246 resultados para Self-Avoiding Walks
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OBJECTIVES: This study sought to investigate whether self-expanding stents are more effective than balloon-expandable stents for reducing stent malapposition at 3 days after implantation in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. BACKGROUND: Acute myocardial infarction is associated with vasoconstriction and large thrombus burden. Resolution of vasoconstriction and thrombus load during the first hours to days after primary percutaneous coronary intervention may lead to stent undersizing and malapposition, which may subsequently lead to stent thrombosis or restenosis. In addition, aggressive stent deployment may cause distal embolization. METHODS: Eighty patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention were randomized to receive a self-expanding stent (STENTYS, STENTYS SA, Paris, France) (n = 43) or a balloon-expandable stent (VISION, Abbott Vascular, Santa Clara, California; or Driver, Medtronic, Minneapolis, Minnesota) (n = 37) at 9 European centers. The primary endpoint was the proportion of stent strut malapposition at 3 days after implantation measured by optical coherence tomography. Secondary endpoints included major adverse cardiac events (cardiac death, recurrent myocardial infarction, emergent bypass surgery, or clinically driven target lesion revascularization). RESULTS: At 3 days after implantation, on a per-strut basis, a lower rate of malapposed stent struts was observed by optical coherence tomography in the self-expanding stent group than in the balloon-expandable group (0.58% vs. 5.46%, p < 0.001). On a per-patient basis, none of the patients in the self-expanding stent group versus 28% in the balloon-expandable group presented ≥5% malapposed struts (p < 0.001). At 6 months, major adverse cardiac events were 2.3% versus 0% in the self-expanding and balloon-expandable groups, respectively (p = NS). CONCLUSIONS: Strut malapposition at 3 days is significantly lower in ST-segment elevation myocardial infarction patients allocated to self-expanding stents when than in those allocated to balloon-expandable stents. The impact of this difference on clinical outcome and the risk of late stent thrombosis need to be evaluated further. (Randomized Comparison Between the STENTYS Self-expanding Coronary Stent and a Balloon-expandable Stent in Acute Myocardial Infarction [APPOSITION II]; NCT01008085).
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We tested whether individuals can exert control over the expression of attitudinal ambivalence and if this control is exerted with self-presentational concerns. Using the self-presentation paradigm, participants reported more ambivalence about Genetically Modified Organisms ("GMO") in a standard and a self-enhancement (present yourself positively) conditions than in a self-depreciation (present yourself negatively) condition, on both felt (Experiments 1a and 2a) and potential ambivalence, in its cognitive (Experiments 1b and 2b) and affective components (Experiments 1b and 2c). The role of ambivalent attitudes in conveying a positive social value was confirmed by the fact that the above effect was found on a controversial attitude object (GMOs) but the opposite appeared on a non-controversial one (e.g. tooth brushing, a truism; Experiment 3). Such a reversal was obtained by directly manipulating the perception of controversy on GMOs (Experiment 4). Attitudinal ambivalence may thus serve an adaptive function, i.e. achieving a positive social value.
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Antonio Damasio's works have brought emotions into line with current trends in neuroscience. They are conceived as the addition, to a perception, of the somatic effects it has induced. Nevertheless, this continuous and relatively steady process of body perception has also led to the less-known hypothesis of the "neural self." Behind the explicit and apparently contradictory reference to William James and Sigmund Freud, there lies a common source: Theodor Meynert's conception of a "cortical self." Our aim is to enlight a stream unified around what we call here "cerebral self." The Self is thus considered as the cerebral projection or presentation of the body. The specificity of this notion is particularly highlighted by its confrontation to the closely, yet disembodied, notion of "cerebral subject.". Pour citer cette revue : Psychiatr. Sci. Hum. Neurosci. 9 (2011).
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Although urothelial progenitor-like cells have been described in the human urinary tract, the existence of stem cells remains to be proven. Using a culture system that favors clonogenic epithelial cell growth, we evaluated and characterized clonal human urothelial cells. We isolated human urothelial cells that were clonogenic, capable of self-renewal and could develop into fully differentiated urothelium once re-implanted into the subcapsular space of nude mice. In addition to final urothelial cell differentiation, spontaneous formation of bladder-like microstructures was observed. By examining an epithelial stem cell signature marker, we found p63 to correlate with the self-renewal capacity of the isolated human urothelial clonal populations. Since a clinically relevant, long-term model for functional reconstitution of human cells does not exist, we sought to establish a culture method for porcine urothelial cells in a clinically relevant porcine model. We isolated cells from porcine ureter, urethra and bladder that were clonogenic and capable of self-renewal and differentiation into fully mature urothelium. In conclusion, we could isolate human and porcine cell populations, behaving as urothelial stem cells and showing clonogenicity, self-renewal and, once re-implanted, morphological differentiation.
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Tumor-initiating cells with stem cell properties are believed to sustain the growth of gliomas, but proposed markers such as CD133 cannot be used to identify these cells with sufficient specificity. We report an alternative isolation method purely based on phenotypic qualities of glioma-initiating cells (GICs), avoiding the use of molecular markers. We exploited intrinsic autofluorescence properties and a distinctive morphology to isolate a subpopulation of cells (FL1(+)) from human glioma or glioma cultures. FL1(+) cells are capable of self-renewal in vitro, tumorigenesis in vivo and preferentially express stem cell genes. The FL1(+) phenotype did not correlate with the expression of proposed GIC markers. Our data propose an alternative approach to investigate tumor-initiating potential in gliomas and to advance the development of new therapies and diagnostics.
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Summary Aims.-To explore whether fatigue-induced changes in spring-mass behavior during a 5000m self-paced run varied according to the runner's training status. Methods and results.-Six highly- and six well-trained triathletes completed a 5000m time trial. Running velocity and vertical stiffness decreased significantly (P < 0.05) with fatigue, whereas leg stiffness remained constant. None of these parameters displayed a significant interaction between fatigue and training status, despite vertical stiffness being higher (P < 0.05) in highly-trained triathletes. Conclusions.-During a 5000m self-paced run, impairments in leg-spring behavior that occur with fatigue are not affected by athletes' training status. © 2009 Elsevier Masson SAS. All rights reserved. Objectifs.-Étudier, chez des athlètes de niveaux différents, les modifications de raideur mécanique liées à l'apparition de la fatigue lors d'une course de 5000 m. Synthèse des faits.-Six triathlètes très entraînés et six autres bien entraînés ont réalisé une course de 5000 m. La vitesse de course et la raideur verticale diminuaient significativement (p < 0,05) avec la fatigue, alors que la raideur de la jambe demeurait inchangée. Aucune interaction entre la fatigue et le niveau d'entraînement n'a été détectée, malgré des niveaux de raideur verticale plus élevés (p < 0,05) chez les sujets les mieux entraînés.
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Hepatitis C virus (HCV) is an important human pathogen, persistently infecting more than 170 million individuals worldwide. Studies of the HCV life cycle have become possible with the development of cell culture systems supporting the replication of viral RNA and the production of infectious virus. However, the exact functions of individual proteins, especially of nonstructural protein 4B (NS4B), remain poorly understood. NS4B triggers the formation of specific, vesicular membrane rearrangements, referred to as membranous webs, which have been reported to represent sites of HCV RNA replication. However, the mechanism of vesicle induction is not known. In this study, a panel of 15 mutants carrying substitutions in the highly conserved NS4B C-terminal domain was generated. Five mutations had only a minor effect on replication, but two of them enhanced assembly and release of infectious virus. Ten mutants were replication defective and used for selection of pseudoreversions. Most of the pseudoreversions also localized to the highly conserved NS4B C-terminal domain and were found to restore replication competence upon insertion into the corresponding primary mutant. Importantly, pseudoreversions restoring replication competence also restored heterotypic NS4B self-interaction, which was disrupted by the primary mutation. Finally, electron microscopy analyses of membrane alterations induced by NS4B mutants revealed striking morphological abnormalities, which were restored to wild-type morphology by the corresponding pseudoreversion. These findings demonstrate the important role of the C-terminal domain in NS4B self-interaction and the formation of functional HCV replication complexes.
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Purpose This study aimed to identify self-perception variables which may predict return to work (RTW) in orthopedic trauma patients 2 years after rehabilitation. Methods A prospective cohort investigated 1,207 orthopedic trauma inpatients, hospitalised in rehabilitation, clinics at admission, discharge, and 2 years after discharge. Information on potential predictors was obtained from self administered questionnaires. Multiple logistic regression models were applied. Results In the final model, a higher likelihood of RTW was predicted by: better general health and lower pain at admission; health and pain improvements during hospitalisation; lower impact of event (IES-R) avoidance behaviour score; higher IES-R hyperarousal score, higher SF-36 mental score and low perceived severity of the injury. Conclusion RTW is not only predicted by perceived health, pain and severity of the accident at the beginning of a rehabilitation program, but also by the changes in pain and health perceptions observed during hospitalisation.
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Introduction: Human experience takes place in the line of mental-time (MT) created through imagination of oneself in different time-points in past or future (self-projection in time). Here we manipulated self-projection in MT not only with respect to one's life-events but also with respect to one's faces from different past and future time-points. Methods: We here compared MTT with respect to one's facial images from different time points in past and future (study 1: MT-faces) as well as with respect to different past and future life events (study 2: MT-events). Participants were asked to make judgments about past and future face images and past and future events from three different time-points: the present (Now), eight years earlier (Past) or eight years later (Future). In addition, as a control task participants were asked to make recognition judgments with respect to faces and memory-related judgments with respect to events without changing their habitual self-location in time. Behavioral measures and functional magnetic resonance imaging (fMRI) activity after subtraction of recognition and memory related activities show both absolute MT and relative MT effects for faces and events, signifying a fundamental brain mechanism of MT, disentangled from episodic memory functions. Results: Behavioural and event-related fMRI activity showed three independent effects characterized by (1) similarity between past recollection and future imagination, (2) facilitation of judgments related to the future as compared to the past, and (3) facilitation of judgments related to time-points distant from the present. These effects were found with respect to faces and events suggesting that the brain mechanisms of MT are independent of whether actual life episodes have to be re-/pre-experienced and recruited a common cerebral network including the medial-temporal, precuneus, inferior-frontal, temporo-parietal, and insular cortices. Conclusions: These behavioural and neural data suggest that self-projection in time is a crucial aspect of MT, relying on neural structures encoding memory, mental imagery, and self. Furthermore our results emphasize the idea that mental temporal processing is more strongly directed to future prediction than to past recollection.