全文获取类型
收费全文 | 377245篇 |
免费 | 37008篇 |
国内免费 | 195篇 |
出版年
2018年 | 3422篇 |
2017年 | 3450篇 |
2016年 | 5933篇 |
2015年 | 9953篇 |
2014年 | 10514篇 |
2013年 | 12172篇 |
2012年 | 12608篇 |
2011年 | 10211篇 |
2010年 | 7433篇 |
2009年 | 7139篇 |
2008年 | 8119篇 |
2007年 | 8216篇 |
2006年 | 8084篇 |
2005年 | 13634篇 |
2004年 | 12290篇 |
2003年 | 10370篇 |
2002年 | 7836篇 |
2001年 | 18416篇 |
2000年 | 17977篇 |
1999年 | 14616篇 |
1998年 | 4268篇 |
1997年 | 4343篇 |
1996年 | 4047篇 |
1995年 | 3715篇 |
1994年 | 3689篇 |
1993年 | 3715篇 |
1992年 | 12096篇 |
1991年 | 12071篇 |
1990年 | 11621篇 |
1989年 | 11392篇 |
1988年 | 10677篇 |
1987年 | 9968篇 |
1986年 | 9030篇 |
1985年 | 8915篇 |
1984年 | 6848篇 |
1983年 | 5865篇 |
1982年 | 4077篇 |
1981年 | 3617篇 |
1980年 | 3417篇 |
1979年 | 6341篇 |
1978年 | 4847篇 |
1977年 | 4321篇 |
1976年 | 3909篇 |
1975年 | 4619篇 |
1974年 | 4877篇 |
1973年 | 4814篇 |
1972年 | 4304篇 |
1971年 | 4055篇 |
1970年 | 3587篇 |
1969年 | 3512篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
A L Nevmiatullin O N Vorob'eva A N Maianski? 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1985,(7):67-71
The neutrophil-stimulating properties of 38 S. aureus strains and 32 S. epidermidis strains were studied in the reaction of luminol-mediated chemiluminescence. All S. aureus strains and 29 S. epidermidis strains were found to possess neutrophil-stimulating activity, the mean activity index for S. aureus being significantly higher. The stimulating activity of the strains varied within a wide range (the variation coefficient was 120.0 +/- 21.9%) and did not correlate with the content of protein A in bacterial cells and the degree of their hydrophoby. The opsonization of staphylococci with normal human serum enhanced the neutrophil reaction 1.5- to 100-fold and simultaneously leveled out the chemiluminescence indices in experiments with different strains (the variation coefficient was 8.0 +/- 1.5%). The nature of the neutrophil-stimulating effect of staphylococci and its relationship to the exploratory reactions of phagocytes are discussed. 相似文献
82.
The effects of 5-hydroxytryptamine and 5-hydroxytryptophan on 86Rb+ efflux from prelabelled ob/ob-mouse islets were studied to better understand the cellular mechanisms underlying the effects of 5-hydroxytryptamine and 5-hydroxytryptophan on insulin release. 5-Hydroxytryptophan (4 mM) had no effect on 86Rb+ efflux either at a low (3 mM) or at a high (20 mM) d-glucose concentration, whereas 5-hydroxytryptamine (4 mM) stimulated 86Rb+ efflux at both glucose concentrations. These results indicate that 5-hydroxytryptamine may reduce glucose-induced insulin release by inhibiting early steps in the β-cell stimulus-secretion coupling. 相似文献
83.
T Smith 《BMJ (Clinical research ed.)》1984,289(6449):909-910
84.
85.
86.
Intraperitoneal stimulation of adoptively sensitized rats with bacterial antigen promotes the localization of lymphoblasts at the site of antigen deposition. Lymphoblast extravasation activity (LEA) is generated only when specifically immune donor lymphocytes and the recipients of these cells share at least on Ag-B haplotype. However, if the specificity criteria for its formation are satisfied, LEA promotes the local development of lymphoblasts of all available specificities and irrespective of their Ag-B genotype. Allogeneic lymphoblasts do not participate actively in the delayed inflammatory reaction even when they are passively recruited into exudates. The results suggest that LEA is a T cell-derived mediator that amplifies the delayed type hypersensitivity reaction by directing recently activated lymphocytes into lesions. 相似文献
87.
88.
89.