全文获取类型
收费全文 | 478篇 |
免费 | 32篇 |
出版年
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 8篇 |
2018年 | 5篇 |
2017年 | 9篇 |
2016年 | 6篇 |
2015年 | 16篇 |
2014年 | 13篇 |
2013年 | 21篇 |
2012年 | 20篇 |
2011年 | 22篇 |
2010年 | 19篇 |
2009年 | 9篇 |
2008年 | 15篇 |
2007年 | 21篇 |
2006年 | 21篇 |
2005年 | 14篇 |
2004年 | 19篇 |
2003年 | 20篇 |
2002年 | 16篇 |
2001年 | 15篇 |
2000年 | 16篇 |
1999年 | 14篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 3篇 |
1994年 | 9篇 |
1993年 | 5篇 |
1992年 | 17篇 |
1991年 | 18篇 |
1990年 | 7篇 |
1989年 | 14篇 |
1988年 | 15篇 |
1987年 | 9篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 8篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 10篇 |
1974年 | 2篇 |
1970年 | 6篇 |
1966年 | 1篇 |
排序方式: 共有510条查询结果,搜索用时 15 毫秒
41.
Abete P Testa G Ferrara N De Santis D Capaccio P Viati L Calabrese C Cacciatore F Longobardi G Condorelli M Napoli C Rengo F 《American journal of physiology. Heart and circulatory physiology》2002,282(6):H1978-H1987
Ischemic preconditioning (PC) has been proposed as an endogenous form of protection against-ischemia reperfusion injury. We have shown that PC does not prevent postischemic dysfunction in the aging heart. This phenomenon could be due to the reduction of cardiac norepinephrine release, and it has also been previously demonstrated that age-related decrease of norepinephrine release from cardiac adrenergic nerves may be restored by caloric restriction. We investigated the effects on mechanical parameters of PC against 20 min of global ischemia followed by 40 min of reperfusion in isolated hearts from adult (6 mo) and "ad libitum"-fed and food-restricted senescent (24 mo) rats. Norepinephrine release in coronary effluent was determined by high-performance liquid chromatography. Final recovery of percent developed pressure was significantly improved after PC in adult hearts versus unconditioned controls (85.2 +/- 19% vs. 51.5 +/- 10%, P < 0.01). The effect of PC on developed pressure recovery was absent in ad libitum-fed rats, but it was restored in food-restricted senescent hearts (66.6 +/- 13% vs. 38.3 +/- 11%, P < 0.05). Accordingly, norepinephrine release significantly increased after PC in both adult and in food-restricted senescent hearts, and depletion of myocardial norepinephrine stores by reserpine abolished the PC effect in both adult and in food-restricted senescent hearts. We conclude that PC reduces postischemic dysfunction in the hearts from adult and food-restricted but not in ad libitum-fed senescent rats. Despite the possibility of multiple age-related mechanisms, the protection afforded by PC was correlated with increased norepinephrine release, and it was blocked by reserpine in both adult and food-restricted senescent hearts. Thus caloric restriction may restore PC in the aging heart probably via increased norepinephrine release. 相似文献
42.
43.
ANGPTL3 stimulates endothelial cell adhesion and migration via integrin alpha vbeta 3 and induces blood vessel formation in vivo 总被引:12,自引:0,他引:12
Camenisch G Pisabarro MT Sherman D Kowalski J Nagel M Hass P Xie MH Gurney A Bodary S Liang XH Clark K Beresini M Ferrara N Gerber HP 《The Journal of biological chemistry》2002,277(19):17281-17290
The angiopoietin family of secreted factors is functionally defined by the C-terminal fibrinogen (FBN)-like domain, which mediates binding to the Tie2 receptor and thereby facilitates a cascade of events ultimately regulating blood vessel formation. By screening expressed sequence tag data bases for homologies to a consensus FBN-like motive, we have identified ANGPTL3, a liver-specific, secreted factor consisting of an N-terminal coiled-coil domain and the C-terminal FBN-like domain. Co-immunoprecipitation experiments, however, failed to detect binding of ANGPTL3 to the Tie2 receptor. A molecular model of the FBN-like domain of ANGPTL3 was generated and predicted potential binding to integrins. This hypothesis was experimentally confirmed by the finding that recombinant ANGPTL3 bound to alpha(v)beta(3) and induced integrin alpha(v)beta(3)-dependent haptotactic endothelial cell adhesion and migration and stimulated signal transduction pathways characteristic for integrin activation, including phosphorylation of Akt, mitogen-activated protein kinase, and focal adhesion kinase. When tested in the rat corneal assay, ANGPTL3 strongly induced angiogenesis with comparable magnitude as observed for vascular endothelial growth factor-A. Moreover, the C-terminal FBN-like domain alone was sufficient to induce endothelial cell adhesion and in vivo angiogenesis. Taken together, our data demonstrate that ANGPTL3 is the first member of the angiopoietin-like family of secreted factors binding to integrin alpha(v)beta(3) and suggest a possible role in the regulation of angiogenesis. 相似文献
44.
45.
Acute graft-versus-host disease does not require alloantigen expression on host epithelium 总被引:21,自引:0,他引:21
Alloantigen expression on host antigen-presenting cells (APCs) is essential to initiate graft-versus-host disease (GvHD); therefore, alloantigen expression on host target epithelium is also thought to be essential for tissue damage. We tested this hypothesis in mouse models of GvHD using bone-marrow chimeras in which either major histocompatibility complex class I or class II alloantigen was expressed only on APCs. We found that acute GvHD does not require alloantigen expression on host target epithelium and that neutralization of tumor necrosis factor-alpha and interleukin-1 prevents acute GvHD. These results pertain particularly to CD4-mediated GvHD but also apply, at least in part, to CD8-mediated GvHD. These results challenge current paradigms about the antigen specificity of GvHD effector mechanisms and confirm the central roles of both host APCs and inflammatory cytokines in acute GvHD. 相似文献
46.
Proteins from bovine tissues and biological fluids: defining a reference electrophoresis map for liver,kidney, muscle,plasma and red blood cells 总被引:1,自引:0,他引:1
Talamo F D'Ambrosio C Arena S Del Vecchio P Ledda L Zehender G Ferrara L Scaloni A 《Proteomics》2003,3(4):440-460
A number of high resolution two-dimensional electrophoresis (2-DE) reference maps for bovine tissues and biological fluids have been determined for animals in basal state. Among the 1863 distinct protein features detected in samples of liver, kidney, muscle, plasma and red blood cells, 509 species were identified and associated to 209 different genes. Difficulties in the identification were related to the poorly characterized Bos taurus genome and were solved by a combined matrix-assisted laser desorption/ionisation-mass spectrometry and liquid chromatography-electrospray ionization tandem mass spectrometry approach. The experimental output allowed us to establish a 2-DE database accessible through the World Wide Web network at the URL address (http://www.iabbam.na.cnr.it/Biochem). These reference maps may serve as a tool in future veterinary medical studies aimed at the evaluation of changes in protein repertoire for altered animal physiological conditions and infectious diseases, to the definition of molecular markers for novel diagnostic kits and vaccines, as well as the characterization of protein modifications in bovine materials following technological processes used in the food industry. 相似文献
47.
A repressor sequence in the juxtamembrane domain of Flt-1 (VEGFR-1) constitutively inhibits vascular endothelial growth factor-dependent phosphatidylinositol 3'-kinase activation and endothelial cell migration
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)
Gille H Kowalski J Yu L Chen H Pisabarro MT Davis-Smyth T Ferrara N 《The EMBO journal》2000,19(15):4064-4073
Vascular endothelial growth factor (VEGF) has two highly homologous tyrosine kinase receptors: Flt-1 (VEGFR-1) and KDR (VEGFR-2). KDR is strongly phosphorylated on tyrosines and can transmit mitogenic and motogenic signals following VEGF binding, while Flt-1 is markedly less effective in mediating such functions. To dissect the regions that account for the differences between the two receptors, we generated a series of chimeric Flt-1-KDR molecules. We found that the juxtamembrane region of Flt-1 prevents key signaling functions. When the juxtamembrane region of Flt-1 is replaced by that of KDR, Flt-1 becomes competent to mediate endothelial cell migration and phosphatidylinositol 3'-kinase activation in response to VEGF. Further mutational analysis shows that a short divergent sequence is responsible for such repressor function. However, mutant Flt-1 receptors lacking this sequence do not transmit effective proliferative signals, suggesting that this receptor function is regulated separately. These results define a novel functional domain that serves to repress Flt-1 activity in endothelial cells. 相似文献
48.
49.
High affinity RGD-binding sites at the plasma membrane of
Arabidopsis thaliana
links the cell wall 总被引:6,自引:0,他引:6
Hervé Canut Antoine Carrasco Jean-Philippe Galaud Catherine Cassan Huguette Bouyssou Natalio Vita Pascual Ferrara Rafael Pont-Lezica 《The Plant journal : for cell and molecular biology》1998,16(1):63-71
The heptapeptide Tyr-Gly- Arg-Gly-Asp- Ser-Pro containing the sequence Arg-Gly-Asp (RGD – the essential structure recognised by animal cells in substrate adhesion molecules) was tested on epidermal cells of onion and cultured cells of Arabidopsis upon plasmolysis. Dramatic changes were observed on both types of cells following treatment: on onion cells, Hechtian strands linking the cell wall to the membrane were lost, while Arabidopsis cells changed from concave to convex plasmolysis. A control heptapeptide Tyr-Gly-Asp-Gly-Arg-Ser-Pro had no effect on the shape of plasmolysed cells. Protoplasts isolated from Arabidopsis cells agglutinate in the presence of ProNectinF, a genetically engineered protein of 72 kDa containing 13 RGD sequences: several protoplasts may adhere to a single molecule of ProNectinF. The addition of the RGD-heptapeptide disrupted the adhesion between the protoplasts. Purified plasma membrane from Arabidopsis cells exhibits specific binding sites for the iodinated RGD-heptapeptide. The binding is saturable, reversible, and two types of high affinity sites (Kd1 1 nM, and Kd2 40 nM) can be discerned. Competitive inhibition by several structurally related peptides and proteins noted the specific requirement for the RGD sequence. Thus, the RGD-binding activity of Arabidopsis fulfils the adhesion features of integrins, i.e. peptide specificity, subcellular location, and involvement in plasma membrane-cell wall attachments. 相似文献
50.
Methods for surveillance of fetal alcohol syndrome: The fetal alcohol syndrome surveillance network II (FASSNetII) – Arizona,Colorado, New York, 2009 ‐ 2014
下载免费PDF全文
![点击此处可从《Birth defects research. Part A, Clinical and molecular teratology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Leslie A. O'Leary Linnette Ortiz April Montgomery Deborah J. Fox Christopher Cunniff Margaret Ruttenber April Breen Sydney Pettygrove Don Klumb Charlotte Druschel Jaime L. Frías Luther K. Robinson Jacquelyn Bertrand Kelly Ferrara Maureen Kelly Suzanne M. Gilboa F. John Meaney for the FASSNetII 《Birth defects research. Part A, Clinical and molecular teratology》2015,103(3):196-202