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51.
Dr. Anaïs Depaix Agnieszka Mlynarska-Cieslak Dr. Marcin Warminski Dr. Pawel J. Sikorski Prof. Dr. Jacek Jemielity Dr. Joanna Kowalska 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(47):12190-12197
Labeled RNAs are invaluable probes for investigation of RNA function and localization. However, mRNA labeling remains challenging. Here, we developed an improved method for 3′-end labeling of in vitro transcribed RNAs. We synthesized novel adenosine 3′,5′-bisphosphate analogues modified at the N6 or C2 position of adenosine with an azide-containing linker, fluorescent label, or biotin and assessed these constructs as substrates for RNA labeling directly by T4 ligase or via postenzymatic strain-promoted alkyne-azide cycloaddition (SPAAC). All analogues were substrates for T4 RNA ligase. Analogues containing bulky fluorescent labels or biotin showed better overall labeling yields than postenzymatic SPAAC. We successfully labeled uncapped RNAs, NAD-capped RNAs, and 5′-fluorescently labeled m7Gp3Am-capped mRNAs. The obtained highly homogenous dually labeled mRNA was translationally active and enabled fluorescence-based monitoring of decapping. This method will facilitate the use of various functionalized mRNA-based probes. 相似文献
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2-(l-acetoxyethyl) acrylonitrile 1 can be stereoselectively converted into 2-ethylidene -3-aminonitriles 4 in good yields in the presence of primary or secondary arnines in THF at room temperature. 相似文献
56.
Assuming that a North-South transfer is the key to effective climate cooperation, we ask when and how much the North should offer to the South in return for a commitment to reduce deforestation and forest degradation. In light of the risk of irreversible damage over time, we examine a negotiation with a deadline. In this case, the North threatens the South over a negotiation dead-end in case an agreement is not reached rapidly. We assess the conditions for an agreement to be immediate or delayed, and discuss those situations likely to result in negotiation failure. Despite the risk of irreversible damage over time, we show that cooperation is likely to be delayed and we identify situations wherein the North and South do not reach an agreement within the deadline. Although Pareto-improving, cooperation may collapse because of inefficiencies related to incomplete information. What’s more, we show that in negotiations with a deadline, uncertainty about the benefits deriving from cooperation and the irreversibility of the damage that will be caused if cooperation is delayed are the two key components affecting choice. 相似文献
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Fanny Danton Dr. Mohamed Othman Dr. Ata Martin Lawson Dr. Ján Moncol Dr. Alina Ghinet Prof. Benoît Rigo Prof. Adam Daïch 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(24):6113-6118
An efficient domino transformation using a phenyliodine(III) diacetate (PIDA)/I2 combination towards Morin 1,4-thiazine compounds has been developed starting from N,S-acetals. The latter leads to “one-step” regioselective methylene insertion without the need for traditional sulfoxide intermediates in good yields. The reaction involves easily accessible N,S-acetals obtained from cost-effective basic ketones and cysteamine as starting materials. This process ultimately leads to 1,4-thiazines related to natural product and fused derivatives necessary for further QSAR study. 相似文献
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Anaïs Coffinet Dr. David Specklin Dr. Laure Vendier Prof. Dr. Michel Etienne Dr. Antoine Simonneau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(63):14300-14303
The first example of a formal 1,3-B−H bond addition across the M−N≡N unit of an end-on dinitrogen complex has been achieved. The use of Piers’ borane HB(C6F5)2 was essential to observe this reactivity and it plays a triple role in this transformation: 1) electrophilic N2-borylation agent, 2) Lewis acid in a frustrated Lewis pair-type B−H bond activation, and 3) hydride shuttle to the metal center. This chemistry is supported by NMR spectroscopy and solid-state characterization of products and intermediates. The combination of chelate effect and strong σ donation in the diphosphine ligand 1,2-bis(diethylphosphino)ethane was mandatory to avoid phosphine dissociation that otherwise led to complexes where borylation of N2 occurred without hydride transfer. 相似文献
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Florent Jasinski Emeline Lobry Lénaïg Lefevre Abraham Chemtob Céline Croutxe‐Barghorn Xavier Allonas Adrien Criqui 《Journal of polymer science. Part A, Polymer chemistry》2014,52(13):1843-1853
The use of UV light to initiate emulsion polymerization processes is generally overlooked, whilst extensive literature exists on photocuring of monomer films. In this study, the unique potential of UV light to produce at ambient temperature polyacrylate latexes without initiator was exploited. Although radical initiators are utilized at low concentration, their cost, toxicity, and odor provide incentives for finding alternatives. Starting with concentrated (30 wt %) and low scattering acrylate miniemulsions (droplet diameter <100 nm), it was demonstrated that acrylate self‐initiation can promote an efficient and fast photopolymerization in micrometer‐scale reactor (spectrophotometric cell) and lab‐scale photoreactor. Herein, all kinetic, colloidal, and mechanistic aspects involved in the self‐initiation of acrylate miniemulsion were extensively examined to provide a complete picture. In particular, the effects of droplet size, initiating wavelength, optical path, and irradiance on the course of the polymerization were thoroughly discussed. A diradical self‐initiation pathway is the most likely mechanism. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1843–1853 相似文献
60.
Dr. Oumaïma Gharbi Dr. Mai T. T. Tran Prof. Mark E. Orazem Dr. Bernard Tribollet Dr. Mireille Turmine Dr. Vincent Vivier 《Chemphyschem》2021,22(13):1371-1378
The different contributions of the interfacial capacitance are identified in the case of passive materials or thin protective coatings deposited on the electrode surface. The method is based on a graphical analysis of the EIS results to determine both the passive-film capacitance in the high-frequency domain and the double-layer capacitance in the low-frequency domain. The proposed analysis is shown to be independent of the physicochemical origins of the frequency dispersion of the interfacial capacitances which results, from an analysis point of view of the experimental results, in the use of a constant-phase element However, for a correct evaluation of the thin-film properties such as its thickness, the high-frequency data must be corrected for the double-layer contribution. In particular, it is shown that if the double-layer capacitance gives a frequency-dispersed response, it is necessary to correct the high-frequency part for the double-layer constant-phase elements. This is first demonstrated on synthetic data and then used for the determination of the thickness of thin oxide film formed on Al in neutral pH solution. 相似文献