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51.
Evaluation of Systematic Position of Helicoprorodontids and Chaeneids (Ciliophora,Litostomatea): An Attempt to Break Long Branches in 18S rRNA Gene Phylogenies
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Phylogenetic position of some free‐living litostomatean taxa has not been correctly determined because of long‐branch artifacts in 18S rRNA gene trees. The main aim of this study was to test the effectiveness of various masking algorithms, tree‐building techniques, binarization of DNA data as well as combining morphological and molecular data to eliminate long‐branch attraction of two problematic groups, helicoprorodontids and chaeneids. Guidance and SlowFaster masking in a combination with PhyloBayesian tree construction erased the artifactual positions of helicoprorodontids and chaeneids. On the other hand, binarization of DNA sequences and the strategy of combining morphological and molecular data eliminated only the artifactual position of chaeneids but not that of helicoprorodontids which were still being attracted by out‐group taxa. According to statistical tree topology tests and comparative morphological studies, helicoprorodontids are classified as a distinct order while chaeneids are considered to be fast evolving members of the order Lacrymariida. The high body contractility, “cephalization” of the anterior body end, and helicalization of the anterior portion of some or all somatic ciliary rows indicate relatedness of helicoprorodontids, chaeneids, and lacrymariids. On the other hand, the dorsal brush separated from the circumoral kinety by dense ciliary files supports kinships of chaeneids, lacrymariids, and didiniids. 相似文献
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The purpose of the article is to test the relationship between national identities and modernisation. We test the hypotheses that not all forms of identity are equally compatible with modernisation as measured by Human Development Index. The less developed societies are characterised by strong ascribed national identities based on birth, territory and religion, but also by strong voluntarist identities based on civic features selected and/or achieved by an individual. While the former decreases with further modernisation, the latter may either decrease or remain at high levels and coexist with instrumental supranational identifications, typical for the most developed countries. The results, which are also confirmed by multilevel regression models, thus demonstrate that increasing modernisation in terms of development contributes to the shifts from classical, especially ascribed, identities towards instrumental identifications. These findings are particularly relevant in the turbulent times increasingly dominated by the hardly predictable effects of the recent mass migrations. 相似文献
56.
PPAR gamma 2 prevents lipotoxicity by controlling adipose tissue expandability and peripheral lipid metabolism
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Medina-Gomez G Gray SL Yetukuri L Shimomura K Virtue S Campbell M Curtis RK Jimenez-Linan M Blount M Yeo GS Lopez M Seppänen-Laakso T Ashcroft FM Oresic M Vidal-Puig A 《PLoS genetics》2007,3(4):e64
Peroxisome proliferator activated receptor gamma 2 (PPARg2) is the nutritionally regulated isoform of PPARg. Ablation of PPARg2 in the ob/ob background, PPARg2−/− Lepob/Lepob (POKO mouse), resulted in decreased fat mass, severe insulin resistance, β-cell failure, and dyslipidaemia. Our results indicate that the PPARg2 isoform plays an important role, mediating adipose tissue expansion in response to positive energy balance. Lipidomic analyses suggest that PPARg2 plays an important antilipotoxic role when induced ectopically in liver and muscle by facilitating deposition of fat as relatively harmless triacylglycerol species and thus preventing accumulation of reactive lipid species. Our data also indicate that PPARg2 may be required for the β-cell hypertrophic adaptive response to insulin resistance. In summary, the PPARg2 isoform prevents lipotoxicity by (a) promoting adipose tissue expansion, (b) increasing the lipid-buffering capacity of peripheral organs, and (c) facilitating the adaptive proliferative response of β-cells to insulin resistance. 相似文献
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Critical review of the IMO international convention on the management of ships’ ballast water and sediments 总被引:2,自引:0,他引:2
Stephan Gollasch Matej David Matthias Voigt Egil Dragsund Chad Hewitt Yasuwo Fukuyo 《Harmful algae》2007,6(4):585-600
The International Maritime Organization (IMO), the United Nations body which administers the international regulatory regime for shipping, noted the negative impact of non-indigenous organisms transported in the ballast water of ships already in the early 1970s. Consequently, measures were taken with the aim to minimize ballast water mediated species invasions through IMO Marine Environmental Protection Committee (MEPC) Resolutions. As a result of long-term IMO efforts, it was determined that an international convention would best meet the needs of the global community, hence the International Convention for the Control and Management of Ships’ Ballast Water and Sediments was adopted in a Diplomatic Conference in 2004 and is now open for signature by IMO Member States. This very complex (and by no means “simple”) Convention aims to reduce the transfer and subsequent impact of aquatic organisms in the ballast water and sediment of ships by acting to reduce the load of these organisms in discharged ballast water. A set of 15 guidelines provides technical guidance for the implementation of the Convention principles. This review considers critical aspects of this Convention and selected guidelines seen from perspectives of biological, shipping and regulatory concerns. 相似文献
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Laxman Yetukuri Mikko Katajamaa Gema Medina-Gomez Tuulikki Seppänen-Laakso Antonio Vidal-Puig Matej Orešič 《BMC systems biology》2007,1(1):12-15
Background
Lipids are an important and highly diverse class of molecules having structural, energy storage and signaling roles. Modern analytical technologies afford screening of many lipid molecular species in parallel. One of the biggest challenges of lipidomics is elucidation of important pathobiological phenomena from the integration of the large amounts of new data becoming available. 相似文献59.
Background
Success of metabolomics as the phenotyping platform largely depends on its ability to detect various sources of biological variability. Removal of platform-specific sources of variability such as systematic error is therefore one of the foremost priorities in data preprocessing. However, chemical diversity of molecular species included in typical metabolic profiling experiments leads to different responses to variations in experimental conditions, making normalization a very demanding task. 相似文献60.
Prelovsek O Mars T Jevsek M Podbregar M Grubic Z 《American journal of physiology. Regulatory, integrative and comparative physiology》2006,291(6):R1651-R1656
A frequent finding in patients surviving critical illness myopathy is chronic muscle dysfunction. Its pathogenesis is mostly unknown; one explanation could be that muscle regeneration, which normally follows myopathy, is insufficient in these patients because of a high glucocorticoid level in their blood. Glucocorticoids can prevent stimulatory effects of proinflammatory factors on the interleukin (IL)-6 secretion, diminishing in this way the autocrine and paracrine IL-6 actions known to stimulate proliferation at the earliest, myoblast stage of muscle formation. To test this hypothesis, we compared the effects of major proinflammatory agents [tumor necrosis factor (TNF)-alpha and endotoxin lipopolysaccharide (LPS)] on the IL-6 secretion from the muscle precursors and then studied the influence of dexamethasone (Dex) on these effects. Mononuclear myoblasts, which still proliferate, were compared with myotubes in which this capacity is already lost. For correct interpretation of results, cultures were examined for putative apoptosis and necrosis. We found that constitutive secretion of IL-6 did not differ significantly between myoblasts and myotubes; however, the TNF-alpha- and LPS-stimulated IL-6 release was more pronounced (P < 0.001) in myoblasts. Dex, applied at the 0.1-100 nM concentration range, prevented constitutive and TNF-alpha- and LPS-stimulated IL-6 release at both developmental stages but only at high concentration (P < 0.01). Although there are still missing links to it, our results support the concept that high concentrations of glucocorticoids, met in critically ill patients, prevent TNF-alpha- and LPS-stimulated IL-6 secretion. This results in reduced IL-6-mediated myoblast proliferation, leading to the reduced final mass of the regenerated muscle. 相似文献