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Endothelial cells (EC) act as leading actors in angiogenesis. Understanding the complex network of signal transduction pathways which regulate angiogenesis might offer insights in the regulation of normal and pathological events, including tumours, vascular, inflammatory and immune diseases. The effects of olive oil and of Blueberry extracts upon the phosphoinositide (PI)-specific phospholipase C (PLC) enzymes were evaluated both in quiescent and inflammatory stimulated human umbilical vein EC (HUVEC) using molecular biology (multiliquid bioanalysis) and immunofluorescence techniques. Oleuropein significantly increased the number of surviving HUVEC compared to untreated controls, suggesting that it favours the survival and proliferation of EC. Our results suggest that Oleuropein might be useful to induce EC proliferation, an important event during angiogenesis, with special regard to wound healing. Blueberry extracts increased the number of surviving HUVEC, although the comparison to untreated controls did not result statistically significant. Lipopolysaccharide (LPS) administration significantly reduced the number of live HUVEC. LPS can also modify the expression of selected PLC genes. Adding Blueberry extracts to LPS treated HUVEC cultures did not significantly modify the variations of PLC expression induced by LPS. Oleuropein increased or reduced the expression of PLC genes, and statistically significant results were identified for selected PLC isoforms. Oleuropein also modified the effects of LPS upon PLC genes’ expression. Thus, our results corroborate the hypothesis that Oleuropein owns anti-inflammatory activity. The intracellular localization of PLC enzymes was modified by the different treatments we used. Podosome-like structures were observed in differently LPS treated HUVEC.  相似文献   
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For women, menopausal transition is a time of significant hormonal changes, which may contribute to altered body composition and regional adipose tissue accumulation. Excess adiposity, and especially adipose tissue accumulation in the central body region, increases women''s risk of cardiovascular and metabolic conditions and affects physical functioning. We investigated the associations between menopausal progression and total and regional body adiposity measured with dual‐energy X‐ray absorptiometry and computed tomography in two longitudinal cohort studies of women aged 47–55 (n = 230 and 148, mean follow‐up times 1.3 ± 0.7 and 3.9 ± 0.2 years, mean baseline BMI 25.5 kg/m2). We also examined associations between menopausal progression and skeletal muscle fiber characteristics, as well as adipose tissue‐derived adipokines. Relative increases of 2%–14% were observed in regional and total body adiposity measures, with a pronounced fat mass increase in the android area (4% and 14% during short‐ and long‐term follow‐ups). Muscle fiber oxidative and glycolytic capacities and intracellular adiposity were not affected by menopause, but were differentially correlated with total and regional body adiposity at different menopausal stages. Menopausal progression and regional adipose tissue masses were positively associated with serum adiponectin and leptin, and negatively associated with resistin levels. Higher diet quality and physical activity level were also inversely associated with several body adiposity measures. Therefore, healthy lifestyle habits before and during menopause might delay the onset of severe metabolic conditions in women.  相似文献   
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Summary Two species ofEuphydryas butterflies were studied in California, USA, and showed considerable diet overlap at the species level. They utilize many of the same plant genera for oviposition. However,E. editha is less likely to use woody perennials than isE. chalcedona.Both butterfly species are known to specialize on different host plants in different populations, so species level divergence may not be a good predictor of community level divergence. Within five communities,E. editha andE. chalcedona showed no dietary overlap. A major component of the niche ofE. editha in one community was occupied byE. chalcedona in a second community, even though both butterfly species occupied both communities. These resource use patterns indicate that community level interactions may affect diet divergence. The degree to which divergence within communities is greater (or less) than expected from a species level comparison may be used to provide a measure of community organization. Equations are given in the Appendix for calculating overlap probabilities from presence/absence types of data; in this study, presence is oviposition on a particular plant species, absence is no oviposition on that plant species. Given the various assumptions of the model,E. editha andE. chalcedona show significant community level components of their dietary divergence in the areas studied. However, in some other communitiesE. editha andE. chalcedona do share host plant species. Therefore, we could not demonstrate community level divergence conclusively, nor has this been demonstrated for any other pair of insect herbivore species. We do not know whether this is because the phenomenon is truly rare or just very hard to demonstrate.  相似文献   
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We have recently demonstrated that in an autosomal dominant porphyria, erythropoietic protoporphyria (EPP), the coinheritance of a ferrochelatase (FECH) gene defect and of a wild-type low-expressed FECH allele is generally involved in the clinical expression of EPP. This mechanism may provide a model for phenotype modulation by minor variations in the expression of the wild-type allele in the other three autosomal dominant porphyrias that exhibit incomplete penetrance: acute intermittent porphyria (AIP), variegata porphyria (VP) and hereditary coproporphyria (HC), which are caused by partial deficiencies of hydroxy-methyl bilane synthase (HMBS), protoporphyrinogen oxidase (PPOX) and coproporphyrinogen oxidase (CPO), respectively. Given the dominant mode of inheritance of EPP, VP, AIP and HC, we first confirmed that the 200 overtly porphyric subjects (55 EPP, 58 AIP, 56 VP; 31 HC) presented a single mutation restricted to one allele (20 novel mutations and 162 known mutations). We then analysed the available single-nucleotide polymorphisms (SNPs) present at high frequencies in the general population and spreading throughout the FECH, HMBS, PPOX and the CPO genes in four case-control association studies. Finally, we explored the functional consequences of polymorphisms on the abundance of wild-type RNA, and used relative allelic mRNA determinations to find out whether low-expressed HMBS, PPOX and the CPO alleles occur in the general population. We confirm that the wild-type low-expressed allele phenomenon is usually operative in the mechanism of variable penetrance in EPP, but conclude that this is not the case in AIP and VP. For HC, the CPO mRNA determinations strongly suggest that normal CPO alleles with low-expression are present, but whether this low-expression of the wild-type allele could modulate the penetrance of a CPO gene defect in HC families remains to be ascertained.  相似文献   
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An extension of J. Roughgarden's [1979, Theor. Pop. Biol. 9, 388; 1979, "An Introduction to Evolutionary Ecology and Population Genetic Theory," Macmillan, New York] formalism for investigating the effects of coevolution on community structure is presented. The extension assumes the result that a coevolved community is asymptotically stable when coevolution takes place at a genetically noninvasible boundary. This is proved for the general case of n interacting species. From this a community persistence function, phi (P), is defined that allows measuring the domain of attraction for the community as well as the resilience time, that is, the time taken for a perturbation to decay to 1-1/e (63%) of its initial value.  相似文献   
110.
Signal transduction pathways, involved in cell cycle and activities, depend on various components including lipid signalling molecules, such as phosphoinositides and related enzymes. Many evidences support the hypothesis that inositol lipid cycle is involved in astrocytes activation during neurodegeneration. Previous studies investigated the pattern of expression of phosphoinositide‐specific phospholipase C (PI‐PLC) family isoforms in astrocytes, individuating in cultured neonatal rat astrocytes, supposed to be quiescent cells, the absence of some isoforms, accordingly to their well known tissue specificity. The same study was conducted in cultured rat astrocytoma C6 cells and designed a different pattern of expression of PI‐PLCs in the neoplastic counterpart, accordingly to literature suggesting a PI signalling involvement in tumour progression. It is not clear the role of PI‐PLC isoforms in inflammation; recent data demonstrate they are involved in cytokines production, with special regard to IL‐6. PI‐PLCs expression in LPS treated neonatal rat astrocytes performed by using RT‐PCR, observed at 3, 6, 18 and 24 h intervals, expressed: PI‐PLC beta1, beta4 and gamma1 in all intervals analysed; PI‐PLC delta1 at 6, 18 and 24 h; PI‐PLC delta3 at 6 h after treatment. PI‐PLC beta3, delta4 and epsilon, present in untreated astrocytes, were not detected after LPS treatment. Immunocytochemical analysis, performed to visualize the sub‐cellular distribution of the expressed isoforms, demonstrated different patterns of localisation at different times of exposure. These observations suggest that PI‐PLCs expression and distribution may play a role in ongoing inflammation process of CNS. J. Cell. Biochem. 109: 1006–1012, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   
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