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1. Availability of suitable habitat is a prerequisite for species reintroduction success, and to ensure population persistence, investigations of a species’ habitat utilisation throughout its life history should be conducted as part of a feasibility study. 2. Habitat utilisation models for burbot, Lota lota, developed using data from field studies conducted in France and Germany and information from the literature were used to assess the feasibility of reintroducing burbot into rivers of its former native range in eastern England. 3. Per cent tree roots, aquatic vegetation and flow types were important predictors of adult burbot abundance. Furthermore, the habitat utilisation models were supplemented with information from the literature, which suggested that off‐channel habitat such as wetlands and backwaters is important for spawning and nursery stages. 4. An assessment of the habitat availability in the rivers of the burbot’s former native range using variables related to spawning and nursery and adult life stages showed that although adult habitat was widely distributed, the availability of spawning and nursery habitat was less abundant, potentially limiting successful reestablishment. 5. Potential suitable habitat was concentrated in the central and southern areas of the species’ former English distribution. Overall, rivers of the burbot’s former range potentially afford suitable habitat to sustain a reintroduced population. However, sites should be preferentially selected on the basis of having appropriate spawning and nursery areas.  相似文献   
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Limited information is available about selection of the threshold for arterial blood pressure in critically ill patients, particularly in sepsis when normal organ blood flow autoregulation may be altered. The present experimental study investigated whether increasing perfusion pressure using norepinephrine in normotensive hyperdynamic porcine bacteremia affects intestinal macro- and microcirculation. Nine pigs received continuous i.v. administration of Pseudomonas aeruginosa (PSAE) to develop hyperdynamic, normotensive (mean arterial pressure [MAP] 65 mm Hg) sepsis. Norepinephrine was used to achieve 10-15 % increase in MAP. Mesenteric arterial blood flow (Q(gut)), ileal mucosal microvascular perfusion (LDF(gut)) and ileal-end-tidal PCO(2) gap (PCO(2) gap) were measured before norepinephrine, after 60 min of norepinephrine infusion and 60 min after norepinephrine infusion had been discontinued. During a 12 h period of PSAE infusion all pigs developed hyperdynamic circulation with significantly decreased MAP. Although the mesenteric blood flow remained unchanged, infusion of PSAE resulted in a gradual fall of ileal microvascular perfusion, which was associated with progressively rising PCO(2) gap. Norepinephrine which induced a 10-15 % increase in perfusion pressure (i.e. titrated to attain near baseline values of MAP) affected neither Q(gut) nor the intestinal blood flow distribution (Q(gut)/CO). Similarly, norepinephrine did not change either LDF(gut) or PCO(2) gap. In this hyperdynamic, normotensive porcine bacteremia, norepinephrine-induced increase in perfusion pressure exhibited neither beneficial nor deleterious effects on intestinal macrocirculatory blood flow and ileal mucosal microcirculation. The lack of changes suggests that the gut perfusion was within its autoregulatory range.  相似文献   
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The aim of this study was to evaluate long-term platinum retention in patients treated with cisplatin and oxaliplatin.  相似文献   
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We have previously described a developmentally regulated mRNA in maize that accumulates in mature embryos and is involved in a variety of stress responses in the plant. The sequence of the encoded 16 kDa protein (MA16) predicts that it is an RNA-binding protein, since it possesses a ribonucleoprotein consensus sequence-type RNA-binding domain (CS-RBD). To assess the predicted RNA binding property of the protein and as a starting point to characterize its function we have used ribohomopolymer-binding assays. Here we show that the MA16-encoded protein binds preferentially to uridine- and guanosine-rich RNAs. In light of these results a likely role for this protein in RNA metabolism during late embryogenesis and in the stress response is discussed.  相似文献   
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In the present study we examine the effects of the drug hadacidin (N-formyl-N- hydroxyglycine) on pinocytosis in the eukaryotic microorganism dictyostelium discoideum. At concentrations of up to approximately 8 mg/ml, hadacidin inhibited the rate of pinocytosis of fluorescein isothiocyanate (FITC) dextran in cells in growth medium in a concentration-dependent manner but had no effect on cells in starvation medium. Because hadacidin also inhibits cellular proliferation at this concentration, the relationship between growth rate and pinocytosis was studied further using another drug, cerulenin, to produce growth-arrest. These experiments showed no changes in the rate pinocytosis even after complete cessation of cellular proliferation. Other studies showed that the transfer of cells from growth to starvation medium reduced the rate of pinocytosis by approximately 50 percent. A reduction of similar magnitude occurred if cells were transferred from growth to starvation medium containing hadacidin. Also, no additional reduction in pinocytosis occurred when cells that had been treated with hadacidin were transferred to starvation medium containing hadacidin. These cells were able to take up [(14)C]hadacidin in the starvation medium. In contrast to the results with hadacidin-treated cells, cells in a cerulenin-induced state of growth-arrest when transferred to starvation medium exhibited the same 50 percent reduction in pinocytosis observed in cells not previously exposed to either drug. Cells treated with azide, in either growth or starvation medium, exhibited an immediate inhibition of all pinocytotic activity. After the transfer of log-phase cells to starvation medium supplemented with glucose, the reduction in rate was only approximately 10-15 percent. In contrast, a 50 percent reduction was observed after supplementation of starvation medium with sucrose, KCl, or concanavalin A. Maintaining the cells in growth medium containing hadacidin for as long as 16 h had no effect on the rate at which cells aggregated. These results are consistent with the conclusion that D. discoideum exhibits two types of pinocytotic activity: one that is nutrient dependent and the other independent of nutrients. This latter activity persists in starvation medium and is unaffected by hadacidin, whereas the nutrient-dependent activity is present in growth medium and is inhibited by hadacidin.  相似文献   
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