全文获取类型
收费全文 | 210篇 |
免费 | 15篇 |
专业分类
225篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 10篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 15篇 |
2014年 | 13篇 |
2013年 | 13篇 |
2012年 | 20篇 |
2011年 | 12篇 |
2010年 | 13篇 |
2009年 | 7篇 |
2008年 | 9篇 |
2007年 | 13篇 |
2006年 | 9篇 |
2005年 | 11篇 |
2004年 | 9篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有225条查询结果,搜索用时 15 毫秒
91.
92.
Appropriate cell number and organ size in a multicellular organism are determined by coordinated cell growth, proliferation, and apoptosis. Disruption of these processes can cause cancer. Recent studies have identified the Large tumor suppressor (Lats)/Warts (Wts) protein kinase as a key component of a pathway that controls the coordination between cell proliferation and apoptosis. Here we describe growth inhibitory functions for a Mob superfamily protein, termed Mats (Mob as tumor suppressor), in Drosophila. Loss of Mats function results in increased cell proliferation, defective apoptosis, and induction of tissue overgrowth. We show that mats and wts function in a common pathway. Mats physically associates with Wts to stimulate the catalytic activity of the Wts kinase. A human Mats ortholog (Mats1) can rescue the lethality associated with loss of Mats function in Drosophila. As Mats1 is mutated in human tumors, Mats-mediated growth inhibition and tumor suppression is likely conserved in humans. 相似文献
93.
Impaired activation of phosphatidylinositol 3-kinase by leptin is a novel mechanism of hepatic leptin resistance in diet-induced obesity 总被引:14,自引:0,他引:14
Huang W Dedousis N Bhatt BA O'Doherty RM 《The Journal of biological chemistry》2004,279(21):21695-21700
Obesity is associated with the development of leptin resistance. However, the effects of leptin resistance on leptin-regulated metabolic processes and the biochemical defects that cause leptin resistance are poorly understood. We have addressed in rats the effect of dietinduced obesity (DIO), a situation of elevated tissue lipid levels, on the well described lipid-lowering effect of leptin in liver, an action that is proposed to be important for the prevention of tissue lipotoxicity and insulin resistance. In addition, we have addressed the role of phosphatidylinositol 3-kinase (PI 3-kinase) in mediating the acute effects of leptin on hepatic lipid levels in lean and DIO animals. A 90-min leptin ( approximately 10 ng/ml) perfusion of isolated livers from lean animals decreased triglyceride levels by 42 +/- 5% (p = 0.006). However, leptin concentrations ranging from approximately 10 to approximately 90 ng/ml had no effect on triglyceride levels in livers from DIO animals. The acute lipid-lowering effect of leptin on livers from lean animals was mediated by a PI 3-kinase-dependent mechanism, because wortmannin and LY294002, the PI 3-kinase inhibitors, blocked the effects of leptin on hepatic triglyceride levels and leptin increased liver PI 3-kinase activity by 183 +/- 6% (p = 0.003) and insulin receptor substrate 1 tyrosine phosphorylation by 185 +/- 30% (p = 0.02) in the absence of PI 3-kinase inhibitors. Contrary to the effects of leptin in lean livers, leptin did not activate PI 3-kinase in livers from DIO rats. These data present evidence for a role for 1). leptin resistance in contributing to the excessive accumulation of tissue lipid in obesity, 2). PI 3-kinase in mediating the acute lipid-lowering effects of leptin in liver, and 3). defective leptin activation of PI 3-kinase as a novel mechanism of leptin resistance. 相似文献
94.
Novel insights regarding the operational characteristics and teleological purpose of the renal Na+-K+-Cl2 cotransporter (NKCC2s) splice variants 下载免费PDF全文
Brunet GM Gagnon E Simard CF Daigle ND Caron L Noël M Lefoll MH Bergeron MJ Isenring P 《The Journal of general physiology》2005,126(4):325-337
The absorptive Na(+)-K(+)-Cl(-) cotransporter (NKCC2) is a polytopic protein that forms homooligomeric complexes in the apical membrane of the thick ascending loop of Henle (TAL). It occurs in at least four splice variants (called B, A, F, and AF) that are identical to one another except for a short region in the membrane-associated domain. Although each of these variants exhibits unique functional properties and distributions along the TAL, their teleological purpose and structural organization remain poorly defined. In the current work, we provide additional insight in these regards by showing in mouse that the administration of either furosemide or an H(2)O-rich diet, which are predicted to alter NKCC2 expression in the TAL, exerts differential effects on mRNA levels for the variants, increasing those of A (furosemide) but decreasing those of F and AF (furosemide or H(2)O). Based on a yeast two-hybrid mapping analysis, we also show that the formation of homooligomeric complexes is mediated by two self-interacting domains in the COOH terminus (residues 671 to 816 and 910 to 1098), and that these complexes could probably include more than one type of variant. Taken together, the data reported here suggest that A, F, and AF each play unique roles that are adapted to specific physiological needs, and that the accomplishment of such roles is coordinated through the splicing machinery as well as complex NKCC2-NKCC2 interactions. 相似文献
95.
An Integrated Proteomic Approach Uncovers Novel Substrates and Functions of the Lon Protease in Escherichia coli 下载免费PDF全文
Jan Arends Marcena Griego Nikolas Thomanek Claudia Lindemann Blanka Kutscher Helmut E. Meyer Franz Narberhaus 《Proteomics》2018,18(13)
Controlling the cellular abundance and proper function of proteins by proteolysis is a universal process in all living organisms. In Escherichia coli, the ATP‐dependent Lon protease is crucial for protein quality control and regulatory processes. To understand how diverse substrates are selected and degraded, unbiased global approaches are needed. We employed a quantitative Super‐SILAC (stable isotope labeling with amino acids in cell culture) mass spectrometry approach and compared the proteomes of a lon mutant and a strain producing the protease to discover Lon‐dependent physiological functions. To identify Lon substrates, we took advantage of a Lon trapping variant, which is able to translocate substrates but unable to degrade them. Lon‐associated proteins were identified by label‐free LC‐MS/MS. The combination of both approaches revealed a total of 14 novel Lon substrates. Besides the identification of known pathways affected by Lon, for example, the superoxide stress response, our cumulative data suggests previously unrecognized fundamental functions of Lon in sulfur assimilation, nucleotide biosynthesis, amino acid and central energy metabolism. 相似文献
96.
Summary Induction of the primitive streak is correlated with specific qualitative and quantitative changes in protein synthesis in the component areas of chick blastoderm. Blastoderm embryos at the initial to intermediate primitive streak stage were labeled with L-[35S] methionine. Radioactively labeled proteins separated by two-dimensional sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis revealed differences in the number and density of spots among the component areas of the epiblast and hypoblast. Protein patterns of the area opaca, marginal zone and central area of the epiblast are very similar qualitatively but show distinct quantitative differences. A comparison between any of the component areas of the epiblast and the hypoblast in chick blastoderm embryos, however, reveals both qualitative and quantitative differences. A protein with a molecular weight of 30,000 unique to the component areas of the epiblast, and proteins with a molecular weight of 22,000 and 37,000 unique to the hypoblast are prominent and seem to be related to the initial appearance of the primitive streak. 相似文献
97.
Alice?E. Davidson Petra Liskova Cerys?J. Evans Lubica Dudakova Lenka Nosková Nikolas Pontikos Hana Hartmannová Kate?ina Hodaňová Viktor Stránecky Zbyněk Kozmík Hannah?J. Levis Nwamaka Idigo Noriaki Sasai Geoffrey?J. Maher James Bellingham Neyme Veli Neil?D. Ebenezer Michael?E. Cheetham Julie?T. Daniels Caroline?M.H. Thaung Katerina Jirsova Vincent Plagnol Martin Filipec Stanislav Kmoch Stephen?J. Tuft Alison?J. Hardcastle 《American journal of human genetics》2016,98(1):75-89
98.
Decreased melanocortin‐4 receptor function conferred by an infrequent variant at the human melanocortin receptor accessory protein 2 gene 下载免费PDF全文
99.
Jana Meiners Martina Reitz Nikolas Rüdiger Jan-Eric Turner Lennart Heepmann Lena Rudolf Wiebke Hartmann Henry J. McSorley Minka Breloer 《PLoS pathogens》2020,16(12)
Parasitic helminths are sensed by the immune system via tissue-derived alarmins that promote the initiation of the appropriate type 2 immune responses. Here we establish the nuclear alarmin cytokine IL-33 as a non-redundant trigger of specifically IL-9-driven and mast cell-mediated immunity to the intestinal parasite Strongyloides ratti. Blockade of endogenous IL-33 using a helminth-derived IL-33 inhibitor elevated intestinal parasite burdens in the context of reduced mast cell activation while stabilization of endogenous IL-33 or application of recombinant IL-33 reciprocally reduced intestinal parasite burdens and increased mast cell activation. Using gene-deficient mice, we show that application of IL-33 triggered rapid mast cell-mediated expulsion of parasites directly in the intestine, independent of the adaptive immune system, basophils, eosinophils or Gr-1+ cells but dependent on functional IL-9 receptor and innate lymphoid cells (ILC). Thereby we connect the described axis of IL-33-mediated ILC2 expansion to the rapid initiation of IL-9-mediated and mast cell-driven intestinal anti-helminth immunity. 相似文献
100.
Nerivânia Nunes Godeiro George Pacheco Shanlin Liu Nikolas Gioia Cipola Waldir Miron Berbel-Filho Feng Zhang Marcus Thomas P. Gilbert Bruno Cavalcante Bellini 《Zoologica scripta》2020,49(3):329-339
Seirinae is one of the most diverse subfamilies of Collembola. To date no detailed phylogeny of Seirinae has been proposed, which leads to difficulties in the understanding of evolutionary patterns regarding this taxon. The main aim of this study is to clarify the phylogenetic relationships within the Neotropical Seirinae, by generating and analysing the mitochondrial genomes of 26 terminal taxa of Entomobryidae, and one species of Paronellidae. Specifically, we first generated Illumina HiSeq 2000 shotgun sequence data from each species, then reconstructed the mitochondrial genome of each species using two methods: MitoZ and MIRA/MITOBim. Using these data, we were able to generate a well-supported phylogeny that combined all the above species as well as three publicly available mitogenomes from other species. Bayesian and maximum likelihood methods were applied using all 13 protein coding genes. In this way, monophyly for the internal groups of Seirinae was obtained based on molecular evidence for the first time, as was the potential validity of three main internal taxa of the subfamily. We furthermore validated that Tyrannoseira is a distinct lineage and propose the elevation of Lepidocyrtinus to genus. Lastly, we anticipate that these newly available mitogenomes will serve as a useful dataset for future studies on the evolution of the Collembola and Hexapoda. 相似文献