全文获取类型
收费全文 | 663篇 |
免费 | 50篇 |
国内免费 | 1篇 |
出版年
2022年 | 8篇 |
2021年 | 12篇 |
2020年 | 9篇 |
2019年 | 14篇 |
2018年 | 21篇 |
2017年 | 18篇 |
2016年 | 14篇 |
2015年 | 33篇 |
2014年 | 38篇 |
2013年 | 36篇 |
2012年 | 39篇 |
2011年 | 41篇 |
2010年 | 18篇 |
2009年 | 26篇 |
2008年 | 21篇 |
2007年 | 28篇 |
2006年 | 24篇 |
2005年 | 20篇 |
2004年 | 21篇 |
2003年 | 16篇 |
2002年 | 15篇 |
2001年 | 11篇 |
2000年 | 19篇 |
1999年 | 14篇 |
1998年 | 14篇 |
1997年 | 10篇 |
1996年 | 9篇 |
1995年 | 9篇 |
1994年 | 4篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 13篇 |
1984年 | 6篇 |
1983年 | 12篇 |
1982年 | 7篇 |
1979年 | 4篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 7篇 |
1971年 | 6篇 |
1970年 | 3篇 |
1969年 | 6篇 |
排序方式: 共有714条查询结果,搜索用时 31 毫秒
681.
Israel Torres-Castro César N. Cortés-Rubio Guadalupe Sandoval Edmundo Lamoyi Carlos Larralde Leonor Huerta 《In vitro cellular & developmental biology. Animal》2014,50(5):453-463
Cell fusion occurs in physiological and pathological conditions and plays a role in regulation of cell fate. The analysis of cell population dynamics and cell cycle in cell–cell fusion experiments is necessary to determine changes in the quantitative equilibrium of cell populations and to identify potential bystander effects. Here, using cocultures of Jurkat HIV-1 envelope expressing cells and CD4+ cells as a model system and flow cytometry for the analysis, the number, viability, and cell cycle status of the populations participating in fusion were determined. In 3-day cocultures, a sustained reduction of the number of CD4+ cells was observed while they showed high viability and normal cell cycle progression; fusion, but not inhibition of proliferation or death, accounted for their decrease. In contrast, the number of Env+ cells decreased in cocultures due to fusion, death, and an inherent arrest at G1. Most of syncytia formed in the first 6 h of coculture showed DNA synthesis activity, indicating that the efficient recruitment of proliferating cells contributed to amplify the removal of CD4+ cells by syncytia formation. Late in cocultures, approximately 50% of syncytia were viable and a subpopulation still underwent DNA synthesis, even when the recruitment of additional cells was prevented by the addition of the fusion inhibitor T-20, indicating that a population of syncytia may progress into the cell cycle. These results show that the quantitative analysis of cellular outcomes of cell–cell fusion can be performed by flow cytometry. 相似文献
682.
Accessing genetic diversity for crop improvement 总被引:1,自引:0,他引:1
683.
Since liver microsomal cytochrome b5 spontaneously associates with liposomes and membranes by means of its C-terminal hydrophobic domain (HP), chimeric proteins containing HP prepared by genetic fusion might also spontaneously associate with liposomes or cellular membranes. Synthetic DNA corresponding to the hydrophobic domain of cytochrome b5 was enzymatically fused in-frame to cloned DNA corresponding to the C-terminus of the Escherichia coli enzyme, beta-galactosidase. This protein, LacZ:HP, synthesized in E. coli and purified from a crude E. coli membrane extract, was shown to spontaneously associated with liposomes, as does cytochrome b5. Association is rapid and stable in the presence of salt and high pH and the fusion protein behaves as an integral membrane protein. LacZ:HP can be readily and extensively purified from crude extracts by association with liposomes and this procedure may provide a convenient purification scheme for proteins not otherwise readily purified, for example polypeptides from cloned gene fragments to be used for antibody production. These hybrid proteins may represent a new potentially useful class of polypeptides capable of hydrophobic interactions with membranes. 相似文献
684.
Developing taste buds in the anterior mandibular floor of perihatching
chicks were studied by high voltage electron microscopic autoradiography in
order to identify proliferating gemmal cell types. Montaged profiles of 29
taste buds in five cases euthanized between embryonic day 21 and
posthatching day 2 were analyzed after a single [3H]thymidine injection
administered on embryonic day 16, 17 or 18. Results showed that dark cells
comprised 55% of identified (n = 900 cells) and 62% of labeled (n = 568
cells) gemmal cells as compared with light, intermediate, basal or
perigemmal bud cells. Dark cells had both a greater (P < 0.05) number of
labeled cells and a greater amount of label (grains/nucleus) than the other
four bud cell types, irrespective of injection day. The nuclear area
(micron 2) of dark cells was not significantly larger (P > 0.05) than
that of the other gemmal cell types and therefore cannot account for the
greater amount for label in the dark cells. Interestingly, only dark cells
showed a positive correlation (P < 0.003) between amount of label and
nuclear area. Results suggest that, during the perihatching period of
robust cell proliferation, dividing dark cells may give rise primarily, but
not exclusively, to dark cell progeny.
相似文献
685.
686.
Herrera-González Azucena Núñez-López Gema Morel Sandrine Amaya-Delgado Lorena Sandoval Georgina Gschaedler Anne Remaud-Simeon Magali Arrizon Javier 《Applied microbiology and biotechnology》2017,101(13):5223-5234
Applied Microbiology and Biotechnology - Enzymatic fructosylation of organic acceptors other than sugar opens access to the production of new molecules that do not exist in nature. These new... 相似文献
687.
α‐Synuclein stimulation of monoamine oxidase‐B and legumain protease mediates the pathology of Parkinson's disease
下载免费PDF全文
![点击此处可从《The EMBO journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Seong Su Kang Eun Hee Ahn Zhentao Zhang Xia Liu Fredric P Manfredsson Ivette M Sandoval Susov Dhakal P Michael Iuvone Xuebing Cao Keqiang Ye 《The EMBO journal》2018,37(12)
Dopaminergic neurodegeneration in Parkinson's disease (PD) is associated with abnormal dopamine metabolism by MAO‐B (monoamine oxidase‐B) and intracellular α‐Synuclein (α‐Syn) aggregates, called the Lewy body. However, the molecular relationship between α‐Syn and MAO‐B remains unclear. Here, we show that α‐Syn directly binds to MAO‐B and stimulates its enzymatic activity, which triggers AEP (asparagine endopeptidase; legumain) activation and subsequent α‐Syn cleavage at N103, leading to dopaminergic neurodegeneration. Interestingly, the dopamine metabolite, DOPAL, strongly activates AEP, and the N103 fragment of α‐Syn binds and activates MAO‐B. Accordingly, overexpression of AEP in SNCA transgenic mice elicits α‐Syn N103 cleavage and accelerates PD pathogenesis, and inhibition of MAO‐B by Rasagiline diminishes α‐Syn‐mediated PD pathology and motor dysfunction. Moreover, virally mediated expression of α‐Syn N103 induces PD pathogenesis in wild‐type, but not MAO‐B‐null mice. Our findings thus support that AEP‐mediated cleavage of α‐Syn at N103 is required for the association and activation of MAO‐B, mediating PD pathogenesis. 相似文献
688.
689.
690.