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11.
12.
Acute graft-versus-host disease does not require alloantigen expression on host epithelium 总被引:21,自引:0,他引:21
Alloantigen expression on host antigen-presenting cells (APCs) is essential to initiate graft-versus-host disease (GvHD); therefore, alloantigen expression on host target epithelium is also thought to be essential for tissue damage. We tested this hypothesis in mouse models of GvHD using bone-marrow chimeras in which either major histocompatibility complex class I or class II alloantigen was expressed only on APCs. We found that acute GvHD does not require alloantigen expression on host target epithelium and that neutralization of tumor necrosis factor-alpha and interleukin-1 prevents acute GvHD. These results pertain particularly to CD4-mediated GvHD but also apply, at least in part, to CD8-mediated GvHD. These results challenge current paradigms about the antigen specificity of GvHD effector mechanisms and confirm the central roles of both host APCs and inflammatory cytokines in acute GvHD. 相似文献
13.
14.
Rao C Foernzler D Loftus SK Liu S McPherson JD Jungers KA Apte SS Pavan WJ Beier DR 《Development (Cambridge, England)》2003,130(19):4665-4672
Several features of the pigment defect in belted (bt) mutant mice suggest that it occurs as a result of a defect in melanocyte development that is unique from those described for other classical white-spotting mutations. We report here that bt mice carry mutations in Adamts20, a novel member of the ADAMTS family of secreted metalloproteases. Adamts20 shows a highly dynamic pattern of expression in the developing embryo that generally precedes the appearance of melanoblasts in the same region, and is not expressed in the migrating cells themselves. Adamts20 shows remarkable homology with GON-1, an ADAMTS family protease required for distal tip cell migration in C. elegans. Our results suggest that the role of ADAMTS proteases in the regulation of cell migration has been conserved in mammalian development. 相似文献
15.
Visco V Lucania G Sansolini T Dolo V Garofalo T Sorice M Frati L Torrisi MR Pavan A 《Histochemistry and cell biology》2000,113(1):43-50
The expression and surface distribution of monosialoganglioside GM3 on the plasma membranes of NIH3T3 fibroblasts cultured
at semiconfluence were analyzed by immunofluorescence as well as by immunogold electron microscopy on thin sections and surface
replicas. The GM3 expression was highly variable from cell to cell and the distribution of the ganglioside on the positive
cells appeared punctate. Quantitative immunogold electron microscopy showed the existence of well-defined GM3 clusters of
different sizes scattered all over the cell surfaces. Double immunofluorescence analysis of 5-bromo-2’-deoxyuridine incorporation
to identify proliferating cells and of GM3 expression indicated that most of the GM3-positive cells appear unable to synthesize
DNA and demonstrated a growth-dependent expression of GM3.
Accepted: 16 November 1999 相似文献
16.
Rao AV JayaSree T Ramesh M Pavan U Sadanandam A 《Indian journal of experimental biology》2000,38(6):617-620
High frequency of streptomycin resistant variants of Lycopersicon esculentum were isolated on selective shoot regeneration medium supplemented with IAA (0.5 mg/L), zeatin (1.5 mg/L) and streptomycin sulphate (500 mg/L). Nonmutagenized (controls) and NMU treated cotyledons were placed on shoot regeneration medium supplemented with antibiotic streptomycin. Resistant shoots appeared at a high frequency in mutagenized cotyledons, whereas in controls morphogenesis was suppressed, accompanied by bleaching. Shoot regeneration occurred from the nodular tissues developed at the cut ends of cotyledons. Resistant shoots developed into complete plantlets on rooting medium containing selective concentration of antibiotic. Stability of streptomycin resistance was confirmed by leaf assay and reciprocal crosses between streptomycin-resistant and sensitive plants. 相似文献
17.
Maurizio Sorice Tina Garofalo Roberta Misasi Agostina Longo Joanna Mikulak Vincenza Dolo Giuseppe Mario Pontieri Antonio Pavan 《Glycoconjugate journal》2000,17(3-4):247-252
The aim of this study was to further elucidate our previous observation on molecular interaction of GM3, CD4 and p56lck in microdomains of human peripheral blood lymphocytes (PBL). We analyzed GM3 distribution by immunoelectron microscopy and the association between GM3 and CD4-p56lck complex by scanning confocal microscopy and co-immunoprecipitation experiments. Scanning confocal microscopy analysis showed an uneven signal distribution of GM3 molecules over the surface of human lymphocytes. Nearly complete colocalization areas indicated that CD4 molecules were distributed in GM3-enriched plasma membrane domains. Co-immunoprecipitation experiments revealed that CD4 and p56lck were immunoprecipitated by IgG anti-GM3, demonstrating that GM3 tightly binds to the CD4-p56lck complex in human PBL. In order to verify whether GM3 association with CD4 molecules may depend on the presence of p56lck, we analyzed this association in U937, a CD4+and p56lck negative cell line. The immunoprecipitation with anti-GM3 revealed the presence of a 58[emsp4 ]kDa band immunostained with anti-CD4 Ab, suggesting that the GM3-CD4 interaction does not require its association with p56lck. These findings support the view that GM3 enriched-domains may represent a functional multimolecular complex involved in signal transduction and cell activation. 相似文献
18.
Vincenza Dolo Sandra D'Ascenzo Maurizio Sorice Antonio Pavan Mariateresa Sciannamblo Alessandro Prinetti Vanna Chigorno Guido Tettamanti Sandro Sonnino 《Glycoconjugate journal》2000,17(3-4):261-268
This paper is the first report on the use of the electron microscopy autoradiography technique to detect metabolically tritium labeled sphingolipids in intact cells in culture.To label cell sphingolipids, human fibroblasts in culture were fed by a 24 hours pulse, repeated 5 times, of 3×10–7 M [1-3H]sphingosine. [1-3H]sphingosine was efficently taken up by the cells and very rapidly used for the biosynthesis of complex sphingolipids, including neutral glycolipids, gangliosides, ceramide and sphingomyelin. The treatment with [1-3H]sphingosine did not induce any morphological alteration of cell structures, and well preserved cells, plasma membranes, and intracellular organelles could be observed by microscopy.Ultrathin sections from metabolic radiolabeled cells were coated with autoradiographic emulsion. One to four weeks of exposition resulted in pictures where the location of radioactive sphingolipids was evidenced by the characteristic appearance of silver grains as irregular coiled ribbons of metallic silver. Radioactive sphingolipids were found at the level of the plasma membranes, on the endoplasmic reticulum and inside of cytoplasmic vesicles. Thus, electron microscopy autoradiography is a very useful technique to study sphingolipid-enriched membrane domain organization and biosynthesis. 相似文献
19.
Sorice M Garofalo T Misasi R Longo A Mikulak J Dolo V Pontieri GM Pavan A 《Glycoconjugate journal》2000,17(3 -4):247-252
The aim of this study was to further elucidate our previous observation on molecular interaction of GM3, CD4 and p56Ick in microdomains of human peripheral blood lymphocytes (PBL). We analyzed GM3 distribution by immunoelectron microscopy and the association between GM3 and CD4-p56Ick complex by scanning confocal microscopy and co-immunoprecipitation experiments. Scanning confocal microscopy analysis showed an uneven signal distribution of GM3 molecules over the surface of human lymphocytes. Nearly complete colocalization areas indicated that CD4 molecules were distributed in GM3-enriched plasma membrane domains. Co-immunoprecipitation experiments revealed that CD4 and p56Ick were immunoprecipitated by IgG anti-GM3, demonstrating that GM3 tightly binds to the CD4-p56Ick complex in human PBL. In order to verify whether GM3 association with CD4 molecules may depend on the presence of p56Ick, we analyzed this association in U937, a CD4 + and p56Ick negative cell line. The immunoprecipitation with anti-GM3 revealed the presence of a 58kDa band immunostained with anti-CD4 Ab, suggesting that the GM3-CD4 interaction does not require its association with p56Ick. These findings support the view that GM3 enriched-domains may represent a functional multimolecular complex involved in signal transduction and cell activation. 相似文献
20.
Ulrike Teichmann Michael E. Ray Jane Ellison Caroline Graham Graeme Wistow Paul S. Meltzer Jeffrey M. Trent William J. Pavan 《Mammalian genome》1998,9(9):715-720
We report the isolation of the murine ortholog of AIM1, a human gene whose expression is associated with the reversal of
tumorigenicity in an experimental model of melanoma. Mouse and human AIM1 are more than 90% identical in amino acid sequence
in the βγ-crystallin repeats and the C-terminal domain, and more than 75% identical in the extended N-terminal domain. Consistent
with the isolated cDNA representing the authentic AIM1 ortholog, linkage analysis localized mouse Aim1 to proximal mouse Chromosome (Chr) 10 in a conserved linkage group with genes localized to human Chr band 6q21. Searches
of EST databases identified a second AIM1-like gene in both mouse and human, suggesting the existence of a gene family. Northern
analysis demonstrates Aim1 is expressed most abundantly in adult skin, lung, heart, liver, and kidney and is temporally regulated during embryogenesis.
Aim1 is expressed highly in the shaft region of the hair follicles and the presumptive ectoderm, but not at detectable levels
in melanocytes or melanocyte precursor cells.
Received: 18 February 1998 / Accepted: 8 May 1998 相似文献