全文获取类型
收费全文 | 544篇 |
免费 | 15篇 |
专业分类
林业 | 60篇 |
农学 | 8篇 |
111篇 | |
综合类 | 37篇 |
农作物 | 3篇 |
水产渔业 | 13篇 |
畜牧兽医 | 288篇 |
园艺 | 18篇 |
植物保护 | 21篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 4篇 |
2021年 | 9篇 |
2020年 | 11篇 |
2019年 | 17篇 |
2018年 | 16篇 |
2017年 | 9篇 |
2016年 | 12篇 |
2015年 | 14篇 |
2014年 | 22篇 |
2013年 | 33篇 |
2012年 | 36篇 |
2011年 | 44篇 |
2010年 | 22篇 |
2009年 | 30篇 |
2008年 | 37篇 |
2007年 | 49篇 |
2006年 | 35篇 |
2005年 | 33篇 |
2004年 | 31篇 |
2003年 | 26篇 |
2002年 | 16篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有559条查询结果,搜索用时 15 毫秒
551.
552.
Riehle MM Guelbeogo WM Gneme A Eiglmeier K Holm I Bischoff E Garnier T Snyder GM Li X Markianos K Sagnon N Vernick KD 《Science (New York, N.Y.)》2011,331(6017):596-598
Population subgroups of the African malaria vector Anopheles gambiae have not been comprehensively characterized owing to the lack of unbiased sampling methods. In the arid savanna zone of West Africa, where potential oviposition sites are scarce, widespread collection from larval pools in the peridomestic human habitat yielded a comprehensive genetic survey of local A. gambiae population subgroups, independent of adult resting behavior and ecological preference. A previously unknown subgroup of exophilic A. gambiae is sympatric with the known endophilic A. gambiae in this region. The exophilic subgroup is abundant, lacks differentiation into M and S molecular forms, and is highly susceptible to infection with wild Plasmodium falciparum. These findings might have implications for the epidemiology of malaria transmission and control. 相似文献
553.
Jacobsson K 《Veterinary microbiology》2003,96(1):103-113
Streptococcus agalactiae is a contagious pathogen in bovine mastitis. It is also one of the leading causes to neonatal pneumonia, sepsis and meningitis in Europe and North America. Although extracellular bacterial proteins that interact with host structures are putative vaccine components, so far only a few receptins have been identified and characterised from this organism. The aim of the present study was to identify fibrinogen-binding receptins from a shotgun phage display library constructed from the bovine type strain CCUG 4208. A novel extracellular receptin was identified after selecting the library against bovine fibrinogen. This protein is a member of a family of at least three proteins that share the fibrinogen-binding region as well as the N-terminal signal sequence, whereas the intervening region varies in size and has almost no sequence similarity. Proteins of this family are present also in human isolates of S. agalactiae, although binding to human fibrinogen has not been detected. 相似文献
554.
Snorre Stuen Wenche O Torsteinb? Karin Bergstr?m Kjetil B?rdsen 《Acta veterinaria Scandinavica》2009,51(1):41
Background
Anaplasma phagocytophilum infection in domestic ruminants is widespread in the coastal areas of southern Norway. The bacteria may persist in mammalian hosts. Several genetic variants of A. phagocytophilum exist. In the present study, we investigate whether superinfection occurs in the acute and persistent phase of the infection.Methods
Five-month-old lambs of the Norwegian Dala breed were experimentally infected with two 16S rRNA gene variants of A. phagocytophilum, i.e. A. phagocytophilum variant 1 (GenBank accession number ) and variant 2 (GenBank acc. no. M73220). Eighteen lambs were used, two lambs in each group. Eight groups were experimentally inoculated with either variant 1 or 2 on day 0. Six of these groups were then challenged with the other variant on either days 7, 42 or 84, respectively. One group was left uninfected. The occurrence of A. phagocytophilum in blood samples was determined using semi-nested PCR analysis and gene sequencing. Specific antibodies were measured by an indirect immunofluorescence antibody assay (IFA). AF336220Results
A. phagocytophilum variant 1 and 2 differed significantly with regards to clinical reaction and cross-immunity in infected lambs. Both variants were found in the blood after challenge. However, variant 1 was detected most frequently.Conclusion
The present experiment indicates that superinfection of different genotypes occurs during the acute as well as the persistent phase of an A. phagocytophilum infection, even in lambs protected against the challenged infection. 相似文献555.
Kerstin Skovgaard Shila Mortensen Mette Boye Karin T. Poulsen Fiona M. Campbell P. David Eckersall Peter M.H. Heegaard 《Veterinary research》2009,40(3)
The acute phase protein response is a well-described generalized early host response to tissue injury, inflammation and infection, observed as pronounced changes in the concentrations of a number of circulating serum proteins. The biological function of this response and its interplay with other parts of innate host defence reactions remain somewhat elusive. In order to gain new insight into this early host defence response in the context of bacterial infection we studied gene expression changes in peripheral lymphoid tissues as compared to hepatic expression changes, 14–18 h after lung infection in pigs. The lung infection was established with the pig specific respiratory pathogen Actinobacillus pleuropneumoniae. Quantitative real-time PCR based expression analysis were performed on samples from liver, tracheobronchial lymph node, tonsils, spleen and on blood leukocytes, supplemented with measurements of interleukin-6 and selected acute phase proteins in serum. C-reactive protein and serum amyloid A were clearly induced 14–18 h after infection. Extrahepatic expression of acute phase proteins was found to be dramatically altered as a result of the lung infection with an extrahepatic acute phase protein response occurring concomitantly with the hepatic response. This suggests that the acute phase protein response is a more disseminated systemic response than previously thought. The current study provides to our knowledge the first example of porcine extrahepatic expression and regulation of C-reactive protein, haptoglobin, fibrinogen, pig major acute phase protein, and transferrin in peripheral lymphoid tissues. 相似文献
556.
Selinheimo E Autio K Kruus K Buchert J 《Journal of agricultural and food chemistry》2007,55(15):6357-6365
Cross-linking enzymes generate covalent bonds in and between food biopolymers. These enzymes are interesting tools for tailoring dough and bread structures, as the characteristics of the biopolymers significantly determine the viscoelastic and fracture properties of dough and bread. In this study, the influence of oxidative cross-linking enzymes, tyrosinase from the filamentous fungus Trichoderma reesei and laccase from the white rot fungus Trametes hirsuta, on dough and bread were examined. Oxidation of low molecular weight phenolic model compounds of flour, cross-linking of gluten proteins, dough rheology, and bread making were characterized during or after the enzymatic treatments. In the dough and bread experiments, laccase and tyrosinase were also studied in combination with xylanase. Of the model compounds tyrosine, p-coumaric acid, caffeic acid, ferulic acid, and Gly-Leu-Tyr tripeptide, tyrosinase oxidized all except ferulic acid. Laccase was able to oxidize each of the studied compounds. The phenolic acids were notably better substrates for laccase than l-tyrosine. When the ability of the enzymes to cross-link isolated gliadin and glutenin proteins was studied by the SDS-PAGE analysis, tyrosinase was found to cross-link the gliadin proteins effectively, whereas polymerization of the gliadins by laccase was observed only when a high enzyme dosage and prolonged incubation were used. Examination of large deformation rheology of dough showed that both laccase and tyrosinase made doughs harder and less extensible, and the effects increased as a function of the enzyme dosage. In bread making, interestingly, the pore size of the breads baked with tyrosinase turned out to be remarkably larger and more irregular when compared to that of the other breads. Nevertheless, both of the oxidative enzymes were found to soften the bread crumb and increase the volume of breads, and the best results were achieved in combination with xylanase. 相似文献
557.
Oberthaler KT Mauldin E McManus PM Shofer FS Sorenmo KU 《Journal of Feline Medicine and Surgery》2009,11(4):259-265
This study examined the efficacy of doxorubicin-based chemotherapy used for rescue therapy in refractory feline lymphoma. Records of 23 cats with lymphoma treated with chemotherapy who received doxorubicin for the first time in a rescue setting were reviewed. Seventeen (74%) of the 23 cats had only one treatment of doxorubicin. Five (22%) of the 23 cats had a positive response to doxorubicin and were given additional doses. The response to therapy in 4/5 of these responders could be assessed objectively, of which, two cats (9%) achieved partial remission (PR) and two cats (9%) achieved complete remission (CR). The two cats that achieved CR had differing response durations (6 weeks and greater than 47 months). Three of these five (60%) responders had also received concurrent other chemotherapy in addition to doxorubicin. Cell type and the use of concurrent chemotherapy were significant predictors of response. Cats with small-medium cell lymphomas (P=0.001) and cats that received concurrent chemotherapy with doxorubicin rescue (P=0.007) were more likely to respond favorably. This study suggests that doxorubicin-based chemotherapy is not an effective rescue protocol for feline lymphoma. 相似文献
558.
Karin Thygesen Lise Nistrup Jørgensen Kim Skov Jensen Lisa Munk 《European journal of plant pathology / European Foundation for Plant Pathology》2009,123(4):435-447
Field experiments, involving various fungicide strategies with pyraclostrobin and/or epoxiconazole were carried out in 2004
and 2005, with the overall purpose of monitoring the evolution of fungicide sensitivity in Mycosphaerella graminicola on different isolates per leaf, leaf levels at different points of time, and points in the field. Sensitivity was assessed
on single isolates by means of epoxiconazole EC50-values, and monitoring of the G143A-mutation, which confers strobilurin resistance. In both years, fungicide application
strategies did not cause any significant shifts in epoxiconazole sensitivity of the population median or variance over time
compared to the starting population. In 2004, the end-population median was the same for all sprayed strategies, although
compared to untreated median sensitivities were higher. In 2005, epoxiconazole sensitivity levels were similar on individual
flag leaves and different points in the field. Measured on all isolates the EC50-values ranged from 0.007–1.15 mg l−1. In 2004, due to the high initial level of pyraclostrobin resistance, stabilisation of pyraclostrobin resistance was observed
following the various combination treatments. No correlation between epoxiconazole sensitivities and pyraclostrobin resistance
were observed. High input strategies using a mixture of epoxiconazole and pyraclostrobin resulted in the best control and
yield response. A subpopulation of the isolates from 2004 was also screened for sensitivity towards five different triazoles
of which tebuconazole proved to be least sensitive, and this could further be split into two subpopulations. 相似文献
559.
Marika Lyly Marjatta Salmenkallio‐Marttila Tapani Suortti Karin Autio Kaisa Poutanen Liisa Lhteenmki 《Cereal Chemistry》2003,80(5):536-541
The aim was to study the effect of concentration and molecular weight of four different β‐glucan preparations on the perceived sensory quality of a beverage prototype. The correlations between sensory and instrumental measures were investigated. Two of the preparations were brantype containing high molecular weight β‐glucan, two were more‐processed low molecular weight β‐glucan preparations. Twelve beverage samples containing 0.25–2% β‐glucan and one reference sample thickened with carboxymethyl cellulose (CMC) were profiled by a sensory panel and analyzed by instrumental measurements (viscosity and molecular weight). Sensory profiles of the beverages varied at the same concentration of β‐glucan, depending on β‐glucan preparation. Beverages made with the bran‐type preparations were more viscous and had higher perceived thickness than beverages made with more‐processed, low molecular weight preparations. Moderate correlations were obtained between perceived thickness and sliminess and instrumental viscosity at all shear rates between 26 and 100/sec (r = 0.63–0.78; P ≤ 0.001). Technologically, more‐processed β‐glucan preparations are easier to add into a beverage in amounts sufficient for achieving a physiologically functional amount of β‐glucan in a product. 相似文献