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61.
Reflection and transmission of traveling and evanescent waves by a layer of material with a negative index of refraction (NIM) is studied by means of the Fresnel coefficients. We derive their values in the “NIM limit”, and we show that this limit is consistent with the exact solution. It is also indicated that simply substituting the negative values of the relative permittivity and permeability of the NIM material into the exact solution leads to incorrect results for evanescent waves. 相似文献
62.
63.
Henk J.A.M. Heijmans Batrice Pesquet-Popescu Gemma Piella 《Applied and Computational Harmonic Analysis》2005,18(3):252-281
In this paper, we propose a technique for building adaptive wavelets by means of an extension of the lifting scheme. Our scheme comprises an adaptive update lifting step and a fixed prediction lifting step. The adaptivity consists hereof that the system can choose between two different update filters, and that this choice is triggered by the local gradient of the original signal. If the gradient is large (in some seminorm sense) it chooses one filter, if it is small the other. We derive necessary and sufficient conditions for the invertibility of such an adaptive system for various scenarios. Furthermore, we present some examples to illustrate our theoretical results. 相似文献
64.
This paper is concerned with the coordination of inventory control in three-echelon serial and distribution systems under
decentralized control. All installations in these supply chains track echelon inventories. Under decentralized control the
installations will decide upon base stock levels that minimize their own inventory costs. In general these levels do not coincide
with the optimal base stock levels in the global optimum of the chain under centralized control. Hence, the total cost under
decentralized control is larger than under centralized control.
To remove this cost inefficiency, two simple coordination mechanisms are presented: one for serial systems and one for distribution
systems. Both mechanisms are initiated by the most downstream installation(s). The upstream installation increases its base
stock level while the downstream installation compensates the upstream one for the increase of costs and provides it with
a part of its gain from coordination. It is shown that both coordination mechanisms result in the global optimum of the chain
being the unique Nash equilibrium of the corresponding strategic game. Furthermore, all installations agree upon the use of
these mechanisms because they result in lower costs per installation. The practical implementation of these mechanisms is
discussed. 相似文献
65.
We introduce the class of ordinal games with a potential, which are characterized by the absence of weak improvement cycles,
the same condition used by Voorneveld and Norde (1997) for ordinal potential games. 相似文献
66.
Kamphuis MM Johnston AP Such GK Dam HH Evans RA Scott AM Nice EC Heath JK Caruso F 《Journal of the American Chemical Society》2010,132(45):15881-15883
Targeted delivery of drugs to specific cells allows a high therapeutic dose to be delivered to the target site with minimal harmful side effects. Combining targeting molecules with nanoengineered drug carriers, such as polymer capsules, micelles and polymersomes, has significant potential to improve the therapeutic delivery and index of a range of drugs. We present a general approach for functionalization of low-fouling, nanoengineered polymer capsules with antibodies using click chemistry. We demonstrate that antibody (Ab)-functionalized capsules specifically bind to colorectal cancer cells even when the target cells constitute less than 0.1% of the total cell population. This precise targeting offers promise for drug delivery applications. 相似文献
67.
Mark Eggink Maikel Wijtmans Ansgar Kretschmer Jeroen Kool Henk Lingeman Iwan J. P. de Esch Wilfried M. A. Niessen Hubertus Irth 《Analytical and bioanalytical chemistry》2010,397(2):665-675
Based on the template of a recently introduced derivatization reagent for aldehydes, 4-(2-(trimethylammonio)ethoxy)benzeneaminium
dibromide (4-APC), a new derivatization agent was designed with additional features for the analysis and screening of biomarkers
of lipid peroxidation. The new derivatization reagent, 4-(2-((4-bromophenethyl)dimethylammonio)ethoxy)benzenaminium dibromide
(4-APEBA) contains a bromophenethyl group to incorporate an isotopic signature to the derivatives and to add additional fragmentation
identifiers, collectively enhancing the abilities for detection and screening of unknown aldehydes. Derivatization can be
achieved under mild conditions (pH 5.7, 10 °C). By changing the secondary reagent (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide
instead of sodium cyanoborohydride), 4-APEBA is also applicable to the selective derivatization of carboxylic acids. Synthesis
of the new label, exploration of the derivatization conditions, characterization of the fragmentation of the aldehyde and
carboxylic acid derivatives in MS/MS, and preliminary applications of the labeling strategy for the analysis of aldehydes
in urine and plasma are described. 相似文献
68.
Ferry Heus Martin Giera Gerdien E. de Kloe Dick van Iperen Joost Buijs Tariq T. Nahar August B. Smit Henk Lingeman Iwan J. P. de Esch Wilfried M. A. Niessen Hubertus Irth Jeroen Kool 《Analytical and bioanalytical chemistry》2010,398(7-8):3023-3032
One way to profile complex mixtures for receptor affinity is to couple liquid chromatography (LC) on-line to biochemical detection (BCD). A drawback of this hyphenated screening approach is the relatively high consumption of sample, receptor protein and (fluorescently labeled) tracer ligand. Here, we worked toward minimization of sample and reagent consumption, by coupling nano-LC on-line to a light-emitting diode (LED) based capillary confocal fluorescence detection system capable of on-line BCD with low-flow rates. In this fluorescence detection system, a capillary with an extended light path (bubble cell) was used as a detection cell in order to enhance sensitivity. The technology was applied to a fluorescent enhancement bioassay for the acetylcholine binding protein, a structural analog of the extracellular ligand-binding domain of neuronal nicotinic acetylcholine receptors. In the miniaturized setup, the sensitive and low void volume LED-induced confocal fluorescence detection system operated in flow injection analysis mode allowing the measurement of IC50 values, which were comparable with those measured by a conventional plate reader bioassay. The current setup uses 50 nL as injection volume with a carrier flow rate of 400 nL/min. Finally, coupling of the detection system to gradient reversed-phase nano-LC allowed analysis of mixtures in order to identify the bioactive compounds present by injecting 10 nL of each mixture. 相似文献
69.
Janssen SA Vos H van Kempen EE Breugelmans OR Miedema HM 《The Journal of the Acoustical Society of America》2011,129(4):1953-1962
Recently, it has been suggested that the annoyance of residents at a given aircraft noise exposure level increases over the years. The objective of the present study was to verify the hypothesized trend and to identify its possible causes. To this end, the large database used to establish earlier exposure-response relationships on aircraft noise was updated with original data from several recent surveys, yielding a database with data from 34 separate airports. Multilevel grouped regression was used to determine the annoyance response per airport, after which meta-regression was used to investigate whether study characteristics could explain the heterogeneity in annoyance response between airports. A significant increase over the years was observed in annoyance at a given level of aircraft noise exposure. Furthermore, the type of annoyance scale, the type of contact, and the response percentage were found to be sources of heterogeneity. Of these, only the scale factor could statistically account for the trend, although other findings rule it out as a satisfactory explanation. No evidence was found for increased self-reported noise sensitivity. The results are of importance to the applicability of current exposure-annoyance relationships for aircraft noise and provide a basis for decisions on whether these need to be updated. 相似文献
70.
Margriet V. D. Z. Park Iseult Lynch Sonia Ram��rez-Garc��a Kenneth A. Dawson Liset de la Fonteyne Eric Gremmer Wout Slob Jacob J. Bried�� Andreas Elsaesser C. Vyvyan Howard Henk van Loveren Wim H. de Jong 《Journal of nanoparticle research》2011,13(12):6775-6787
The biological response to four well-characterized amorphous silica nanoparticles was investigated in RAW 264.7 macrophages in view of their potential application as drug carriers to sites of inflammation. All silica nanoparticles-induced cell membrane damage, reduced metabolic activity, generated ROS and released various cytokines, but to different extents. Two silica nanoparticles of 34 nm (A and B) with different zetapotentials were more cytotoxic than (aggregated) 11 and 248 nm nanoparticles, while cytokines were mostly induced by the (aggregated) 11 nm and only one of the 34 nm nanoparticles (34A). The results indicate that specific silica nanoparticles may have counterproductive effects, for example when used as carriers of anti-inflammatory drugs. The physicochemical properties determining the response of nanoparticles vary for different responses, implying that a screening approach for the safe development of nanoparticles needs to consider the role of combinations of (dynamic) physicochemical properties and needs to include multiple toxicity endpoints. 相似文献