Two-dimensional (2D) nanomaterials have attracted a great deal of attention since the discovery of graphene in 2004, due to their intriguing physicochemical properties and wide-ranging applications in catalysis, energy-related devices, electronics and optoelectronics. To maximize the potential of 2D nanomaterials for their technological applications, controlled assembly of 2D nanobulding blocks into integrated systems is critically needed. This mini review summarizes the reported strategies of 2D materials-based assembly into integrated functional nanostructures, from in-situ assembly method to post-synthesis assembly. The applications of 2D assembled integrated structures are also covered, especially in the areas of energy, electronics and sensing, and we conclude with discussion on the remaining challenges and potential directions in this emerging field.
A. D. Baddeley, N. Thomson, and M. Buchanan (1975) suggested that articulatory rehearsal rate determines the amount of verbal material that can be maintained in working memory. In the current study, 12 children with spastic diplegic cerebral palsy (SDCP) and 38 normal children were tested on measures of articulation rate and memory span for 1-, 2-, and 3-syllable words. Across all conditions, articulation rate for the SDCP group was significantly slower than for the normal group; nonetheless, memory span was equivalent for both groups. This finding implies that covert rehearsal proceeded normally for the SDCP group, in spite of decrements in speech rate. Thus, the relationship between overt and covert rehearsal rates differs for children with SDCP compared with normal children. Findings from the current study further suggest that normal speech rates are not necessary for development of normal covert rehearsal rates. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
Lysine-specific demethylase 1 (LSD1) has evolved as a promising therapeutic target for cancer treatment, especially in acute myeloid leukaemia (AML). To approach the challenge of site-specific LSD1 inhibition, we developed an enzyme-prodrug system with the bacterial nitroreductase NfsB (NTR) that was expressed in the virally transfected AML cell line THP1-NTR+. The cellular activity of the NTR was proven with a new luminescent NTR probe. We synthesised a diverse set of nitroaromatic prodrugs that by design do not affect LSD1 and are reduced by the NTR to release an active LSD1 inhibitor. The emerging side products were differentially analysed using negative controls, thereby revealing cytotoxic effects. The 2-nitroimidazolyl prodrug of a potent LSD1 inhibitor emerged as one of the best prodrug candidates with a pronounced selectivity window between wild-type and transfected THP1 cells. Our prodrugs are selectively activated and release the LSD1 inhibitor locally, proving their suitability for future targeting approaches. 相似文献
Screening tools such as the MMSE have been used extensively in driving research studies to determine mild cognitive impairment or dementia. While some studies have shown the MMSE to correlate with driving performance, few studies have shown the predictive validity of the MMSE in determining on-road performance. In a sample of 168 community dwelling older adults, including 20 with Parkinson's disease (PD), the primary objective was to determine the validity of the MMSE to predict pass/fail outcomes of an on-road driving test using receiver operating characteristics curves. The area under the curve (AUC), an index of discriminability, for the total sample was .654, 95% CI = 0.536–0.772, p = .009. Meanwhile, the AUC for the PD group was 0.791, 95% CI = 0.587–0.996, p = .036. The total sample showed statistically significant yet poor predictive validity. However, the PD group showed statistically significant and good predictive validity of the MMSE to predict pass/fail outcomes on the road test, but caution is warranted as the confidence intervals are wide (due to small sample) and the positive and negative predictive values are less than desirable due to the associated error. The findings show that using the current cut-off point of ≤24 on the MMSE is not adequately sensitive to predict on-road performance in both community dwelling older drivers and in drivers with PD. This study offers strong evidence to support the current best practice of not using the MMSE in isolation to predict on-road performance. 相似文献
Sudanese unaccompanied minors were separated from their parents in childhood and lived apart from their families in refugee camps for close to a decade before being resettled in the United States. This phenomenological study examines the refugees’ experiences of living in American foster families after living in peer groups in the camps. Interviews with 18 young adults, 7 years after resettlement, revealed that nearly all of the youth struggled with parental authority initially, and nearly half of them changed placements because of relationship difficulties with their foster parents. Misunderstandings based on cultural differences often exacerbated conflicts. However, 15 of 18 youth currently had a positive relationship with at least 1 foster parent, sometimes with a parent from their second or third placement. Changing foster families is often considered a failure in the child welfare system, but several Sudanese youth reported that having supportive relationships helped them during the acculturation process whether those relationships developed during the first or last placement. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
For production of electrodes for lithium-ion batteries, conductive carbon black (CB) has to be dispersed within the anode and cathode slurry. A sufficient dispersing degree has to be reached in order to ensure the formation of an adequate conductive network within the electrodes. As intermediate product, CB is dispersed in binder solution, prior to addition of active materials. As binder system on anode side carboxymethylcellulose in water is used, whereas on cathode side polyvinylidene fluoride in N-Methyl-2-pyrrolidone is applied. The conductive carbon slurry facilitates the characterization of the slurry properties, based on changes of CB. The structure and amount of conductive carbon black influences the slurry properties decisively. Viscosity increases with increasing CB content, which affects the shear stress within the mixing process. Rheological properties and particle size distributions are investigated over time while dispersing CB with various tip speeds in a dissolver. Dispersion kinetics are described on behalf of an existing model for tip speed variations. Based on the investigations of rheological changes due to varying amount of CB, an extended model enclosing the CB concentration as variable was developed. Using the extended model, particle sizes for new process parameters can be predicted. 相似文献
Self-assembling peptide nanofibrils (PNF) have gained increasing attention as versatile molecules in material science and biomedicine. One important application of PNF is to enhance retroviral gene transfer, a technology that has been central for gene therapy approaches. The best-investigated and commercially available PNF is derived from a 12-mer peptide termed EF-C. The mechanism of transduction enhancement depends on the polycationic surface of EF-C PNF, which bind to the negatively charged membranes of viruses and cells, thereby overcoming electrostatic repulsions and increasing virion attachment and fusion. To better understand how EF-C PNF interact with the cell surface, scanning electron and time-lapse confocal microscopy were performed. The fibrils are found to be actively engaged by cellular protrusions such as filopodia. Consequently, chemical suppression of protrusion formation abrogates fibril binding and virion delivery to the cell surface of immortalized and primary T cells. Vice versa, induction of plasma membrane blebs result in increased fibril binding. Thus, the mechanism of PNF-mediated viral transduction enhancement involves an active engagement of virus-loaded fibrils by cellular protrusions, which may explain its superior performance over soluble transduction enhancers. 相似文献