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861.
Jakob Nielsen 《Acta Mathematica》1932,58(1):87-167
Ohne Zusammenfassung 相似文献
862.
Yvonne Becker Sina Roth Maximilian Scheurer Dr. Andreas Jakob Dr. Daniel A. Gacek Prof. Dr. Peter J. Walla Prof. Dr. Andreas Dreuw Prof. Dr. Josef Wachtveitl Prof. Dr. Alexander Heckel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(6):2212-2218
We developed three bathochromic, green-light activatable, photolabile protecting groups based on a nitrodibenzofuran (NDBF) core with D-π-A push–pull structures. Variation of donor substituents (D) at the favored ring position enabled us to observe their impact on the photolysis quantum yields. Comparing our new azetidinyl-NDBF (Az-NDBF) photolabile protecting group with our earlier published DMA-NDBF, we obtained insight into its excitation-specific photochemistry. While the “two-photon-only” cage DMA-NDBF was inert against one-photon excitation (1PE) in the visible spectral range, we were able to efficiently release glutamic acid from azetidinyl-NDBF with irradiation at 420 and 530 nm. Thus, a minimal change (a cyclization adding only one carbon atom) resulted in a drastically changed photochemical behavior, which enables photolysis in the green part of the spectrum. 相似文献
863.
Jakob Kunz 《欧洲无机化学杂志》1898,31(2):1528-1531
864.
865.
Dr. Raju Bej Dr. Chuanxiong Nie Dr. Kai Ludwig Dr. Vahid Ahmadi Dr. Jakob Trimpert Julia M. Adler Dr. Tatyana L. Povolotsky Dr. Katharina Achazi Marten Kagelmacher Ricardo Martin Vidal Dr. Jens Dernedde Dr. Benedikt B. Kaufer Prof. Dr. Rainer Haag 《Angewandte Chemie (International ed. in English)》2023,62(29):e202304010
Mucins are the key component of the defensive mucus barrier. They are extended fibers of very high molecular weight with diverse biological functions depending strongly on their specific structural parameters. Here, we present a mucin-inspired nanostructure, produced via a synthetic methodology to prepare methacrylate-based dendronized polysulfates ( MIP-1 ) on a multi gram-scale with high molecular weight (MW=450 kDa) and thiol end-functionalized mucin-inspired polymer ( MIP ) via RAFT polymerization. Cryo-electron tomography (Cryo-ET) analysis of MIP-1 confirmed a mucin-mimetic wormlike single-chain fiber structure (length=144±59 nm) in aqueous solution. This biocompatible fiber showed promising activity against SARS-CoV-2 and its mutant strain, with a remarkable low half maximal (IC50) inhibitory concentration (IC50=10.0 nM). Additionally, we investigate the impact of fiber length on SARS-CoV-2 inhibition by testing other functional polymers ( MIPs ) of varying fiber lengths. 相似文献
866.
The partial wave crossing relations derived in a recent paper by Steiner [1] are used for a calculation of the πN S-wave amplitudes in the region 8 ≦ s ≦ (M − 1)2. The corresponding Argand diagrams show the pseudoresonance behaviour predicted in [1]. The results for the real parts are compared with an independent calculation using fixed-t dispersion relations. 相似文献
867.
868.
Jakob Lebon Alexandros Mortis Dr. Cäcilia Maichle-Mössmer Dr. Manfred Manßen Dr. Peter Sirsch Prof. Dr. Reiner Anwander 《Angewandte Chemie (International ed. in English)》2023,62(6):e202214599
Commercially available stock solutions of organolithium reagents are well-implemented tools in organic and organometallic chemistry. However, such solutions are inherently contaminated with lithium halide salts, which can complicate certain synthesis protocols and purification processes. Here, we report the isolation of chloride-free methyllithium employing K[N(SiMe3)2] as a halide-trapping reagent. The influence of distinct LiCl contaminations on the 7Li-NMR chemical shift is examined and their quantification demonstrated. The structural parameters of new chloride-free monomeric methyllithium complex [(Me3TACN)LiCH3], ligated by an azacrown ether, are assessed by comparison with a halide-contaminated variant and monomeric lithium chloride [(Me3TACN)LiCl], further emphasizing the effect of halide impurities. 相似文献
869.
870.
Jianyang Han Jakob Arnold Christophe Pannecouque Graciela Andrei Robert Snoeck Clemens Richert 《Helvetica chimica acta》2023,106(1):e202200157
Strongly pairing ethynylpyridone C-nucleosides are attractive surrogates for thymidine in oligonucleotides. Exploratory work on the antiviral activity of 3′-azidothymidine (AZT) derivatives with ethynylpyridone as base had identified strong lipophilicity as a limiting factor. Two strategies are being pursued to overcome this issue. In order to make the base more polar, the ethynyl group has been replaced with a cyano group, leading to a cyanopyridone C-nucleoside, whose eleven-step synthesis is reported here, together with the synthesis of a 3′-azido-2′,3′-dideoxynucleoside derivative. The base pairing with adenine in a DNA duplex was studied by UV melting analysis of a self-complementary hexamer containing the 6-cyano-2′-deoxynucleoside instead of thymidine. A melting point increase of 2 °C compared to the unmodified control was found. The other strategy employs a phosphoramidate prodrug design with less lipophilic amino acid esters. Here, anti-HIV test of the alaninyl and prolinyl methyl esters of AZT gave promising results in cell culture experiments, increasing the selectivity index up to 5.8-fold for the IIIB strain and up to 5-fold for the ROD strain of the virus, as compared to the parent nucleoside. These findings help to design the next generation of pyridone C-nucleosides with potential applications as antivirals. 相似文献