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961.
Dasha Mihaylova Aneta Popova Ivelina Desseva Ivan Manolov Nadezhda Petkova Radka Vrancheva Alexander Peltekov Anton Slavov Argir Zhivondov 《Molecules (Basel, Switzerland)》2021,26(9)
Peaches are one of the most preferred seasonal fruits, and a reliable source of nutrients. They possess biologically active substances that largely differ among varieties. Hence, revealing the potential of several late season peaches is of present interest. Three commonly consumed varieties (“Flat Queen”; “Evmolpiya”; “Morsiani 90”) were studied in terms of nutritive and phytochemical content, as well as antioxidant activity with the use of reliable spectrophotometric and High Performance Liquid Chromatographic (HPLC) methods. An analysis of the soil was also made. The phytochemical data were subjected to principal component analysis in order to evaluate their relationship. The “Morsiani 90” variety had the highest minerals concentration (2349.03 mg/kg fw), total carbohydrates (16.21 g/100 g fw), and α-tocopherol (395.75 µg/100 g fresh weight (fw)). Similar amounts of TDF (approx. 3 g/100 g fw) were reported for all three varieties. “Flat Queen’s” peel extract was the richest in monomeric anthocyanins (2279.33 µg cyanidin-3-glucoside (C3GE)/100 g fw). The “Morsiani 90” variety extracts had the highest antioxidant potential, defined by 2,2-diphenil-1-picrylhydrazyl (DPPH), ferric-reducing antioxidant power (FRAP) and cupric ion-reducing antioxidant capacity (CUPRAC) assays. 相似文献
962.
Manuel Reiter Arthur Markus Anton Jian Chang Friedrich Kremer Miriam M. Unterlass Jiayin Yuan 《Journal of polymer science. Part A, Polymer chemistry》2021,59(14):1518-1527
Herein, we report a simple and versatile synthetic approach towards siloxane-based poly(ionic liquid)s (PILs) with unusually low glass transition temperatures (Tg) down to −73°C, and thus “liquid-like” behavior at room temperature. We designed a polydimethylsiloxane-derived copolymer carrying dialkylimidazolium moieties, and by careful selection of the side-chain length and the type of anions we were able to manipulate its Tg over a wide range and reach high ionic conductivities (σDC) up to 4.8 × 10−5 S/cm at 300 K. The ionized species make up only a minor fraction (<25 mol%) of the overall repeating units and are supposedly randomly distributed: Yet our results indicate dramatic effects on the thermal properties due to repulsive interactions between ionic and non-ionic segments. 相似文献
963.
Anton Kudashev Prof. Dr. Olivier Baudoin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(70):17688-17694
A ligand-controlled site-selective C(sp3)−H arylation of heteroaromatic ketones has been developed using Pd catalysis. The reaction occurred selectively at the α- or β-position of the ketone side-chain. The switch from α- to β-arylation was realized by addition of a pyridone ligand. The α-arylation process showed broad scope and high site- and chemoselectivity, whereas the β-arylation was more limited. Mechanistic investigations suggested that α-arylation occurs through C−H activation/oxidative addition/reductive elimination whereas β-arylation involves desaturation and aryl insertion. 相似文献
964.
Bondarenko Marina Zaytseva Olga Trusova Valeriya Moiseenko Anton Rukin Aleksey Utytskykh Tetyana Morozova Oksana 《Journal of fluorescence》2021,31(4):1065-1073
Journal of Fluorescence - This study is devoted to the development of a methodological approach to mathematical analysis and data interpretation of blood serum phosphorescence intensity in cancer... 相似文献
965.
966.
We consider optimal control problems with distributed control that involve a time-stepping formulation of dynamic one body contact problems as constraints. We link the continuous and the time-stepping formulation by a nonconforming finite element discretization and derive existence of optimal solutions and strong stationarity conditions. We use this information for a steepest descent type optimization scheme based on the resulting adjoint scheme and implement its numerical application. 相似文献
967.
Aza-peptides are promising drug leads, however extensive study of their properties is hampered by low yielding aza-peptide bond formation during conventional Fmoc SPPS. The kinetics of aza-peptide bond formation in the model peptide H-Ala-AzAla-Phe-NH2 was compared with various conventional amino acid activators. The reaction rates and yields were dependent on the activator structure. The reaction time of aza-peptide formation using oxyma-based agents was approximately 30 times longer than in typical peptide synthesis. Therefore, new activators are required to increase the reactivity of the activated amino acid to achieve effective acylation of the semicarbazide moiety during aza-peptide bond formation. 相似文献
968.
We introduce novel classes of higher-order spatial optical solitons in analogy with Laguerre-Gaussian and Hermite-Gaussian linear eigenmodes. We reveal that stable higher-order optical solitons can exist in nonlocal nonlinear media in the various forms of soliton necklaces and soliton matrices. Modulational instability can lead to nontrivial transformations between energetically close solitons with different symmetries through the intermediate states resembling generalized Hermite-Laguerre-Gaussian modes. 相似文献
969.
We introduce a novel class of stable lattice solitons with a complex phase structure composed of many single-charge discrete vortices in a triangular photonic lattice. We demonstrate that such nonlinear self-trapped states are linked to the resonant Bloch modes, which bear a honeycomb pattern of phase dislocations. 相似文献
970.
Malavasic C Brulc B Cebasek P Dahmann G Heine N Bevk D Groselj U Meden A Stanovnik B Svete J 《Journal of combinatorial chemistry》2007,9(2):219-229
Solution-phase combinatorial synthesis of (2S,4S)-4-acylamino-5-oxopyrrolidine-2-carboxamides was studied. First, di-tert-butyl (2S,4S)-4-amino-5-oxopyrrolidine-1,2-dicarboxylate hydrochloride was prepared as the key intermediate in five steps from (S)-pyroglutamic acid. Acylation of the amino group followed by acidolytic deprotection gave (2S,4S)-4-acylamino-5-oxopyrrolidine-2-carboxylic acids, which were then coupled with amines to furnish a library of (2S,4S)-4-acylamino-5-oxopyrrolidine-2-carboxamides. Four coupling reagents, BPC, EEDQ, TBTU, and PFTU, were tested for the amidation reactions in the final step. Amidations with EEDQ and TBTU led to the desired carboxamides. On the other hand, BPC and PFTU were not suited, since diketopiperazines were sometimes obtained instead of the desired carboxamides. 相似文献