全文获取类型
收费全文 | 311篇 |
免费 | 26篇 |
国内免费 | 19篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 3篇 |
2014年 | 9篇 |
2013年 | 13篇 |
2012年 | 15篇 |
2011年 | 12篇 |
2010年 | 9篇 |
2009年 | 17篇 |
2008年 | 14篇 |
2007年 | 14篇 |
2006年 | 16篇 |
2005年 | 8篇 |
2004年 | 12篇 |
2003年 | 20篇 |
2002年 | 12篇 |
2001年 | 7篇 |
2000年 | 9篇 |
1999年 | 11篇 |
1998年 | 8篇 |
1997年 | 14篇 |
1996年 | 9篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 11篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 8篇 |
1985年 | 2篇 |
1984年 | 7篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有356条查询结果,搜索用时 15 毫秒
111.
The concept of superantigens is well-known and widely accepted. In this brief communication, we analyze the behaviour of antigen-presenting cells after T-cell activation by staphylococcal enterotoxin B, a representative superantigen. We tried to activate murine T cells by inflammatory mouse peritoneal macrophage in the presence of staphylococcal enterotoxin B, but no T-cell activation was observed. We, therefore, analyzed surface-specific antigens of the macrophages. They expressed insufficient amounts of MHC class II, CD80 and CD86 molecules on the surface of the cells. On the contrary, increased amounts of MHC class II and CD86 molecules on the cell surfaces were observed after incubation with interferon gamma. Interferon gamma-primed macrophages were found to be competent to activate T cells in the presence of staphylococcal enterotoxin B. To our surprise, these macrophages underwent apoptosis in parallel with T-cell activation. 相似文献
112.
113.
Abstract A culture filtrate of Clostridium spiroforme grown in a brain-heart-infusion peptone medium at 37°C for 24 h was concentrated by ultrafiltration, and the toxic fraction separated by ion exchange chromatography. This material was dermonecrotic in depilated guinea pigs, lethal in mice, enterotoxic in rabbit ileal loops and infant mice and cytophathic for HeLa cells. All activity was neutralised by Clostridium perfringens Type E antitoxin. Analysis by size exclusion high-performance liquid chromatography produced a single symmetrical peak corresponding to an M r of 41 000 to 42 000. 相似文献
114.
Yusuke Sato'o Katsuhiko Omoe Hisaya K. Ono Akio Nakane Dong‐Liang Hu 《Microbiology and immunology》2013,57(2):91-99
Staphylococcus aureus pathogenicity islands (SaPIs) form a growing family of mobile genetic elements (MGEs) in Staphylococci. Horizontal genetic transfer by MGEs plays an important role in the evolution of S. aureus. Several SaPIs carry staphylococcal enterotoxin and SE‐like toxin genes. To comprehensively investigate the diversity of SaPIs, a series of primers corresponding to sequences flanking six SaPI insertion sites in S. aureus genome were designed and a long and accurate (LA)‐PCR analysis method established. LA‐PCR products of 13–17 kbp were observed in strains with seb, selk or selq genes. Restriction fragment length polymorphism (RFLP) analysis showed that the products have different RFLP characteristics than do previously described SaPIs; they were therefore predicted to include new SaPIs. Nucleotide sequencing analysis revealed seven novel SaPIs: seb‐harboring SaPIivm10, SaPishikawa11, SaPIivm60, SaPIno10 and SaPIhirosaki4, selk and selq‐harboring SaPIj11 and non‐superantigen‐harboring SaPIhhms2. These SaPIs have mosaic structures containing components of known SaPIs and other unknown genes. Strains carrying different SaPIs were found to have significantly different production of superantigen toxins. The present results show that the LA‐PCR approach can comprehensively identify SaPI diversity and is useful for investigating the evolution of S. aureus pathogenicity. 相似文献
115.
Cholera toxin (Ctx) from Vibrio cholerae and its closely related homologue, heat-labile enterotoxin (Etx) from Escherichia coli have become superb tools for illuminating pathways of cellular trafficking and immune cell function. These bacterial protein toxins should be viewed as conglomerates of highly evolved, multi-functional elements equipped to engage the trafficking and signalling machineries of cells. Ctx and Etx are members of a larger family of A-B toxins of bacterial (and plant) origin that are comprised of structurally and functionally distinct enzymatically active A and receptor-binding B sub-units or domains. Intoxication of mammalian cells by Ctx and Etx involves B pentamer-mediated receptor binding and entry into a vesicular pathway, followed by translocation of the enzymatic A1 domain of the A sub-unit into the target cell cytosol, where covalent modification of intracellular targets leads to activation of adenylate cyclase and a sequence of events culminating in life-threatening diarrhoeal disease. Importantly, Ctx and Etx also have the capacity to induce a wide spectrum of remarkable immunological processes. With respect to the latter, it has been found that these toxins activate signalling pathways that modulate the immune system. This review explores the complexities of the cellular interactions that are engaged by these bacterial protein toxins, and highlights some of the new insights to have recently emerged. 相似文献
116.
Farnoush Jafari Iri-Sofla Fatemeh Rahbarizadeh Davoud Ahmadvand Mohammad J. Rasaee 《Experimental cell research》2011,317(18):2630
The crucial role of T lymphocytes in anti-tumor immunity has led to the development of novel strategies that can target and activate T cells against tumor cells. Recombinant DNA technology has been used to generate non-MHC-restricted chimeric antigen receptors (CARs). Here, we constructed a panel of recombinant CAR that harbors the anti-MUC1 nanobody and the signaling and co-signaling moieties (CD3ζ/CD28) with different spacer regions derived from human IgG3 with one or two repeats of the hinge sequence or the hinge region of FcγRII. The PhiC31 integrase system was employed to investigate if the recombination efficiency could be recruited for high and stable expression of T cell chimeric receptor genes. The effect of nuclear localization signal (NLS) and two different promoters (CMV and CAG) on efficacy of PhiC31 integrase in human T cell lines was evaluated. The presence of integrase in combination with NLS, mediated up to 7.6 and 8.5 fold increases in CAR expression in ZCHN-attB and ZCHHN-attB cassette integrated T cells, respectively. Our results showed that highly efficient and stable transduction of the Jurkat cell line by PhiC31 integrase is a feasible modality for generating anti-cancer chimeric T cells for use in cancer immunotherapy. 相似文献
117.
The adapter 3BP2 is involved in leukocyte signaling downstream Src/Syk-kinases coupled immunoreceptors. Here, we show that 3BP2 directly interacts with the endocytic scaffold protein CIN85 and the actin-binding protein HIP-55. 3BP2 co-localized with CIN85 and HIP-55 in T cell rafts and at the T cell/APC synapse, an active zone of receptors and proteins recycling. A binding region of CIN85 SH3 domains on 3BP2 was mapped to a PVPTPR motif in the first proline-rich region of 3BP2, whereas the C-terminal SH3 domain of HIP-55 bound a more distal proline-rich domain of 3BP2. Together, our data suggest an unexpected role of 3BP2 in endocytic and cytoskeletal regulation through its interaction with CIN85 and HIP-55. 相似文献
118.
R.N. Haddadin A.M. Assaf A. Homsi P.J. Collier A. Shehabi 《Journal of applied microbiology》2019,127(1):88-98
119.
Sepsis, a health-threatening progressive infectious disease, is the major cause of morbidity and mortality worldwide. Cell therapy using mesenchymal stromal cells (MSCs) is an innovative strategy with excessive therapeutic potential in the treatment of sepsis. Staphylococcal enterotoxin B (SEB) preconditioning aims to prolong the interval of survival of transplanted MSCs which induces the production of cytoprotective agents, anti-apoptotic and anti-inflammatory factors. The MSCs were preconditioned with an optimum dose of SEB (470 μmol/L). The expression levels of apoptosis genes and antibacterial activity of MSC and SEB-MSC and their conditioned medium (CM), as well as cell survival, were studied in vitro in an oxidative stress and serum deprivation condition. Following treatment of the septic mice with MSCs and SEB-MSCs, pro/anti-inflammatory cytokines, hematological factors, bacterial clearance and animal survival were assessed. The apoptotic and pro-inflammatory cytokine's genes expression was down-regulated while antibacterial peptides and anti-inflammatory cytokines were up-regulated in SEB-MSC–treated mice. The animal survival rates were improved; bacterial clearance was enhanced in the peritoneal fluids, blood and organs; aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were reduced in blood, compared with saline and MSCs alone. This research concludes that transplantation of SEB-MSCs presents improved therapeutic effects on a live bacterial model of sepsis. 相似文献
120.
Menezes CA Amianti J Harayama HS Koga PC Trabulsi LR Piazza RM 《FEMS microbiology letters》2002,216(1):67-70
Escherichia coli producing heat-labile enterotoxin is responsible for numerous cases of diarrhea worldwide, leading to considerable morbidity and mortality. The B subunits of this toxin are responsible for the binding to the receptor, the complex ganglioside GM1 which has galactose as its terminal sugar. In this study we showed that analogs of galactose (gal) and N-acetylgalactosamine (GalNAc) interfere with the binding of heat-labile toxin to GM1. Antibodies to lectins which mimic sugar structures and neoglycoprotein were employed. These compounds were able to inhibit heat-labile toxin activity efficiently in Vero cells: 37 microg of IgG-enriched fraction from an antiserum inhibited up to 70% of this activity, and 50% of the binding of heat-labile toxin to GM1. Neoglycoprotein was more efficient than antibodies, since 2.5 microg of this ligand completely abolished the activity of heat-labile toxin on Vero cells. These data suggest that these molecules could be developed for prophylaxis and diagnosis of diarrhea caused by heat-labile toxin. 相似文献