全文获取类型
收费全文 | 57篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
58篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 4篇 |
2012年 | 3篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 6篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有58条查询结果,搜索用时 15 毫秒
1.
Emilie M. M. Santos Wiro J. Niessen Albert J. Yoo Olvert A. Berkhemer Ludo F. Beenen Charles B. Majoie Henk. A. Marquering MR CLEAN investigators 《PloS one》2016,11(1)
Background and Purpose
In acute ischemic stroke (AIS) management, CT-based thrombus density has been associated with treatment success. However, currently used thrombus measurements are prone to inter-observer variability and oversimplify the heterogeneous thrombus composition. Our aim was first to introduce an automated method to assess the entire thrombus density and then to compare the measured entire thrombus density with respect to current standard manual measurements.Materials and Method
In 135 AIS patients, the density distribution of the entire thrombus was determined. Density distributions were described using medians, interquartile ranges (IQR), kurtosis, and skewedness. Differences between the median of entire thrombus measurements and commonly applied manual measurements using 3 regions of interest were determined using linear regression.Results
Density distributions varied considerably with medians ranging from 20.0 to 62.8 HU and IQRs ranging from 9.3 to 55.8 HU. The average median of the thrombus density distributions (43.5 ± 10.2 HU) was lower than the manual assessment (49.6 ± 8.0 HU) (p<0.05). The difference between manual measurements and median density of entire thrombus decreased with increasing density (r = 0.64; p<0.05), revealing relatively higher manual measurements for low density thrombi such that manual density measurement tend overestimates the real thrombus density.Conclusions
Automatic measurements of the full thrombus expose a wide variety of thrombi density distribution, which is not grasped with currently used manual measurement. Furthermore, discrimination of low and high density thrombi is improved with the automated method. 相似文献2.
Pericellular proteolysis by leukocytes and tumor cells on substrates: focal activation and the role of urokinase-type plasminogen activator 总被引:12,自引:1,他引:11
Kindzelskii AL Amhad I Keller D Zhou MJ Haugland RP Garni-Wagner BA Gyetko MR Todd RF Petty HR 《Histochemistry and cell biology》2004,121(4):299-310
Previous studies have shown that the urokinase-type plasminogen activator receptor (uPAR) is localized to the adherence sites of leukocytes and tumor cells suggesting that pericellular proteolysis may accompany focal activation of adherence. To assess for focused pericellular proteolytic activity, we prepared two-dimensional substrates coated with FITC-casein or Bodipy FL-BSA. These molecules are poorly fluorescent, but become highly fluorescent after proteolytic degradation. Fluorescent peptide products were observed at adherence sites of stationary human neutrophils and at lamellipodia of polarized neutrophils. During cell migration, multiple regions of proteolysis appeared sequentially beneath the cell. Similarly, proteolytic action was restricted to adherence sites of resting HT1080 tumor cells but localized to the invadopodia of active cells. Using an extracellular fluorescence quenching method, we demonstrate that these fluorescent peptide products are extracellular. The uPA/uPAR system played an important role in the observed proteolytic activation. Plasminogen activator inhibitor-1 significantly reduced focal proteolysis. Sites of focal proteolysis matched the membrane distribution of uPAR. When uPA was dissociated from uPAR by acid washing, substantially reduced pericellular proteolysis was found. uPAR-negative T47D tumor cells did not express significant levels of substrate proteolysis. However, transfectant clones expressing uPAR (for example, T47D-26) displayed high levels of fluorescence indicating proteolysis at adherence sites. To provide further evidence for the role of the uPA/uPAR system in pericellular proteolysis, peritoneal macrophages from uPA knock-out (uPA–/–) and control (uPA+/+) mice were studied. Pericellular proteolysis was dramatically reduced in uPA-negative peritoneal macrophages. Thus, we have: (1) developed a novel methodology to detect pericellular proteolytic function, (2) demonstrated focused activation of proteolytic enzymatic activity in several cell types, (3) demonstrated its usefulness in real-time studies of cell migration, and (4) showed that the uPA/uPAR system is an important contributor to focal pericellular proteolysis. 相似文献
3.
Towards a framework for the evolutionary genomics of Kinetoplastids: what kind of data and how much?
The current status of kinetoplastids phylogeny and evolution is discussed in view of the recent progresses on genomics. Some ideas on a potential framework for the evolutionary genomics of kinetoplastids are presented. 相似文献
4.
5.
6.
Carlier SG Coen VL Sabaté M Kay IP Ligthart JM Van Der Giessen WJ Levendag PC Bom K Serruys PW 《International journal of cardiovascular interventions》2000,3(1):3-12
Intracoronary brachytherapy has recently emerged as a new therapy to prevent restenosis. Initial experimental work was achieved in animal models and the results were assessed by histomorphometry. Initial clinical trials used angiography to guide dosimetry and to assess efficacy. Intravascular ultrasound (IVUS) permits tomographic examination of the vessel wall, elucidating the true morphology of the lumen and transmural components, which cannot be investigated on the lumenogram obtained by angiography. This paper reviews the use of IVUS in the clinical studies of brachytherapy conducted to date. IVUS allows clinicians to make a thorough assessment of the remodeling of the vessel and appears to have a major role to play in facilitating understanding of the underlying mechanisms of action in this emerging field. The authors propose that state-of-the-art IVUS techniques should be employed to further knowledge of the mechanisms of action of brachytherapy in atherosclerotic human coronary arteries. 相似文献
7.
Juliana S Bernardes Alberto MR Dávila Vítor S Costa Gerson Zaverucha 《BMC bioinformatics》2007,8(1):435
Background
Remote homology detection is a challenging problem in Bioinformatics. Arguably, profile Hidden Markov Models (pHMMs) are one of the most successful approaches in addressing this important problem. pHMM packages present a relatively small computational cost, and perform particularly well at recognizing remote homologies. This raises the question of whether structural alignments could impact the performance of pHMMs trained from proteins in the Twilight Zone, as structural alignments are often more accurate than sequence alignments at identifying motifs and functional residues. Next, we assess the impact of using structural alignments in pHMM performance. 相似文献8.
Urokinase plasminogen activator (uPA) is a serine protease that catalyzes the conversion of plasminogen to plasmin. The plasminogen/plasmin system includes the uPA, its receptor, and its inhibitor (plasminogen activator inhibitor-1). Interactions between these molecules regulate cellular proteolysis as well as adhesion, cellular proliferation, and migration, processes germane to the pathogenesis of lung injury and neoplasia. In previous studies, we found that uPA regulates cell surface fibrinolysis by regulating its own expression as well as that of the uPA receptor and plasminogen activator inhibitor-1. In this study, we found that uPA alters expression of the tumor suppressor protein p53 in Beas2B airway epithelial cells in both a time- and concentration-dependent manner. These effects do not require uPA catalytic activity because the amino-terminal fragment of uPA lacking catalytic activity was as potent as two chain active uPA. Single chain uPA also enhanced p53 expression to the same extent as intact two chain active uPA and the amino-terminal fragment. Pretreatment of cells with anti-beta1 integrin antibody blocked uPA-induced p53 expression. uPA-induced p53 expression occurs without increased p53 mRNA expression. However, uPA induced oncoprotein MDM2 in a concentration-dependent manner. uPA-induced p53 expression does not require activation of tyrosine kinases. Inactivation of protein-tyrosine phosphatase SHP-2 inhibits both basal and uPA-induced p53 expression. Plasmin did not alter uPA-mediated p53 expression. The induction of p53 expression by exposure of lung epithelial cells to uPA is a newly recognized pathway by which urokinase may influence the proliferation of lung epithelial cells. This pathway could regulate pathophysiologic alterations of p53 expression in the setting of lung inflammation or neoplasia. 相似文献
9.
10.
Danilo ML Prado Fabiana B Benatti Ana L de Sá-Pinto Ana P Hayashi Bruno Gualano Rosa MR Pereira Adriana ME Sallum Eloisa Bonfá Clovis A Silva Hamilton Roschel 《Arthritis research & therapy》2013,15(2):R46