全文获取类型
收费全文 | 169771篇 |
免费 | 9253篇 |
国内免费 | 260篇 |
专业分类
179284篇 |
出版年
2021年 | 1332篇 |
2020年 | 1074篇 |
2019年 | 1208篇 |
2018年 | 2605篇 |
2017年 | 2641篇 |
2016年 | 4764篇 |
2015年 | 8401篇 |
2014年 | 8446篇 |
2013年 | 8979篇 |
2012年 | 8964篇 |
2011年 | 6291篇 |
2010年 | 4922篇 |
2009年 | 4772篇 |
2008年 | 4260篇 |
2007年 | 4089篇 |
2006年 | 3954篇 |
2005年 | 9454篇 |
2004年 | 8158篇 |
2003年 | 6076篇 |
2002年 | 3568篇 |
2001年 | 4981篇 |
2000年 | 3882篇 |
1999年 | 4149篇 |
1998年 | 1490篇 |
1997年 | 1128篇 |
1992年 | 3598篇 |
1991年 | 3531篇 |
1990年 | 3478篇 |
1989年 | 3329篇 |
1988年 | 3148篇 |
1987年 | 2986篇 |
1986年 | 2641篇 |
1985年 | 2667篇 |
1984年 | 1873篇 |
1983年 | 1551篇 |
1982年 | 1021篇 |
1979年 | 1874篇 |
1978年 | 1352篇 |
1977年 | 1170篇 |
1976年 | 1135篇 |
1975年 | 1529篇 |
1974年 | 1730篇 |
1973年 | 1707篇 |
1972年 | 1634篇 |
1971年 | 1576篇 |
1970年 | 1451篇 |
1969年 | 1461篇 |
1968年 | 1266篇 |
1967年 | 1209篇 |
1966年 | 1110篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
V A Frolov G Mall P Rieger Kh Derks Z Antoni 《Biulleten' eksperimental'no? biologii i meditsiny》1987,104(12):739-741
Intensive synthesis of collagen-like substance was revealed in the rabbit myocardium during experimental diphtheria intoxication. It was more marked in the right ventricle 24 hours after the injection of diphtheria toxin. Since similar changes (the substance was mainly formed around blood vessels) have been observed in other cases of toxic myocardial alterations (i.e. ethanol intoxication, injection of pharmacological agents, etc.), it can be assumed that it is a standard protective reaction of the altered heart to the penetration of toxic agents from the blood into the myocardial tissue. 相似文献
12.
13.
14.
15.
The Biopolymer Markup Language. 总被引:6,自引:0,他引:6
D Feny? 《Bioinformatics (Oxford, England)》1999,15(4):339-340
SUMMARY: An XML derived from a data model designed to be a hierarchical representation of an organism has been specified and a browser to use this language has been developed. AVAILABILITY: The language definition is available in HTML form at http://www.proteometrics.com/BIOML/. The BioML browser is available on request from the author. 相似文献
16.
17.
18.
19.
Auranofin affects early events in human polymorphonuclear neutrophil activation by receptor-mediated stimuli 总被引:1,自引:0,他引:1
I Hafstr?m B E Seligmann M M Friedman J I Gallin 《Journal of immunology (Baltimore, Md. : 1950)》1984,132(4):2007-2014
Auranofin, a new oral antirheumatic gold compound, in concentrations achieved therapeutically, inhibits neutrophil phagocytosis, chemotaxis, chemiluminescence, reduction of cytochrome c, and release of lysosomal enzymes. To further characterize the mechanism by which auranofin affects neutrophils, we studied the effects of auranofin on unstimulated properties and functions of neutrophils as well as on rapidly stimulated functions. When examined by electron microscopy, 4 micrograms/ml of auranofin significantly decreased the number of visualized centriole-associated microtubules in resting cells. Furthermore, auranofin inhibited neutrophil spreading on glass and caused a decrease in negative surface charge (electrophoretic mobility). In addition, auranofin inhibited several fmet-leu-phe-stimulated responses such as shape change, increases in centriole-associated microtubules, decreases in surface charge, and elicited membrane potential changes (di-O-C5(3) dye response). Auranofin (1 micrograms/ml) inhibited fmet-leu-phe-stimulated superoxide and hydrogen peroxide production by 80% (p less than 0.05), and also increased the affinity of receptors for fmet-leu-phe (from Ka 0.035 to Ka 0.48, p less than 0.001). Auranofin also affected neutrophil responses to phorbol myristic acetate (PMA). The total amount of PMA-stimulated superoxide production was suppressed by as little as 0.4 micrograms/ml of auranofin, but the lag time for activation was shortened by low concentrations of auranofin (0.5 to 1 microgram/ml). Four micrograms per milliliter of auranofin suppressed the decrease in surface charge induced by PMA. However, auranofin did not influence superoxide production elicited by the ionophore A23187. The results indicate that auranofin affects the earliest detected responses in neutrophil activation by certain receptor-mediated stimuli. 相似文献
20.
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