全文获取类型
收费全文 | 167篇 |
免费 | 33篇 |
出版年
2019年 | 2篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 4篇 |
2012年 | 6篇 |
2011年 | 4篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 5篇 |
2007年 | 4篇 |
2006年 | 6篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 4篇 |
1970年 | 4篇 |
1969年 | 2篇 |
1968年 | 6篇 |
1967年 | 3篇 |
1966年 | 4篇 |
1965年 | 2篇 |
1964年 | 2篇 |
1959年 | 1篇 |
1955年 | 1篇 |
1948年 | 2篇 |
排序方式: 共有200条查询结果,搜索用时 298 毫秒
31.
Øystein Bruserud Laila Mentzoni Brynjar Foss Jann Bergheim Sigbjørn Berentsen Ingerid Nesthus 《Cancer immunology, immunotherapy : CII》1997,43(5):275-282
Normal peripheral blood mononuclear cells (PBMC responders) were cultured together with non-irradiated allogeneic PBMC (more
than 95% leukaemia blasts) derived from patients with acute leukaemia (referred to as leukaemic PBMC stimulators). Cytokine
secretion was determined as cytokine concentrations in supernatants. Both normal PBMC and enriched CD4+ and CD8+ T cells responded to allostimulation with interferon (IFNγ) secretion. Interleukin-1 (IL-1) receptor antagonist and IL-2-neutralizing
antibodies decreased IFNγ secretion. Exogenous IL-1β, IL-2 and IL-7 increased allostimulated IFNγ secretion, whereas decreased
levels were seen in the presence of IL-6, IL-10 and granulocyte-colony-stimulating factor (G-CSF). During allorecognition
IFNγ -neutralizing antibodies decreased acute myelogenous leukaemia (AML) blast secretion of G-CSF. We conclude that (i) both
CD4+ and CD8+ T cells show allostimulated cytokine secretion in response to allogeneic stimulator cells containing a dominating population
of native, cytokine-secreting leukaemia blasts, and (ii) IFNγ released during this response can modulate the function of allogeneic
AML blasts.
Received: 4 June 1996 / Accepted: 15 October 1996 相似文献
32.
The use-dilution test for evaluating the effectiveness of disinfectants against bacteria was modified to determine the effectiveness of disinfectants against a group of viruses. Modifications were kept to a minimum to retain the general principles of the test and thereby retain the test's familiarity among testing laboratory personnel. Modifications included the use of a standard allantoic fluid suspension of Newcastle disease virus instead of a standard bacterial culture. The only other modification was the inoculation of six embryonated chicken eggs (10 to 12 days old) with 0.1 ml of nutrient broth into which a carrier ring was transferred after a standard period in diluted disinfectant. The death or survival of 60 embryos, then, is the criterion by which a disinfectant can be judged effective at use-dilution. Experiments are described which establish the validity of the modified test procedure. The effectiveness of nine common disinfectants against Newcastle disease virus as judged by this test procedure is reported. 相似文献
33.
The O-specific polysaccharide moieties (PS) of the O18A, O18A1, O18B, and O18B1 antigens (lipopolysaccharides, LPS) consist of L-rhamnose (Rha), N-acetyl-D-glucosamine, D-galactose, and D-glucose in different molar ratios. By using chemical fragmentation, methylation, as well as one- and two-dimensional NMR spectroscopy, the structures of these polysaccharides were found to be [formula: see text] In O18A-PS and O18A1-PS x = 2, whereas in O18B-PS and in O18B11-PS x = 3. In all four polysaccharides alpha-D-Galp (residue D) is substituted at O-3. This substituent L (residue E) is beta-D-GlcpNAc-(1 in O18A-PS and O18A1-PS and it is alpha-D-Glcp-(1 in O18B-PS and O18B1-PS. Whereas there is no further substituent on the main chain of the O18A and O18B polysaccharides, in O18A1-PS and O18B1-PS the alpha-D-GlcpNAc residue A is substituted with alpha-Glcp-(1 (residue F), which is linked to O-6 in O18A1-PS and to O-4 in O18B1-PS. These results show that the O18 antigen comprises a group of four related LPS (O18A and O18B, with their glucosylated forms O18A1 and O18B1). The results are discussed with respect to epitope definition and biochemical implications. 相似文献
34.
Biosynthesis of the Escherichia coli K5 polysaccharide, a representative of group II capsular polysaccharides: polymerization in vitro and characterization of the product. 总被引:7,自引:6,他引:1
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Biosynthesis of the capsular K5 polysaccharide of Escherichia coli, which has the structure 4)-beta GlcA-1,4-alpha GlcNAc-(1, was studied with membrane preparations from an E. coli K5 wild-type strain and from a recombinant K-12 strain expressing the K5 capsule. Polymerization occurs at the inner face of the cytoplasmic membrane without the participation of lipid-linked oligosaccharides. The serological K5 specificity of the in vitro product was determined with a K5-specific monoclonal antibody in an antigen-binding assay. The K5 polysaccharide, as obtained from the membranes after an in vitro incubation, has 2-keto-3-deoxyoctulosonic acid as the reducing sugar, which indicates that the polysaccharide grows by chain elongation at the nonreducing end. 相似文献
35.
An open reading frame (ORF) of 141 bp was observed upstream from the Pseudomonas aeruginosa lysA gene. The translation product of this ORF contains a signal peptide with a lipoprotein box, Ile-Ala-Ala-Cys, at the predicted signal peptidase cleavage site. The Escherichia coli phoA gene without its signal sequence was fused in frame to this ORF in a broad host-range plasmid. The resulting construct expressed a hybrid protein exhibiting alkaline phosphatase activity in phoA mutants of both E. coli and P. aeruginosa. This indicates that the ORF encodes a peptide, part of which acts as an export signal. The hybrid peptide was identified by immunoblotting with alkaline phosphatase antiserum. The accumulation of a precursor form was observed when P. aeruginosa cells carrying this gene fusion on a plasmid were treated with globomycin. Moreover, the mature form could be labelled with 2-[3H]-glycerol, indicating that lipidic residues may be linked to the hybrid protein. Taken together, these results strongly suggest that the ORF encodes a lipopeptide. We propose that the gene is called IppL. 相似文献
36.
37.
N. Riegman H. Hoschützky I. van Die W. Hoekstra K. Jann H. Bergmans 《Molecular microbiology》1990,4(7):1193-1198
Antibodies recognizing the non-adhesive minor P-fimbral subunit protein E and the P-fimbrial adhesin were used in an immunocytochemical analysis of P-fimbrial structure. It was demonstrated that P-fimbriae of the serotypes F71, F72 and F11 carry their adhesin in a complex with protein E. These complexes are commonly found at the tip of the fimbrial structure. In P-fimbriae of serotype F9, expressed by the uropathogenic Escherichia coli strain 21086, adhesin-protein E complexes are localized at the tips as well as along the shafts of the fimbriae. Protein E of F71 fimbriae (FsoE) plays a catalysing role in the biogenesis of the adhesin, but has no effect on the eventual localization of the adhesin. 相似文献
38.
Structure of the K95 antigen from Escherichia coli O75:K95:H5, a capsular polysaccharide containing furanosidic KDO-residues 总被引:1,自引:0,他引:1
The structure of the K95 antigenic capsular polysaccharide (K95 antigen) of Escherichia coli O75:K95:H5 was elucidated by determination of the composition, 1H- and 13C-n.m.r. spectroscopy, periodate oxidation, and methylation analysis. The K95 polysaccharide, which contains furanosidic 3-deoxy-D-manno-2-octulosonic acid (KDOf) residues, consists of----3)-beta-D-Rib-(1----8)-KDOf-(2----repeating units, has a molecular weight of approximately 25,000 (approximately 65 repeating units), and is randomly O-acetylated (1 acetyl group per repeating unit at unknown positions). 相似文献
39.
Abstract Monoclonal antibodies of subclasses IgG1 and IgG2b and specific for the O4 antigen of Escherichia coli 20025 (O4 : K12 : H− ) and the capsular K12 polysaccharide of the same strain (IgM) were obtained with the hybridoma technique using spleen cells from Balb/c mice, immunized with a crude bacterial extract, and Sp2/O-Ag8 myeloma cells. The anti-O4 antibodies reacted exclusively with the O4 lipopolysaccharide and not with those from serologically O-cross reactive E. coli . The anti-K12 antibodies recognized as epitope (part of) the KDO moiety of the capsular K12 polysaccharide. Not only anti-K12, but also anti-O4 antibodies effectively phagoopsonized encapsulated E. coli 20025. The opsonized bacteria were killed in subsequent in vitro phagocytosis by human leokocytes in the presence of human serum complement. 相似文献
40.