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71.
The presence of emotional stimuli results in a central/peripheral tradeoff effect in memory: memory for central details is enhanced at the cost of peripheral items. It has been assumed that emotion-modulated differences in memory are the result of differences in attention, but this has not been tested directly. The present experiment used eye movement monitoring as an index of overt attention allocation and mediation analysis to determine whether differences in attention were related to subsequent memory. Participants viewed negative and neutral scenes surrounded by three neutral objects and were then given a recognition memory test. The results revealed evidence in support of a central/peripheral tradeoff in both attention and memory. However, contrary with previous assumptions, whereas attention partially mediated emotion-enhanced memory for central pictures, it did not explain the entire relationship. Further, although centrally presented emotional stimuli led to decreased number of eye fixations toward the periphery, these differences in viewing did not contribute to emotion-impaired memory for specific details pertaining to the periphery. These findings suggest that the differential influence of negative emotion on central versus peripheral memory may result from other cognitive influences in addition to overt visual attention or on postencoding processes. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
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Using receiver operating characteristics, the authors examined outcome predictors (variables associated with outcome regardless of treatment) and moderators (variables identifying subgroups with differential treatment effectiveness) in the Multimodal Treatment Study of Children with Attention-Deficit/Hyperactivity Disorder (ADHD; MTA). Treatment response was determined using parent- and teacher-reported ADHD and oppositional defiant symptoms, with levels near or within the normal range indicating excellent response. Among 9 baseline child and family characteristics, none predicted but 3 moderated treatment response. In medication management and combined treatments, parental depressive symptoms and severity of child ADHD were associated with decreased rates of excellent response; when these 2 characteristics were present, below-average child IQ was an additional moderator. No predictors or moderators emerged for behavioral and community comparison treatments. The authors discuss conceptual and clinical implications of research on treatment moderators. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Experimental results are presented on the mechanisms of tensile cyclic fatigue crack growth in an A1203-33-vol%-SiC-whisker composite at 1400°C. The ceramic composite exhibits subcritical fatigue crack propagation at stress-intensity-fator values far below the fracture toughness. The fatigue characterized by the stressintensity-factor range, ΔK, and crack propagation rates are found to be strongly sensitive to the mean stress (load ratio) and the frequency of the fatigue cycle. Detailed transmission electron microscopy of the fatigue crack-tip region, in conjunction with optical microscopy, reveals that the principal mechanism of permanent damage ahead of the advancing crack is the nucleation and growth of interfacial flaws. The oxidation of Sic whiskers in the crack-tip region leads to the formation of a silica-glass phase in the 1400°C air environment. The viscous flow of glass causes debonding of the whisker-matrix interface; the nucleation, growth, and coalescence of interfacial cavities aids in developing a diffuse microcrack zone at the fatigue crack tip. The shielding effect and periodic crack branching promoted by the microcracks result in an apparently benefcial fatigue crack-growth resistance in the A1203—SiC composite, as compared with the unreinforced alumina with a comparable grain size. A comparison of static and cyclic load crack velocities is provided to gain insight into the mechanisms of elevated temperature fatigue in ceramic composites.  相似文献   
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In this study, the efficacy of the Strong African American Families Program (SAAF) was tested. The trial, which included 332 families, indicated that families who participated in SAAF experienced increases over time in regulated, communicative parenting; increases in targeted parenting behaviors, according to youths' reports; and low rates of high-risk behavior initiation among youths. Changes in regulated, communicative parenting mediated the intervention's impact on youths' recognition of changes in parenting, which in turn was linked to changes in youths' high-risk behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Tens of thousands of proteins have been identified as a result of recent large scale genomic and proteomic efforts. With this large influx of new proteins, the formidable task of elucidating their function begins. However, this task becomes more manageable if proteins are divided into families based upon sequence homology, thereby allowing tools for their systematic study to be developed based upon their common structural and mechanistic characteristics. Combinatorial chemistry is ideally suited for the systematic study of protein families because a large amount of diversity can be readily displayed about a common scaffold designed to target a given protein family. Targeted combinatorial libraries have been particularly effective for the study of a ubiquitous family of proteins, the proteases. Substrate-specificity profiles of many proteases have been determined by using combinatorial libraries of appropriately labeled peptides. This specificity information been utilized to identify the physiological protein substrates of these enzymes and has facilitated inhibitor design efforts. Furthermore, combinatorial libraries of small molecules prepared with mechanism-based scaffolds have resulted in the identification of potent, small-molecule inhibitors of numerous proteases. Cell-permeable small-molecule inhibitors identified by these methods have served as powerful chemical tools to study protease function in vitro and in vivo and have served as leads for the development of therapeutic agents.  相似文献   
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Wang H  Ou LM  Suo Y  Yu HZ 《Analytical chemistry》2011,83(5):1557-1563
A method for the convenient detection of lead at the parts-per-billion (ppb)-level has been developed; it uses a conventional compact disc (CD) as the platform for preparing DNAzyme assays and an unmodified optical drive of ordinary desktop/laptop computers as the readout device. In particular, by immobilization of Pb(2+)-specific DNAzyme sensing constructs on the "transparent side" of a conventional CD-R via mild surface reactions, the Pb(2+) concentration can be determined by a free diagnostic program that checks the error distribution on the CD (i.e., it extracts the number of errors in a prerecorded audio file). The reading errors increase monotonically over a wide range of Pb(2+) concentrations (from 10 nM to 1 mM), and the selectivity is confirmed by testing several other divalent cations (Zn(2+), Ba(2+), Mg(2+), Ca(2+), Cu(2+), and Hg(2+)).  相似文献   
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<正> China's listed petroleum and chemical firmsposted their records for the first nine monthsrespectively. The 290 petroleum and chemicalcompanies listed on the nation's equityexchange markets achieved combined operatingrevenue of RMB3.05 trillion in the pastthree quarters,up 35% year-on-year. The netprofits aggregated to RMB184.8 billion,up20% from a year earlier.The top three oil giants in China all hadsatisfactory performances with growth inrevenues,net profit and production.  相似文献   
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