Characterization of the mitochondrial processing peptidase of Neurospora crassa

The mitochondrial processing peptidase (MPP) of Neurospora crassa is constituted by an alpha- and a beta-subunit. We have purified alpha-MPP after expression in Escherichia coli while beta-MPP was purified from mitochondria. A fusion protein between precytochrome b2 and mouse dihydrofolate reductase was expressed in E. coli, and the purified protein was used as substrate for MPP. Both subunits of MPP are required for processing. MPP removes the matrix targeting signal of cytochrome b2 by a single cut, and the resulting presequence peptide is 31 amino acid residues in length. It acts as a competitive inhibitor of processing but has a approximately 30-fold lower affinity for MPP than the preprotein. Competition assays show that MPP recognizes the COOH- terminal portion of the presequence of cytochrome b2 rather than the NH2-terminal part which has the potential to form an amphiphilic helix. Substitution of arginine in position -2 of the matrix targeting sequence of cytochrome b2 prevents processing but not import of a chimeric precursor. Substitution of the tyrosyl residue in position +1 also prevents processing, indicating that MPP interacts with sequences COOH-terminal to the cleavage site. Non-cleavable preprotein is still recognized by MPP. Our data suggest that processing peptidase and import machinery recognize distinct structural elements in preproteins which, however, can be overlapping

Sustainable product development: Provision of information in early automotive engineering phases

Sustainable product development is an important influencing factor in automotive engineering, whereby a comprehensive evaluation of its efforts and benefits is very complex. In addition, lots of information is not available in advance of mass production. This leads to the question, how results from impact assessment can be transferred to the beginning of the development process, where important decisions about product and production characteristics are made. The present paper discusses approaches for life cycle estimation and decision support in the concept phase of automotive engineering, especially focusing on the design engineer’s requirements. It includes an overview of current development processes and discusses by use of examples different approaches to integrate relevant information concerning sustainable product development in development processes

Autonomous Charging of Electric Vehicles in Industrial Environment

Modern industrial manufacturing involves several manually and automated driven vehicles - not only for logistics and production purposes, but also for services, maintenance, resources supply and cleaning. These different types of vehicles are increasingly driven by electric powertrains that operate in the production halls, warehouses and other involved areas. Today, electric charging of these mobile devices is accomplished mainly manually and by use of a number of different not standardized charging interfaces, which leads to increased time and cost efforts. The paper evaluates different charging technologies for the use in industrial environments and introduces a new approach for automated, robot-controlled charging of electric vehicles, which is based on a standardized charging interface. The technology has been developed to fully automated charge different types of cars and other vehicles and consists of a vision system to identify the vehicle and the charging connector position in combination with a fully-controlled robotic system that plugs-in and -off the charging connector. In this way, the system is universally applicable for different types of autonomously and manually driven vehicles in a professional context, e.g. in production, logistics and warehouses

Greenhouse Gas Emissions of Electric Cars - A Comprehensive Evaluation

As an important trend in the automotive industry, electrification of propulsion systems has potential to significantly reduce greenhouse gas emissions of the transportation sector. Whereas electric vehicles do not produce exhaust emissions during driving, the impact of electricity provision for charging the batteries as well as the impact of vehicle production play an essential role in a holistic consideration of the carbon footprint. The paper introduces a comprehensive evaluation of greenhouse gas emission-related factors of battery-electric cars, considering the entire product life cycle. This comprises vehicle production, including battery system, electric powertrain and other relevant components, the car’s use phase under consideration of different electricity mixes, user patterns and the end-of-life phase. The results of the study can serve as a basis for comparison with the characteristics of cars driven by conventional propulsion systems and allow a detailed discussion of the different technologies, especially under consideration of future development trends

Nonclassical Recrystallization

Applications in the fields of materials science and nanotechnology increasingly demand monodisperse nanoparticles in size and shape. Up to now, no general purification procedure exists to thoroughly narrow the size and shape distributions of nanoparticles. Here, we show by analytical ultracentrifugation (AUC) as an absolute and quantitative high-resolution method that multiple recrystallizations of nanocrystals to mesocrystals is a very efficient tool to generate nanocrystals with an excellent and so-far unsurpassed size-distribution (PDIc=1.0001) and shape. Similar to the crystallization of molecular building blocks, nonclassical recrystallization removes “colloidal” impurities (i.e., nanoparticles, which are different in shape and size from the majority) by assembling them into a mesocrystal. In the case of nanocrystals, this assembly can be size- and shape-selective, since mesocrystals show both long-range packing ordering and preferable crystallographic orientation of nanocrystals. Besides the generation of highly monodisperse nanoparticles, these findings provide highly relevant insights into the crystallization of mesocrystals. © 2020 The Authors. Published by Wiley-VCH Gmb

Managing hospital visitor admission during Covid-19: A discrete-event simulation by the data of a German University Hospital

The Corona pandemic and the associated need for visitor restrictions have defined an entirely new management task in hospitals: The hospital visitor management. The admission process of hospital visitors and the implementation of associated infection-prevention strategies such as the delivery of face masks thereby pose major challenges. In this work, we evaluate both implemented and planned admission processes in a German University Hospital based on a discrete-event simulation model and provide distinct recommendations for hospital visitor management with special consideration of digitalization, antigen testing, waiting times, space and staff utilization. We find the extraordinary potential of digitalization with a reduction of visitor waiting and service times of up to 90 percent, the significant burden for personnel and room capacity, in terms of antigen testing, especially, and the need for visitor restrictions in terms of a maximum number of visitors per inpatient