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BACKGROUND: The Wistar Hannover rat has been considered as an alternative animal model to the Sprague-Dawley rat in the safety evaluation of candidate pharmaceuticals for potential reproductive and developmental toxicity. Hematology and clinical chemistry results may provide useful evidence of maternal toxicity in the absence of fetal effects. OBJECTIVE: The purpose of this study was to evaluate differences in routine laboratory values between nonmated and pregnant (near-term)Wistar Hannover rats during a control developmental study. METHODS: One hundred fifty pregnant female Wistar Hannover rats (Tac:Glx:WlfBR) were dosed orally once per day with distilled water from gestation days (GDs) 6 through 17. An additional 150 nonmated (nonpregnant) females used as age-matched controls were dosed from study days (SDs) 7 through 18. Blood samples were collected on GD 18 or 19 (SD 19 or 20) for routine hematology and plasma clinical chemistry tests. Reference intervals were established for pregnant and nonmated animals. RESULTS: On GD 18/19, pregnant rats had a lower RBC count, hemoglobin concentration, and HCT, and higher MCH, MCHC, reticulocyte percentage, and platelet, WBC, absolute reticulocyte, segmented neutrophil, lymphocyte, and monocyte counts compared with nonmated rats. Pregnant rats had lower albumin, glucose, urea, and chloride concentrations, lower creatine kinase and alkaline phosphatase activities, higher total bilirubin, cholesterol, triglyceride, calcium, phosphorus, and globulin concentrations, and higher ALT activity than nonmated rats. Serum triglyceride concentration was approximately fourfold higher in pregnant rats compared with nonmated controls. CONCLUSION: Differences in hematology and chemistry values in pregnant Wistar Hannover rats are similar to those in Sprague-Dawley rats and support use of the Wistar Hannover rat as an animal model in the assessment of maternal toxicity. Differences in laboratory values of pregnant rats should be considered when interpreting data following exposure to candidate pharmaceuticals.  相似文献   
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The apparent microbial conversion of acetate to methane ranges seasonally from 0.7 to 88 micromoles per liter of whole wet sediment per hour in the top 5 centimeters of methane-producing sediments underlying sulfate-reducing sediments in Cape Lookout Bight, North Carolina. The associated methane flux across the sediment-water interface into overlying waters exhibits the same seasonal pattern. Significant methane production from acetate is observed only in sulfate-depleted sediments.  相似文献   
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Aquarium experiments were performed to quantify the inorganic fraction of suspended particles deposited on the external surface of aquatic biota. The mass of suspended particles retained on the surfaces of microalgae growing on submerged substrates and the algal biomass were determined by comparing the scandium content of suspended material with that in algal communities. Scandium, a predominantly soil-associated trace element, has been used as a ‘tracer’ for the inorganic component of suspended particles, because this element is geologically ubiquitous in soils, and it is recognized that it cannot cross natural membranes of plants and other organisms. The algal biomass determined using the scandium content was compared with biomass values calculated using phytopigments as estimates of periphyton biomass. The results indicate that the suspended particle mass adhering to the external periphyton surface may accounted for up to 55% of the total mass collected on submerged artificial substrates.  相似文献   
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A pilot re‐circulating system was used for the cultivation of two Mediterranean calanoid copepods: Temora stylifera and Centropages typicus. The system automatically concentrated the naupliar and copepodite stages. Temora stylifera was fed the flagellate Rhodomonas baltica or Prorocentrum minimum, whereas C. typicus was fed with a mixture of R. baltica or P. minimum and Tetraselmis suecica. Both copepods also received Isochrysis galbana. After 21 days, the T. stylifera population increased 26‐fold, reaching a density of 38 000 individuals, mostly represented by nauplii (88%). The maximum density recorded was 380 ind. L?1, with a production of 370 nauplii L?1. On average, the egg hatching success for this copepod during the rearing period was 54%, with the highest viability in April and May (>75%). The C. typicus population increased more than 10‐fold after 7 weeks of rearing, reaching a density of 123 000 individuals, mainly represented by nauplii (>90%). The highest naupliar production was 100 ind. L?1, with a mean egg hatching success of 68%. This system may be useful to produce nauplii and copepodite stages to be used as live, alternative or complementary food for fish larvae or to provide a ready source of organisms for physiological and bioassay studies.  相似文献   
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European Journal of Plant Pathology - Lethal wilting was observed on young olive trees cv Favolosa in a grove in central Italy. White mycelial strands wrapped the basal portion of the stems that...  相似文献   
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Marine organisms with fast growth rates and great biological adaptive capacity might have biotechnological interests, since ecological competitiveness might rely on enhanced physiological or biochemical processes’ capability promoting protection, defense, or repair intracellular damages. The invasive seagrass Halophila stipulacea, a non-indigenous species widespread in the Mediterranean Sea, belongs to this category. This is the premise to investigate the biotechnological interest of this species. In this study, we investigated the antioxidant activity in vitro, both in scavenging reactive oxygen species and in repairing damages from oxidative stress on the fibroblast human cell line WI-38. Together with the biochemical analysis, the antioxidant activity was characterized by the study of the expression of oxidative stress gene in WI-38 cells in presence or absence of the H. stipulacea extract. Concomitantly, the pigment pool of the extracts, as well as their macromolecular composition was characterized. This study was done separately on mature and young leaves. Results indicated that mature leaves exerted a great activity in scavenging reactive oxygen species and repairing damages from oxidative stress in the WI-38 cell line. This activity was paralleled to an enhanced carotenoids content in the mature leaf extracts and a higher carbohydrate contribution to organic matter. Our results suggest a potential of the old leaves of H. stipulacea as oxidative stress damage protecting or repair agents in fibroblast cell lines. This study paves the way to transmute the invasive H. stipulacea environmental threat in goods for human health.  相似文献   
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Cryopreservation is a valuable tool for aquaculture as it provides continuous seed production, regardless of the spawning season of the brood stock. The selection of a suitable cryoprotectant with low toxicity and high water solubility is important to avoid membrane injuries and intracellular ice crystallization. This study has been aimed at the assessment of the toxic effects of two usually applied cryoprotectants, 1‐2 propylene glycol (PG) and methanol (MetOH), on spermatozoa of the of lion‐paw scallop Nodipecten nodosus, by evaluating the sperm motility and the development of D larvae after fertilization procedure. Sperm was exposed at room temperature (22°C) for 10, 20 and 30 min to different concentration ranges of two cryoprotectants. Regarding the sperm motility, PG5%, PG7%, MetOH4% and MetOH6% did not show differences compared to control (semen incubated in seawater) (P < 0.05). The development of D larvae was not affected by the exposition to PG5%, MetOH 4% and MetOH 6%. These results indicate the potential use of both cryoprotectants for cryopreservation procedures.  相似文献   
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Evidence from research in the Pripyat catchment, reviewed here, indicates that under the ecological conditions prevalent in this area, radiocaesium (137Cs) is highly mobile in both river water and poorly drained organic soils. Data collected at three different spatial and temporal scales demonstrate the effects of hydrological events on 137Cs mobility. During the period 1988–1994, 137Cs contamination in some poorly drained organic soils in the Pripyat catchment and in the milk from cows grazing on these soils are generally declining much faster than the radioactive half life. However, sharp increases in levels of 137Cs in both floodplain soils and milk to 2–3 times that observed immediately after the initial deposition have been measured immediately after summer floods. The processes causing these observed changes have not yet been fully explained but the sites where enhanced 137Cs mobility has been detected are clearly associated with the spatial patterns of organic soils and river flooding.  相似文献   
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