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101.
Bales BC Pitié M Meunier B Greenberg MM 《Journal of the American Chemical Society》2002,124(31):9062-9063
Copper-phenanthroline complexes and their conjugates are useful reagents for studying nucleic acid interactions. Although DNA cleavage by such complexes was discovered more than 20 years ago, significant questions remain unanswered regarding the chemical mechanism(s) by which DNA is damaged. Kinetic evidence is provided, which demonstrates that the major pathway for DNA damage by a minor groove binding molecule conjugated to copper phenanthroline (6) involves C1'-oxidation. Additional experiments using 6 and a DNA substrate containing 2-deoxyribonolactone (1) show that direct strand breaks are produced via beta-elimination from 1. These studies support the original mechanism for DNA damage by copper phenanthroline put forth by Sigman and a more recent proposal concerning the mechanism for direct strand break formation. 相似文献
102.
An updated compendium of silatrane structural data is presented. The relationships between nonplanarity at silicon (Si) andd(N-Si), the length of the dative bond, and nonplanarity at nitrogen N andd(N-Si) are examined. Excluding a platinum-substituted derivative: the Si relationship is strong and predicts the limiting length of a strong N Si bond, while the N relationship is weak. A good relationship between I for the four (non-N) exo- and endocyclic substituents attached to Si holds for silatranes, methyl, keto, and diketo derivatives as well as for 2-carbasilatranes. The relationship fails for strong -donor exocyclic substituents, implicating resonance, and for benzo- and tribenzosilatranes, where steric effects dominate.On Leave of Absence from Academia Sinica, Beijing, People's Republic of China. 相似文献
103.
Michael R. Greenberg 《Annals of Operations Research》2011,187(1):121-136
Using the literature and drawing upon several decades of experience in risk analysis, the author identifies three elements
that appear particularly challenging for port security applications. The first of these is identifying a set of realistic
scenarios for risk assessment. The second is estimating the likelihood of a successful attack on a port. The third is understanding
the regional and national economic consequences of these events. The author offers suggestions for addressing these challenges. 相似文献
104.
105.
Structural Chemistry - The resonance energy of an amide can be calculated through comparison with a model amine and a model ketone (or aldehyde) with subtraction of the “residual”... 相似文献
106.
Lorraine M. Deck Jacob A. Greenberg Taylor S. Busby Elizabeth R. Bright Lisa J. Whalen David L. Vander Jagt Robert E. Royer 《Tetrahedron letters》2013
As part of ongoing research to investigate structural requirements for lactate dehydrogenase inhibition by highly substituted naphthoic and indenoic acids, certain naphthalene and indene precursors to those types of compounds are required. Described here are efficient preparations of 1-naphthoic acid precursors 6-benzyl-2,3-dimethoxy-1-propylnaphthalenes, including compounds with substituted benzyl groups and 7-benzyl-2,3-dimethoxy-1-propylnaphthalene. Also described are the syntheses of indenoic acid precursors 2-benzyl-5,6-dimethoxy-7-propyl-1H-indenes, including compounds with substituted benzyl groups. These compounds were made from the key intermediates 6,7-dimethoxy-5-propyl-1-tetralone, 6,7-dimethoxy-8-propyl-1-tetralone, and 5,6-dimethoxy-4-propyl-1-indanone. 相似文献
107.
108.
M. S. Pushkin A. V. Inozemtsev B. A. Greenberg A. M. Patselov M. A. Ivanov O. V. Slautin Yu. P. Besshaposhnikov 《Bulletin of the Russian Academy of Sciences: Physics》2016,80(10):1273-1278
The interface relief of copper–titanium compounds and its evolution upon the intensification of explosion welding are investigated. Typical structures are revealed: splashes, waves consisting of ledges, interrupted waves, and transient states generated by interrupted waves combined into bands. The effect the mutual solubility of the initial elements has on the formation of a welded joint’s structure is determined. Intermetallic compounds are detected both on ledge surfaces and inside areas of local melting. 相似文献
109.
A 5-(2'-Deoxyuridinyl)methyl radical (1) was independently generated from three photochemical precursors and is the first example of a DNA radical that forms interstrand cross-links. Oxygen labeling experiments support generation of 1 by all precursors. Interstrand cross-links are produced upon irradiation of DNA containing any of the precursors. Cross-linking occurs via reaction with the opposing 2'-deoxyadenosine and is independent of O(2). The independence of cross-link formation on O(2) is explained by kinetic analysis, which shows that the radical reacts reversibly with O(2). Examination of the effects of glutathione on cross-link formation under anaerobic conditions suggests that adoption of the syn-conformation by 1 is the rate-limiting step in the process. Interstrand cross-link formation is reversible in the presence of a good nucleophile. The stability of the interstrand cross-link suggests that the isolated molecule is a rearrangement product of that formed in solution. The rearrangement is a consequence of the isolation procedure but also occurs slowly in solution. Oxygen independent cross-link formation may be useful for the purposeful damage of DNA in hypoxic tumor cells, where O(2) is deficient. 相似文献
110.