全文获取类型
收费全文 | 1443篇 |
免费 | 180篇 |
国内免费 | 1篇 |
出版年
2021年 | 19篇 |
2020年 | 11篇 |
2019年 | 27篇 |
2018年 | 16篇 |
2017年 | 20篇 |
2016年 | 26篇 |
2015年 | 32篇 |
2014年 | 44篇 |
2013年 | 60篇 |
2012年 | 53篇 |
2011年 | 46篇 |
2010年 | 31篇 |
2009年 | 42篇 |
2008年 | 63篇 |
2007年 | 46篇 |
2006年 | 43篇 |
2005年 | 58篇 |
2004年 | 56篇 |
2003年 | 60篇 |
2002年 | 54篇 |
2001年 | 61篇 |
2000年 | 67篇 |
1999年 | 48篇 |
1998年 | 22篇 |
1997年 | 32篇 |
1996年 | 21篇 |
1995年 | 14篇 |
1994年 | 29篇 |
1993年 | 23篇 |
1992年 | 37篇 |
1991年 | 28篇 |
1990年 | 27篇 |
1989年 | 36篇 |
1988年 | 37篇 |
1987年 | 45篇 |
1986年 | 22篇 |
1985年 | 27篇 |
1984年 | 17篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 14篇 |
1980年 | 10篇 |
1979年 | 10篇 |
1978年 | 13篇 |
1975年 | 10篇 |
1974年 | 9篇 |
1973年 | 13篇 |
1972年 | 9篇 |
1969年 | 12篇 |
1968年 | 10篇 |
排序方式: 共有1624条查询结果,搜索用时 15 毫秒
51.
Dyer C 《BMJ (Clinical research ed.)》1993,306(6889):1365
52.
53.
James B. Kramer Diane H. Boschelli David T. Connor Catherine R. Kostlan Paul J. Kuipers John A. Kennedy Clifford D. Wright Dirk A. Bornemeier Richard D. Dyer 《Bioorganic & medicinal chemistry letters》1993,3(12):2827-2830
The preparation of a series of 1,3,4-thiadiazoles and 1,3,4-oxadizoles linked by a thioether to 2,6-di-t-butylphenol and the inhibition of cyclooxygenase (CO) and 5-lipoxygenase (5-LO) by these compounds is dicussed. 相似文献
54.
55.
56.
Bonny Breckinridge DiNovo Richard Doan Roy B. Dyer Samuel Baron Norbert K. Herzog David W. Niesel 《FEMS immunology and medical microbiology》1996,15(2-3):149-158
Abstract Pathogenesis mediated by Shigella flexneri requires invasion of the gastrointestinal epithelium. It has been previously shown that HeLa cells challenged with S. flexneri show alterations in their phosphotyrosine-containing protein profile. In this report, we demonstrated that bacterial water extracts (WE) abrogated the invasion of HeLa cells by S. flexneri in a dose-dependent manner. A proteinaceous component of S. flexneri was shown to be responsible for this inhibitory activity. Proteins encoded on the 140-MDa plasmid were not responsible for the observed inhibition. WE from other Gram-negative bacteria also inhibited Shigella invasion of HeLa cells. HeLa cells pretreated with WE showed changes in the profile and the intensity of phosphotyrosine-containing protein bands. These data were consistent with a surface protein component in WE which initiated aberrant host cell signaling at the membrane which may account for the inhibition of bacterial entry. 相似文献
57.
Identification of alcaligin as the siderophore produced by Bordetella pertussis and B. bronchiseptica. 总被引:6,自引:5,他引:1 下载免费PDF全文
C H Moore L A Foster D G Gerbig Jr D W Dyer B W Gibson 《Journal of bacteriology》1995,177(4):1116-1118
The siderophores produced by iron-starved Bordetella pertussis and B. bronchiseptica were purified and were found to be identical. Using mass spectrometry and proton nuclear magnetic resonance, we determined that the siderophore produced by these organisms was identical to alcaligin, a siderophore produced by Alcaligenes denitrificans. 相似文献
58.
Structural heterogeneity of the various forms of apomyoglobin: implications for protein folding. 总被引:1,自引:1,他引:0 下载免费PDF全文
R. Gilmanshin R. B. Dyer R. H. Callender 《Protein science : a publication of the Protein Society》1997,6(10):2134-2142
Temperature-induced denaturation transitions of different structural forms of apomyoglobin were studied monitoring intrinsic tryptophan fluorescence. It was found that the tryptophans are effectively screened from solvent both in native and acid forms throughout most of the temperature range tested. Thus, the tryptophans' surrounding do not show a considerable change in structure where major protein conformational transitions have been found in apomyoglobin using other techniques. At high temperatures and under strong destabilizing conditions, the tryptophans' fluorescence parameters show sigmoidal thermal denaturation. These results, combined with previous studies, show that the structure of this protein is heterogeneous, including native-like (tightly packed) and molten globule-like substructures that exhibit conformation (denaturation) transitions under different conditions of pH and temperature (and denaturants). The results suggest that the folding of this protein proceeds via two "nucleation" events whereby native-like contacts are formed. One of these events, which involves AGH "core" formation, appears to occur very early in the folding process, even before significant hydrophobic collapse in the rest of the protein molecule. From the current studies and other results, a rather detailed picture of the folding of myoglobin is presented, on the level of specific structures and their thermodynamical properties as well as formation kinetics. 相似文献
59.
60.
Haemopoietic cell growth factor mediates cell survival via its action on glucose transport 总被引:6,自引:2,他引:4 下载免费PDF全文
A number of haematopoietic precursor cell lines have been established which exhibit an absolute dependence on haematopoietic cell growth factor (HCGF) which is secreted by WEHI-3 myelomonocytic leukaemia cells. In the presence of HCGF, ATP levels are maintained in these factor-dependent cells (FDC-P cells); in the absence of HCGF, intracellular ATP levels undergo a steady depletion. The cell death that follows this ATP depletion can be prevented by supplying exogenous ATP suggesting that HCGF maintains these cells via its effects on energy metabolism. We have investigated the effect of HCGF on FDC-P cells further and found that: (i) HCGF markedly and rapidly increases lactate production; (ii) high extracellular glucose or glycolytic intermediate concentrations can maintain FDC-P cell viability to some extent whilst stimulating lactate production; (iii) the uptake of 2-deoxyglucose by FDC-P2 cells is stimulated by HCGF in a dose-dependent fashion. This uptake is inhibited by cytochalasin B; (iv) HCGF does not stimulate L-glucose uptake by FDC-P cells. These results suggest that HCGF acts to maintain FDC-P cells via its action on glucose transport. The significance of these results to haemopoiesis and leukaemogenesis is discussed. 相似文献