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21.
A. Coppa V. Foglietti E. Giovine A. Doria G.P. Gallerano E. Giovenale A. Cetronio C. Lanzieri M. Peroni F. Evangelisti 《Infrared Physics & Technology》2008,51(5):470-472
An active two dimensional near field imaging of a High Electron Mobility Transistor (HEMT) used as THz detector has been performed. The reflective imaging system developed at the ENEA FEL Facility in Frascati has been used to this purpose. This imaging technique has shown to be particularly powerful in resolving various coupling mechanisms of the incident radiation with the device. 相似文献
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Sylvia Marhold Ernst Koller Isabella Meyer Otto S. Wolfbeis 《Fresenius' Journal of Analytical Chemistry》1990,336(2):111-113
Summary A new fluorimetric assay for cationic surfactants is based on their capability of quenching the fluorescence of 8-octadecyloxypyrene-1,3,6-trisulfonate (PTS-18). It is specific for cationic surfactants which can be determined in the 40–400 g concentration range. The method is considered to be advantageous over former methods in that it only requires addition of the sample solution to the fluorophore solution, followed by measurement of fluorescence intensity of the probe. This is in contrast to existing methods where the detergent/dye ion pair has to be extracted before measurement. 相似文献
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Banci L Bertini I Felli IC Sarrou J 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2005,172(2):191-200
CH(alpha) residual dipolar couplings (Deltardc's) were measured for the oxidized cytochrome b562 from Escherichia coli as a result of its partial self-orientation in high magnetic fields due to the anisotropy of the overall magnetic susceptibility tensor. Both the low spin iron (III) heme and the four-helix bundle fold contribute to the magnetic anisotropy tensor. CH(alpha) Deltardc's, which span a larger range than the analogous NH values (already available in the literature) sample large space variations at variance with NH Deltardc's, which are largely isooriented within alpha helices. The whole structure is now significantly refined with the chemical shift index and CH(alpha) Deltardc's. The latter are particularly useful also in defining the molecular magnetic anisotropy parameters. It is shown here that the backbone folding can be conveniently and accurately determined using backbone restraints only, which include NOEs, hydrogen bonds, residual dipolar couplings, pseudocontact shifts, and chemical shift index. All these restraints are easily and quickly determined from the backbone assignment. The calculated backbone structure is comparable to that obtained by using also side chain restraint. Furthermore, the structure obtained with backbone only restraints is, in its whole, very similar to that obtained with the complete set of restraints. The paramagnetism based restraints are shown to be absolutely relevant, especially for Deltardc's. 相似文献
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Peptide-based enzyme-linked immunosorbent assays have been found to be enough sensitive and specific for the diagnosis of human immunodeficiency virus specific antibodies in acquired immunodeficiency syndrome patients. This review provides an overview of the most important peptides developed for use as synthetic antigens in immunodiagnosis of HIV-infected patients. In particular, many studies have been devoted to discriminate between the two retroviruses HIV-1 and HIV-2, as well as different subtypes. 相似文献
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In this paper we consider the Bounded Length Median Path Problem which can be defined as the problem of locating a path-shaped facility that departures from a given origin and arrives at a given destination in a network. The length of the path is assumed to be bounded by a given maximum length. At each vertex of the network (customer-point) the demand for the service is given and the cost to reach the closest service-point is computed. The objective is to minimize the sum of these costs over all the customer-points in the network. 相似文献
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2-Propylbenzo[d][1,3,2]dioxaborole and related derivatives are shown to initiate a range of radical reactions under mild conditions. 相似文献