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311.
Blattman SB Landis GS Knight M Panetta TF Sclafani SJ Burack JH 《The Annals of thoracic surgery》2002,74(1):237-239
Endovascular therapy affords the opportunity to decrease surgical morbidity and improve operative planning in complex penetrating injuries of the chest. In this case report we describe a hemodynamically stable patient with a single gunshot wound to the base of the neck (zone I), with combined vascular and tracheal injuries. We present a novel approach to the repair of this type of injury using combined endovascular and open techniques. 相似文献
312.
Concrete, highly imageable words (e.g. banana) are easier to understand than abstract words for which it is difficult to generate an image (e.g. justice). This effect of concreteness or imageability has been taken by some as evidence for the existence of separable verbal- and image-based semantic systems. Instead, however, effects of concreteness may result from better associations to relevant contextual representations for concrete than for abstract words within a single semantic system. In this study, target words of high and low imageability were preceded by supportive (related) or non-supportive (unrelated) context words. The influence of contextual support on the imageability effect was measured by recording event-related brain potentials (ERPs) to the high and low imageable target words in both context conditions. The topographic distributions of the ERPs elicited by the high versus low imageable target words were found to be different, and this effect was independent of contextual support. These data are consistent with the idea that distinct verbal- and image-based semantic codes exist for word representations, and that as a result, concrete words that are highly imageable can be understood more easily. 相似文献
313.
Learning novel visuomotor tasks requires precise processing and transformation of incoming sensory information to produce accurate motor responses. The present study characterized neural activity associated with sensorimotor processes during novel visuomotor learning. We hypothesized that the acquisition of a visuomotor skill would be accompanied by experience-dependent modulation of sensorimotor cortical activity. Subjects controlled a cursor on a computer screen with a joystick. With the goal to move the cursor to a cued target after a brief delay, the relationship between joystick and cursor movement was manipulated such that joystick movement controlled cursor velocity, not displacement (rate task). Individual trials in this task were further divided into early (rate1) and late (rate2) blocks. Event-related potentials (ERPs) were averaged to target presentation, the cue for movement, and movement onset. Subjects were more accurate after practice in late rate2 compared to early rate1 blocks. ERPs associated with movement onset were larger in amplitude and occurred earlier over centroparietal sites following practice. In contrast, ERPs to the cue to move were enhanced frontocentrally initially and diminished with practice. The results suggest that practice on a novel visuomotor task is associated with changes in frontoparietal networks involved in motor preparation and sensorimotor integration. Specifically, practice-related enhancement of movement-related ERPs supports experience-dependent alterations in the network subserving motor preparation. 相似文献
314.
Dendritic cells,antigen distribution and the initiation of primary immune responses to self and non-self antigens 总被引:2,自引:0,他引:2
Immunity or tolerance are determined through the bone marrow-derived, antigen-presenting cells, dendritic cells (DC). Stimulation of lymphocytes by different types of DC, DC at different stages of maturity and DC producing and responding to different growth factors modulate immune responses. Innate receptors for foreign or self antigens provide scope in DC for discrimination between different antigenic stimuli. DC also transfer processed antigens to other DC. We propose that DC do not stimulate responses to antigens in their own environment but only to antigens acquired from other DC, providing a mechanism for discriminating between environmental and non-environmental antigens. 相似文献
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318.
Anthony Suruda Thomas J Burns Stacey Knight J Michael Dean 《BMC health services research》2005,5(1):29
Background
It is estimated that approximately half of emergency department (ED) usage in the U.S. and other developed countries is for non-urgent conditions and that this usage is related to availability, social, and economic factors. We examined pediatric ED usage in a U.S. state with respect to income, health insurance status, types of medical conditions, and whether introduction of managed care affected utilization by Medicaid children. 相似文献319.
Recovery from substance abuse and mental health disorders (dual-diagnosis) requires time, hard work and a broad array of coping skills. Empirical evidence has demonstrated the buffering role of social support in stressful situations. This paper investigates the associations among social support (including dual-recovery mutual aid), recovery status and personal well-being in dually-diagnosed individuals (N = 310) using cross-sectional self-report data. Persons with higher levels of support and greater participation in dual-recovery mutual aid reported less substance use and mental health distress and higher levels of well-being. Participation in mutual aid was indirectly associated with recovery through perceived levels of support. The association between mutual aid and recovery held for dual-recovery groups but not for traditional, single-focus self-help groups. The important role of specialized mutual aid groups in the dual recovery process is discussed. 相似文献
320.
Alastair E Cribb M Joy Knight Dagny Dryer Judy Guernsey Kimberly Hender Marvin Tesch Tarek M Saleh 《Cancer epidemiology, biomarkers & prevention》2006,15(3):551-558
Estrogen and its metabolites are believed to play important roles in breast cancer. The influence of genetic polymorphisms in the enzymes responsible for formation and disposition of estrogen on breast cancer risk may shed light on the importance of estrogen metabolites in this disease. However, for such studies to be valid, it is important to correctly identify the enzymes involved in estrogen bioactivation. Therefore, we assessed the human cytochrome P450-dependent oxidation of estrone using substrate concentrations that more closely approximate the maximum expected concentrations in breast tissue. The in vitro metabolism of estrone by recombinant human cytochrome P450 enzymes and human liver microsomes was studied. The formation of estrone metabolites (2-hydroxyestrone, 4-hydroxyestrone, and 16alpha-hydroxyestrone) was monitored by high-performance liquid chromatography. 2-Hydroxyestrone formation was catalyzed predominantly by CYP1A2, CYP1A1, and CYP1B1 enzymes; 4-hydroxyestrone formation was catalyzed predominantly by CYP1B1, CYP1A2, and CYP1A1 enzymes; and 16alpha-hydroxyestrone formation was catalyzed predominantly by CYP2C19, CYP1A1, and CYP3A5. This study confirms the important role of members of the CYP1 family in the 2-hydroxylation and 4-hydroxylation of estrone, but the enzymes identified as responsible for the 16alpha-hydroxylation of estrone are different from those previously identified. The relative importance of these enzymes in vivo would depend on the specific tissue expression of the enzymes. These enzymes are all known to be genetically variant in the human population, and additional studies to assess the role CYP1A2, CYP2C19, and CYP3A5 in breast cancer risk are indicated. 相似文献