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51.
A genetic fingerprinting technique (AFLP) was used to determine the relationships among Capparis spp. Genetic distances, based on AFLP data were estimated for 45 accessions of Capparis species, from Spain, Morocco and Syria. The results of this analysis support the differentiation of four of the five taxa involved. The group of plants recognised as C. spinosa on the basis of morphological characters, includes several cultivars and appears in an intermediate position between C. orientalis and C. sicula and overlaps with C. orientalis. The other two species C. aegyptia and C. ovata are separate from the rest. Capparis spinosa had a low number of unique bands in comparison with the other species. Although these results cannot confirm the hybrid origin of C. spinosa, the distribution of the bands supports this hypothesis, the most likely parental species being C. orientalis and C. sicula.  相似文献   
52.
The UK's Department for Environment, Food and Rural Affairs supports the use of systematic tools for the prioritisation of known and well defined animal diseases to facilitate long and medium term planning of surveillance and disease control activities. The recognition that emerging events were not covered by the existing disease-specific approaches led to the establishment of the Veterinary Risk Group (VRG), constituted of government officials, and supporting structures such as the Risk Management Cycle and the Emerging Threat Highlight Report (ETHiR), to facilitate the identification, reporting and assessment of emerging threats to UK's animal health. Since its inception in November 2009 to the end of February 2011, the VRG reviewed 111 threats and vulnerabilities (T&V) reported through ETHiR. In July 2010 a decision support system (DSS) based on multi-criteria-decision-analysis (MCDA) improved ETHiR to allow the systematic prioritisation of emerging T&V. The DSS allows the regular ranking of emerging T&V by calculating a set of measurement indices related to the actual impact, possible impact on public perception and level of available capabilities associated with every T&V. The systematic characterisation of the processes leading to the assessment of T&V by the VRG has led to a consistent, auditable and transparent approach to the identification and assessment of emerging risks. The regular use of MCDA to manage a portfolio of emerging risks represents a different and novel application of MCDA in a health related context.  相似文献   
53.
The excitatory amino acid domoic acid is the causative agent of amnesic shellfish poisoning in humans. The in vitro effects of domoic acid on rat neonatal brain microglia were compared with E. coli lipopolysaccharide (LPS), a known activator of microglia mediator release over a 4 to 24 hour observation period. LPS [3 ng/mL] but not domoic acid [1 mM] stimulated a statistically significant increase in TNF-alpha mRNA and protein generation. Furthermore, both LPS and domoic acid did not significantly affect TGF-beta1 gene expression and protein release. Finally, an in vitro exposure of microglia to LPS resulted in statistically significant MMP-9 expression and release, thus extending and confirming our previous observations. However, in contrast, no statistically significant increase in MMP-9 expression and release was observed after domoic acid treatment. Taken together our observations do not support the hypothesis that a short term (4 to 24 hours) in vitro exposure to domoic acid, at a concentration toxic to neuronal cells, activates rat neonatal microglia and the concomitant release of the pro-inflammatory mediators tumor necrosis factor-alpha (TNF-alpha) and matrix metalloproteinases-9 (MMP-9), as well as the anti-inflammatory cytokine transforming growth factor beta1 (TGF-beta1).  相似文献   
54.
The herbicide sulfentrazone is classified as highly mobile and persistent and this study aimed to examine degradation of this compound on a Typic Hapludox soil that is representative of regions where sulfentrazone is used in Brazil. Soil samples were supplemented with sulfentrazone (0.7 μg active ingredient (a.i.) g?1 soil), and maintained at 27 °C. Soil moisture was corrected to 30%, 70%, or 100% water-holding capacity (WHC) and maintained constant until the end of the experimental period. Soils without added herbicide were used as controls. Aliquots were taken after 14, 30, 60, 120, 180, and 255 days of incubation for quantitative analysis of sulfentrazone residues by gas chromatography. Another experiment was conducted in soil samples, with and without the herbicide, at different temperatures (15, 30, and 40 °C), with moisture kept constant at 70% of WHC. The sulfentrazone residues were quantified by gas chromatography after 14, 30, 60, and 120 days of incubation. Sulfentrazone degradation was not affected by soil moisture. A significant effect was observed for the temperature factor after 120 days on herbicide degradation, which was higher at 30 °C. A half-life of 146.5 days was recorded. It was observed that the herbicide stimulated growth of actinomycetes, whereas bacterial and fungal growth was not affected. The microorganisms selected as potential sulfentrazone degraders were Rhizobium radiobacter, Ralstonia pickettii, Methylobacterium radiotolerans, Cladosporium sp., Eupenicillium sp., and Paecilomyces sp.  相似文献   
55.
The Spanish populations of Juniperus oxycedrus subsp. macrocarpa are restricted to coastal dune habitats of the Mediterranean and Atlantic coasts. Here, we investigate the genetic structure in this taxon and the possible existence of detailed phylogeographic structure associated with the Strait of Gibraltar using data from amplified fragment length polymorphism (AFLP) and plastid markers for 14 populations in three regions: Andalusia, the Valencian Community and the Balearic Islands. Principal coordinate analysis (PCOA) data revealed a lack of clear genetic structure in J. oxycedrus subsp. macrocarpa based on AFLP. The highest AFLP genetic diversity was found in Andalusia. Plastid markers revealed 14 haplotypes, only two of them were shared among the regions. Andalusian populations had the highest number of exclusive haplotypes. Our results support Andalusia as a reservoir of genetic diversity for J. oxycedrus subsp. macrocarpa, and, as for other gymnosperms, this area could be considered as a genetic refugium. The frequent presence of common and exclusive haplotypes in Andalusia might indicate the colonisation of the Spanish Mediterranean coast from the Atlantic populations. Colonisation of these new areas could be promoted by biological factors, such as the existence of long-lived individuals or potential for seed dispersal. Finally, the Strait of Gibraltar did not constitute a natural barrier to the expansion of this species along the coast, as identical haplotypes are found on the Atlantic and Mediterranean coasts.  相似文献   
56.
Magnesium, calcium, phosphate, total protein and free fatty acid concentrations, and a lipase activity using p-nitrophenylpalmitate NP-C16) as a substrate, were determined in the serum of 15 pregnant Aberdeen Angus cows grazing a Phalaris tuberosa pasture with a tendency to induce tetany. A gradual decrease in magnesium concentrations, but no definite change in the other parameters, was observed when the results were plotted directly against the time of the experiment. When the results were plotted as a function of the stage of pregnancy or lactation of the animals, magnesium concentrations showed a more steady decrease which was associated with increases in calcium concentrations and, at the lowest magnesium concentrations, with increases in phosphate concentrations. Total proteins and free fatty acids remained fairly constant and the highest lipase activity was associated with parturition. The lowest magnesium concentrations in serum did not correspond with high levels of either lipase or free fatty acids. The hypomagnesaemia observed in this experiment was attributed to the high potassium:calcium and magnesium ratio in the pasture and to the physiological condition (pregnant and lactating) of the animals. None of the parameters evaluated in this paper would be more sensitive than serum magnesium levels for the early detection of the conditions that predispose grazing cattle to grass tetany.  相似文献   
57.
58.
The isotopically labeled compounds [5,6-(2)H(2)]-(Z)-1, 5-octadien-3-one (d-I) and [1-(2)H(1;2),2-(2)H(1;1)]-1-octen-3-one (d-II), as well as the unlabeled reference compound (Z)-1, 5-octadien-3-one (I) were prepared by improved synthesis procedures. Labeling position, chemical purity, and isotopic distribution of the compounds were characterized by various MS and NMR techniques. These molecules are used as internal standards in quantification experiments based on isotope dilution assay. The newly prepared compound d-II was synthesized in a simple two-step procedure, and formation of the main isotopomers was studied in model systems.  相似文献   
59.
It is important to understand the likely response of plant pathogens to increased temperatures due to anthropogenic climate change. This includes evolutionary change due to selection on genetically based variation in growth rate with temperature. We attempted to quantify this in two ways. First, radial mycelial growth rates in agar culture were determined for a collection of 44 English isolates of Leptosphaeria maculans and 17 isolates of L. biglobosa, at 14 temperatures. For L. maculans the genotypic variances in four parameters were measured: minimum temperature allowing growth, optimum temperature, growth rate at the optimum temperature, and growth rate at the highest usable temperature, 31.8°C. The standard deviations were 0.068°C, 1.28°C, 0.21 mm/day, and 0.31 mm⋅day−1⋅°C−1, respectively. For L. biglobosa, these figures were, respectively: immeasurably small, 1.31°C, 0.053 mm/day, and 0.53 mm⋅day−1⋅°C−1. In addition, the incidence and severity of phoma stem canker in planta over a natural growing cycle at four temperatures (16, 20, 24, and 28°C) around the average culture optimum were determined. There was no correlation between in vitro and in planta growth, and the decrease in pathogen measures either side of the optimum temperature was much less for in planta growth than for in vitro growth. We conclude that both pathogens have the capacity to evolve to adapt to changes in environmental conditions, but that predictions of the effect of this adaptation, or estimates of heritability in natural conditions, cannot be made from measurements in vitro.  相似文献   
60.
Baker's yeast was shown to catalyze the transformation of cysteine-furfural conjugate into 2-furfurylthiol. The biotransformation's yield and kinetics were influenced by the reaction parameters such as pH, incubation mode (aerobic and anaerobic), and substrate concentration. 2-Furfurylthiol was obtained in an optimal 37% yield when cysteine-furfural conjugate at a 20 mM concentration was anaerobically incubated with whole cell baker's yeast at pH 8.0 and 30 degrees C. Similarly to 2-furfurylthiol, 5-methyl-2-furfurylthiol (11%), benzylthiol (8%), 2-thiophenemethanethiol (22%), 3-methyl-2-thiophenemethanethiol (3%), and 2-pyrrolemethanethiol (6%) were obtained from the corresponding cysteine-aldehyde conjugates by incubation with baker's yeast. This work indicates the versatile bioconversion capacity of baker's yeast for the generation of thiols from cysteine-aldehyde conjugates. Thanks to its food-grade character, baker's yeast provides a biochemical tool to produce thiols, which can be used as flavorings in foods and beverages.  相似文献   
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