SDS electrophoresis of legume seed proteins in horizontal ultrathin-layer pore gradient gels

Summary Horizontal SDS electrophoresis of 18 legume seed protein extracts was performed in ultrathin-layer polyacrylamide gels on foil supports. Separation results of the SD S pore gradient electrophoresis (T=4–22.5%) are compared to those of SDS electrophoresis in a constant pore size gel (T=10%). Resolution as well as the sensitivity (0.1 g protein per band) of the ultrathin-layer SDS pore-gradient electrophoresis were extremely high. Because of the very low gel thickness, separation, staining and drying were completed in substantially shorter times than achieved with conventional thick gels. An easy technique for casting ultrathin-layer (360 gm) concave gradient gels for 10 cm separation distance and a width of 25 cm is described. The even distribution of the concave exponential pore-gradient over the whole gel width is demonstrated. Molecular weights of the legume proteins are detected from 5,000 to 110,000 daltons. The protein patterns are genus- and species-specific.

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Horizontale Ultradünnschicht SDS-Gradientengel-Elektrophorese von Leguminosensamenproteinen

Zusammenfassung Die ausgezeichnete Trennschärfe der horizontalen Ultradünnschicht-SDS-Gradienten-gel Elektrophorese wird am Beispiel von Samenproteinen 18 verschiedener Leguminosengattungen, -arten und -sorten gezeigt. Es werden die Trennergebnisse der SDS-Elektrophorese mit Gelgradienten (T=4-22,5%) bzw. mit Gelen konstanter Porengröße (T=10%) verglichen. Das höchste Auslösungsvermögen und die beste Trennschärfe zeigen ultradünne Gradientengele. Die Nachweisempfindlichkeit ist bei allen Ultradünn-schicht-SDS-Elektrophoresen sehr hoch (0,1 g Protein/Bande). Da die auf Folie polymerisierten Gele sehr dünn sind (360 m) kann mit wesentlich verkürzten Trenn-, Färbe-, Entfärbe- und Trocknungszeiten gear-beitet werden. Es wird eine einfache Herstellung ultradünner Polyacrylamidgele mit exponentiellen konkaven Gradienten für die Trenndistanz von 10 cm mit einer Breite von 25 cm beschrieben. Die gerade und gleichmäßige Verteilung des Gradienten über die gesamte Gelbreite wird gezeigt. Mit der beschriebenen Methode werden bei den untersuchten Leguminosen-proteinen Molekulargewichte von 5 000 his 110 000 Dalton gefunden. Die Proteinmuster erweisen sich als gattungs- und artspezifisch.

     

An automated Thixo‐Forging Plant for Steel Parts

The scope of the article is to describe the automated production of a thixoformed steel part. The production plant was set up within a prototype initiative at the Institute of Metal Forming in cooperation with the Institute of Automatic Control of RWTH Aachen University and industrial partners. Preliminary experiments showed that the quality of the formed parts varied to a great extent due to changing production conditions since the handling of the billet was carried out manually. To eliminate the possible disturbances introduced by the manual handling of the billet, an automation concept has been elaborated in order to guarantee a defined production environment. An industrial robot (KUKA) fulfils the handling tasks like the feeding of the induction coil with the feedstock material and the placing of the heated billet into the hydraulic press. The removal of the formed part from the press is realised by a simple mechanical device in order to be able to use only one gripper. The design of the gripper ensures a minimal heat loss during handling. The induction coil, the gripper system and the cavity are flooded with inert gas in order to prevent scaling. The sequence control for the production of a part is realised on the controller of the robot which provides sufficient PLC functionality and can be easily equipped with the required I/O components to trigger the different automation components.     

Performance Comparison of Four Fiber-Reinforced Polymer Deck Panels

In an effort to assess the constructability and performance of bridges with fiber-reinforced polymer (FRP) composite decks, the short-term and long-term responses of a 207 m, five-span bridge retrofitted with four different FRP panel systems were monitored. The overall aspects of the panel systems, connection details, and construction techniques are presented prior to presentation of the observed and measured responses. Key design parameters (impact factors, girder distribution factors, and level of composite action) for FRP and reinforced concrete decks are evaluated. This paper demonstrates that FRP replacement decks are a viable alternative to reinforced concrete decks and identifies the differences in performances of various FRP deck systems. Two of the FRP panel systems were found to perform considerably better than the other deck systems. Issues that may reduce the service life of FRP deck systems are presented and discussed.     

Error diffusion in cell-oriented Fourier-transform computer-generated holograms to compensate for printing constraints

Abstract

Error-diffused quantization has been applied to the generation of cell-oriented computer-generated Fourier transform holograms, resulting in reduced reconstruction errors. Improvements are demonstrated when applied to the algorithms of Lohmann, Lee and Burckhardt after invoking realistic constraints on the minimum size of the printable spot for an electrophotographic laser printer.     

Quality assurance and traceability of foods of animal origin: major findings from the research project IT FoodTrace

Based on the information needs of stakeholders (from animal feed to consumers, including the authorities and organizations involved) an integrated IT-system without structural fractures and barriers shall be developed. It will be designed to enable the merging, internal exchange and utilization of relevant data and parameters. Subprojects of the interdisciplinary research consortium cover the entire supply chain and also address cross-section issues, such as logistics, costs and benefits, veterinarian services, quality assurance systems, a comprehensive IT-solution including data format standards (agroXML), and requirements for sustainability. Substantial added value has been generated from intensive interdisciplinary co-operation. The interdisciplinary research project IT FoodTrace () aims at achieving traceability and quality assurance along the food chain of “meat and meat products”. The aim of this paper is the presentation of (a) the complexity of underlying problems, (b) the project structure, (c) available results from selected sub-projects and (d) the added values from interdisciplinary co-operation. Selected findings include an optimized single animal data collection and information management in livestock systems, benefits gained by linking animal-health-related information to an integrated animal-health system, requirements and features of an integrated IT-System, including consequences for data protection and security, and findings from a Delphi-based cost–benefit-analysis of an integrated quality assurance and traceability system.     

Near‐Infrared Intraoperative Chemiluminescence Imaging

Intraoperative imaging technologies recently entered the operating room, and their implementation is revolutionizing how physicians plan, monitor, and perform surgical interventions. In this work, we present a novel surgical imaging reporter system: intraoperative chemiluminescence imaging (ICI). To this end, we have leveraged the ability of a chemiluminescent metal complex to generate near‐infrared light upon exposure to an aqueous solution of Ce⁴⁺ in the presence of reducing tissue or blood components. An optical camera spatially resolves the resulting photon flux. We describe the construction and application of a prototype imaging setup, which achieves a detection limit as low as 6.9 pmol cm^?2 of the transition‐metal‐based ICI agent. As a proof of concept, we use ICI for the in vivo detection of our transition metal tracer following both systemic and subdermal injections. The very high signal‐to‐noise ratios make ICI an interesting candidate for the development of new intraoperative imaging technologies.     

Time‐resolved investigation of Cu(In,Ga)Se2 growth and Ga gradient formation during fast selenisation of metallic precursors

Ga segregation at the backside of Cu(In,Ga)Se₂ solar cell absorbers is a commonly observed phenomenon for a large variety of sequential fabrication processes. Here, we investigate the correlation between Se incorporation, phase formation and Ga segregation during fast selenisation of Cu–In–Ga precursor films in elemental selenium vapour. Se incorporation and phase formation are analysed by real‐time synchrotron‐based X‐ray diffraction and fluorescence analysis. Correlations between phase formation and depth distributions are gained by interrupting the process at several points and by subsequent ex situ cross‐sectional electron microscopy and Raman spectroscopy. The presented results reveal that the main share of Se incorporation takes place within a few seconds during formation of In–Se at the top part of the film, accompanied by outdiffusion of In out of a ternary Cu–In–Ga phase. Surprisingly, CuInSe₂ starts to form at the surface on top of the In–Se layer, leading to an intermediate double graded Cu depth distribution. The remaining Ga‐rich metal phase at the back is finally selenised by indiffusion of Se. On the basis of a proposed growth model, we discuss possible strategies and limitations for the avoidance of Ga segregation during fast selenisation of metallic precursors. Solar cells made from samples selenised with a total annealing time of 6.5 min reached conversion efficiencies of up to 14.2 % (total area, without anti‐reflective coating). The evolution of the Cu(In,Ga)Se₂ diffraction signals reveals that the minimum process time for high‐quality Cu(In,Ga)Se₂ absorbers is limited by cation ordering rather than Se incorporation. Copyright © 2014 John Wiley & Sons, Ltd.