A Selection of Benchmark Problems in Solid Mechanics and Applied Mathematics

In this contribution we provide benchmark problems in the field of computational solid mechanics. In detail, we address classical fields as elasticity, incompressibility, material interfaces, thin structures and plasticity at finite deformations. For this we describe explicit setups of the benchmarks and introduce the numerical schemes. For the computations the various participating groups use different (mixed) Galerkin finite element and isogeometric analysis formulations. Some programming codes are available open-source. The output is measured in terms of carefully designed quantities of interest that allow for a comparison of other models, discretizations, and implementations. Furthermore, computational robustness is shown in terms of mesh refinement studies. This paper presents benchmarks, which were developed within the Priority Programme of the German Research Foundation ‘SPP 1748 Reliable Simulation Techniques in Solid Mechanics—Development of Non-Standard Discretisation Methods, Mechanical and Mathematical Analysis’. © 2020, The Author(s)

Gene expression of NMDA receptor subunits in the cerebellum of elderly patients with schizophrenia

To determine if NMDA receptor alterations are present in the cerebellum in schizophrenia, we measured NMDA receptor binding and gene expression of the NMDA receptor subunits in a post-mortem study of elderly patients with schizophrenia and non-affected subjects. Furthermore, we assessed influence of genetic variation in the candidate gene neuregulin-1 (NRG1) on the expression of the NMDA receptor in an exploratory study. Post-mortem samples from the cerebellar cortex of ten schizophrenic patients were compared with nine normal subjects. We investigated NMDA receptor binding by receptor autoradiography and gene expression of the NMDA receptor subunits NR1, NR2A, NR2B, NR2C and NR2D by in situ hybridization. For the genetic study, we genotyped the NRG1 polymorphism rs35753505 (SNP8NRG221533). Additionally, we treated rats with the antipsychotics haloperidol or clozapine and assessed cerebellar NMDA receptor binding and gene expression of subunits to examine the effects of antipsychotic treatment. Gene expression of the NR2D subunit was increased in the right cerebellum of schizophrenic patients compared to controls. Individuals carrying at least one C allele of rs35753505 (SNP8NRG221533) showed decreased expression of the NR2C subunit in the right cerebellum, compared to individuals homozygous for the T allele. Correlation with medication parameters and the animal model revealed no treatment effects. In conclusion, increased NR2D expression results in a hyperexcitable NMDA receptor suggesting an adaptive effect due to receptor hypofunction. The decreased NR2C expression in NRG1 risk variant may cause a deficit in NMDA receptor function. This supports the hypothesis of an abnormal glutamatergic neurotransmission in the right cerebellum in the pathophysiology of schizophrenia

Uncovering novel peptide chemistry from bacterial natural products

Nature has evolved a remarkable array of biosynthetic enzymes that install diverse chemistries into natural products (NPs), bestowing them with a range of important biological properties that are of considerable therapeutic value. This is epitomized by the ribosomally synthesized and post-translationally modified peptides (RiPPs), a class of peptide natural products that undergo extensive post-translational modifications to produce structurally diverse bioactive peptides. In this review, we provide an overview of our research into the proteusin RiPP family, describing characterized members and the maturation enzymes responsible for their unique chemical structures and biological activities. The diverse enzymology identified in the first two proteusin pathways highlights the enormous potential of the RiPP class for new lead structures and novel pharmacophore-installing maturases as biocatalytic tools for drug discovery efforts.ISSN:0009-429

Ruthenium(II)-Catalyzed C–H Arylation of Azoarenes by Carboxylate Assistance

Ruthenium­(II)­carboxylate complexes enabled the unprecedented direct C–H arylation of azoarenes with aryl halides through chelation assistance. The mild reaction conditions of the optimized C–H functionalization process resulted in a remarkable functional group tolerance. The proximity-induced C–H arylation proceeded with high positional selectivity and could be performed in a one-pot protocol along with a azoarene reduction, providing expedient access to ortho-arylated anilines

A Selection of Benchmark Problems in Solid Mechanics and Applied Mathematics

In this contribution we provide benchmark problems in the field of computational solid mechanics. In detail, we address classical fields as elasticity, incompressibility, material interfaces, thin structures and plasticity at finite deformations. For this we describe explicit setups of the benchmarks and introduce the numerical schemes. For the computations the various participating groups use different (mixed) Galerkin finite element and isogeometric analysis formulations. Some programming codes are available open-source. The output is measured in terms of carefully designed quantities of interest that allow for a comparison of other models, discretizations, and implementations. Furthermore, computational robustness is shown in terms of mesh refinement studies. This paper presents benchmarks, which were developed within the Priority Programme of the German Research Foundation ‘SPP 1748 Reliable Simulation Techniques in Solid Mechanics—Development of NonStandard Discretisation Methods, Mechanical and Mathematical Analysis’