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221.
Structural Modifications of cis‐Glycofused Benzopyran Compounds and Their Influence on the Binding to Amyloid‐β Peptide 下载免费PDF全文
Dr. Cristina Airoldi Dr. Giuseppe D'Orazio Dr. Barbara Richichi Dr. Cinzia Guzzi Dr. Veronica Baldoneschi Dr. Laura Colombo Dr. Mario Salmona Prof. Cristina Nativi Prof. Francesco Nicotra Prof. Barbara La Ferla 《化学:亚洲杂志》2016,11(2):299-309
A small library of glycofused tricyclic compounds with a central pyran ring chemically modified in the position para to the ring oxygen has been synthesised. The influence of the chemical modification on the structural conformation of the compounds and on their ability to bind Aβ peptide has been evaluated respectively using molecular mechanics (MM) and molecular dynamics (MD) simulations, and STD NMR spectroscopy. The introduction of particularly polar/charged groups leads to the loss of binding ability, without a significant change in the conformation, whilst other substitutions does not significantly affect either the structural conformation or the binding. 相似文献
222.
Mamoru Ohashi Takashi Lino Tomoyuki Takahashi Michiaki Yoneda Soichiro Kyushin Kazuo Tsujimoto 《Journal of mass spectrometry : JMS》1990,25(2):109-114
Liquid secondary ion mass spectra of choline and acetylcholine halides exhibit several series of cluster ions whose origins were investigated using B/E and B2/E linked-scan techniques. In the case of choline halides three series of cluster ions were identified as (Me3$ \mathop {\rm N}\limits^ + $CH2CH2OH + nM), (Me3$ \mathop {\rm N}\limits^ + $CH2CH2OMe + nM) and (Me3N$ \mathop {\rm N}\limits^ + $CH2CH2OH · Me3$ \mathop {\rm N}\limits^ + $CH2CH2O? + nM), while (CH3COOCH2CH2$ \mathop {\rm N}\limits^ + $Me3 + nM), (Me3$ \mathop {\rm N}\limits^ + $CH2CH2OH + nM) and (CH2 = CH$ \mathop {\rm N}\limits^ + $Me3 + nM) were observed in the spectra of acetylcholine halides. For these cluster ions, bimolecular reactions induced on ion bombardment under secondary ion mass spectrometric conditions are discussed. 相似文献
223.
Ceramic open-cell foams were obtained from a preceramic polymer (a silicone resin) and blown polyurethanes, by pyrolysis at 1200°C in nitrogen. Silicon carbide submicron powders were also added to the silicone resin to give SiOC + SiC composite foams. The morphology of the foams was dependent on the architecture of the blown polyurethanes. The crushing strength as well as the elastic modulus increased with increasing relative density, reaching values as high as 14 and 450 MPa, respectively. Some of the foams displayed an excellent thermal stability (resistance to oxidation in air and decomposition in inert atmosphere) up to elevated temperatures. 相似文献
224.
225.
The Rh-catalyzed hydrogenations of dimethyl itaconate and methyl acetamido acrylate using selected heterocombinations of pentafluorobenzyl- and methoxybenzyl-derived binaphthyl phosphites proved to be highly enantioselective (ee 93-99%). In these selected cases the Rh-heterocomplexes, which were formed in a statistical amount (ca. 50% by 31P NMR), turned out to be more active and selective than the two homocomplexes. 相似文献
226.
We developed a microscopic theory of electron transport in superlattices within the Wannier–Stark approach by including the interaction associated with Zener tunneling between the energy levels pertaining to adjacent quantum wells. By using a Monte Carlo technique we have simulated the hopping motion associated with absorption and emission of polar optical phonons and determined the main transport parameters for the case of a GaAs/GaAlAs structure at room temperature. Interaction between the levels is found to be responsible for a systematic increase of the level energy with respect to the bottom of the quantum well at electric fields above about 20 kV/cm. When compared with the non-interacting case, at the highest fields the average carrier energy evidences a consistent increase, which leads to a significant softening of the negative slope of both the drift velocity and diffusivity versus electric field behavior. 相似文献
227.
Rainer Richter Uwe Schrder Lothar Beyer Jorge Angulo‐Cornejo Maria Lino‐Pacheco 《无机化学与普通化学杂志》2001,627(8):1877-1881
Mononuclear Copper(II) Complexes of Dioxaalkylene and Alkylene Bridged Bis‐isoureas By reaction of N‐benzoylthiocarbamic‐O,S‐diethylester with primary diamines (oxa)alkylene bridged isoureas 1 have been prepared. They yield with CuII neutral chelates 2 with tetradentate ligand coordination. The structures of the ligand 1 a and of the related CuII complex 2 a have been determined by X‐ray crystal structure analysis. They show an enamine tautomer in the ligand and a slightly tetrahedrally distorted coordination with an (oxa)alkylene bridge between the trans arranged N ligator atoms in the complex. 相似文献
228.
Silvia Bradamante Silvana Colombo Giorgio Vittadini 《Journal of heterocyclic chemistry》1981,18(7):1399-1403
The product obtained condensing l-methyl-5-nitroimidazole-2-aldehyde with 2-amino-4-trideuteriomethyl-pyrimidine and showing total deuterium incorporation at one of the olefinic carbons and partial deuterium incorporation para to the amino group, served to assign 13C and 1H resonances in the condensation products 3. The nature of the species undergoing condensation has been inferred from labelling experiments and from 1H and 13C nmr spectra of precursors and products in dimethylsulfoxide and trifluoroacetic acid. 相似文献
229.
Amato E Diaz-Fernandez YA Taglietti A Pallavicini P Pasotti L Cucca L Milanese C Grisoli P Dacarro C Fernandez-Hechavarria JM Necchi V 《Langmuir : the ACS journal of surfaces and colloids》2011,27(15):9165-9173
In the present work, we describe a simple procedure to produce biomimetically coated silver nanoparticles (Ag NPs), based on the postfunctionalization and purification of colloidal silver stabilized by citrate. Two biological capping agents have been used (cysteine Cys and glutathione GSH). The composition of the capped colloids has been ascertained by different techniques and antibacterial tests on GSH-capped Ag NPs have been conducted under physiological conditions, obtaining values of Minimum Inhibitory Concentration (MIC) of 180 and 15 μg/mL for Staphylococcus aureus and Escherichia coli, respectively. The antibacterial activity of these GSH capped NPs can be ascribed to the direct action of metallic silver NPs, rather than to the bulk release of Ag(+). 相似文献
230.
G. Guzzi A. Colombo F. Girardi R. Pietra G. Rossi N. Toussaint 《Journal of Radioanalytical and Nuclear Chemistry》1977,39(1-2):263-276
Three different analytical techniques: INAA, X-ray fluorescence and atomic absorption spectrometry were used at the JRC Ispra
to test the total homogeneity of four candidate botanic reference materials supplied by NBS. Without adopting complex statistical
formalities a “degree of inhomogeneity” was estimated in each sample for the elements considered in the test. The operating
procedures and the results obtained are presented and discussed. 相似文献