全文获取类型
收费全文 | 13165篇 |
免费 | 1125篇 |
国内免费 | 7篇 |
出版年
2023年 | 75篇 |
2022年 | 148篇 |
2021年 | 284篇 |
2020年 | 153篇 |
2019年 | 184篇 |
2018年 | 288篇 |
2017年 | 249篇 |
2016年 | 418篇 |
2015年 | 649篇 |
2014年 | 821篇 |
2013年 | 893篇 |
2012年 | 1230篇 |
2011年 | 1107篇 |
2010年 | 729篇 |
2009年 | 665篇 |
2008年 | 839篇 |
2007年 | 815篇 |
2006年 | 772篇 |
2005年 | 770篇 |
2004年 | 675篇 |
2003年 | 617篇 |
2002年 | 582篇 |
2001年 | 127篇 |
2000年 | 93篇 |
1999年 | 130篇 |
1998年 | 127篇 |
1997年 | 89篇 |
1996年 | 90篇 |
1995年 | 68篇 |
1994年 | 62篇 |
1993年 | 69篇 |
1992年 | 52篇 |
1991年 | 43篇 |
1990年 | 34篇 |
1989年 | 33篇 |
1988年 | 33篇 |
1987年 | 15篇 |
1986年 | 19篇 |
1985年 | 18篇 |
1984年 | 27篇 |
1983年 | 23篇 |
1982年 | 11篇 |
1981年 | 14篇 |
1980年 | 17篇 |
1979年 | 13篇 |
1978年 | 10篇 |
1977年 | 11篇 |
1976年 | 13篇 |
1974年 | 8篇 |
1973年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
Conclusion From this brief review it appears that at least three categories of human glioma-associated antigens may exist. The first seems to be restricted and common to gliomas. The second is shared between gliomas, normal adult brain, and fetal brain. The third is present on cells from adult and fetal tissue and on cells from tumours derived from the neural crest. The expression of glioma-associated antigens is highly variable from one tumour, or tumour cell line, to another, and reflects the phenotypic heterogeneity of the glioma group. Moreover, this heterogeneity has been found in different clones of individual glioma cell lines [1]. The fact that gliomas share some antigens with normal brain is of critical importance for immunodiagnosis or immunotherapy. It is evident that active immunotherapy for gliomas should be performed with cultured cells and not with tumour extracts, because such extracts may contain MBP.The exact nature of the various glioma-associated antigens remains to be clearly defined, however. They may belong to a group of surface glycoproteins such as those described by Lloyd et al. [24] for melanoma or more recently by Lubitz et al. [25] for glial cells. 相似文献
142.
143.
Construction of an apparatus for the determination of the cell contact potential difference and the measuring method are described. The contact potential differences are attributed to the degree of hydrophobic properties of the cell surface and referred to human erythrocytes and chloroplasts. 相似文献
144.
145.
146.
147.
Elmar Porten Beate Seliger Verena A. Schneider Stefan W?ll Daniela Stangel Rene Ramseger Stephan Kr?ger 《The Journal of biological chemistry》2010,285(5):3114-3125
Clustering or overexpression of the transmembrane form of the extracellular matrix proteoglycan agrin in neurons results in the formation of numerous highly motile filopodia-like processes extending from axons and dendrites. Here we show that similar processes can be induced by overexpression of transmembrane-agrin in several non-neuronal cell lines. Mapping of the process-inducing activity in neurons and non-neuronal cells demonstrates that the cytoplasmic part of transmembrane agrin is dispensable and that the extracellular region is necessary for process formation. Site-directed mutagenesis reveals an essential role for the loop between β-sheets 3 and 4 within the Kazal subdomain of the seventh follistatin-like domain of TM-agrin. An aspartic acid residue within this loop is critical for process formation. The seventh follistatin-like domain could be functionally replaced by the first and sixth but not by the eighth follistatin-like domain, demonstrating a functional redundancy among some follistatin-like domains of agrin. Moreover, a critical distance of the seventh follistatin-like domain to the plasma membrane appears to be required for process formation. These results demonstrate that different regions within the agrin protein are responsible for synapse formation at the neuromuscular junction and for process formation in central nervous system neurons and suggest a role for agrin''s follistatin-like domains in the developing central nervous system. 相似文献
148.
149.
150.
Lavaill Maxence Trichilo Silvia Scheiner Stefan Forwood Mark R. Cooper David M. L. Pivonka Peter 《Biomechanics and modeling in mechanobiology》2020,19(5):1765-1780
Biomechanics and Modeling in Mechanobiology - One of only a few approved and available anabolic treatments for severe osteoporosis is daily injections of PTH (1-34). This drug has a specific dual... 相似文献