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71.
The sensitivity to decomposition of the nitric oxide (NO) donor ion, 1-[2-(carboxylato)pyrrolidin-1-yl]diazen-1-ium-1,2-diolate (PROLI/NO), complicates direct electrophilic substitution to form useful prodrug derivatives. A modified general synthetic approach involving 1-[2-(hydroxymethyl)pyrrolidin-1-yl]diazen-1-ium-1,2-diolate ion (structure A, above) was used to prepare several PROLI/NO prodrugs including the previously inaccessible O2-vinyl derivative, V-PROLI/NO. Metabolism of V-PROLI/NO by liver microsomes enriched in human cytochrome P450 isoforms was demonstrated. 相似文献
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73.
We present experimental studies of interacting excitable and oscillatory catalytic particles in well-stirred and spatially distributed systems. A number of distinct paths to synchronized oscillatory behavior are described. We present an example of a Kuramoto type transition in a well-stirred system with a collective rhythm emerging on increasing the number density of oscillatory particles. Groups of spatially distributed oscillatory particles become entrained to a common frequency by organizing centers. Quorum sensing type transitions are found in populations of globally and locally coupled excitable particles, with a sharp transition from steady state to fully synchronized behavior at a critical density or group size. 相似文献
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75.
Vladimir G. Beylin Norman L. Colbry Anne B. Giordani Om P. Goel Donald R. Johnson Robert L. Leeds Boguslawa Leja Edward P. Lewis David M. Lustgarten H. D. Hollis Showalter Anthony D. Sercel Michael D. Reily Susan E. Uhlendorf Katherine A. Zisek Peter Mcdonnell 《Journal of heterocyclic chemistry》1991,28(2):517-527
Improved processes for the synthesis of bulk quantities of the benzothiopyranoindazole clinical agent CI-958 and A-ring congeners is reported. The process chosen for scale-up operations achieves β-aminoethylation of an anilino precursor via a three-step sequence (acylation, reduction, deprotection) starting from N-(trityl)glycine. Detailed analytical data are reported for the target compounds and most intermediates, and detailed spectroscopy is given for CI-958. 相似文献
76.
R. E. Showalter 《Applicable analysis》2013,92(2):81-99
Partial differential equations of the form MDtU+LU = f are considered in which M and L denote realizations of regular elliptic linear partial differential operators of respective orders 2 m and 2 l. The abstract existence results of Part I lead to existence of generalized solutions of the equation. Regularity results are obtained by the technique of interpolation theory. The results include the parabolic equation (m = 0) and pseudo-parabolic equations m≧l. The extensive bibliography contains about 36 references to the literature on this class of equations 相似文献
77.
Domains containing spiral waves form on a stationary background in a photosensitive Belousov-Zhabotinsky reaction with light-induced alternating nonlocal feedback. Complex behavior of colliding and splitting wave fragments is found with feedback radii comparable to the spiral wavelength. A linear stability analysis of the uniform stationary states in an Oregonator model reveals a spatial symmetry breaking instability. Numerical simulations show behavior in agreement with that found experimentally and also predict a variety of other new patterns. 相似文献
78.
A much improved glycosylation procedure for fhe synthesis of pentostatin-like nucleosides is described. 相似文献
79.
Vladimir G. Beylin Norman L. Colbry Om P. Goel Jerome E. Haky Donald R. Johnson Judith L. Johnson Gerald D. Kanter Robert L. Leeds Boguslawa Leja Edward P. Lewis Christopher D. Rithner H. D. Hollis Showalter Anthony D. Sercel William R. Turner Susan E. Uhlendorf 《Journal of heterocyclic chemistry》1989,26(1):85-96
Improved processes for the synthesis of bulk quantities of the anthrapyrazole clinical agents CI-937, CI-941, and piroxantrone hydrochloride are reported. Reported also are detailed analytical and spectroscopic data for these agents and intermediates of the synthetic sequences. 相似文献
80.
The transverse coupling of chemical waves is investigated using a model scheme for excitable media. Chemical waves supported on the surfaces of a semipermeable membrane couple via diffusion through the membrane, resulting in new types of spatiotemporal behavior. The model studies show that spontaneous wave sources may develop from interacting planar waves, giving rise to a complex sequence of patterns accessible only by perturbation. Coupled circular waves result in the spontaneous formation of spiral waves, which subsequently develop patterns in distinct domains with characteristic features. The long time entrainment behavior of coupled spiral waves reveals regions of 1:2 phase locking. 相似文献