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    US modelling study estimates impact of school closures for COVID-19 on US health-care workforce and associated mortality

    US policymakers considering physical distancing measures to slow the spread of COVID-19 face a difficult trade-off between closing schools to reduce transmission and new cases, and potential health-care worker absenteeism due to additional childcare needs that could ultimately increase mortality from COVID-19, according to new modelling research. …read more

    Source:: Sciencedaily

          

    Divergent Chemistry Paths for 3D and 1D Metallo‐Covalent Organic Frameworks

    The marriage of dynamic covalent chemistry (DCC) and coordination chemistry is a powerful tool for assembling complex architectures from simple building units. Recently, the synthesis of woven covalent organic frameworks (COFs) with topologically fascinating structures has been achieved using this approach. However, the scope is highly limited and there is a need to discover new pathways that can assemble covalently linked organic threads into crystalline frameworks. Here, we have identified branching pathways leading to the assembly of three‐dimensional (3D) woven COFs or one‐dimensional (1D) metallo‐COFs (mCOFs), where the mechanism is underpinned by the absence or presence of ligand exchange.

    …read more

    Source:: Angewandte Chemie Int. edition

          

    Single‐Layered Chiral Nanosheets with Dual Chiral Void Spaces for Highly Efficient Enantiomer Absorption

    Although considerable effort in recent years has been devoted to the development of 2‐dimensional nanostructures, single layered chiral sheet structures using lateral assembly of discrete clusters remain elusive. Here, we report single‐layered chiral 2D sheet structures with dual chiral void spaces in which the discrete clusters of planar aromatic segments are arranged with in‐plane AB order in aqueous methanol solution. The chirality of the sheet is induced by the slipped‐cofacial stacks of rectangular plate‐like aromatic segments in the discrete clusters which are arranged laterally with up the down packing, resulting in dual chiral void spaces. The chiral nanosheets function as superfast enantiomer separation nanomaterials which absorb rapidly a single enantiomer in a racemic mixture with greater than 99 % ee .

    …read more

    Source:: Angewandte Chemie Int. edition

          

    NASA’s Perseverance Mars rover gets its wheels and air brakes

    Final assembly and testing of NASA’s Perseverance rover continues at Kennedy Space Center in Florida as the July launch window approaches. In some of the last steps required prior to stacking the spacecraft components in the configuration they’ll be in atop the Atlas V rocket, the rover’s wheels and parachute have been installed. …read more

    Source:: Physorg Latest

          

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