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991.
In our efforts to develop new approaches to treat and prevent human vascular diseases, we report herein our results on the proliferation and migration of human smooth muscles cells (SMCs) and endothelial cells (ECs) using epigallocatechin-3-gallate conjugated gold nanoparticles (EGCg-AuNPs) as possible alternatives to drug coated stents. Detailed in vitro stability studies of EGCg-AuNPs in various biological fluids, affinity and selectivity towards SMCs and ECs have been investigated. The EGCg-AuNPs showed selective inhibitory efficacy toward the migration of SMCs. However, the endothelial cells remained unaffected under similar experimental conditions. The cellular internalization studies have indicated that EGCg-AuNPs internalize into the SMCs and ECs within short periods of time through laminin receptor mediated endocytosis mode. Favorable toxicity profiles and selective affinity toward SMCs and ECs suggest that EGCg-AuNPs may provide attractive alternatives to drug coated stents and therefore offer new therapeutic approaches in treating cardiovascular diseases.  相似文献   
992.
This paper describes the creation of two models of the steady‐state fluid dynamic processes occurring in a high‐recirculation airlift reactor. The new models were created to provide information to assist in the design of a reactor, in particular considering the selection of parameters to adjust in order to achieve a steady state solution. The modelling of two‐phase flow of air and water in small‐scale airlift bioreactors is considered. This modelling was applied to the high‐recirculation airlift reactor process. New computer simulations were created and tests performed to evaluate the new models. The results of this evaluation are presented. The evaluation showed that variation of the superficial gas velocity or the simultaneous variation of the downcomer and riser diameters could be used to produce a steady‐state design solution. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
993.
In recent years, substantial consideration within the food industry has been aimed at the development of food‐grade nanoemulsions (NE) as promising systems for encapsulating, stabilizing, and delivering bioactive compounds. Although numerous studies have revealed the critical potential of NE, there are still several challenges to overcome them. These include the extensive amounts of synthetic emulsifiers needed for NE formulation, which can potentially be toxic for human health. The interest in safety, and natural emulsifiers have stimulated food manufacturers to develop "label‐friendly" formulations by replacing synthetic emulsifiers with natural alternatives. This review represents a critical and comprehensive summary of the application of natural emulsifiers as potential substitutes for synthetic emulsifiers in NE production, with particular emphasis on the newly identified natural emulsifiers. Some recent reports showed the excellent emulsifying properties of various natural emulsifier extracted from natural resources, to produce NE, and therefore, might be generalized for further industrial applications. Future trends are encouraged to identify novel natural emulsifiers from industrial food by‐products that may demonstrate highly effective emulsifiers.  相似文献   
994.
Growing cells on surfaces bearing nanotopography signals makes many changes in cell gene expression and downstream changes in phenotype but the mechanisms for this have, so far, been obscure. We consider the question of whether the topography directly nanoimprints onto the cell as a component of the signal transduction system. Evidence we present from SEM, TEM and fluorescence detection of the arrangements of cytoskeletal components is consistent with the possibility that cells are nanoimprinted by the substrate. The nanoprinting does not interfere with integrin-mediated adhesion processes and may perhaps work through them. Time-lapse video studies of cells moving from areas bearing nanotopography to flat areas and vice versa suggests that the nanoimprinting takes 1-6h to appear on the cell and a similar time to disappear when the cell moves from a flat surface to a nanotopographic one and back. This nanoprinting of cells would appear to be a novel type of cell signalling.  相似文献   
995.
996.
Cognitive performance exhibits patterns of trial-to-trial variation that can be described as 1/f or pink noise, as do repeated measures of locomotor performance. Although cognitive and locomotor performances are known to interact when performed concurrently, it is not known whether concurrent performance affects the tasks’ pink noise dynamical structure. In this study, participants performed a cognitive task (repeatedly producing a temporal interval) and a motor task (walking on a treadmill) in single- and dual-task conditions. In single-task conditions both tasks exhibited pink noise structure. For concurrent performance the dynamical structure of the cognitive task changed reliably in the direction of white (random) noise. The dynamical structure of locomotion remained pink noise. The change in cognitive dynamics occurred despite no reliable changes in mean or standard deviation measures for either task. The results suggest a functional reorganization of cognitive dynamics supporting successful task performance in dual-task conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
997.

A strong difference in the physico-chemical properties of the plastic lubricants studied was found in this study through pressure drop, thermal analysis, vibration damping, texture hardness and rheological measurements. Oxidation aging of the lubricant sample containing rapeseed oil additive was proposed. Its higher thermal sensitivity was simultaneously confirmed by frequency dependent complex shear modulus of elasticity measurements as well as by rheological testing. Rapeseed oil modified lubricant showed a higher decrease in both storage and moduli losses due to a temperature increase from 16 to 26 ° C compared to the rapeseed oil free sample. Simultaneously, the flow curves were shifted to the higher shear stresses (for plastic lubricant without rapeseed oil additive) typical for rheopectic fluids. For the rapeseed oil modified lubricant, the flow curves were shifted to the lower shear stresses, indicating its thixotropic fluid behaviour. The synthetic lubricant without rapeseed oil additive exhibited higher dissipative rheological behaviour as reflected by decreasing first resonance frequency peak position compared to the rapeseed oil modified lubricant as obtained from vibration damping measurements. It was found that the synthetic lubricant exhibited better vibration damping properties and mechanical energy dissipation into heat due to its higher viscous friction than the rapeseed oil modified lubricant under experimental conditions.

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998.
999.
Service Middleware for Self-Managing Large-Scale Systems   总被引:1,自引:0,他引:1  
Resource management poses particular challenges in large-scale systems, such as server clusters that simultaneously process requests from a large number of clients. A resource management scheme for such systems must scale both in the in the number of cluster nodes and the number of applications the cluster supports. Current solutions do not exhibit both of these properties at the same time. Many are centralized, which limits their scalability in terms of the number of nodes, or they are decentralized but rely on replicated directories, which also reduces their ability to scale. In this paper, we propose novel solutions to request routing and application placement- two key mechanisms in a scalable resource management scheme. Our solution to request routing is based on selective update propagation, which ensures that the control load on a cluster node is independent of the system size. Application placement is approached in a decentralized manner, by using a distributed algorithm that maximizes resource utilization and allows for service differentiation under overload. The paper demonstrates how the above solutions can be integrated into an overall design for a peer-to-peer management middleware that exhibits properties of self-organization. Through complexity analysis and simulation, we show to which extent the system design is scalable. We have built a prototype using accepted technologies and have evaluated it using a standard benchmark. The testbed measurements show that the implementation, within the parameter range tested, operates efficiently, quickly adapts to a changing environment and allows for effective service differentiation by a system administrator.  相似文献   
1000.
Authors of the current study examined the contributions of four factors on the advisory working alliance from counseling psychology advisees' perspectives: (a) anxious attachment orientation, (b) avoidant attachment orientation, (c) frequency of advising meetings, and (d) method of pairing an advisee to a faculty advisor. Participants were 109 counseling psychology doctoral students who were enrolled in American Psychological Association-accredited programs. A mixed model analysis indicated that lower attachment-anxiety scores, lower attachment-avoidance scores, and advisees choosing advisors each contributed to higher advisory working alliance scores. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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