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1.
The removal of the cyanobacterial peptide toxin microcystin-LR at 4 and 37 degrees C by six commercial probiotic strains and Lactobacillus plantarum strains IS-10506 and IS-20506 isolated from dadih, Indonesian traditional fermented milk, was assessed in this study. The aim was to evaluate the main factors influencing the viability and metabolic activity of the probiotic strains, as well as their capacity to remove microcystin-LR. Both L. plantarum strains isolated from dadih, as well as Bifidobacterium lactis strains Bb12 and 420, were shown to be more resistant, and >85% remained viable in phosphate-buffered saline (PBS) solution for 48 h of incubation at either temperature, while the viability of the other four commercial bacteria decreased markedly over time. The effect of glucose on viability and removal of toxin was shown to be a strain-specific and strain-dependent property, but in general, the efficiency of microcystin-LR removal increased when glucose was added to the solution. A maximum removal of 95% was observed for L. plantarum strain IS-20506 (37 degrees C, 10 (11) colony-forming units mL(-1)) with 1-2% glucose supplementation and 75% in PBS alone.  相似文献   
2.
The effect of low temperature exposure on the motility of Diphyl-lobothrium latum plerocercoids was studied, with the particular aim of finding the exposure that immobilizes all the larvae in fish freezing. Both isolated larvae immersed in normal horse serum and larvae enclosed in pieces of muscle tissue of the size of 1 cm3 were tested. The pieces of tissue containing a larva were placed in the middle of a plastic beaker filled with densely packed minced fish flesh. In the central part of this phantom, where the plerocercoids were situated, the temperature decline was considered to take place in the same way as in the interior of a whole fish. A total of 200 isolated larvae were tested, and a temperature of −14° G was found to have a fully immobilizing effect on them. The number of plerocercoids frozen enclosed in muscular tissue was 453, and −10° G was found to immobilize them. The observed difference seems to be mainly due to the cryoprotective properties of serum.  相似文献   
3.
Feline immunodeficiency virus (FIV) was first isolated and identified in 1986. Since then it has been shown to have a worldwide distribution, and the infection generally appears to have reached a state of endemicity. This is the 1st study of FIV-prevalence in Finland. Serum samples of 196 free-roaming cats were tested for antibodies to FIV and FeLV antigens (Feline leukemia virus). With a combined enzyme-linked immunosorbent assay (ELISA), 13 of the cats (6.6%) turned out to be positive for FIV and 2 for FeLV (1.0%). Adult male cats in the capital area of Finland had a FIV prevalence of 24%, a relative proportion 4.7 times higher than that for females.  相似文献   
4.
Soil faunal activity stimulates terrestrial carbon and nutrient cycling and maintains soil physical structure. Interestingly, the effects of faunal activity on soil microbial community composition and activity is less clear, although the microbial community evidently is the key element of terrestrial decomposition processes and nutrient cycling. We manipulated the composition of soil fauna in mesh bags with various mesh sizes (5, 45, and 1,000 µm) to exclude faunal groups based on body size. Our experiment indicated that feeding and foraging activity of nematodes and enchytraeids modified the physical–chemical properties of the soil and had long-term effects on soil bacterial community composition (measured by denaturing gel electrophoresis, colony-forming unit counts, and phospholipid fatty acid pattern). However, microbial enzyme (phosphomonoesterase, butyrate-esterase, ß-glucosidase, N-acetyl-glucosamidase, and ß-cellobiosidase) activities (measured by fluorogenic model substrates), decomposition rate of woody and cellulose material, or C and N status of the soil were not altered by the faunal treatment. Instead, enzyme activity was reduced by soil drying. Our results give support to ideas that functional redundancy is a common characteristic of the soil organisms, but no support was found for the idea that the community composition of soil decomposers had a strong link to the regulation of C and N cycles in the soil.  相似文献   
5.
The mechanics of fresh wood with and without a fatigue pre-treatment that mimics a mechanical pulping process was experimentally studied. The mechanical properties of Norway spruce samples under compression are considered with the macroscopic stress–strain data and from local strain properties via digital image correlation technique. The results highlight the effects of the orientation of the wood annual rings compared to the loading direction and of the pre-fatigue. The wood presents a low yield point when the annual rings are tilted compared to the load axis, but the Young’s modulus and yield stress are higher when the annual rings are either parallel or perpendicular to the load direction. In the last case, buckling of softest layers occurs. The fatigue treatment makes the wood less stiff as deduced from the decreases of Young’s modulus and yield stress, whatever the orientation of annual rings. Secondly, it creates a thin and localized softened layer.  相似文献   
6.
7.
Both drought and fungal disease increase needle litterfall of Scots pine (Pinus sylvestris L.) trees, but most factors causing annual variation in needle litterfall are poorly understood. We hypothesized that radial growth and weather conditions favorable to growth correlate positively with needle litterfall with a lag equal to the number of needle cohorts (here being 5-6). We studied the time series of needle litterfall, stem increment, pollen cone litter and daily weather conditions in a Scots pine stand over 43 years (1961-2004). The cross-correlations of standardized time series were estimated with various lags. Model predictions of annual needle litterfall were tested against independent data. Changes in annual growth and needle litterfall correlated with lags of 0 and 4 years. The best predictors for needle litterfall were May to mid July temperature sum with a lag of 4 years, May rainfall with a lag of 2 years and September temperature with a lag of 6 years. Pollen cone litter correlated negatively with needle litterfall with a lag of 2 years. The study provided empirical evidence that needle litterfall of Scots pine in northern Finland is influenced by needle production and needle mass development that occurred 4 to 6 years earlier.  相似文献   
8.
Intra-annual height growth of Scots pine (Pinus sylvestris L.) in four stands was followed for up to four growing seasons (2000-2003) in the northern boreal zone in Lapland. Elongation of the leader shoot correlated with temperature sum expressed as degree-days. Total length of the leader shoot correlated with growth rate but not with duration of the height-growth period. The longer the annual shoot at the end of the season, the greater the height increment per degree- and growing day. Height-growth cessation was defined as the date when 95% of the total shoot length was achieved. In all stands and all years, height growth ceased when, on average, 41% of the relative temperature sum of the site was achieved (range of variation 38-43%). The relative temperature sum was calculated by dividing the actual temperature sum by the long-term mean for the site. Our results suggest that annual height growth is finished when a location-specific temperature sum threshold is attained.  相似文献   
9.
Lipid alterations due to experimental intoxication by methyl mercury were studied in rat brain. The methyl mercury was administered perorally as a hydroxide bound to bovine liver protein. The lipids were separated by thin layer chromatography and the fatty acids identified by gasliquid chromatography. The lipids studied included free fatty acids, cholesterol and the main phosphatidylesters, phosphatidylcholine and phosphatidylethanolamine.The methyl mercury treatment resulted in an increase in total brain lipids and palmitic acid (16:0) in the free fatty acid fraction. This increase is interpreted as the cellular response to compensate for the loss of membrane proteins known to take place in the brain due to methyl mercury intoxication.  相似文献   
10.
Rapeseed and pine bark are rich sources of phenolic compounds that have in previous studies been shown to exhibit antioxidant and anti-inflammatory properties. In this study, the antioxidant effect of rapeseed and pine bark phenolics in inhibiting the oxidation of lipids and proteins in meat was tested as a possible functional food application. The cooked pork meat with added plant material was oxidized for 9 days at 5 degrees C under light. The suitable level of plant material addition was first screened by following lipid oxidation only. For further investigations plant materials were added at a level preventing lipid oxidation by >80%. The oxidation was followed by measuring the formation of hexanal by headspace gas chromatography and the formation of protein carbonyls by converting them to 2,4-dinitrophenylhydrazones and measured by spectrophotometer. It was shown that rapeseed and pine bark were excellent antioxidants toward protein oxidation (inhibitions between 42 and 64%). These results indicate that rapeseed and pine bark could be potential sources of antioxidants in meat products.  相似文献   
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