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71.
Frank R. Fronczek Nadia N. St Luce Robert M. Strongin 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(12):1423-1425
The space group of the title compound, C7H7BO3, previously reported to be P, is properly Cc. There is no disorder of the formyl group or in the H atoms of the B(OH)2 group. Molecules lie on approximate twofold axes and are related by approximate centers, which relate all but the formyl O atom and boronic acid H atoms. The B—O distances are 1.363 (2) and 1.370 (2) Å. 相似文献
72.
E. Rexer J. Enß E. Einecke L. R. Luce F. Mylius A. Lecrenier E. W. Washburn M. Fulda J. D. Cauwood J. H. Davidson und V. Dimbleby 《Fresenius' Journal of Analytical Chemistry》1932,88(7-8):303-309
Ohne Zusammenfassung 相似文献
73.
Nelly Barrau Roland Becker Eric Dubach Robert Luce 《Comptes Rendus Mathematique》2012,350(15-16):789-792
In this note, we propose a modification of the NXFEM proposed in Hansbo and Hansbo (2002) [4] for the elliptic interface problem. It leads to a robust method not only with respect to the mesh-interface geometry, but also with respect to the diffusion parameters. 相似文献
74.
Dehaen G Eliseeva SV Kimpe K Laurent S Vander Elst L Muller RN Dehaen W Binnemans K Parac-Vogt TN 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(1):293-302
A ditopic chelating ligand (H(6)4) that bears catechol and diethylenetriamine-N,N,N',N',N'-pentaacetate (DTPA) has been designed and shown to specifically bind lanthanide(III) ions at the DTPA core ([Ln(H(2)4)(H(2)O)](-)) and further self-assemble with titanium(IV), thereby giving rise to the formation of a supramolecular metallostar complex with a lanthanide(III)-to-titanium(IV) ratio of 3:1, [(Ln4)(3)Ti(H(2)O)(3)](5-) (Ln=La, Eu, Gd). The efficacy of the metallostar complex as a potential bimodal optical/magnetic resonance imaging (MRI) agent has been evaluated. Nuclear magnetic relaxation dispersion (NMRD) measurements for the [(Gd4)(3)Ti(H(2)O)(3)](5-) complex have demonstrated an enhanced r(1) relaxivity that corresponds to 36.9 s(-1) mM(-1) per metallostar molecule at 20 MHz and 310 K, which is a result of a decreased tumbling rate. The ability of the complex to bind to human serum albumin (HSA) was also examined by relaxometric measurements. In addition, upon UV irradiation the [(Gd4)(3)Ti(H(2)O)(3)](5-) complex exhibits broad-band green emission in the range 400-750 nm with a maximum at 490 nm. Taking into account the high relaxivity and luminescence properties, the [(Gd4)(3)Ti(H(2)O)(3)](5-) complex is a good lead compound for the development of efficient bimodal contrast agents. 相似文献
75.
He M Johnson RJ Escobedo JO Beck PA Kim KK St Luce NN Davis CJ Lewis PT Fronczek FR Melancon BJ Mrse AA Treleaven WD Strongin RM 《Journal of the American Chemical Society》2002,124(18):5000-5009
The colorimetric properties of resorcinarene solutions had not been investigated since Baeyer's initial synthesis. We recently reported that solutions containing resorcinarene macrocycles develop color upon heating or standing. In the presence of saccharides, these solutions exhibit significant color changes which are easily seen. We herein present strong evidence that the solution color is due to macrocycle ring opening and oxidation. The optical responses to saccharides are due to complexation of the sugar with the acyclic chromophores. We apply these mechanistic insights toward the challenging problem of the visual detection of neutral oligosaccharides by simple chromogens. In addition, we also report the first single-crystal X-ray crystal structure determination of a rarely observed "diamond" resorcinarene stereoisomer. 相似文献
76.
Novel chromophoric compound 1 promotes the HPLC postcolumn detection of mono- and oligosaccharides. The detection of chromatographic peaks in the visible region for glucose, fructose, maltodextrins, sialic acid, and a ganglioside can be accomplished with a standard UV-vis detector. The use of selective, reversible binding agents in automated HPLC assays should allow for improved monitoring of specific analytes as well as material recovery. [structure: see text] 相似文献
77.
Neural coding and psychophysical discrimination data 总被引:1,自引:0,他引:1
78.
Kubícek V Rudovský J Kotek J Hermann P Vander Elst L Muller RN Kolar ZI Wolterbeek HT Peters JA Lukes I 《Journal of the American Chemical Society》2005,127(47):16477-16485
A new macrocyclic DOTA-like ligand (BPAMD) for bone imaging and therapy containing a monoamide bis(phosphonic acid) bone-seeking group was designed and synthesized. Its lanthanide(III) complexes were prepared and characterized by 1H and 31P NMR spectroscopy. The Gd(III)-BPAMD complex was investigated in detail by 1H and 17O relaxometric studies to inspect parameters relevant for its potential application as an MRI contrast agent. Sorption experiments were conducted with Gd(III) and Tb(III) complexes using hydroxyapatite (HA) as a model of bone surface. Very effective uptake of the Gd-BPAMD complex by the HA surface was observed in NMR experiments. Radiochemical studies with the (160Tb-BPAMD)-HA system proved the sorption to be remarkably fast and strong on one hand and fully reversible on the other hand. The strong (Gd-BPAMD)-HA interaction was also supported by 1H NMRD measurements in the presence of a hydroxyapatite slurry, which showed an increase of the rotational correlation time upon adsorption of the complex on the HA surface, resulting in a significant relaxivity enhancement. The amide-bis(phosphonate) moiety is the only factor responsible for the binding of the complex to HA. 相似文献
79.
80.
The procedure for identifying triterpenes in mixtures is based on the simulation of 13C-NMR spectra for probable mixtures and comparison of these with a specialized spectral data bank. The system was designed to facilitate the analysis of complex mixtures of terpenoid compounds. A special matching procedure was developed and its efficiency is discussed. The method is demonstrated for a mixture of five triterpenes isolated from Vernonia cognata. 相似文献