Chirality Dependence of Amyloid β Cellular Uptake and a New Mechanistic Perspective

Amyloid β is an inherently disordered peptide that can form diverse neurotoxic aggregates, and its 42-amino-acid isoform is believed to be the agent responsible for Alzheimer's disease (AD). Cellular uptake of the peptide is a pivotal step for it to be able to exert many of its toxic actions. The cellular uptake process is complex, and numerous competing internalization pathways have been proposed. To date, it remains unclear which of the uptake mechanisms are particularly important for the overall process, and improvement of this understanding is needed, so that better molecular AD therapeutics can be designed. Chirality can be used as a unique tool to study this process, because some of the proposed mechanisms are expected to proceed in stereoselective fashion, whereas others are not. To shed light on this important issue, we synthesized fluorescently labeled enantiomers of amyloid β and quantified their cellular uptake, finding that uptake occurs in stereoselective fashion, with a typical preference for the l stereoisomer of ≈5:1. This suggests that the process is predominantly receptor-mediated, with likely minor contributions of non-stereoselective mechanisms.     

Cation exchange resin from sulfonated poly-N-vinylcarbazole–formaldehyde copolymer

A cross-linked copolymer of poly-N-vinylcarbazole and formaldehyde has been sulfonated to yield a cation exchange resin. The resin has been characterized by elemental analysis and by evaluation of total and salt-splitting capacities and pH-metric titration behavior. The resin has improved capacity (ion exchange) relative to other N-vinylcarbazole based resins and behaves as a polymeric dye.     

Evolution, dissolution and reversible generation of gold and silver nanoclusters in micelle by UV-activation

Gold and silver nanoparticles were produced separately by UV photoactivation (with variable flux density) in the presence of nonionic micelle, TX-100. Even their cyano complexes break down in TX-100 under UV and hence dissolution and reevolution of almost monodispersed nanoparticles (∼ 3 nm) are possible.     

Mathematical model of COREX melter gasifier: Part II. Dynamic model

A dynamic model of the COREX melter gasifier is developed to study the transient behavior of the furnace. The effect of pulse disturbance and step disturbance on the process performance has been studied. This study shows that the effect of pulse disturbance decays asymptotically. The step change brings the system to a new steady state after a delay of about 5 hours. The dynamic behavior of the melter gasifier with respect to a shutdown/blow-on condition and the effect of tapping are also studied. The results show that the time response of the melter gasifier is much less than that of a blast furnace.     

Sensitivity analysis and optimal design in charge transport problems

The focus of this paper is the accurate and efficient determination of sensitivities of electrostatic potential and charge density in charge transport problems, and the use of these sensitivities to carry out optimal design. Direct differentiations of the boundary integral formulation of Poisson's equation for charge conservation and of the non-linear partial differential equation for current continuity are carried out to obtain equations satisfied by the sensitivities. Methods for solving the sensitivity equations are discussed. A numerical implementation of the methods is validated through several examples. It is demonstrated that the Design Sensitivity Coefficients (DSCs) of the quantities of interest in charge transport are obtained accurately and that optimal design problems can be solved efficiently using these DSCs.     

Adaptive Cross-Layer Routing Protocol for Optimizing Energy Harvesting Time in WSN

Wireless Personal Communications - Trade-off between energy conservation and efficiency is one of the most important issues in designing Wireless Sensor Network (WSN) based applications. Network...     

The strategic choice to continue outsourcing,switch vendors,or backsource: Do switching costs matter?

IT outsourcing contracts are often discontinued in favor of other alternatives (returning to in-house development, or switching to another vendor). Switching costs are experienced when terminating a business relationship and securing an alternative. We tried to answer the question: do switching costs matter significantly in the strategic choice to continue outsourcing, switch vendors, or backsource? Switching costs were considered, such as those due to IT operations (sunk investment, lost performance, system upgrades, uncertainty, and induction–retraining–performance), personnel-replacement costs (candidate search, and IT/setup), and in-house learning (cognitive/behavioral learning). A field survey was conducted, and, for each of these cost types, the differences between group means across the three groups (outsourcing continuation, vendor switching, and backsourcing) were determined. The findings suggested that customer organizations preferred outsourcing continuation most and backsourcing least when their switching costs were high. However, the relative preference for vendor switching depended on the switching cost type.     

High‐rejection wide‐stopband lowpass filters using signal interference technique

A design of compact, sharp rejection microstrip lowpass filters (LPF) with wide‐stopband is presented by using signal interference technique. The filter parameters can be easily controlled by the characteristic impedances of the configuration. Explicit design equations with graphs are presented. To validate the theoretical prediction, two prototype LPFs are fabricated. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010.     

Usability is more valuable predictor than product personality for product choice in human-product physical interaction

Product personality and product usability are two important factors which can influence consumers' product choice. Published literature are available regarding independent impact of product personality and product usability on product choice but no research has been reported so far for understanding their collective influence on product choice. In addition, which factor between usability and product personality contributing more in product choice is still not clear. Current research thus aimed to bridge these research gaps by establishing inter-relationships among product personality, usability and product choice. To achieve this goal, two separate experiments were conducted. Results of first experiment revealed that products having high product usability also possessed strong product personality. Following second experiment, it was observed that solitary influence of product usability on product choice was more than the standalone influence of product personality in human-product physical interaction. Moreover, it unfolded the fact that product usability mediates the influence of product personality towards product choice. Established interrelationships among product personality, usability and product choice, would help designer and ergonomists to decide how product attributes could be manipulated to enhance product personality and/or product usability to ensure product choice.