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31.
ABSTRACT: The mycotoxin T-2 toxin and Salmonella Typhimurium infections pose a significant threat to human and animal health. Interactions between both agents may result in a different outcome of the infection. Therefore, the aim of the presented study was to investigate the effects of low and relevant concentrations of T-2 toxin on the course of a Salmonella Typhimurium infection in pigs. We showed that the presence of 15 and 83 μg T-2 toxin per kg feed significantly decreased the amount of Salmonella Typhimurium bacteria present in the cecum contents, and a tendency to a reduced colonization of the jejunum, ileum, cecum, colon and colon contents was noticed. In vitro, proteomic analysis of porcine enterocytes revealed that a very low concentration of T-2 toxin (5 ng/mL) affects the protein expression of mitochondrial, endoplasmatic reticulum and cytoskeleton associated proteins, proteins involved in protein synthesis and folding, RNA synthesis, mitogen-activated protein kinase signaling and regulatory processes. Similarly low concentrations (1-100 ng/mL) promoted the susceptibility of porcine macrophages and intestinal epithelial cells to Salmonella Typhimurium invasion, in a SPI-1 independent manner. Furthermore, T-2 toxin (1-5 ng/mL) promoted the translocation of Salmonella Typhimurium over an intestinal porcine epithelial cell monolayer. Although these findings may seem in favour of Salmonella Typhimurium, microarray analysis showed that T-2 toxin (5 ng/mL) causes an intoxication of Salmonella Typhimurium, represented by a reduced motility and a downregulation of metabolic and Salmonella Pathogenicity Island 1 genes. This study demonstrates marked interactions of T-2 toxin with Salmonella Typhimurium pathogenesis, resulting in bacterial intoxication.  相似文献   
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Mining activities for almost thousand years have caused large S emissions in the Falun area, central Sweden. Since the beginning of the 20th century, the S deposition has decreased considerably. The soil S concentrations and S isotope compositions were analyzed for ΣS and adsorbed SO42- for three soil profiles close to the mining area in order to identify the soil S sources. The δ34S values were found to be different for ΣS and adsorbed SO42- and ranged from –3.7‰ to +2.6‰. In the B-horizon, the observed ΣS δ34S values (and hence calculated δ34S values for organic S) were mostly lower than those of the adsorbed SO42-. In the O-horizon, ΣS showed similar δ34S values as the adsorbed SO42- in the mineral soil. The adsorbed SO42- showed nearly constant δ34S values with depth. The δ34S values in the soils are interpreted to reflect a mixture of historical and modern deposition due to soil S circulation with no or negligible fractionation. The lower δ34S values of organic S in the B-horizon suggests preservation of acid deposition originating from mining activities back in time. The adsorbed SO42- in the mineral soil and the organic S in the O-horizon reflect a response to a new δ34S composition in the atmosphere due to fossil fuel burning during the 20th century.  相似文献   
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Rye breads made from commercial rye blends lower the postprandial insulin demand and appear to facilitate glucose regulation. However, differences in metabolic responses may occur between rye varieties. In the present work, five rye varieties (Amilo, Evolo, Kaskelott, Picasso. and Vicello) and a commercial blend of rye grown in Sweden were investigated with regard to their postprandial insulin, glucose, and appetite regulation properties in a randomized crossover study in 20 healthy subjects. The rye flours were baked into whole grain breads, and a white wheat bread (WWB) was used as reference (50 g of available starch). Picasso and Vicello rye bread showed lower glycemic indices (GIs) compared with WWB (80 and 79, respectively) (P < .0.05). In addition to the GI, two measures of the glycemic profile (GP and GP(2)) were calculated by dividing the incremental duration of the plasma glucose curve with the incremental glucose peak and squared incremental glucose peak, respectively. Vicello and Picasso ryes were characterized by a higher GP(2) than that of the WWB, suggesting a better regulated course of glycemia. Rye bread made from not only Vicello and Picasso but also Amilo and Kaskelott displayed significantly lower insulin indices (IIs) than WWB (74-82). A high GP and GP(2) and a low GI were related to a lower II and insulin incremental peak. A high content of insoluble fibers and a high GP(2) were related to a higher subjective satiety in the early and late postprandial phase (tAUC 0-60 min and tAUC 120-180 min, respectively). The results suggest that there may be differences in the course of glycemia following different rye varieties, affecting postprandial insulin responses and subjective satiety.  相似文献   
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This paper reports on the seasonal patterns in leaf metal concentrations as influenced by artificial acidification and acidification due to acid precipitation at ambient levels in Southern Norway. The effects of change in soil nutrient availability can be concealed for a long time because of ability of plants to retranslocate mobile nutrients including Cu, Mg, K, and Zn. Exceptions are, e.g., Ca and Mn which are relatively immobile in the indigenous plant species studied. It appears from this work that long-term exposure to episodes of artificial rainfall of pH 3.2, or to acid precipitation at ambient pH levels, may alter the seasonal patterns in tissue metal concentrations of vascular plants. An enhanced retention of Mg and Zn in senescent leaves of deciduous species was observed. Foliar leaching of K on exposure to acid deposition may not be adequately compensated by root uptake.  相似文献   
37.
Egg Quality in Wild and Broodstock Cod Gadus morhua L.   总被引:1,自引:0,他引:1  
Problems concerning egg viability or egg quality have received increasing attention, in relation to cultivation as well as to the assessment of reproduction of wild fishes. One important aspect of this paper is to discuss the use of cell morphological characteristics as indicators of egg quality in cod. Early cellular malformation rates in egg batches show a positive correlation with their later egg and larval survival, and can be used as a rough prediction of normal development and mortality rates.
The natural mortality rate offish eggs is not well understood, and observed egg viability of captive cod is are discussed in relation to egg viability in the wild. Results from recent work indicated that approximately 10% of naturally spawned cod eggs from both wild fish (planktonic samples) and from a broodstock had abnormal cleavages at the 2–128 cell stage. Eggs with observed early abnormal cell-cleavage showed very poor survival and hatching rates. For broodstock cod, egg viability was highest during the peak of the spawning season.
The North Atlantic cod may provide a good model species for studies of egg viability variations in wild and captive individuals, as its reproductive biology is well studied. It is now documented that the egg production in cod is dependent on fish age, nutritional status, batch number, and stress factors.  相似文献   
38.
Atlantic halibut, Hippoglossus hippoglossus L., eat larger satiation meals (mean 11.7% body weight) than lemon sole, Microstomus kitt (Walbaum), (2.6% body weight). Total gut clearance time was about 120 h for halibut and 72 h for lemon sole. There are marked differences in feeding behaviour between the two species; halibut feed in midwater and require several body lengths of approach swimming before taking large items of food, while lemon sole eat only off the bottom. In shared tanks, no aggressive interaction was observed. A duoculture system holding small numbers of lemon sole with the more valuable halibut is recommended as a means of minimizing food waste and tank fouling. Oxygen uptakes of 0.07-0.11 ml O2 g fish wt−1 h−1 (depending on nutritional state) were recorded for the two species. Ammonia nitrogen outputs were also similar. Starved halibut excreted 2.32 μg N g−1 h−1, fed animals 5.08 μg N g−1 h−1. The corresponding values for lemon sole were 3.26 μg N g−1 h−1 and 6.37 μg N g−1 h−1, respectively.  相似文献   
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Carbonatite originating from the Lillebukt Alkaline Complex at Stjernøy in Northern Norway possesses favorable lime and potassium (K) fertilizer characteristics. However, enrichments of barium (Ba) and strontium (Sr) in carbonatite may cause an undesired uptake by plants when applied to agroecosystems. A field survey was carried out to compare concentrations of Ba, Sr, and macronutrients in indigenous plants growing in mineral soil developed on a bedrock of apatite–biotite–carbonatite (high in Ba and Sr) and of apatite–hornblende–pyroxenite (low in Ba and Sr) at Stjernøy. Samples of soil and vegetation were collected from three sites, two on carbonatite bedrock and one on pyroxenite bedrock. Ammonium lactate (AL)‐extracted soil samples and nitric acid microwave‐digested samples of soil, grasses, dwarf shrubs, and herbs were analyzed for element concentration using ICP‐MS and ICP‐OES. Concentrations of magnesium (Mg) and calcium (Ca) in both soil (AL) and plants were equal to or higher compared to values commonly reported. A high transfer of phosphorus (P) from soil to plants indicates that the apatite‐P is available to plants, particularly in pyroxenite soil. The non‐exchangeable K reservoir in the soil made a significant contribution to the elevated K transfer from soil to plant. Total concentrations of Ba and Sr in surface soil exhibited a high spatial variation ranging from 490 to 5,300 mg Ba kg?1 and from 320 to 1,300 mg Sr kg?1. The transfer of AL‐extractable elements from soil to plants increased in the order Ba < Sr < Ca < Mg < K, hence reflecting the chemical binding strength of these elements. Concentrations of Ba and Sr were low in grasses (≈ 20 mg kg?1), intermediate in dwarf shrubs and highest in herbs. Plant species and their affinity for Ca seemed more important in explaining the uptake of Ba and Sr than the soil concentration of these elements. The leguminous plant species Vicia cracca acted as an accumulator of both Ba (1.800 mg kg?1) and Sr (2.300 mg kg?1).  相似文献   
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