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91.
Origin of Extraordinary Stability of Square‐Planar Carbon Atoms in Surface Carbides of Cobalt and Nickel 下载免费PDF全文
Anjan Nandula Quang Thang Trinh Prof. Mark Saeys Prof. Anastassia N. Alexandrova 《Angewandte Chemie (International ed. in English)》2015,54(18):5312-5316
Surface carbides of cobalt and nickel are exceptionally stable, having stabilities competitive with those of graphitic C on these surfaces. The unusual structure of these carbides has attracted much attention: C assumes a tetracoordinate square‐planar arrangement, in‐plane with the metal surface, and its binding favors a spontaneous p4g clock surface reconstruction. A chemical bonding model for these systems is presented and explains the unusual structure, special stability, and the reconstruction. C promotes local two‐dimensional aromaticity on the surface and the aromatic arrangement is so powerful that the required number of electrons is taken from the void M4 squares, thus leading to Peierls instability. Moreover, this model predicts a series of new transition‐metal and main‐group‐element surface alloys: carbides, borides, and nitrides, which feature high stability, square‐planar coordination, aromaticity, and a predictable degree of surface reconstruction. 相似文献
92.
Acetyl trimethylaminoethyl ester iodide derivatives have been used to selectively analyze isomeric long-chain hydroxy fatty acids by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The binary derivatives of 2-, 3-, 12- and 16-hydroxypalmitic acids afford remarkably different product ion spectra. Further discrimination between isomers is possible by acylating with pivaloyl chloride. 2- and omega-Hydroxy long-chain fatty acids form pivaloyl esters in quantitative yield whereas other secondary alcohols only partially react. Cotton-based filter paper used for blood collection contains substantial amounts of esterified long-chain hydroxy fatty acids. From the product ion spectra of the acetyl trimethylaminoethyl esters the hydroxydocosanoic and -tetracosanoic acids are >90% omega-hydroxy. All remaining saturated and unsaturated hydroxy acids are >90% 2-hydroxy acids. A method for the quantification of free 3-hydroxypalmitic acid in plasma by ESI-MS/MS for the diagnosis of long-chain 3-hydroxyacyl CoA dehydrogenase deficiency (LCHAD) is described. Median plasma concentrations of 0.43 micromol/L (control, n = 22) and 12.2 micromol/L (LCHAD, n = 3) were obtained from 5 microL plasma samples. 相似文献
93.
Anton N. Yurchenko Olga F. Smetanina Elena V. Ivanets Trinh Thi Hoai Phan Ngoc Thi Duy Ngo Olesya I. Zhuravleva 《Natural product research》2020,34(18):2589-2594
AbstractTwo new auroglaucin-derived compounds, niveoglaucins A (1) and B (2), together with four known related compounds were isolated from extract of the marine sediment-derived strain of Aspergillus niveoglaucus. The structures of these compounds were determined by 1D and 2D NMR spectroscopy and high resolution MS. The plausible biosynthetic pathway was proposed for new compounds 1 and 2. The neuroprotective activity in 6-OHDA-induced Parkinson’s disease cell model was shown for niveoglaucin A (1). 相似文献
94.
Zsfia Hegedüs Fruzsina Hbor Deborah K. Shoemark Sergio Celis Lu-Yun Lian Chi H. Trinh Richard B. Sessions Thomas A. Edwards Andrew J. Wilson 《Chemical science》2021,12(6):2286
β-Strand mediated protein–protein interactions (PPIs) represent underexploited targets for chemical probe development despite representing a significant proportion of known and therapeutically relevant PPI targets. β-Strand mimicry is challenging given that both amino acid side-chains and backbone hydrogen-bonds are typically required for molecular recognition, yet these are oriented along perpendicular vectors. This paper describes an alternative approach, using GKAP/SHANK1 PDZ as a model and dynamic ligation screening to identify small-molecule replacements for tranches of peptide sequence. A peptide truncation of GKAP functionalized at the N- and C-termini with acylhydrazone groups was used as an anchor. Reversible acylhydrazone bond exchange with a library of aldehyde fragments in the presence of the protein as template and in situ screening using a fluorescence anisotropy (FA) assay identified peptide hybrid hits with comparable affinity to the GKAP peptide binding sequence. Identified hits were validated using FA, ITC, NMR and X-ray crystallography to confirm selective inhibition of the target PDZ-mediated PPI and mode of binding. These analyses together with molecular dynamics simulations demonstrated the ligands make transient interactions with an unoccupied basic patch through electrostatic interactions, establishing proof-of-concept that this unbiased approach to ligand discovery represents a powerful addition to the armory of tools that can be used to identify PPI modulators.Dynamic ligation screening is used to identify acylhydrazone-linked peptide-fragment hybrids which bind to the SHANK1 PDZ domain with comparable affinity to the native GKAP peptide as shown by biophysical and structural analyses. 相似文献
95.
Tien Doan Phan Thao My Trinh Thi Thu Khiem Le Hong Frontasyeva Marina Zinicovscaia Inga Son Nguyen An Van Dung Do 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(6):2743-2750
Journal of Radioanalytical and Nuclear Chemistry - Forty-five moss samples were collected at the end of the 2019 rainy season in Hanoi capital and some other cities in Red River Delta and the south... 相似文献
96.
Lee Byoung-Hwa Trinh Viet Thieu Kim Seung-Mo Jeon Chung-Hwan 《Journal of Thermal Analysis and Calorimetry》2022,147(13):7399-7410
Journal of Thermal Analysis and Calorimetry - Recently, ashless pretreatment of lignocellulosic biomass prior to pyrolysis has been used for removing mineral matters to prevent slagging and... 相似文献
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Journal of Statistical Physics - This paper studies beta ensembles on the real line in a high temperature regime, that is, the regime where $$\beta N \rightarrow const \in (0, \infty )$$, with N... 相似文献
100.