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排序方式: 共有516条查询结果,搜索用时 15 毫秒
1.
Redox Communication within Multinuclear Iron–Sulfur Complexes Related to Electronic Interplay in the Active Site of [FeFe]Hydrogenase 下载免费PDF全文
Kai‐Ti Chu Dr. Yu‐Chiao Liu Yi‐Lan Huang Dr. Gene‐Hsiang Lee Dr. Mei‐Chun Tseng Prof. Ming‐Hsi Chiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(18):6852-6861
The one‐electron oxidations of a Fe2 complex lead to the formation of a persistent metal‐stabilized thiyl radical Fe2 species, mixed‐valent Fe4, and Fe8 complexes. The unpaired spin in the Fe2 radical species delocalizes over the Fe2 and the aromatic dithiolate, mostly on the terminal sulfur. The subsequent dimerization of the singly oxidized Fe2 to the Fe4 retains the partial thiyl radical character. For an analogue with less steric hindrance, the π–π stacking interaction between the dithiolato aromatic rings induces generation of the Fe8, in which process electronic structures of the species are modulated through reducing the thiyl radical to the thiolate. Electronic reorganization repeats when the Fe8 is converted to Fe4. Electronic interplay in the complexes decreases the energy gap of frontier MOs and buffers electronic impacts upon redox events. Easier accessible redox potentials and increased stability of the species are facilitated. The results demonstrate that electronic versatility of the benzenedithiolate exerts pronounced influences on electronic and coordination structure of the metal complexes. 相似文献
2.
Inside Back Cover: A Reversible Proton Relay Process Mediated by Hydrogen‐Bonding Interactions in [FeFe]Hydrogenase Modeling (Chem. Eur. J. 31/2015) 下载免费PDF全文
3.
Regan J. Anderson Benjamin J. Compton Ching-wen Tang Astrid Authier-Hall Colin M. Hayman Gene W. Swinerd Renata Kowalczyk Paul Harris Margaret A. Brimble David S. Larsen Olivier Gasser Robert Weinkove Ian F. Hermans Gavin F. Painter 《Chemical science》2015,6(9):5120-5127
It is known that T cells can eliminate tumour cells through recognition of unique or aberrantly expressed antigens presented as peptide epitopes by major histocompatibility complex (MHC) molecules on the tumour cell surface. With recent advances in defining tumour-associated antigens, it should now be possible to devise therapeutic vaccines that expand specific populations of anti-tumour T cells. However there remains a need to develop simpler efficacious synthetic vaccines that possess clinical utility. We present here the synthesis and analysis of vaccines based on conjugation of MHC-binding peptide epitopes to α-galactosylceramide, a glycolipid presented by the nonpolymorphic antigen-presenting molecule CD1d to provoke the stimulatory activity of type I natural killer T (NKT) cells. The chemical design incorporates an enzymatically cleavable linker that effects controlled release of the active components in vivo. Chemical and biological analysis of different linkages with different enzymatic targets enabled selection of a synthetic vaccine construct with potent therapeutic anti-tumour activity in mice, and marked in vitro activity in human blood. 相似文献
4.
Gene Senges Dr. Lin Li Dr. Artur Wodyński Dr. Helmut Beckers Dr. Robert Müller Prof. Dr. Martin Kaupp Prof. Dr. Sebastian Riedel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(54):13642-13650
Molecular platinum fluorides PtFn, n=1–6, are prepared by two different routes, photo-initiated fluorine elimination from PtF6 embedded in solid noble-gas matrices, and the reaction of elemental fluorine with laser-ablated platinum atoms. IR spectra of the reaction products isolated in rare-gas matrices under cryogenic conditions provide, for the first time, experimental vibrational frequencies of molecular PtF3, PtF4 and PtF5. Photolysis of PtF6 enabled a highly efficient and almost quantitative formation of molecular PtF4, whereas both PtF5 and PtF3 were formed simultaneously by subsequent UV irradiation of PtF4. The vibrational spectra of these molecular platinum fluorides were assigned with the help of one- and two-component quasirelativistic DFT computation to account for scalar relativistic and spin–orbit coupling effects. Competing Jahn-Teller and spin–orbit coupling effects result in a magnetic bistability of PtF4, for which a spin-triplet (3B2g, D2h) coexists with an electronic singlet state (1A1g, D4h) in solid neon matrices. 相似文献
5.
白洋淀内水体的流动特征研究 总被引:2,自引:0,他引:2
研究了风对白洋淀内水体循环流动的影响,研究指出:(1)风应力可看作是水体循环
的主要驱动力. (2)在风应力的作用下,水体表层的流动主方向与风的方向一致,下层水体
的流动方向与表层方向相逆或近似相逆. (3)表层以下水体流动复杂,次表层水平流动有明
显的双涡结构. (4)淀底地形对水体垂向流动影响很大,垂向速度变化复杂,垂向上有双涡
流动现象. 从动力学角度研究了淀内水体流动的情况. 相似文献
6.
Shayani Rad M. Kompany A. Khorsand Zak A. Javidi M. Mortazavi S. M. 《Journal of nanoparticle research》2013,15(9):1-8
A novel method, recently proved useful for the synthesis of nanoparticles, has been now used for the preparation of very stable silver iodide–trihexyl(tetradecyl)phosphonium chloride ionanofluids. Only the ionic liquid and the AgI bulk powder were needed. Synthesized nanofluids are much more stable than those obtained by simple dispersion of the nanoparticles in the base fluid. The ionanofluids were synthesized at different concentrations (up to 50 % w/w) and characterized in terms of physical, electrical, and thermal properties (density, viscosity, refractive index, electric conductivity, and specific heat capacity). A very high increase in the electric conductivity of the base ionic liquid was expected due to the high concentration of nanoparticles achieved. Nonetheless, it was not found, probably due to the reduction of ions mobility caused by the increase of the viscosity in ionanofluids with concentrations over 20 % w/w. An appropriate characterization of nanoparticles composing the nanofluids was carried out (UV–Vis absorbance, shape and size distribution). The diameter of the particles was measured and calculated by different techniques and approximations, obtaining a value of 2–4 nm. They were spherical, well-defined, and not agglomerated, with a narrow size distribution. The X-ray powder diffraction confirmed that no structural change took place in the transformation of the bulk solid to nanoparticles. 相似文献
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10.
Radosław Bonikowski Józef Kula Anna Bujacz Anna Wajs-Bonikowska Małgorzata Zakłos-Szyda Stanisław Wysocki 《Tetrahedron: Asymmetry》2012,23(14):1038-1045
Ten enantiomerically pure hydroindene-derived compounds obtained by the transformation of (+)-carotol, the main constituent of carrot seed essential oil, were examined for their ability to inhibit the growth of myeloid leukaemia (HL-60) cancer cell lines. All compounds showed significant activity, which was comparable to the most active volatile organic compounds, such as trans–trans-farnesol, citral and nerolidol. Based on the bioactivity and molecular modelling, a 3D QSAR pharmacophore model was generated. 相似文献