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631.
632.
The aim of the present study is to investigate the urea-induced denaturation of bovine serum albumin. The native and denatured bovine serum albumin interactions with 32π-Norcorrole were investigated, respectively. The circular dichroism spectra indicated that the α-helix content of bovine serum albumin reduces in the presence of urea and 32π-Norcorrole. The Stern–Volmer quenching constant indicated that both dynamic and static quenching exist in the interaction; moreover, the denaturation of bovine serum albumin leads to the decrease of Stern–Volmer quenching constant. Binding constant illustrated that the native bovine serum albumin has stronger combination capacity than the denatured bovine serum albumin. The fluorescence lifetime studies demonstrated that denaturation lead to the fluorescence decay of bovine serum albumin. The binding sites experiment and molecular docking studies demonstrated that the binding site of 32π-Norcorrole on bovine serum albumin is mainly located in site I. 相似文献
633.
634.
SupposeG is an arbitrary additively written primary abelian group with a fixed large subgroupL. It is shown thatG is (a) summable; (b) σ-summable; (c) a Σ-group; (d) pω+1-projecrive only when so isL. These claims extend results of such a kind obtained by Benabdallah, Eisenstadt, Irwin and Poluianov,Acta Math. Acad. Sci. Hungaricae (1970) and Khan,Proc. Indian Acad. Sci. Sect. A (1978). 相似文献
635.
This paper identifies a certain class of locally supersoluble groups (called soluble hall-T groups) which contains the soluble T-groups as well as the nilpotent groups. The main result states that the product of a normal soluble hall-T subgroup and a subnormal locally supersoluble subgroup is always locally supersoluble.AMS Subject Classification (1991): 20E25, 20F16, 20F19 相似文献
636.
Takehiko Mori 《Journal of solid state chemistry》2002,168(2):433-437
Inter-dimer magnetic interactions J in BEDT-TTF (bis(ethylenedithio)tetrathiafulvalene) salts in the Mott insulator regime are estimated from the intermolecular overlap integrals. The estimated J values are compared with the experimental results, and the stable spin alignment and the dimensionality of the spin systems are discussed. 相似文献
637.
Deirdre Longacher Smeltzer 《Designs, Codes and Cryptography》1999,16(3):291-306
A ( v, k, λ)-difference set D in a group G can be used to create a symmetric 2-( v, k, λ) design,
, from which arises a code C, generated by vectors corresponding to the characteristic function of blocks of
. This paper examines properties of the code C, and of a subcode, C
o=JC, where J is the radical of the group algebra of G over
. When G is a 2-group, it is shown that Co is equivalent to the first-order Reed-Muller code,
, precisely when the 2-divisor of Co is maximal. In addition, ifD is a non-trivial difference set in an elementary abelian 2-group, and if D is generated by a quadratic bent function, then Co is equal to a power of the radical. Finally, an example is given of a difference set whose characteristic function is not
quadratic, although the 2-divisor of Co is maximal. 相似文献
638.
Development of synthetic methods for silole-containing or –fused polycyclic aromatic compounds has been in great demand. Described in this paper is an easy synthetic method for the high-efficient synthesis of chrysenosilole derivatives from silatricyclic compounds via the Mallory photocyclization reaction. It is noteworthy that those conventional transition-metal and Lewis acid catalyzed or mediated CC bond coupling reactions did not work well for this aryl-aryl coupling reaction. 相似文献
639.
ABSTRACTCyclobis(paraquat-p-phenylene) (CBPQT4+) cyclophane represents an ideal π-electron deficient macrocycles, which demonstrates the extraordinary ability of hosting a variety of π-electron-rich guests in its rigid, preorganised cavity. However, this macrocycle undergoes large ring strain and therefore its preparation is often low yielding. In order to increase its yields, high-dilution conditions and template-directed synthesis are employed, which are rather time-consuming, i.e. a few weeks including template removal. Herein, we attempt to solve these problems by either using click reaction, or decreasing the ring strain by using a flexible linker. Three analogues of CBPQT4+ ring were synthesised without the need of guest template, each of which contains two bipyridinium units. Two of these three macrocycles are able to recognise π-electron rich guests within their cavities. However, the one obtained via click reaction demonstrates low guest recognition ability. 相似文献
640.
Dr. Wiktor Zierkiewicz Dr. Rafał Wysokiński Mariusz Michalczyk Prof. Steve Scheiner 《Chemphyschem》2020,21(9):870-877
The ability of the central M atom of the MCl3− anion, with M=Be, Mg, Ca, Sr, Ba, to engage in a noncovalent bond with an approaching nucleophile is gauged by ab initio methods. The N atom of pyridine forms a M⋅⋅⋅N bond with an interaction energy between 12 and 21 kcal mol−1, even though the π-hole above the M atom is not necessarily positive in sign. Despite a strong Coulombic repulsion between two anions, CN− is also able to approach the M atom so as to engage in a metastable complex that is higher in energy than the individual anions. The energy barrier separating this complex from its constituent anion pair is roughly 20 kcal mol−1. Despite the endothermic formation reaction energy of the CN−⋅⋅⋅MCl3− complex, the electron topology signals a strong interaction, more so than in pyridine⋅⋅⋅MCl3− with its exothermic binding energy. The dianionic complex is held together largely on the strength of interorbital interactions, thereby overcoming a repulsive electrostatic component. The latter is partially alleviated by the pyramidalization of the MCl3 unit which makes its π-hole more positive. The complex sinks below the separate monomers in energy when the system is immersed in an aqueous medium, with a binding energy that varies from as much as 20 kcal mol−1 for Be down to 1.2 kcal mol−1 for Ba. 相似文献