o-Quinodimethane Atropisomers: Enantioselective Synthesis and Stereospecific Transformation

o-Quinodimethanes have remarkable utility as reactive inter-mediates in Diels-Alder reactions, enabling significantly accelerated routes to complex polycyclic compounds. The discovery of different discrete pre-cursors to thermally generate o-quinodimethanes thereby greatly augmented their availability and versatility. However, due to the required high tem-peratures and the immense reactivity of o-quino-di-methanes, stereo-selectivity to afford iso-merically defined products still constitutes a critical challenge. Herein, we describe the accessibility of atropisomeric o-quino-dimethanes, the enantio-selective synthesis of their precursors, their remarkable configurational stability and the stereo-specific transformation by the benz-annulation of dienophiles. A catalyst-stereo-controlled [2+2+2] cyclo-addition, the generation of o-quino-dimethane atrop-isomers and ensuing stereo-specific Diels-Alder reactions enabled enantio-selectivities through these transient inter-mediates with of up to 96:4 e.r

Importance of co-captured gases in the underground storage of CO2 : Quantification of mineral alterations in chemical experiments

AbstractCarbon dioxide capture and geological storage (CCS) is being developed to reduce the carbon dioxide (CO2) emissions from anthropogenic point sources, e.g. fossil-fuel power plants, to the atmosphere. To establish CCS technology, it is indispensable to develop a reliable database and geochemical models concerning the geological storage of CO2, e.g. in saline aquifers, which are to be filled with “overwhelmingly CO2” (Directive 2009/31/EC). To establish reliable models it is essential to have applicable thermodynamic properties, kinetic data, and a good understanding of the occurring chemical reactions. So far most experiments and existing data apply to pure CO2 gas instead of the captured CO2 waste gas that will contain minor amounts of co-captured gases, e.g. O2, N2, NOx, SOx, CO, H2, H2S. Quantitative measures of the chemical alterations due to these accessory gases are scarce.In the national COORAL project “ CO2 Purity for Separation and Storage”, a number of institutions work towards a better understanding of environmentally and economically feasible concentrations of the accessory gases during capture, transport, injection and storage. The sub-project at BGR focuses on high-pressure and high-temperature (HPHT) experiments to elucidate mineral and fluid alterations and quantify kinetic rates for the mineral-fluid- CO2-co-injected gas system. An unstirred batch-reactor system allows for four contemporaneous experiments at precisely defined p-T conditions of up to p≤590 bar T≤350 °C. Runs are conducted using three components: (1) natural mono-minerals, (2) salt solutions representing brines of deep saline aquifers in Northern Germany and (3) binary gas mixtures of CO2 plus one accessory gas. All experiments take place in an inert environment, using gold reaction cells with volumes of up to 130 ml, which allow the addition or removal of fluids throughout the experiment without altering the experimental conditions. Further experiments comprise experiments using (1) multi-mineral set-ups in a batch experiment and (2) up to 45-cm-long sedimentary rock cores in flow-through reactors. The latter system is currently under construction, while batch - and capsular - experiments run successfully.To further optimize the experimental design and to evaluate the experiments the project combines laboratory experiments and numerical simulations, applying the geochemical simulators PHREEQC and ChemApp which will be coupled to OpenGeoSys (OGS) for thermo-hydro-mechanical-chemical (THMC) process simulations

16p11.2 600 kb Duplications confer risk for typical and atypical Rolandic epilepsy

Rolandic epilepsy (RE) is the most common idiopathic focal childhood epilepsy. Its molecular basis is largely unknown and a complex genetic etiology is assumed in the majority of affected individuals. The present study tested whether six large recurrent copy number variants at 1q21, 15q11.2, 15q13.3, 16p11.2, 16p13.11 and 22q11.2 previously associated with neurodevelopmental disorders also increase risk of RE. Our association analyses revealed a significant excess of the 600 kb genomic duplication at the 16p11.2 locus (chr16: 29.5-30.1 Mb) in 393 unrelated patients with typical (n = 339) and atypical (ARE; n = 54) RE compared with the prevalence in 65 046 European population controls (5/393 cases versus 32/65 046 controls; Fisher's exact test P = 2.83 × 10−6, odds ratio = 26.2, 95% confidence interval: 7.9-68.2). In contrast, the 16p11.2 duplication was not detected in 1738 European epilepsy patients with either temporal lobe epilepsy (n = 330) and genetic generalized epilepsies (n = 1408), suggesting a selective enrichment of the 16p11.2 duplication in idiopathic focal childhood epilepsies (Fisher's exact test P = 2.1 × 10−4). In a subsequent screen among children carrying the 16p11.2 600 kb rearrangement we identified three patients with RE-spectrum epilepsies in 117 duplication carriers (2.6%) but none in 202 carriers of the reciprocal deletion. Our results suggest that the 16p11.2 duplication represents a significant genetic risk factor for typical and atypical R

Reliability as a Key Driver for a Sustainable Design of Adaptive Load-Bearing Structures

The consumption of construction materials and the pollution caused by their production can be reduced by the use of reliable adaptive load-bearing structures. Adaptive load-bearing structures are able to adapt to different load cases by specifically manipulating internal stresses using actuators installed in the structure. One main aspect of quality is reliability. A verification of reliability, and thus the safety of conventional structures, was a design issue. When it comes to adaptive load-bearing structures, the material savings reduce the stiffness of the structure, whereby integrated actuators with sensors and a control take over the stiffening. This article explains why the conventional design process is not sufficient for adaptive load-bearing structures and proposes a method for demonstrating improved reliability and environmental sustainability. For this purpose, an exemplary adaptive load-bearing structure is introduced. A linear elastic model, simulating tension in the elements of the adaptive load-bearing structure, supports the analysis. By means of a representative local load-spectrum, the operating life is estimated based on Woehler curves given by the Eurocode for the critical notches. Environmental sustainability is increased by including reliability and sustainability in design. For an exemplary high-rise adaptive load-bearing structure, this increase is more than 50%

Consideration of reliability and sustainability in mechanical and civil engineering design to reduce oversizing without risking disasters

Technical systems have to be designed that the requirements regarding service life are met with high reliability to ensure safe product operation. In many cases, the design is still based on single events, such as extreme load levels and additional safety factors, in order to ensure reliability, which is accompanied by a high degree of oversizing. This means that significantly more resources are consumed than actually needed in order to ensure the reliability requirement. To prevent reliability from being ensured solely by oversizing, reliability criteria must be supplemented by the claim for sustainability starting with the product design. On the one hand, profound reliability considerations make safety factors obsolete. On the other hand, oversizing is limited by the claim for sustainability. The overall result is a sustainable design while ensuring reliability at the same time. Within this work, two case studies from two different industrial sectors are introduced to show the trade-off in which the design has to be developed and how an overall solution proposal can look like. In both case studies, the savings in terms of resources and greenhouse gases emitted are shown while considering reliability and sustainability during the product design phase