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1.
The focus of this paper is on the following problem. Given a linear space F of complex-valued functions on a set X and a polynomial p(z), is there an algebraic composition operator on F whose characteristic polynomial equals p(z)? We show that the supply of all the polynomials p(z) for which the answer to this question is affirmative depends heavily on the structure of the space F. 相似文献
2.
[chemical reaction: see text]. Prior to detachment of compounds synthesized on sulfonamide based safety-catch linkers, the molecular anchor has to be activated. This is achieved by alkylation of the nitrogen atom of the N-acylsulfonamide using different established protocols. As an addition to the existing repertoire of activating reagents, we suggest the use of O,N,N'-trialkylisoureas. Besides the demonstration of the feasibility of these mild alkylating agents for this purpose, custom-tailored novel O,N,N'-trialkylisoureas prepared from electron-deficient alcohols are reported. 相似文献
3.
A. Cappelli R. Tuffi K. Schwertassek K. Czapla J. Plail E. Freedman H. Nechamkin R. Gerber K. Lathrop H. Rath O. Mecheels J. W. Groß E. v. Roll K. Heidler S. G. Barker B. A. Ryberg W. I. Tepnin P. M. Heertjes H. Anton F. Riecke W. Sserdjukow und N. A. Juschkow 《Fresenius' Journal of Analytical Chemistry》1944,127(1):220-227
Ohne Zusammenfassung 相似文献
4.
Sing M Glawion S Schlachter M Scholz MR Goss K Heidler J Berner G Claessen R 《Physical review letters》2011,106(5):056403
The spectral weight evolution of the low-dimensional Mott insulator TiOCl upon alkali-metal dosing has been studied by photoelectron spectroscopy. We observe a spectral weight transfer between the lower Hubbard band and an additional peak upon electron doping, in line with quantitative expectations in the atomic limit for changing the number of singly and doubly occupied sites. This observation is an unconditional hallmark of correlated bands and has not been reported before. In contrast, the absence of a metallic quasiparticle peak can be traced back to a simple one-particle effect. 相似文献
5.
Non-functional analogs of the cofactors ATP and NAD are putative inhibitors of ATP- or NAD-dependant enzymes. Since pathogenic
protozoa rely heavily on the salvage of purine nucleosides from the bloodstream of their host, such compounds are of interest
as antiplasmodial and antitrypanosomal agents with a multitude of molecular targets. By replacing the negatively charged phosphate
residues with a constrained unsaturated amide spacer and the nicotinamide moiety of NAD with various lipophilic substituents,
15 new ATP/NAD analogs were obtained in screening quantities. In these compounds, a 5′-desoxyadenosine moiety was conserved
as key molecular recognition motif. The inhibition of P. falciparum and T. brucei ssp. in a whole parasite in vitro assay is reported. 相似文献
6.
Vida Zohrabi-Kalantari Philipp Heidler Marcel Kaiser Reto Brun Christoph Kamper Andreas Link 《Molecular diversity》2010,14(2):307-320
Abstract
A series of 30 adenosine derivatives with three different substituents at the N6-position were prepared in order to evaluate their potential to inhibit the pathogenic protozoa Plasmodium falciparum and Trypanosoma brucei in vitro. The rationale for synthesis of these structures was the high probability of interactions with multiple adenosine associated targets and the assumption that N6-substitutents should increase stability against adenosine deaminases and allow the molecules to diffuse across parasite membranes. Starting from inosine, the new compounds were prepared as single isomers using a polymer-assisted acylation protocol enabling the straightforward isolation of the target compounds in pure form. Three of the compounds displayed anti-plasmodial and one anti-trypanosomal activity in the single digit micromolar concentration range. 相似文献7.
Ohne ZusammenfassungVgl. das abstract Nr. 74T-E15 in den Notices of the Am. Math. Soc.21, 2 (1974), S.A-318. 相似文献
8.
Glawion S Heidler J Haverkort MW Duda LC Schmitt T Strocov VN Monney C Zhou KJ Ruff A Sing M Claessen R 《Physical review letters》2011,107(10):107402
We combine high-resolution resonant inelastic x-ray scattering with cluster calculations utilizing a recently derived effective magnetic scattering operator to analyze the polarization, excitation energy, and momentum-dependent excitation spectrum of the low-dimensional quantum magnet TiOCl in the range expected for orbital and magnetic excitations (0-2.5?eV). Ti 3d orbital excitations yield complete information on the temperature-dependent crystal-field splitting. In the spin-Peierls phase we observe a dispersive two-spinon excitation and estimate the inter- and intradimer magnetic exchange coupling from a comparison to cluster calculations. 相似文献
9.
R. V. Chopdekar J. Heidler C. Piamonteze Y. Takamura A. Scholl S. Rusponi H. Brune L. J. Heyderman F. Nolting 《The European Physical Journal B - Condensed Matter and Complex Systems》2013,86(6):1-7
We present a detailed study on the strain-induced magnetic domain structure of a (La,Sr)MnO3 thin film epitaxially grown on a BaTiO3 substrate through the use of polarization-dependent X-ray photoemission electron microscopy and X-ray absorption spectroscopy. Angular-dependent measurements allow us to detect vector magnetization on a single-domain scale, and we relate the strain-induced changes in magnetic anisotropy of the ferromagnetic film to the ferroelectric domain structure of the underlying substrate using X-ray magnetic circular and linear dichroism spectro-microscopy. Comparisons to measurements on a nearly strain free film of (La,Sr)MnO3 grown on a (La,Sr)(Al,Ta)O3 substrate illustrate that the BaTiO3 ferroelectric domain structure imprints specific domain sizes and wall orientations in the (La,Sr)MnO3/BaTiO3 artificial multiferroic heterostructure. Furthermore, a change of the BaTiO3 ferroelectric domain structure either with temperature or with applied electric field results in a corresponding change in the (La,Sr)MnO3 ferromagnetic domain structure, thus showing a possible route to obtain room-temperature electric field control of magnetic anisotropy at the nanoscale. 相似文献
10.
Jens Totz Aad van den Boogaart Sabine Van Huffel Danielle Graveron-Demilly Ioannis Dologlou Ralf Heidler Dieter Michel 《Journal of magnetic resonance (San Diego, Calif. : 1997)》1997,124(2):400-409
In this paper, it is shown how the advantages of continuous regularization (CR) can be exploited to achieve an improved, fully automated LPSVD analysis of MRS time-domain data. The main advantage of CR is its ability to determine the number of spectral components even at low signal-to-noise ratios, which suggested its use forin vivospectroscopy. Estimation of the spectral parameters is possible. Two alternatives of automated data-analysis schemes are thoroughly investigated by means of Monte Carlo studies. The results suggest the combination of CR for model-order estimation with other methods for more-accurate parameter estimation. Several possible combinations, including those with an improved enhancement procedure and a total-least-squares method for quantitation, are discussed. Recommendations are given for spectral analysis, and a new data-analysis protocol which performs significantly better than previously used protocols of the same type is proposed. 相似文献