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Feline immunodeficiency virus (FIV) vaccine, Fel-O-Vax FIV, was released for sale in the US in 2002. The antibodies of vaccinated cats interfere with serological assays by currently available FIV diagnostic kits. In this study, we investigated whether it is possible to distinguish serologically cats vaccinated with Fel-O-Vax FIV from cats experimentally or naturally infected with FIV. A total of 153 sera taken from 97 cats were used as serum samples. Enzyme linked immunosorbent assay (ELISA) was performed using whole FIV antigen and formalin treated whole FIV antigen, recombinant-gag (r-gag) antigen, and transmembrane (TM) peptide. Statistical analysis was performed using ELISA optical density (O.D.) values obtained with each antigen as variables. Except for the ELISA O.D. values obtained with r-gag antigen, a significant difference in ELISA O.D. values was observed between the vaccinated and the infected groups. However, it was not possible to distinguish both groups unequivocally. Using discriminant analysis, it was possible to distinguish the two groups with an accuracy of 97.1% with two discriminating variables (ELISA O.D. values obtained with formalin treated whole FIV antigen, and TM peptide), 97.8% with three discriminating variables (ELISA O.D. values obtained with whole FIV antigen, formalin treated whole FIV antigen, and TM peptide). Therefore, it was considered possible to distinguish cats vaccinated with Fel-O-Vax FIV from FIV-infected cats by ELISA using two types of antigens including formalin treated whole FIV antigen and TM peptide, or three types of antigens including formalin treated whole FIV antigen, TM peptide and whole FIV antigen.  相似文献   
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Feline morbillivirus (FmoPV) is an emerging virus that was recently discovered in domestic cats with chronic nephritis. Despite the potential role of FmoPV in chronic nephritis, little is known about its biological characteristics. In this study, we established a quantitative assay of FmoPV by using an indirect immunofluorescence technique. Viral titers of FmoPV were determined in one week. Treatment with polybrene® or trypsin which was previously used in virus isolation did not augment the virus titers. FmoPV was notably stable at 4°C, retaining high titers for at least 12 days. Heat-treatment at 60°C and 70°C effectively inactivated FmoPV in 10 and 2 min, respectively. The biological characteristics of FmoPV reported here will be beneficial for establishing an efficient virus isolation method and will provide important information to take a measure to reduce the risk of FmoPV infection.  相似文献   
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Vibrio vulnificus is the causative agent of primary septicemia, wound infection and gastroenteritis in immunocompromised people. In this study, signature-tagged mutagenesis (STM) was applied to identify the virulence genes of V. vulnificus. Using STM, 6,480 mutants in total were constructed and divided into 81 sets (INPUT pools); each mutant in a set was assigned a different tag. Each INPUT pool was intraperitoneally injected into iron-overloaded mice, and in vivo surviving mutants were collected from blood samples from the heart (OUTPUT pools). From the genomic DNA of mixed INPUT or OUTPUT pools, digoxigenin-labeled DNA probes against the tagged region were prepared and used for dot hybridization. Thirty tentatively attenuated mutants, which were hybridized clearly with INPUT probes but barely with OUTPUT probes, were negatively selected. Lethal doses of 11 of the 30 mutants were reduced to more than 1/100; of these, the lethal doses of 2 were reduced to as low as 1/100,000. Transposon-inserted genes in the 11 attenuated mutants were those for IMP dehydrogenase, UDP-N-acetylglucosamine-2-epimerase, aspartokinase, phosphoribosylformylglycinamidine cyclo-ligase, malate Na (+) symporter and hypothetical protein. When mice were immunized with an attenuated mutant strain into which IMP dehydrogenase had been inserted with a transposon, they were protected against V. vulnificus infection. In this study, we demonstrated that the STM method can be used to search for the virulence genes of V. vulnificus.  相似文献   
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To understand the effect of the NH3 emissions from vehicles, the NH4 + bulk deposition and concentrations of gaseous NH3 and particulate NH4 + were measured at two sites in Saitama prefecture, Japan, one at the roadside of an arterial road (Kounosu), and the other in an agricultural area (Kisai). We observed that the NH4 + bulk deposition and NH3 concentration were significantly increased in Kounosu; the effect of NH3 emissions from vehicles was confirmed. NOx was a primary pollutant mainly emitted by vehicle exhaust in the vicinity of arterial roads, and the relationship between NO x and sum of gaseous NH3 and particulate NH4 + (T-NH4 +) was examined. The [T-NH4 +/NO x ] ratios in Kounosu ranged from 0.08 to 0.23 (average 0.15), and in Kisai they ranged from 0.16 to 0.67 (average 0.39). In Kounosu, the effect of vehicle exhaust was great, but seasonal variation was small. The contribution ratio of NH3 from vehicle emissions increased at low temperatures, while that from the non-vehicle emissions increased at high temperatures.  相似文献   
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Seedlings of Chamaecyparis obtusa, Cryptomeria japonica D. Don, and Abies firma Sieb. et Zucco were grown hydroponically for 4 weeks in the presence or absence of aluminum (Al) and with or without reduced pH. Under exposure to AI, root and shoot growth of C. obtusa was enhanced. A. firma showed the same tendency as C. obtusa, though not significantly. Only in C. japonica, growth was reduced with Al, especially shoot growth. In all the species, callose production in the root tips was observed in the presence of Al. A positive correlation was observed between the relative root callose content and relative root growth (r = 0.83), and significant root elongation with AI treatment was observed in all the species. Therefore, it is considered that callose deposition in the root tips of these species may not indicate the Al-induced root cell injury causing root growth inhibition. The highest callose content in the root tip and strong callose fluorescence in the epidermis and zones of cell contact were observed in C. obtusa. Since the Al translocation rate from roots to leaves was the lowest in C. obtusa and since significant growth enhancement was observed in the presence of Al, it is possible that the accumulation of callose in the root epidermis and in the zones of cell contact is related to Al-resistance in C. obtusa.  相似文献   
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Salmonella Typhimurium DT104 (DT104) is unwanted in products for human consumption due to its antibiotic resistance and ability to cause disease. We intended to set up an improved monitoring and management program to aid in deciding when to use pork contaminated with DT104 for production of sausages without jeopardizing consumer safety. We started by carrying out two assessments of the risk for human health associated with consumption of sausages produced by: (1) Danish pork from average slaughter days; (2) imported pork (IMP) with average prevalence of DT104. The assessments showed that, if Salmonella is present, it is usually in lower numbers (≤50 per 400 cm2 surface). Additionally, during processing, the numbers will be reduced by at least 2 log-units. In Danish (DK) pork, DT104 constitutes 0.2–1.0% of the Salmonella isolates reported, while in imported pork (IMP), 18%. We estimated that out of one million, 25 g servings of DK dry-cured sausages, up to two DT104 bacteria could be found in each of 245 servings. Out of one million servings of 25 g IMP dry-cured sausages, up to two DT104 bacteria would occur in each of 19,260 servings.  相似文献   
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An internal fruit rot with a malodor was found in netted melons (Cucumis melo L.) in commercial greenhouses in Kochi Prefecture, Japan, in 1998, despite their healthy appearance and lack of water-soaking or brown spots on the surface. A yellow bacterium was consistently isolated from the affected fruits. To confirm the pathogenicity of eight representative isolates of the yellow bacterium, we stub-inoculated ovaries (immature-fruits) 5–7 days after artificial pollination, with a pin smeared with bacteria. After the melon fruits had grown for 60 more days, an internal fruit rot resembling the natural infection appeared, and the inoculated bacterium was reisolated. The melon isolates had properties identical with Pantoea ananatis, such as gram-negative staining, facultative anaerobic growth, indole production, phenylalanine deaminase absence, and acid production from melibiose, sorbitol, glycerol, and inositol. Phylogenetic analysis based on 16S rDNA sequences showed that the melon bacterium positioned closely with known P. ananatis strains. The melon bacterium had indole acetic acid (IAA) biosynthesis genes (iaaM and iaaH) and a cytokinin biosynthesis gene (etz). The bacterium could be distinguished from the other ‘Pantoea’ group strains by rep-PCR genomic fingerprinting. From these results, the causal agent of internal fruit rot was identified as a strain of P.ananatis [Serrano in (Philipp J Sci 36:271–305, 1928); Mergaert et al. in (Int J Syst Bacteriol 43:162–173, 1993)]. The nucleotide sequence data reported are available in the DDBJ database under accessions AB297969, AB373739, AB373740, AB373741, AB373742, AB373743 and AB373744.  相似文献   
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