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991.
992.
[structure: see text] An O-glycosylated peptide carrying two core 2 sialopentasaccharides of different glycoform was synthesized as a model of the heterogeneous surface of mucin glycoprotein. Solid-phase synthesis and the subsequent enzymatic sialylation gave two segments, which were coupled by selective thioester activation to produce the title compound. 相似文献
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Okuma K Shigetomi T Nibu Y Shioji K Yoshida M Yokomori Y 《Journal of the American Chemical Society》2004,126(31):9508-9509
Reaction of di-tert-butyl thioketene S-oxide with Lawesson reagent gave 3,3-di-tert-butylthiirane-2-thione in 88% yield. Oxidation of thiirane-2-thione with m-chloroperbenzoic acid afforded 3,3-di-tert-butylthiirane-2-thione S-oxide. The reaction of thiirane-thione was described. 相似文献
998.
Keiji?Matsumoto Toshiyuki?Shimono Andreas?WinterEmail author 《Communications in Mathematical Physics》2004,246(3):427-442
The purpose of this article is to discuss the relation between the additivity questions regarding the quantities (Holevo)capacityofaquantumchannelT and entanglementofformationofabipartitestate . In particular, using the Stinespring dilation theorem, we give a formula for the channel capacity involving entanglement of formation. This can be used to show that additivity of the latter for some states can be inferred from the additivity of capacity for certain channels. We demonstrate this connection for some families of channels, allowing us to calculate the entanglement cost for many states, including some where a strictly smaller upper bound on the distillable entanglement is known. Group symmetry is used for more sophisticated analysis, giving formulas valid for a class of channels. This is presented in a general framework, extending recent findings of Vidal, Dür and Cirac. We also discuss the property of superadditivity of the entanglement of formation, which would imply both the general additivity of this function under tensor products and of the Holevo capacity (with or without linear cost constraints). 相似文献
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[reaction: see text] A fused four-membered ring has a powerful directing ability in effecting the regioselective reactions of benzyne with ketene silyl acetal, nucleophile, and alpha-alkoxyfuran. 相似文献
1000.
Tsuda S Yokoya T Takano Y Kito H Matsushita A Yin F Itoh J Harima H Shin S 《Physical review letters》2003,91(12):127001
The superconducting-gap of MgB2 has been studied by high-resolution angle-resolved photoemission spectroscopy. The results show that superconducting gaps with values of 5.5 and 2.2 meV open on the sigma band and the pi band, respectively, but both the gaps close at the bulk transition temperature, providing a definitive experimental evidence for the two-band superconductivity with strong interband pairing interaction in MgB2. The experiments validate the role of k-dependent electron-phonon coupling as the origin of multiple-gap superconductivity as well as the high transition temperature of MgB2. 相似文献