Interactions between DNA and histones－ a dynamic process of nucleosome formation

We have studied the dynamic process of interactions between a DNA chain and a histone octamer by numerical simulations.It is found that DNA indeed may wrap around the histone octamer about two turns as in the actual situations.The simulation shows that the interaction potential between DNA and histone is a key factor for the wrapping of DNA,and the temperature is also an important parameter in the process.     

T1ρ space dependence in rigid polymers by effective radio frequency gradient

An extension of the solid-state nuclear magnetic resonance (NMR) imaging based on magic angle in the rotating frame (MARF) line narrowing approach is presented. The modified magic angle in the rotating frame imaging sequence is able to yield T_1ρ maps of large band polymers with remarkable contrast sensitivity and without contrast parameter alteration referable to the narrowing procedure. This last feature is examined closely in order to outline the actual effectiveness of the method. Further experimental details, especially regarding probe coil design, recently improved, are discussed and some new results are presented.     

Chirality Induction through Nano-Phase Separation: Alternating Network Gyroid Phase by Thermotropic Self-Assembly of X-Shaped Bolapolyphiles

The single gyroid phase as well as the alternating double network gyroid, composed of two alternating single gyroid networks, hold a significant place in ordered nanoscale morphologies for their potential applications as photonic crystals, metamaterials and templates for porous ceramics and metals. Here, we report the first alternating network cubic liquid crystals. They form through self-assembly of X-shaped polyphiles, where glycerol-capped terphenyl rods lie on the gyroid surface while semiperfluorinated and aliphatic side-chains fill their respective separate channel networks. This new self-assembly mode can be considered as a two-color symmetry-broken double gyroid morphology, providing a tailored way to fabricate novel chiral structures with sub-10 nm periodicities using achiral compounds.     

Feasible Fabrication of Hollow Micro-vesicles by Non-amphiphilic Macromolecules Based on Interfacial Cononsolvency

Herein we present a new perspective showing that water-soluble liquids, when added to water, undergo transient emulsification before complete dissolution. Thus, non-amphiphilic macromolecules can self-assemble at the two-miscible-phase interface when cononsolvent effect appears. A representative case shown here is that when poly(N-isopropylacrylamide)(PNIPAm), prepared by aqueous radical polymerization, in methanol solution is added into water, the polymer chains rapidly self-assemble into hollow micro-vesicles based on the cononsolvency at water/methanol interface. This finding provides a subtle strategy to prepare hollow micro-vesicles by non-amphiphilic polymers without template participating. We proposed a new concept "interfacial cononsolvency" to describe the formation process. Due to the easy modification process, sugar-contained PNIPAm chains are synthesized by copolymerization. As an application example, it is shown that these sugar-contained PNIPAm chains can afford "sweet" micro-vesicles(containing glucose residues). And the "sweet" micro-vesicles can well mimick the protocells which are involved in the recognition of bacteria.     

Lasso Proteins: Modular Design,Cellular Synthesis,and Topological Transformation

Entangled proteins have attracted significant research interest. Herein, we report the first rationally designed lasso proteins, or protein [1]rotaxanes, by using a p53dim-entwined dimer for intramolecular entanglement and a SpyTag-SpyCatcher reaction for side-chain ring closure. The lasso structures were confirmed by proteolytic digestion, mutation, NMR spectrometry, and controlled ligation. Their dynamic properties were probed by experiments such as end-capping, proteolytic digestion, and heating/cooling. As a versatile topological intermediate, a lasso protein could be converted to a rotaxane, a heterocatenane, and a “slide-ring” network. Being entirely genetically encoded, this robust and modular lasso-protein motif is a valuable addition to the topological protein repertoire and a promising candidate for protein-based biomaterials.     

Polymer hydrogel confined palladium nanoparticles as recyclable catalysts for Suzuki and Heck cross-coupling reactions

Reusable palladium nanoparticles highly dispersed in porous and hydrophilic interpenetrating polymer networks(IPN),i.e.,Pd@IPN hybrid gels,are employed for catalysis of Suzuki and Heck coupling reactions.Good yields are obtained with high turnover frequencies when the reactions are run with very low Pdloadings.The use of IPN gives better recyclability than that of crosslinked polyvinyl alcohol alone.The polymer networks allow the reactants to have easy access to the Pd metals.The catalysts combine high activity with the reusability offered by the heterogeneous system,without the need for strong coordination or chelating ligands.     

The Role of Early-Career Chemists in European Policy-Making

Global societal challenges emphasize the importance of collaboration between scientists and policy-makers, while the participation of a diverse group of professionals, including early-career scientists, is critical towards a sustainable future. The European Young Chemists’ Network (EYCN) has been actively working with the European Chemical Society (EuChemS) to create a platform for early-career chemists in policy advice. This article comments on the possible roles of scientists in policy-making and provides an overview of relevant initiatives and platforms at the European level that could facilitate involvement. Opportunities for participation in policy advice from the perspective of early-career chemists are discussed and examples of impact are provided, hoping to stimulate further discussions and engagement in policy-making.     

Building a Cocrystal by Using Supramolecular Synthons for Pressure-Accelerated Heteromolecular Azide–Alkyne Cycloaddition

Facilitated by the supramolecular synthons of carboxylic acids and amides through cooperative hydrogen-bonding and arene–perfluoroarene interactions, the azide–alkyne cycloaddition reaction between two different molecules in a cocrystal was achieved. This reaction could be accelerated by pressure using a common hydraulic press equipment with excellent regioselectivity to yield 1,4-triazole products. The absence of decarboxylation side reactions in the products in the solid state demonstrated that this strategy can provide a green synthetic route for products not directly accessible by traditional syntheses in solution.     

Self-Propagated para-Fluoro-Thiol Reaction

We introduce a protecting-group-free concept for the powerful para-fluoro-thiol reaction (PFTR) employing a source of fluoride ions as base. The reaction is shown to be self-propagating, with under-stoichiometric amounts of base, thus effectively foregoing the need for high base concentrations. Careful tuning of the solvent–thiol combination allows for quantitative conversion, in some cases within a short timeframe, when only minimal amounts of base are used, allowing the PFTR reaction to essentially proceed base-free.