Progress in NMR in general and in biomolecular applications in particular is driven by increasing magnetic-field strengths leading to improved resolution and sensitivity of the NMR spectra. Recently, persistent superconducting magnets at a magnetic field strength (magnetic induction) of 28.2 T corresponding to 1200 MHz proton resonance frequency became commercially available. We present here a collection of high-field NMR spectra of a variety of proteins, including molecular machines, membrane proteins, viral capsids, fibrils and large molecular assemblies. We show this large panel in order to provide an overview over a range of representative systems under study, rather than a single best performing model system. We discuss both carbon-13 and proton-detected experiments, and show that in 13C spectra substantially higher numbers of peaks can be resolved compared to 850 MHz while for 1H spectra the most impressive increase in resolution is observed for aliphatic side-chain resonances.

Recently, the topographic patterning of surfaces by lithography and nanoimprinting has emerged as a new and powerful tool for producing single structural domains of liquid crystals and other soft materials. Here the use of surface topography is extended to the organization of liquid crystals of bent-core molecules, soft materials that, on the one hand, exhibit a rich, exciting, and intensely studied array of novel phases, but that, on the other hand, have proved very difficult to align. Among the most notorious in this regard are the polarization splay modulated (B7) phases, in which the symmetry-required preference for ferroelectric polarization to be locally bouquet-like or "splayed" is expressed. Filling space with splay of a single sign requires defects and in the B7 splay is accommodated in the form of periodic splay stripes spaced by defects and coupled to smectic layer undulations. Upon cooling from the isotropic phase this structure grows via a first order transition in the form of an exotic array of twisted filaments and focal conic defects that are influenced very little by classic alignment methods. By contrast, growth under conditions of confinement in rectangular topographic channels is found to produce completely new growth morphology, generating highly ordered periodic layering patterns. The resulting macroscopic order will be of great use in further exploration of the physical properties of bent-core phases and offers a route for application of difficult-to-align soft materials as are encountered in organic electronic and optical applications.topographical confinement | monodomain | banana shaped | anchoring L iquid crystals (LCs) of bent-core "banana-shaped" molecules have come under intense investigation following the discovery of smectic phases in which polar ordering and macroscopic chirality appear as spontaneously broken symmetries (1, 2). Among the more exotic of these are the B7 phases, in which the polarization field exhibits a periodic splay modulation, leading, in combination with the fluid smectic layering, to intricate textures in bulk samples (3-6). As for many smectics appearing upon cooling directly from the isotropic phase via a first order transition, i.e., having no intervening nematic phase, the B7s are not easily aligned into macroscopically oriented domains of any sort with the anisotropic surface treatment methods such as optical-or mechanical-rubbed polymer surfaces or obliquely deposited silicon monoxide (SiOx) (7-11) that are typically useful for aligning LCs. Topographic patterning has been demonstrated to align LCs (12-14) and has recently emerged as an effective alignment technique for both nematic and smectic LCs, and in particular for layered LC phases growing directly from the isotropic (15)(16)(17)(18).In this paper we report the successful use of topographical confinement to control the spatial organization of the B7 smectic phase, employing linear micron-scale channels of rectangular cross-section etched into the surface of silicon wafers. Smectic layer orientat...

Summary In this paper, a numerical model to predict flow‐induced shear failure along pre‐existing fractures is presented. The framework is based on a discrete fracture representation embedded in a continuum describing the damaged matrix. A finite volume method is used to compute both flow and mechanical equilibrium, whereas specifically tailored basis functions are used to account for the physics at discontinuities. The failure criterion is based on a maximum shear strength limit, which changes with varying compressive stress on the fracture manifold. The displacements along fracture manifolds are obtained such that force balance is achieved under conditions, where shear stress of the failing fracture segment is constrained to the maximum shear strength at the segment. Simultaneously, the fluid pressure is computed independently of the shear slip. A relaxation model approach is used to obtain the maximum shear limit on the fracture manifold, which leads to grid convergence.

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