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51.
The first examples of rotaxanes based on calixarenes threaded by dialkylammonium ions, which also represent the first examples of calixarene-based molecular shuttles, are reported. The base/acid treatment demonstrated that these systems act as molecular shuttles, which move between three sites on the axle. When small OMe groups are appended at the calix[6]arene lower rim an unprecedented inversion of its shuttling direction is observed, which occurs through a cone-to-cone inversion of the macrocycle. 相似文献
52.
We present a method for compressing binary images via monochromatic pattern substitution. Such method has no relevant loss of compression effectiveness if the image is partitioned into up to a thousand blocks, approximately, and each block is compressed independently. Therefore, it can be implemented on a distributed system with no interprocessor communication. In the theoretical context of unbounded parallelism, interprocessor communication is needed. Compression effectiveness has a bell-shaped behaviour which is again competitive with the sequential performance when the highest degree of parallelism is reached. Finally, the method has a speed-up if applied sequentially to an image partitioned into up to 256 blocks. It follows that such speed-up can be applied to a parallel implementation on a small scale system. 相似文献
53.
Bianchi F Giannetto M Mori G D'Agostino G Careri M Mangia A 《Analytical and bioanalytical chemistry》2012,403(8):2411-2418
A molecularly imprinted polymer with trinitrotoluene as the template molecule was synthesized and used as the novel coating for solid-phase microextraction of the nitroaromatic explosive 2,4,6-trinitrotoluene for its selective determination. The fiber was characterized in terms of coating thickness, morphology, intra- and inter-batch repeatability and extraction efficiency. An average thickness of 50 ± 4 μm with a uniform distribution of the coating was obtained. Good performances of the developed procedure in term of both intra-batch and inter-batch repeatability with relative standard deviations <8% were obtained. Finally, detection and quantitation limits in the low nanogram per kilogram levels were achieved proving the superior extraction capability of the developed coating, obtaining gas chromatography-mass spectrometry responses about two times higher than those achieved using commercial devices. 相似文献
54.
Rosa Di Mundo Vincenzo De Benedictis Riccardo d’Agostino 《Applied Surface Science》2009,255(10):5461-5465
In this work the roughening of polystyrene by means of radiofrequency plasmas fed with CF4 has been studied. The effect of the Ar addition to the feed, the input power and the treatment duration has been investigated in terms of etching and fluorination degree. Wettability and reflectance performances of selected textured surfaces, coated with a fluorocarbon film from a C4F8 fed plasma, have been characterized. All the considered surfaces, even those poorly structured, once coated, show slippery superhydrophobicity, while antireflective transparency appears to be limited to precise texturing characteristics. 相似文献
55.
We consider the effects of misalignment in a two-beam interferometer resulting from lateral displacement as well as angular misalignment of the beams. Furthermore, a technique to determine such misalignments is discussed and examples of measurement strategies and expected performance are given. It is found that, when the waist of the beam used to illuminate the interferometer is larger than 0.7 mm (∼1000λ), such an approach allows alignment to be made resulting in a relative interferometric error smaller than 1×10−10 provided that the diffraction effect is fully accounted for. 相似文献
56.
Pietro Tundo Fabio Aricò Guillaume Gauthier Agostino Baldacci 《Comptes Rendus Chimie》2011,14(7-8):652-655
In this work the synthesis of a tricyclic isosorbide derivative in moderate yield directly from the dicarboxymethyl isosorbide in a continuous-flow apparatus is reported. The tricyclic structure has been isolated as pure and fully characterized. This product confirms the potentiality of dimethylcarbonate (DMC) as dehydrating agent also for complicated structure and opens up further investigation and application of DMC chemistry on renewable starting materials. 相似文献
57.
58.
R. Coniglione P. Sapienza R. Alba C. Agodi C. Maiolino A. Del Zoppo M. Colonna G. Bellia P. Finocchiaro V. Greco K. Loukachine E. Migneco P. Piattelli D. Santonocito N. Colonna M. Bruno M. D’Agostino G. Vannini P. F. Mastinu F. Gramegna I. Iori L. Fabbietti A. Moroni G. V. Margagliotti P. M. Milazzo R. Rui Y. Blumenfeld J. A. Scarpaci 《Acta Physica Hungarica A》2002,16(1-4):387-396
Experimental results concerning the 58Ni + 58Ni at 30 MeV/u and 58Ni + 197Au at 30 and 45 MeV/u reactions are presented. The emission mechanism of hard photons has been exploited to get information on the time evolution of the reactions. From the measured hard gamma multiplicity associated to different classes of heavy residues a quantitative estimate of the reaction centrality has been obtained. Moreover, evidence of a prompt Intermediate Mass Fragment (IMF) emission is shown for the Ni + Au reaction at 45 MeV/u for central collisions exploring the correlation function between thermal photons and IMF’s. 相似文献
59.
Irene Izzo Elvira Avallone Agostino Casapullo Francesco De Riccardis 《Tetrahedron》2004,60(26):5587-5593
The synthesis of two potentially anti-inflammatory steroidal hybrid compounds has been accomplished through a 16- and 17-step sequence, respectively, starting from commercially available androst-5-en-3β-ol-17-one. The synthetic strategies are based both on stereoselective side chains elaboration and high yielding functional group transformations. 相似文献
60.
Simon?EatonEmail author Agostino?Pierro 《Monatshefte für Chemie / Chemical Monthly》2005,136(8):1483-1492
Summary. Fatty acid oxidation is usually thought of as being a preferred ATP source during sepsis, as shown by the decrease in respiratory quotient in septic patients and animals. However, fatty acid oxidation may be impaired relative to circulating triglyceride levels, resulting in increased cycling between triglycerides and non-esterified fatty acids. The rate of fatty acid oxidation is critically dependent on the stage of sepsis. Carnitine may be depleted during sepsis by a combination of muscle wasting, erythrocyte haemolysis, decreased tissue uptake, reduced kidney reabsorption of free carnitine, and increased excretion of acyl-carnitines. Whether there may be any beneficial effects of carnitine supplementation during sepsis, is, as yet, uncertain. 相似文献