全文获取类型
收费全文 | 3493篇 |
免费 | 243篇 |
国内免费 | 1篇 |
出版年
2023年 | 9篇 |
2022年 | 11篇 |
2021年 | 49篇 |
2020年 | 23篇 |
2019年 | 37篇 |
2018年 | 61篇 |
2017年 | 33篇 |
2016年 | 82篇 |
2015年 | 134篇 |
2014年 | 170篇 |
2013年 | 207篇 |
2012年 | 266篇 |
2011年 | 245篇 |
2010年 | 146篇 |
2009年 | 154篇 |
2008年 | 200篇 |
2007年 | 198篇 |
2006年 | 210篇 |
2005年 | 190篇 |
2004年 | 186篇 |
2003年 | 196篇 |
2002年 | 163篇 |
2001年 | 49篇 |
2000年 | 49篇 |
1999年 | 62篇 |
1998年 | 42篇 |
1997年 | 47篇 |
1996年 | 37篇 |
1995年 | 35篇 |
1994年 | 33篇 |
1993年 | 27篇 |
1992年 | 30篇 |
1991年 | 39篇 |
1990年 | 34篇 |
1989年 | 24篇 |
1988年 | 28篇 |
1987年 | 19篇 |
1986年 | 13篇 |
1985年 | 16篇 |
1984年 | 23篇 |
1983年 | 17篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 10篇 |
1979年 | 10篇 |
1977年 | 8篇 |
1976年 | 8篇 |
1974年 | 10篇 |
1973年 | 11篇 |
1970年 | 11篇 |
排序方式: 共有3737条查询结果,搜索用时 31 毫秒
31.
32.
33.
34.
S L Hauser A K Bahn M Che F Gilles H L Weiner 《Journal of immunology (Baltimore, Md. : 1950)》1984,133(6):3037-3042
Experimental allergic encephalomyelitis (EAE) was induced in SJL/J mice by using two injections of spinal cord homogenate in incomplete Freund's adjuvant supplemented with mycobacteria. Analysis of circulating Lyt-bearing subsets by indirect immunofluorescence during the course of acute EAE revealed the following: 1) during the pre-clinical phase of EAE (1 to 2 days before the onset of paralysis), there was a decrease in the percentage of Lyt-1- but not of Lyt-2-bearing cells in peripheral blood, and of both Lyt-1- and Lyt-2-bearing cells in spleen; 2) with the onset of clinically evident EAE, there was a decrease in both Lyt-1 and Lyt-2 cells in peripheral blood and an increase in the percentage of Lyt-1-bearing cells in pooled inguinal and axillary lymph node; and 3) after these early changes, there was a rapid reconstitution of the percentages of total Lyt-bearing cells and of both Lyt-1- and Lyt-2-bearing cells in peripheral blood. Immunohistochemical analysis of the central nervous system infiltrate revealed that the earliest lesions consisted predominantly of Lyt-1 T lymphocytes, with few Lyt-2 cells present. These results demonstrate that the influx of cells of the Lyt-1 inducer subset to the central nervous system in acute EAE is accompanied by a transient decrease in Lyt-1 cells in peripheral blood. 相似文献
35.
36.
37.
Phosphorylation of phospholamban by either a cAMP-dependent or a calmodulin-dependent kinase stimulates the Ca2+ transporting activity of cardiac sarcoplasmic reticulum membranes. It has now been found that phospholamban consists of 2 distinct proteins; one is the specific substrate for the cAMP-dependent phosphorylation, and the other for the calmodulin-dependent kinase. In spite of functional diversity, the 2 polypeptides share a number of properties. Among them, the proteolipid character, Mr, resistance to trypsinization, and subunit composition. 相似文献
38.
CCK nerve terminals in the rat striatal and limbic areas originate partly in the brain stem and partly in telencephalic structures 总被引:1,自引:0,他引:1
After direct injection of colchicine into the rat rostral caudateputamen, levels of cholecystokinin-like immunoreactive (CCK-IR) material in this part of the nucleus are significantly lowered, and CCK-IR neuronal cell bodies are not demonstrable in the caudateputamen, although numerous ones are revealed in some adjacent telencephalic regions. Direct injection of kainic acid into the rostral caudate-putamen is not followed by a decrease of CCK-IR material in the lesioned region. Twenty one days after injection of 6-hydroxydopamine into the rat ventral mesencephalon, a significant decrease of CCK-IR material is observed in the frontal pole, the pyriform cortex, the nucleus accumbens and the ventral mesencephalon itself, but not in the caudate-putamen. After brain stem hemitransection, no decrease in CCK-IR material is observed in the rostral caudate-putamen. 相似文献
39.
40.
Murine responses to both the male specific histocompatibility antigen H-Y and the erythrocyte alloantigen Ea-1 are regulated by genetic factors. In each case a single major gene that controls the immune response has been identified, but additional modifying factors can be demonstrated if appropriate strain combinations are studied. A single gene controlling the response to Ea-1 antigens, which segregates when strains YBR and B10.D2 are crossed, has been shown not to be an allele of theIr-2 locus. A new phenomenon has also been observed in the control of anti-Ea-1 antibody production in that the mating of two responding strains, YBR and HTG, produces an F1 generation of complete nonresponders. By linkage tests it was shown that the responding strain HTG possesses the nonresponder allele at theIr- 2 locus, so there appear to be recessive genes in the background which are able to overcome the suppressive influence of this allele. 相似文献