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991.
S. Lohmander S. Moskalewski K. Madsen J. Thyberg U. Friberg 《Experimental cell research》1976,99(2):333-345
Fetal guinea-pig epiphyseal chondrocytes were cultured in monolayers and as aggregates in the presence of antimicrotubular agents. Colchicine and vinblastine caused a dissociation of the Golgi complex, in addition to the disappearance of microtubules. Synthesis and secretion of proteoglycans and collagen were studied using radioactive precursors. Colchicine inhibited the synthesis of proteoglycans. The drug also inhibited secretion with an intracellular accumulation of these molecules. The proteoglycans secreted by the colchicine-treated cells had a smaller molecular size and contained a smaller proportion of aggregated molecules than proteoglycans in control cultures. However, there was no difference in the average size of the chondroitin sulfate side chains of the proteoglycan molecules. Nor was there any increase in the breakdown of proteoglycans in colchicine-treated cultures. Vinblastine was also found to inhibit synthesis and secretion of proteoglycans. Deuterium oxide also inhibited the synthesis of these molecules but stimulated their secretion into the medium. Colchicine caused an inhibition of both synthesis and secretion of collagen. It is suggested that the quantitative and qualitative effects of colchicine could be the result of disturbances in the Golgi complex, possibly in combination with a retarded translocation of secretory vacuoles. However, as the colchicine-treated chondrocytes were still able to continue a large part of their matrix biosynthesis with only moderate changes in the structure of the secreted molecules, it is probable that alternative pathways for the secretion of matrix molecules exist and/or the Golgi complex is able to retain a major part of its function despite the structural alterations. 相似文献
992.
Identification and characterization of a human T cell line-derived lymphokine with MAF-like activity distinct from interferon-gamma 总被引:5,自引:0,他引:5
J C Lee L Rebar P Young F W Ruscetti N Hanna G Poste 《Journal of immunology (Baltimore, Md. : 1950)》1986,136(4):1322-1328
Culture supernatants of several human T cell leukemia cell lines were screened for macrophage-activating activity (MAF) as defined by induction of tumoricidal activity against human melanoma cells in a 72-hr assay. Two cell lines, MT-2 and C10/MJ2, were found to produce high levels of MAF activity constitutively, but the MT-2 cell line, unlike C10/MJ2, produced little IFN-gamma. This observation was confirmed by Northern blot analysis performed with specific IFN-gamma cDNA probe. The MT-2 cell line thus provides a useful system to evaluate the existence of lymphokines with MAF activity that are distinct from IFN-gamma. The MAF activity produced by MT-2 cells was distinguished from IFN-gamma by the following criteria. MAF activity was not removed by immunoaffinity chromatography with the use of immobilized specific polyclonal antibodies to IFN-gamma and was not neutralized by a monoclonal antibody to IFN-gamma. Heat or acid treatments of IFN-gamma resulted in loss of its antiviral activity, but these treatments had no effect on MAF activity. MAF activity was not abolished by polymyxin B sulfate, suggesting that this activity is not mediated by or dependent on LPS. Initial characterization studies performed by using membrane filtration, gel filtration chromatography, and isoelectric focusing indicate that the non-IFN-gamma MAF activity produced by MT-2 cells has an apparent m.w. of 55,000 and an isoelectric point of 5.5. Collectively, these data suggest that the MT-2 human T cell line constitutively produces high levels of MAF and low levels of IFN-gamma and offers a useful source for the further purification of a unique human lymphokine with macrophage-activating activity that is distinct from IFN-gamma. 相似文献
993.
The binding of [3H]cytochalasin B (CB) to intact cells was compared in lymphocytes, polymorphonuclear leukocytes (PMNLs) and erythrocytes over a broad range of cytochalasin concentrations. Binding curves consistent with the presence of high and low affinity binding sites were demonstrated in all three cell types. However, in contrast to observations in erythrocytes, in lymphocytes and PMNLs CB binding was unaffected by d-glucose. p-Hydroxymercuribenzoate and p-hydroxymercurisulfonate were only partially inhibitory and unlabeled cytochalasins E, D and A (CE, CD, CA) inhibited [3H]CB binding more effectively than unlabeled CB. While attempts to demonstrate that plasma membrane-rich subcellular fractions from lymphocytes selectively bind [3H]CB were inconclusive, radioautographic studies on unbroken cells indicated that most or all of the high affinity CB-binding sites in lymphocytes and PMNLs were in close proximity to the cell surface. 相似文献
994.
Hydatidiform mole: genetic origin in polyploid conceptuses 总被引:1,自引:1,他引:0
Summary The origin of 29 polyploid conceptuses with villous cystic swelling was examined. One tetraploid specimen showed one maternal and three paternal contributions to the genome. Informative cytogenetic markers in 24 triploids were consistent with fertilization by dispermy. Analysis of cytogenetic markers indicated that polyspermy may account for essentially all polyploid conceptions with an excess of paternal to maternal chromosome complements. The origin of the genome was primarily demonstrated by the study of cytogenetic markers, while HLA determination and enzyme analysis were less informative. 相似文献
995.
Aline Santos Sampaio Ana Gabriela Hounie Kátia Petribú Carolina Cappi Ivanil Morais Homero Vallada Maria Concei??o do Rosário S. Evelyn Stewart Jesen Fargeness Carol Mathews Paul Arnold Gregory L. Hanna Margaret Richter James Kennedy Leonardo Fontenelle Carlos Alberto de Bragan?a Pereira David L. Pauls Eurípedes Constantino Miguel 《PloS one》2015,10(3)
Objective
Obsessive-compulsive disorder (OCD) is a common and debilitating psychiatric illness. Although a genetic component contributes to its etiology, no single gene or mechanism has been identified to the OCD susceptibility. The catechol-O-methyltransferase (COMT) and monoamine oxidase A (MAO-A) genes have been investigated in previous OCD studies, but the results are still unclear. More recently, Taylor (2013) in a comprehensive meta-analysis of genetic association studies has identified COMT and MAO-A polymorphisms involved with OCD. In an effort to clarify the role of these two genes in OCD vulnerability, a family-based association investigation was performed as an alternative strategy to the classical case-control design.Methods
Transmission disequilibrium analyses were performed after genotyping 13 single-nucleotide polymorphisms (eight in COMT and five in MAO-A) in 783 OCD trios (probands and their parents). Four different OCD phenotypes (from narrow to broad OCD definitions) and a SNP x SNP epistasis were also analyzed.Results
OCD, broad and narrow phenotypes,were not associated with any of the investigated COMT and MAO-A polymorphisms. In addition, the analyses of gene-gene interaction did not show significant epistatic influences on phenotype between COMT and MAO-A.Conclusions
The findings do not support an association between DSM-IV OCD and the variants of COMT or MAO-A. However, results from this study cannot exclude the contribution of these genes in the manifestation of OCD. The evaluation of broader spectrum phenotypes could help to understand the role of these and other genes in the pathophysiology of OCD and its spectrum disorders. 相似文献996.
Bj?rn Forsstr?m Barbara Bis?awska Axn?s Johan Rockberg Hanna Danielsson Anna Bohlin Mathias Uhlen 《PloS one》2015,10(3)
An important issue for the performance and specificity of an antibody is the nature of the binding to its protein target, including if the recognition involves linear or conformational epitopes. Here, we dissect polyclonal sera by creating epitope-specific antibody fractions using a combination of epitope mapping and an affinity capture approach involving both synthesized peptides and recombinant protein fragments. This allowed us to study the relative amounts of antibodies to linear and conformational epitopes in the polyclonal sera as well as the ability of each antibody-fraction to detect its target protein in Western blot assays. The majority of the analyzed polyclonal sera were found to have most of the target-specific antibodies directed towards linear epitopes and these were in many cases giving Western blot bands of correct molecular weight. In contrast, many of the antibodies towards conformational epitopes did not bind their target proteins in the Western blot assays. The results from this work have given us insights regarding the nature of the antibody response generated by immunization with recombinant protein fragments and has demonstrated the advantage of using antibodies recognizing linear epitopes for immunoassay involving wholly or partially denatured protein targets. 相似文献
997.
998.
Identification and characterization of SNJ2, the first temperate pleolipovirus integrating into the genome of the SNJ1‐lysogenic archaeal strain 下载免费PDF全文
Ying Liu Jiao Wang Yang Liu Yuchen Wang Ziqian Zhang Hanna M. Oksanen Dennis H. Bamford Xiangdong Chen 《Molecular microbiology》2015,98(6):1002-1020
Proviral regions have been identified in the genomes of many haloarchaea, but only a few archaeal halophilic temperate viruses have been studied. Here, we report a new virus, SNJ2, originating from archaeal strain Natrinema sp. J7‐1. We demonstrate that this temperate virus coexists with SNJ1 virus and is dependent on SNJ1 for efficient production. Here, we show that SNJ1 is an icosahedral membrane‐containing virus, whereas SNJ2 is a pleomorphic one. Instead of producing progeny virions and forming plaques, SNJ2 integrates into the host tRNAMet gene. The virion contains a discontinuous, circular, double‐stranded DNA genome of 16 992 bp, in which both nicks and single‐stranded regions are present preceded by a ‘GCCCA’ motif. Among 25 putative SNJ2 open reading frames (ORFs), five of them form a cluster of conserved ORFs homologous to archaeal pleolipoviruses isolated from hypersaline environments. Two structural protein encoding genes in the conserved cluster were verified in SNJ2. Furthermore, SNJ2‐like proviruses containing the conserved gene cluster were identified in the chromosomes of archaea belonging to 10 different genera. Comparison of SNJ2 and these proviruses suggests that they employ a similar integration strategy into a tRNA gene. 相似文献
999.
1000.
Ingmar Sch?fer Marc Pawels Claudia Küver Nadine Janis Pohontsch Martin Scherer Hendrik van den Bussche Hanna Kaduszkiewicz 《PloS one》2014,9(4)