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101.
Thomas Albers Joseph Grobe Andreas H. Maulitz Ernst‐Ulrich Würthwein 《无机化学与普通化学杂志》2005,631(8):1430-1438
Reactive E=C(p‐p)π‐Systems. 54 [1] Reactions of perfluoro‐2‐arsapropene, F3CAs=CF2 (1), with H‐acidic compounds Me2EH (E = N, P, As) and MeE′H (E′ = O, S, Se) The reactions of the perfluoro‐2‐arsapropene ( 1 ) with H‐acidic compounds Me2EH (E = N, P, As) and MeE′H (E′ = O, S, Se), respectively, proceed via addition to the As=C double bond yielding either secondary arsanes F3C(H)AsCF2X (X = NMe2, PMe2, OMe, SMe) or AsX derivatives (X = AsMe2, SeMe). Me2‐AsH is obviously a border case nucleophile because, besides the AsX derivative as main product, small amounts of the arsane are formed indicative for the reverse addition pathway. With the strong base Me2NH, the addition is followed immediately by HF elimination producing the fairly stable arsaalkene F3CAs=C(F)NMe2 ( 4 ) which had already been obtained by reaction of HAs(CF3)2 with three equivalents of Me2NH. The novel rather labile compounds were identified by spectroscopic (NMR, GC/MS) investigations. – Quantum chemical DFT calculations [B3LYP/6‐311+G(d,p)] were carried out to determine the relative energy of the isomeric products and the thermodynamics of the addition reactions. 相似文献
102.
Dr. Niall M. McLoughlin Marvin A. Albers Dr. Estel Collado Camps Dr. Jannik Paulus Youri A. Ran Dr. Saskia Neubacher Dr. Sven Hennig Prof. Dr. Roland Brock Prof. Dr. Tom N. Grossmann 《Angewandte Chemie (International ed. in English)》2023,62(41):e202308028
Double-stranded RNAs (dsRNA) possess immense potential for biomedical applications. However, their therapeutic utility is limited by low stability and poor cellular uptake. Different strategies have been explored to enhance the stability of dsRNA, including the incorporation of modified nucleotides, and the use of diverse carrier systems. Nevertheless, these have not resulted in a broadly applicable approach thereby preventing the wide-spread application of dsRNA for therapeutic purposes. Herein, we report the design of dimeric stapled peptides based on the RNA-binding protein TAV2b. These dimers are obtained via disulfide formation and mimic the natural TAV2b assembly. They bind and stabilize dsRNA in the presence of serum, protecting it from degradation. In addition, peptide binding also promotes cellular uptake of dsRNA. Importantly, peptide dimers monomerize under reducing conditions which results in a loss of RNA binding. These findings highlight the potential of peptide-based RNA binders for the stabilization and protection of dsRNA, representing an appealing strategy towards the environment-triggered release of RNA. This can broaden the applicability of dsRNA, such as short interfering RNAs (siRNA), for therapeutic applications. 相似文献
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The concentration and identity of the compounds detected in the vapor above six ionic liquids by headspace gas chromatography (HS-GC) at 100 degrees C are reported. In addition, the partition coefficients for 10 different compounds in these ionic liquids and limits of detection were measured. These results provide quantitative guidance for the application of ionic liquids for HS-GC. 相似文献
106.
Miller EW Albers AE Pralle A Isacoff EY Chang CJ 《Journal of the American Chemical Society》2005,127(47):16652-16659
The syntheses, properties, and biological applications of the Peroxysensor family, a new class of fluorescent probes for hydrogen peroxide, are presented. These reagents utilize a boronate deprotection mechanism to provide high selectivity and optical dynamic range for detecting H2O2 in aqueous solution over similar reactive oxygen species (ROS) including superoxide, nitric oxide, tert-butyl hydroperoxide, hypochlorite, singlet oxygen, ozone, and hydroxyl radical. Peroxyresorufin-1 (PR1), Peroxyfluor-1 (PF1), and Peroxyxanthone-1 (PX1) are first-generation probes that respond to H2O2 by an increase in red, green, and blue fluorescence, respectively. The boronate dyes are cell-permeable and can detect micromolar changes in H2O2 concentrations in living cells, including hippocampal neurons, using confocal microscopy and two-photon microscopy. The unique combination of ROS selectivity, membrane permeability, and a range of available excitation/emission colors establishes the potential value of PR1, PF1, PX1, and related probes for interrogating the physiology and pathology of cellular H2O2. 相似文献
107.
V. G. Ostroumov I. A. Shcherbakov E. V. Zharikov Ch. Pfistner P. Albers H. P. Weber 《Optical and Quantum Electronics》1990,22(Z1):S133-S139
In this paper some spectroscopic properties of Y3Sc2Ga3O12 (YSGG):Cr,Ho, YSGG:Cr,Tm and YSGG:Cr,Tm,Ho are presented. The three lowest energetic manifolds of Ho3+ and Tm3+ in YSGG have been determined at 10 K. Time-resolved fluorescence build-up and decay of the laser active ions was measured in three crystals with different dopant concentrations. The transitions investigated were5I7 5I8 for Ho3+ near 2000 nm and3H4 3H6 for Tm3+ near 1800 nm. The data found on time-resolved fluorescence and energy level positions are useful for the discussion of the energy transfer characteristics of the system. 相似文献
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The operation of an eightfold longitudinally diode laser pumped 1.06m cw Nd:YAG slab laser is demonstrated. The 809 nm diode radiation is focused through a dichroic coating into each laser channel starting from the reflection points of the 1.06m beam in the slab crystal. At an absorbed pump power in the crystal of 2830 mW a maximum cw TEM00 output of 1075 mW was achieved with a corresponding slope efficiency of 42.5%. 相似文献