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Alan Christoffels Sydney Brenner Byrappa Venkatesh 《Comparative biochemistry and physiology. Part D, Genomics & proteomics》2006,1(1):13
A whole-genome duplication in the ray-finned fish lineage has been supported by the analyses of the genome sequence of the Japanese pufferfish, Fugu rubripes. Recently, genome sequence of a second teleost fish, the freshwater pufferfish, Tetraodon nigroviridis, was completed. Comparisons of long-range synteny between the Tetraodon and human genomes provided additional evidence for the whole-genome duplication in the ray-finned fish lineage. In the present study, we conducted phylogenetic analysis of the Tetraodon and human proteins to identify ray-finned fish lineage-specific (‘fish-specific’) duplicate genes in the Tetraodon genome. Our analyses provide evidence for 1087 well defined fish-specific duplicate genes in Tetraodon. We also analyzed the Fugu proteome that was predicted in the recent Fugu genome assembly, and identified 346 duplicate genes in addition to the 425 duplicates previously identified. We estimated the ages of duplicate genes using the molecular clock. The ages of duplicate genes in the two pufferfishes independently support a large-scale gene duplication around 380–400 Myr ago. In addition, a burst of recent gene duplications was evident in the Tetraodon lineage. These findings provide further evidence for a whole-genome duplication early in the evolution of ray-finned fishes, and suggest that independent gene duplications have occurred recently in the Tetraodon lineage. 相似文献
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Cyclohexanehexol inhibitors of Abeta aggregation prevent and reverse Alzheimer phenotype in a mouse model 总被引:2,自引:0,他引:2
McLaurin J Kierstead ME Brown ME Hawkes CA Lambermon MH Phinney AL Darabie AA Cousins JE French JE Lan MF Chen F Wong SS Mount HT Fraser PE Westaway D St George-Hyslop P 《Nature medicine》2006,12(7):801-808
When given orally to a transgenic mouse model of Alzheimer disease, cyclohexanehexol stereoisomers inhibit aggregation of amyloid beta peptide (Abeta) into high-molecular-weight oligomers in the brain and ameliorate several Alzheimer disease-like phenotypes in these mice, including impaired cognition, altered synaptic physiology, cerebral Abeta pathology and accelerated mortality. These therapeutic effects, which occur regardless of whether the compounds are given before or well after the onset of the Alzheimer disease-like phenotype, support the idea that the accumulation of Abeta oligomers has a central role in the pathogenesis of Alzheimer disease. 相似文献
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Zakrzewski JL Kochman AA Lu SX Terwey TH Kim TD Hubbard VM Muriglan SJ Suh D Smith OM Grubin J Patel N Chow A Cabrera-Perez J Radhakrishnan R Diab A Perales MA Rizzuto G Menet E Pamer EG Heller G Zúñiga-Pflücker JC Alpdogan O van den Brink MR 《Nature medicine》2006,12(9):1039-1047
Immunoincompetence after allogeneic hematopoietic stem cell transplantation (HSCT) affects in particular the T-cell lineage and is associated with an increased risk for infections, graft failure and malignant relapse. To generate large numbers of T-cell precursors for adoptive therapy, we cultured mouse hematopoietic stem cells (HSCs) in vitro on OP9 mouse stromal cells expressing the Notch-1 ligand Delta-like-1 (OP9-DL1). We infused these cells, together with T-cell-depleted mouse bone marrow or purified HSCs, into lethally irradiated allogeneic recipients and determined their effect on T-cell reconstitution after transplantation. Recipients of OP9-DL1-derived T-cell precursors showed increased thymic cellularity and substantially improved donor T-cell chimerism (versus recipients of bone marrow or HSCs only). OP9-DL1-derived T-cell precursors gave rise to host-tolerant CD4+ and CD8+ populations with normal T-cell antigen receptor repertoires, cytokine secretion and proliferative responses to antigen. Administration of OP9-DL1-derived T-cell precursors increased resistance to infection with Listeria monocytogenes and mediated significant graft-versus-tumor (GVT) activity but not graft-versus-host disease (GVHD). We conclude that the adoptive transfer of OP9-DL1-derived T-cell precursors markedly enhances T-cell reconstitution after transplantation, resulting in GVT activity without GVHD. 相似文献
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Glucose-yeast extract or glucose-casein hydrolysate-grown Thiobacillus intermedius cells, which use glucose for energy generation, possess high specific activities of the Entner-Doudoroff pathway and related enzymes, 6-phosphogluconate dehydrase, 2-keto-3-deoxy-6-phosphogluconate aldolase, glucokinase, and glucose-6-phosphate dehydrogenase, but low activities of enzymes unique to the pentose shunt and Embden-Meyerhof pathways. Although the synthesis of the latter enzymes remains largely unaffected by the growth environment, that of the former is stimulated by glucose. Radiorespirometric measurements demonstrate an early and parallel respiration of glucose carbon atoms one and four in glucose-casein hydrolysate broth. It is concluded that the Entner-Doudoroff pathway performs an energetic role in glucose metabolism by T. intermedius with the pentose shunt and Embden-Meyerhof pathways functioning mainly in biosynthesis. The presence of thiosulfate in the growth medium inhibits the synthesis of the Entner-Doudoroff pathway and related enzymes. In addition, both thiosulfate and glucose inhibit the synthesis of the Krebs cycle enzymes, nicotinamide adenine dinucleotide phosphate-linked isocitrate and alpha-ketoglutarate dehydrogenases. Thus, repression of enzymes is of significance in the adaptation of T. intermedius to its nutritional environment. The activity of glucose-6-phosphate dehydrogenase of T. intermedius is inhibited by adenosine triphosphate. Such a control could afford the organism a mechanism to regulate the flow of glucose into major energetic and biosynthetic routes. 相似文献
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Érico Silva Loreto Liliane A. Scheid Cristina W. Nogueira Gilson Zeni Janio M. Santurio Sydney H. Alves 《Mycopathologia》2010,169(6):431-443
Candida dubliniensis is an emerging pathogen first described in 1995, which shares many phenotypic features with Candida albicans and therefore may be misidentified in microbial laboratories. Despite various phenotypic techniques described in the literature
to differentiate the two species, the correct identification of C. dubliniensis remains problematic due to phenotypic similarities between these species. Thus, as the differences between both are best
characterized at genetic levels, several molecular methods have been proposed to provide a specific and rapid identification
of this species. Epidemiological studies have shown that C. dubliniensis is prevalent throughout the world and it is primarily associated with oral carriage and oropharyngeal infections in patients
infected with human immunodeficiency virus (HIV). However, data acquired from its isolation from other healthy and immunocompromised
patients are variable, and there is still no real consensus on the epidemiological relevance of this species. In this article,
we review the various phenotypic methods used in the identification of C. dubliniensis and the epidemiological impact of this new species. 相似文献
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