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71.
72.
Phil M. Pithan Christopher Kuhlmann Prof. Dr. Carsten Engelhard Prof. Dr. Heiko Ihmels 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(70):16088-16098
A series of new 5-mono- and 5,5′-bisamino-substituted azothiazole derivatives was synthesized from the readily available diethyl azothiazole-4,4′-dicarboxylate. This reaction most likely comprises an initial Michael-type addition by the respective primary alkyl and aromatic amines at the carbon atom C5 of the substrate. Subsequently, the resulting intermediates are readily oxidized by molecular oxygen to afford the amino-substituted azothiazole derivatives. The latter exhibit remarkably red-shifted absorption bands (λabs=507–661 nm) with high molar extinction coefficients and show a strong positive solvatochromism. As revealed by spectrometric titrations and circular and linear dichroism studies, the water-soluble, bis-(dimethylaminopropylamino)-substituted azo dye associates with duplex DNA by formation of aggregates along the phosphate backbone at high ligand–DNA ratios (LDR) and by intercalation at low LDR, which also leads to a significant increase of the otherwise low emission intensity at 671 nm. 相似文献
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75.
Jeong Young Eun Kumar Pullur Anil Ha Heon Phil Lee Kwan-young 《Research on Chemical Intermediates》2018,44(11):6803-6829
Research on Chemical Intermediates - Herein, we investigated the NOx reduction performance of Sb–V–CeO2/TiO2 (SbVCT) catalyst subjected to hydrothermal aging, where 6 vol% of H2O was... 相似文献
76.
Tae-Yeon Seong Jung-Ja Yang Mee Yi Ryu Jong-In Song Phil W. Yu 《Journal of Electronic Materials》1998,27(5):409-413
Chemical beam epitaxial (CBE) GaxIn1?xP layers (x≈0.5) grown on (001) GaAs substrates at temperatures ranging from 490 to 580°C have been investigated using transmission electron diffraction (TED), transmission electron microscopy, and photoluminescence (PL). TED examination revealed the presence of diffuse scattering 1/2{111}B positions, indicating the occurrence of typical CuPt-type ordering in the GaInP CBE layers. As the growth temperature decreased from 580 to 490°C, maxima in the intensity of the diffuse scattering moved from ½{111}B to ½{?1+δ,1?δ,0} positions, where δ is a positive value. As the growth temperature increased from 490 to 550°C, the maxima in the diffuse scattering intensity progressively approached positions of $\frac{1}{2}\{\bar 110\} $ , i.e., the value of δ decreased from 0.25 to 0.17. Bandgap reduction (~45 meV) was observed in the CBE GaInP layers and was attributed to the presence of ordered structures. 相似文献
77.
We study new posets Q obtained by removing from a geometric lattice L ofa biased graph certain flats indexed by a simplicial complex
. (One example of L is the lattice of flats of thevector matroid of a root system B
n
.) We study the structureand compute the characteristic polynomial of Q. With certainchoices of L and
, including ones for which Q is alattice interpolating between those of B
n
and D
n
, we observe curious relationships among the roots of thecharacteristic polynomials of Q, L, and
. 相似文献
78.
Phil Hanlon Richard P. Stanley 《Transactions of the American Mathematical Society》1998,350(11):4445-4459
Let be the arrangement of hyperplanes consisting of the reflecting hyperplanes for the root system . Let be the Varchenko matrix for this arrangement with all hyperplane parameters equal to . We show that is the matrix with rows and columns indexed by permutations with entry equal to where is the number of inversions of . Equivalently is the matrix for left multiplication on by
Clearly commutes with the right-regular action of on . A general theorem of Varchenko applied in this special case shows that is singular exactly when is a root of for some between and . In this paper we prove two results which partially solve the problem (originally posed by Varchenko) of describing the -module structure of the nullspace of in the case that is singular. Our first result is that
in the case that where Lie denotes the multilinear part of the free Lie algebra with generators. Our second result gives an elegant formula for the determinant of restricted to the virtual -module with characteristic the power sum symmetric function .
79.
Phil Opitz Laura Besch Martin Panthöfer Anke Kabelitz Ronald E. Unger Franziska Emmerling Mihail Mondeshki Wolfgang Tremel 《Advanced functional materials》2021,31(3):2007830
A protein-free formation of bone-like apatite from amorphous precursors through ball-milling is reported. Mg2+ ions are crucial to achieve full amorphization of CaCO3. Mg2+ incorporation generates defects which strongly retard a recrystallization of ball-milled Mg-doped amorphous calcium carbonate (BM-aMCC), which promotes the growth of osteoblastic and endothelial cells in simulated body fluid and has no effect on endothelial cell gene expression. Ex situ snapshots of the processes revealed the reaction mechanisms. For low Mg contents (<30%) a two phase system consisting of Mg-doped amorphous calcium carbonate (ACC) and calcite “impurities” was formed. For high (>40%) Mg2+ contents, BM-aMCC follows a different crystallization path via magnesian calcite and monohydrocalcite to aragonite. While pure ACC crystallizes rapidly to calcite in aqueous media, Mg-doped ACC forms in the presence of phosphate ions bone-like hydroxycarbonate apatite (dahllite), a carbonate apatite with carbonate substitution in both type A (OH−) and type B (PO43−) sites, which grows on calcite “impurities” via heterogeneous nucleation. This process produces an endotoxin-free material and makes BM-aMCC an excellent “ion storage buffer” that promotes cell growth by stimulating cell viability and metabolism with promising applications in the treatment of bone defects and bone degenerative diseases. 相似文献
80.