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141.
142.
Kenneth Turnbull Thomas L. Blackburn John J. Miller 《Journal of heterocyclic chemistry》1996,33(2):485-487
Exclusive aryl ring nitration of a series of 3-arylsydnones 1 with electron donors (di- or tri-methyl) on the aryl ring is reported. 相似文献
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146.
Casper DM Blackburn JR Maroules CD Brady T Esken JM Ferrence GM Standard JM Hitchcock SR 《The Journal of organic chemistry》2002,67(25):8871-8876
Pseudoephedrine-based [1,3,4]-oxadiazinan-2-ones acylated at the N(3)-position with either acetyl (2a), propionyl (2b), or phenylacetyl (2c) substituents are known to undergo conformational changes that are observable by (13)C NMR spectroscopy. The conformational properties of new [1,3,4]-oxadiazinan-2-one derivatives 2d-k are examined by X-ray crystallography and variable-temperature (13)C NMR spectroscopy and further evaluated by semiempirical AM1 calculations. The collected data reveal that the conformational changes of the overall ring system are dependent upon the stereoelectronic factors of the N(3)-substituent. 相似文献
147.
Ralle M Berry SM Nilges MJ Gieselman MD van der Donk WA Lu Y Blackburn NJ 《Journal of the American Chemical Society》2004,126(23):7244-7256
Azurin is a small electron-transfer protein belonging to the cupredoxin family. The Cu atom is located within a trigonal plane coordinated by two histidines (His46 and His117) and a cysteine (Cys112) with two more distant ligands (Gly45 and Met121) providing axial interactions. A Cys112SeCys derivative has been prepared by expressed protein ligation, and detailed UV/vis, EPR and EXAFS studies at the Cu and Se K-edges have been carried out. Marked changes are observed between the EPR parameters of the Cys112SeCys and WT azurin derivatives, which include a 2-fold increase in A(||), a decrease in g-values, and a large increase in rhombicity of the g-tensor. The Cu-Se and Se-Cu bond lengths obtained from analysis of the Cu and Se K-EXAFS of the oxidized protein were found to be 2.30 and 2.31 A, respectively, 0.14 A longer than the Cu-S distance of the WT protein. Unexpectedly, the Cu-Se bond lengths were found to undergo only minor changes during reduction, suggesting a very similar structure in both redox states and extending the "rack" hypothesis to the Se-substituted protein. 相似文献
148.
Sukow DW Blackburn KL Spain AR Babcock KJ Bennett JV Gavrielides A 《Optics letters》2004,29(20):2393-2395
We demonstrate experimental chaos synchronization between two chaotic semiconductor lasers subjected to polarization-rotated optical feedback and unidirectional injection. This system allows high-quality synchronization to be obtained between dissimilar lasers in a wide range of chaotic operating regimes. Another feature of this system is its operation at high characteristic frequencies, taking advantage of all-optical implementation. Time series and RF spectra showing synchronization are confirmed by high correlation coefficients in excess of 0.85. 相似文献
149.
Alan R. Healy Douglas R. Houston Lucy Remnant Anne-Sophie Huart Veronika Brychtova Magda M. Maslon Olivia Meers Petr Muller Adam Krejci Elizabeth A. Blackburn Borek Vojtesek Lenka Hernychova Malcolm D. Walkinshaw Nicholas J. Westwood Ted R. Hupp 《Chemical science》2015,6(5):3109-3116
Developing approaches to discover protein–protein interactions (PPIs) remains a fundamental challenge. A chemical biology platform is applied here to identify novel PPIs for the AAA+ superfamily oncoprotein reptin. An in silico screen coupled with chemical optimization provided Liddean, a nucleotide-mimetic which modulates reptin''s oligomerization status, protein-binding activity and global conformation. Combinatorial peptide phage library screening of Liddean-bound reptin with next generation sequencing identified interaction motifs including a novel reptin docking site on the p53 tumor suppressor protein. Proximity ligation assays demonstrated that endogenous reptin forms a predominantly cytoplasmic complex with its paralog pontin in cancer cells and Liddean promotes a shift of this complex to the nucleus. An emerging view of PPIs in higher eukaryotes is that they occur through a striking diversity of linear peptide motifs. The discovery of a compound that alters reptin''s protein interaction landscape potentially leads to novel avenues for therapeutic development. 相似文献
150.
OA Blackburn M Tropiano TJ Sørensen J Thom A Beeby LM Bushby D Parker LS Natrajan S Faulkner 《Physical chemistry chemical physics : PCCP》2012,14(38):13378-13384
Thulium salts and complexes are shown to be emissive from three states in the excited state manifold of Tm(3+). Formation of the (1)D(2) state can result in luminescence, or in energy transfer to the lower energy (1)G(4) and (3)H(4) emissive states. Where chromophores are present in the ligand structure, emission is restricted to thulium centred emissive states that are lower in energy than the chromophore centred donor state. We have also observed direct multi-photon excitation of the thulium excited state manifold. Furthermore, additional transitions are observed in the multi-photon excitation spectra that are consistent with upconversion as a consequence of sequential single photon absorption and relaxation processes within the thulium excited state manifold. 相似文献