline AIDS, and to suggest what this may mean for HIV vaccine development. 相似文献
85.
Dogs and cats living in a household have previously been identified as a risk factor for human infection with Campylobacter and Helicobacter. In this study, carried out between July 2006 to September 2007, feces and oral swabs from 267 dogs and 61 cats were examined for the presence of the emerging pathogen Arcobacter. Isolates, obtained by an Arcobacter selective isolation procedure, were identified with an Arcobacter species-specific multiplex-PCR and characterized by modified enterobacterial repetitive intergenic concensus PCR. No arcobacters were isolated from cats. Five dogs excreted arcobacters in the feces and two other dogs carried arcobacters in the mouth. In the follow-up, one dog excreted the same Arcobacter butzleri strain for at least 1 week. Six dogs carried each an unique A. cryaerophilus strain although three of them lived in the same family. Therefore, beside the consumption of food and water, contact with dogs is another potential source of Arcobacter infection. 相似文献
86.
Dupont D Johansson A Marchin S Rolet-Repecaud O Marchesseau S Leonil J 《Journal of agricultural and food chemistry》2011,59(15):8375-8384
Several theoretical models of the casein micelle structure have been proposed in the past, but the exact organization of the four individual caseins (α(s1), α(s2), β, and κ) within this supramolecular structure remains unknown. The present study aims at determining the topography of the casein micelle surface by following the interaction between 44 monoclonal antibodies specific for different epitopes of α(s1)-, α(s2)-, β-, and κ-casein and the casein micelle in real time and no labeling using a surface plasmon resonance (SPR)-based biosensor. Although the four individual caseins were found to be accessible for antibody binding, data confirmed that the C-terminal extremity of κ-casein was highly accessible and located at the periphery of the structure. When casein micelles were submitted to proteolysis, the C-terminal extremity of κ-casein was rapidly hydrolyzed. Disintegration of the micellar structure resulted in an increased access for antibodies to hydrophobic areas of α(s1)- and α(s2)-casein. 相似文献
87.
Jean-Franois Delcros Lalatiana Rakotozafy Aline Boussard Sylvie Davidou Catherine Porte Jacques Potus Jacques Nicolas 《Cereal Chemistry》1998,75(1):85-93
The effect of mixing has been tested on the extractable activities of lipoxygenase, peroxidase, and catalase from dough after 2, 5, and 20 min of mixing, and 30 min of rest period after 20 min of mixing. Different mixing conditions have been studied including temperature, atmosphere, speed, amount of water added to the dough, buffer solutions between pH 3.6 and 7.5 added to the dough, and different additives (linoleic acid, guaiacol, hydrogen peroxide, ascorbic acid, cysteine, yeast, and sodium chloride). In all the mixing conditions tested, the dough peroxidase activity remains equivalent to the initial flour activity, whereas losses in lipoxygenase and catalase activities largely varied according to mixing conditions. The results show that a self-destruction mechanism as well as physicochemical denaturation are responsible for these losses. Lipoxygenase losses seem mainly associated with the former mechanism, whereas catalase losses are highly increased in acidic conditions (physicochemical denaturation). Therefore, the relative impact of the three oxidoreducing enzymes may be largely modulated by mixing conditions. 相似文献
88.
The degradation and formation of major chlorinated metabolites of terbuthylazine and atrazine in three soils (loamy clay, calcareous clay and high clay) were studied in laboratory experiments using molecules labelled with 14C on the s-triazine ring. Soil microcosms were treated with the equivalent of 1 kg ha-1 of herbicide and incubated in the dark for 45 days at 20(±1)°C. The quantity of [14C]carbon dioxide evolved in the soils treated with atrazine was negligible and could not be attributed to mineralization of the parent molecule. The mineralization of terbuthylazine accounted for 0·9–1·2% of the initial radioactivity. In the soils studied, the extrapolated half-lives varied from 88 to 116 days for terbuthylazine and 66 to 105 days for atrazine, with no significant differences for the three soils and the two molecules. The deethyl metabolites of the two s-triazines and the deisopropyl-atrazine metabolite appeared during the incubation in the three soils. The completely dealkylated metabolite was not detected in any of the soils. After 45 days of incubation, the non-extractable soil residues for the high clay, loamy clay and calcareous clay soils represented for terbuthylazine, 33·5, 38·3 and 43·1% and for atrazine, 19·8, 20·8 and 22·3% of the initial radioactivity. © 1997 SCI. 相似文献
89.
Scale-dependent determinants of heterogeneity in fire frequency in a coniferous boreal forest of eastern Canada 总被引:1,自引:0,他引:1
Despite the recognized importance of fire in North American boreal forests, the relative importance of stochastic and determinist
portions of intra-regional spatial variability in fire frequency is still poorly understood. The first objective of this study
is to identify sources of spatial variability in fire frequency in a landscape of eastern Quebec’s coniferous boreal forest.
Broad-scale environmental factors considered included latitude, longitude, human activities and belonging to a given bioclimatic
domain, whereas fine-scale factors included slope, position on the slope, aspect, elevation, surficial deposit and drainage.
The average distance to waterbodies was also considered as a potential intermediate-scale source of variability in fire frequency.
In order to assess these environmental factors’ potential influence, they were incorporated into a proportional hazard model,
a semi-parametric form of survival analysis. We also used a digital elevation model in order to evaluate the dominant aspect
within neighborhoods of varying sizes and successively incorporated these covariates into the proportional hazard model. We
found that longitude significantly affects fire frequency, suggesting a maritime influence on fire frequency in this coastal
landscape. We also found that position on the slope was related to fire frequency since hilltops and upperslopes were subject
to a lower fire frequency. Dominant aspect was also related to fire frequency, but only when characterized within a neighborhood
delimited by 4,000 to 10,000-m radii (5,027–31,416 ha). A 2–6-fold variation in fire frequency can be induced by geographic
and topographic contexts, suggesting a substantial intra-regional heterogeneity in disturbance regime with potential consequences
on forest dynamics and biodiversity patterns. Implications for forest management are also briefly discussed.
Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献
90.
Torsten Seuberlich Catherine Botteron Sylvie L Benestad Hervé Brünisholz Reto Wyss Ulrich Kihm Heinzpeter Schwermer Martina Friess Alexandra Nicolier Dagmar Heim Andreas Zurbriggen 《Journal of veterinary diagnostic investigation》2007,19(1):2-8
Different types of transmissible spongiform encephalopathies (TSEs) affect sheep and goats. In addition to the classical form of scrapie, both species are susceptible to experimental infections with the bovine spongiform encephalopathy (BSE) agent, and in recent years atypical scrapie cases have been reported in sheep from different European countries. Atypical scrapie in sheep is characterized by distinct histopathologic lesions and molecular characteristics of the abnormal scrapie prion protein (PrP(sc)). Characteristics of atypical scrapie have not yet been described in detail in goats. A goat presenting features of atypical scrapie was identified in Switzerland. Although there was no difference between the molecular characteristics of PrP(sc) in this animal and those of atypical scrapie in sheep, differences in the distribution of histopathologic lesions and PrP(sc) deposition were observed. In particular the cerebellar cortex, a major site of PrP(sc) deposition in atypical scrapie in sheep, was found to be virtually unaffected in this goat. In contrast, severe lesions and PrP(sc) deposition were detected in more rostral brain structures, such as thalamus and midbrain. Two TSE screening tests and PrP(sc) immunohistochemistry were either negative or barely positive when applied to cerebellum and obex tissues, the target samples for TSE surveillance in sheep and goats. These findings suggest that such cases may have been missed in the past and could be overlooked in the future if sampling and testing procedures are not adapted. The epidemiological and veterinary public health implications of these atypical cases, however, are not yet known. 相似文献