全文获取类型
收费全文 | 361篇 |
免费 | 36篇 |
出版年
2022年 | 2篇 |
2021年 | 11篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 12篇 |
2014年 | 16篇 |
2013年 | 21篇 |
2012年 | 25篇 |
2011年 | 18篇 |
2010年 | 24篇 |
2009年 | 10篇 |
2008年 | 12篇 |
2007年 | 21篇 |
2006年 | 20篇 |
2005年 | 12篇 |
2004年 | 21篇 |
2003年 | 11篇 |
2002年 | 12篇 |
2001年 | 10篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1975年 | 6篇 |
1974年 | 2篇 |
1971年 | 3篇 |
1970年 | 4篇 |
1969年 | 2篇 |
1967年 | 3篇 |
1936年 | 1篇 |
排序方式: 共有397条查询结果,搜索用时 15 毫秒
71.
Specific Interaction of the Unmodified Bacteriocin Lactococcin 972 with the Cell Wall Precursor Lipid II
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Beatriz Martínez Tim Bttiger Tanja Schneider Ana Rodríguez Hans-Georg Sahl Imke Wiedemann 《Applied microbiology》2008,74(15):4666-4670
Lactococcin 972 (Lcn972) is a nonlantibiotic bacteriocin that inhibits septum biosynthesis in Lactococcus lactis rather than forming pores in the cytoplasmic membrane. In this study, a deeper analysis of the molecular basis of the mode of action of Lcn972 was performed. Of several lipid cell wall precursors, only lipid II antagonized Lcn972 inhibitory activity in vivo. Likewise, Lcn972 only coprecipitated with lipid II micelles. This bacteriocin inhibited the in vitro polymerization of lipid II by the recombinant S. aureus PBP2 and the addition to lipid II of the first glycine catalyzed by FemX. These experiments demonstrate that Lcn972 specifically interacts with lipid II, the substrate of both enzymes. In the presence of Lcn972, nisin pore formation was partially hindered in whole cells. However, binding of Lcn972 to lipid II could not compete with nisin in lipid II-doped 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) liposomes, possibly indicating a distinct binding site. The existence of a putative cotarget for Lcn972 activity is discussed in the context of its narrow inhibitory spectrum and the localized action at the division septum. To our knowledge, this is the first unmodified bacteriocin that binds to the cell wall precursor lipid II. 相似文献
72.
Simon Lumb Sarah J. Fleischer Annika Wiedemann Capucine Daridon Alison Maloney Anthony Shock Thomas Dörner 《Journal of cell communication and signaling》2016,10(2):143-151
The binding of antigen to the B cell receptor (BCR) results in a cascade of signalling events that ultimately drive B cell activation. Uncontrolled B cell activation is regulated by negative feedback loops that involve inhibitory co-receptors such as CD22 and CD32B that exert their functions following phosphorylation of immunoreceptor tyrosine-based inhibition motifs (ITIMs). The CD22-targeted antibody epratuzumab has previously been shown to inhibit BCR-driven signalling events, but its effects on ITIM phosphorylation of CD22 and CD32B have not been properly evaluated. The present study therefore employed both immunoprecipitation and flow cytometry approaches to elucidate the effects of epratuzumab on direct phosphorylation of key tyrosine (Tyr) residues on both these proteins, using both transformed B cell lines and primary human B cells. Epratuzumab induced the phosphorylation of Tyr822 on CD22 and enhanced its co-localisation with SHP-1. Additionally, in spite of high basal phosphorylation of other key ITIMs on CD22, in primary human B cells epratuzumab also enhanced phosphorylation of Tyr807, a residue involved in the recruitment of Grb2. Such initiation events could explain the effects of epratuzumab on downstream signalling in B cells. Finally, we were able to demonstrate that epratuzumab stimulated the phosphorylation of Tyr292 on the low affinity inhibitory Fc receptor CD32B which would further attenuate BCR-induced signalling. Together, these data demonstrate that engagement of CD22 with epratuzumab leads to the direct phosphorylation of key upstream inhibitory receptors of BCR signalling and may help to explain how this antibody modulates B cell function. 相似文献
73.
Nonproductive kappa immunoglobulin genes: recombinational abnormalities and other lesions affecting transcription, RNA processing, turnover, and translation. 总被引:24,自引:7,他引:17
下载免费PDF全文
![点击此处可从《Molecular and cellular biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
74.
75.
Summary This review is an attempt to define a group of storage diseases which exhibit signs and symptoms of both the mucopolysaccharidoses and sphingolipidoses. Lacking some of the characteristics of the mucopolysaccharidoses while resembling to this group of thesaurismoses in other respects, these diseases frequently were described as Hurler variants.In Gm1 gangliosidosis types I and II, Fucosidosis, Mannosidosis and in infantile Sulfatidosis with mucopolysacchariduria enzyme defects have been identified which are thought to be causally related to the diseases. In others the pathogenesis is unknown. They are tentatively named Mucolipidosis I, II and III.Supported by grants Wi 80 and Sp 63/2 of the Deutsche Forschungsgemeinschaft. 相似文献
76.
77.
78.
79.
80.
Philipp Wiedemann Jean S. Guez Hans B. Wiegemann Florian Egner Juan C. Quintana Diego Asanza‐Maldonado Marcos Filipaki Jeff Wilkesman Christian Schwiebert Jean P. Cassar Pascal Dhulster Hajo Suhr 《Biotechnology and bioengineering》2011,108(12):2884-2893
Current state of the art to determine the viability of animal cell suspension cultures is based on sampling and subsequent counting using specific staining assays. We demonstrate for the first time a noninvasive in situ imaging cytometry capable of determining the statistics of a morphologic transition during cell death in suspension cultures. To this end, we measure morphometric inhomogeneity—defined as information entropy—in cell in situ micrographs. We found that the cells are partitioned into two discrete entropy states broadened by phenotypical variability. During the normal course of a culture or by inducing cell death, we observe the transition of cells between these states. As shown by comparison with ex situ diagnostics, the entropy transition happens before or while the cytoplasmatic membrane is loosing its ability to exclude charged dyes. Therefore, measurement of morphometric inhomogeneity constitutes a noninvasive assessment of viability in real time. Biotechnol. Bioeng. 2011;108: 2884–2893. © 2011 Wiley Periodicals, Inc. 相似文献