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71.
Inside Back Cover: Fragment‐Based Discovery of a Dual pan‐RET/VEGFR2 Kinase Inhibitor Optimized for Single‐Agent Polypharmacology (Angew. Chem. Int. Ed. 30/2015) 下载免费PDF全文
72.
Mono‐, di‐ and trimethylated homologues of isoprenoid tetraether lipid cores in archaea and environmental samples: mass spectrometric identification and significance 下载免费PDF全文
Chris Knappy Daniela Barillà James Chong Dominic Hodgson Hugh Morgan Muhammad Suleman Christine Tan Peng Yao Brendan Keely 《Journal of mass spectrometry : JMS》2015,50(12):1420-1432
Higher homologues of widely reported C86 isoprenoid diglycerol tetraether lipid cores, containing 0–6 cyclopentyl rings, have been identified in (hyper)thermophilic archaea, representing up to 21% of total tetraether lipids in the cells. Liquid chromatography‐tandem mass spectrometry confirms that the additional carbon atoms in the C87‐88 homologues are located in the etherified chains. Structures identified include dialkyl and monoalkyl (‘H‐shaped’) tetraethers containing C40‐42 or C81‐82 hydrocarbons, respectively, many representing novel compounds. Gas chromatography‐mass spectrometric analysis of hydrocarbons released from the lipid cores by ether cleavage suggests that the C40 chains are biphytanes and the C41 chains 13‐methylbiphytanes. Multiple isomers, having different chain combinations, were recognised among the dialkyl lipids. Methylated tetraethers are produced by Methanothermobacter thermautotrophicus in varying proportions depending on growth conditions, suggesting that methylation may be an adaptive mechanism to regulate cellular function. The detection of methylated lipids in Pyrobaculum sp. AQ1.S2 and Sulfolobus acidocaldarius represents the first reported occurrences in Crenarchaeota. Soils and aquatic sediments from geographically distinct mesotemperate environments that were screened for homologues contained monomethylated tetraethers, with di‐ and trimethylated structures being detected occasionally. The structural diversity and range of occurrences of the C87‐89 tetraethers highlight their potential as complementary biomarkers for archaea in natural environments. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
73.
Benzylic Functionalization of Anthrones via the Asymmetric Ring Opening of Oxabicycles Utilizing a Fourth‐Generation Rhodium Catalytic System 下载免费PDF全文
Dr. Charles C. J. Loh Dr. Xiang Fang Brendan Peters Prof. Dr. Mark Lautens 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(40):13883-13887
While anthrones exist as privileged scaffolds in bioactive molecules, the enantioselective functionalization of anthrones is surprisingly scarce in the literature, with no asymmetric transition metal catalyzed example to date. Herein, we report the first asymmetric transition metal catalyzed benzylic functionalization of anthrones through the rhodium(I) catalyzed desymmetrization of oxabicycles. As previously developed rhodium(I) systems were found to be unsuitable for this substrate, a new robust fourth‐generation [Rh(cod)OH]2 based catalytic system was developed to address synthetic challenges in this protocol. 相似文献
74.
Brendan Dubsky 《代数通讯》2017,45(9):4084-4092
We prove Koszulity of certain linear path categories obtained from connected graphs with some infinite directed walk. These categories can be viewed as locally quadratic dual to preprojective algebras. 相似文献
75.
Brendan M. SmithAndrew E. Graham 《Tetrahedron letters》2011,52(47):6281-6283
Acyclic acetals and ketals undergo exchange reactions in the presence of catalytic quantities of indium(III) triflate and diols to generate the corresponding cyclic acetals and ketals in excellent yield. The protocol is rapid, employs mild conditions and can be adapted to employ solvent-free reaction conditions. We have further developed this methodology to encompass a tandem acetalisation-acetal exchange protocol which provides facile access to cyclic ketals from unreactive ketones also under very mild, solvent-free reaction conditions. 相似文献
76.
Brendan J. Kennedy Qingdi Zhou Maxim Avdeev 《Journal of solid state chemistry》2011,184(11):2987-2993
The synthesis of bulk samples of polycrystalline CdTiO3 in both the rhombohedral ilmenite and orthorhombic perovskite forms is described and the structures of these have been refined using powder neutron diffraction data. This involved the preparation of samples enriched in 114Cd. Cooling perovskite-type CdTiO3 to 4 K induces a ferroelectric phase transition, with the neutron data suggesting the low temperature structure is in Pna21. Mode analysis shows the polar mode to be dominant at low temperatures. The ilmenite-structure of CdTiO3 is compared with that of ZnTiO3. The refined scattering length of the 114Cd is estimated to be 5.56 fm. Attempts to dope CdTiO3 with Ca and Sr are described. 相似文献
77.
Independently, Claytor [Ann. Math. 35 (1934), 809–835] and Thomassen [Combinatorica 24 (2004), 699–718] proved that a 2-connected, compact, locally connected metric space is homeomorphic to a subset of the sphere
if and only if it does not contain K
5 or K
3;3. The “thumbtack space” consisting of a disc plus an arc attaching just at the centre of the disc shows the assumption of
2-connectedness cannot be dropped. In this work, we introduce “generalized thumbtacks” and show that a compact, locally connected
metric space is homeomorphic to a subset of the sphere if and only if it does not contain K
5, K
3;3, or any generalized thumbtack, or the disjoint union of a sphere and a point. 相似文献
78.
Constantin Bacuta Brendan McCracken 《Journal of Computational and Applied Mathematics》2011,235(6):1614-1628
In this paper, we introduce and analyze Uzawa algorithms for non-symmetric saddle point systems. Convergence for the algorithms is established based on new spectral results about Schur complements. A new Uzawa type algorithm with optimal relaxation parameters at each new iteration is introduced and analyzed in a general framework. Numerical results supporting the efficiency of the algorithms are presented for finite element discretization of steady state Navier-Stokes equations. 相似文献
79.
Grothendieck polynomials, introduced by Lascoux and Schützenberger, are certain K-theory representatives for Schubert varieties. Symplectic Grothendieck polynomials, described more recently by Wyser and Yong, represent the K-theory classes of orbit closures for the complex symplectic group acting on the complete flag variety. We prove a transition formula for symplectic Grothendieck polynomials and study their stable limits. We show that each of the K-theoretic Schur P-functions of Ikeda and Naruse arises from a limiting procedure applied to symplectic Grothendieck polynomials representing certain “Grassmannian” orbit closures. 相似文献
80.
R. Berg O. Wurm A. Pass A. M. Ward L. C. Hurd R. W. Evans M. Delépine C. E. Barrs H. Ter Meulen Frl H. J. Ravenswaay L. Bey und A. Jaworowski 《Fresenius' Journal of Analytical Chemistry》1934,98(7-8):287-291
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