Rational protein design of ThDP-dependent enzymes-engineering stereoselectivity

Benzoylformate decarboxylase (BFD) from Pseudomonas putida is an exceptional thiamin diphosphate-dependent enzyme, as it catalyzes the formation of (S)-2-hydroxy-1-phenylpropan-1-one from benzaldehyde and acetaldehyde. This is the only currently known S-selective reaction (92 % ee) catalyzed by this otherwise R-selective class of enzymes. Here we describe the molecular basis of the introduction of S selectivity into ThDP-dependent decarboxylases. By shaping the active site of BFD through the use of rational protein design, structural analysis, and molecular modeling, optimal steric stabilization of the acceptor aldehyde in a structural element called the S pocket was identified as the predominant interaction for adjusting stereoselectivity. Our studies revealed Leu461 as a hot spot for stereoselectivity in BFD. Exchange to alanine and glycine resulted in variants that catalyze the S-stereoselective addition of larger acceptor aldehydes, such as propanal with benzaldehyde and its derivatives-a reaction not catalyzed by the wild-type enzyme. Crystal structure analysis of the variant BFDL461A supports the modeling studies.     

Performance of the radphi detector and trigger in a high rate tagged photon beam

We describe the design and operation of a detector system for measuring all-photon decays of mesons photoproduced in a tagged photon beam with energies between 4.3 and 5.4 GeV and a flux of 5×10⁷ tagged photons per second. Photons from meson decays were detected with a lead-glass calorimeter with an energy resolution of 11% at 1 GeV. Various veto and trigger components were also present. Final states with as many as six photons were successfully detected and reconstructed.     

Extraction and quantification of phytoestrogens in foods using automated solid-phase extraction and LC/MS/MS

Phytoestrogens are a group of polyphenolic plant metabolites that can induce biological responses. Their bioactivity is based on their similarity to 17beta-estradiol and their ability to bind to the beta-estrogen receptor. Although epidemiological data are inconclusive, phytoestrogens are considered to be beneficial for a variety of conditions, for example, hormone-related cancers like breast and prostate cancer. To investigate the biological effects of these compounds and to assess the exposure of larger cohorts or the general public, reliable data on the phytoestrogen content of food is necessary. Previously, food analysis for phytoestrogens was performed using either HPLC-UV or GC/MS. Here, we describe the development of the first generic method for the analysis of phytoestrogens in food, using automated solid-phase extraction and liquid chromatography-tandem mass spectrometry. The presented method shows a good reproducibility and can be easily adapted to other phytoestrogens if required.     

A comprehensive database schema integration method based on the theory of formal concepts

Integrating heterogeneous database schemata is a major task in federated database design where preexisting and heterogeneous database systems need to be integrated virtually by providing a homogenization database interface. Most proposed schema integration methods suffer from very complex result schemata and insufficient handling of extensional relations, i.e. in the way how redundant data of the input systems are dealt with. Redundancy among the input systems may thus remain undetected and, hence, remains uncontrolled.Our GIM (Generic Integration Model) method is based on the elegant and mathematically founded theory of formal concept analysis (FCA). The main idea is to integrate schemata into one formal context which is a binary relation between a set of attributes and a set of base extensions (set of potential objects). From that context we apply an FCA-algorithm to semi-automatically derive a concept lattice which we interpret as an inheritance hierarchy of classes for a homogenized schema. Thus, the integration task following our method can be supported by tools.     

A Contactless Inductive Velocity Reconstruction Method for Metallic and Semiconducting Melts

The knowledge of the flow in metallic and semiconducting melts is important for a number of industrial problems. Optical methods cannot be applied due to the opaqueness of those fluids. Ultrasonic methods have problems with wetting and thermal stability when applied in hot metallic melts. Evidently, contactless methods for velocity determination would be highly desirable. In some applications, even a coarse knowledge of the flow topology and the direction of the main eddies would be of high value. The study examines the possibility of velocity reconstruction in electrically conducting fluids from external measurements of different induced magnetic fields. It is shown that, for a reliable velocity reconstruction, the effect of the electric potential at the fluid boundary on the induced magnetic field should be taken into account.     

Japanese Manufacturing Techniques: Nine Hidden Lessons in Simplicity

Compound orthogonal arrays (COAs) and single arrays are alternatives to the inner–outer arrays advocated by Taguchi for robust parameter design experiments. A criterion based on the word type pattern and strength of COAs is proposed to select optimal COAs. Single arrays are classified into prodigal single arrays (PSAs) and economical single arrays (ESAs) according to their relative estimation capacities, and various optimality criteria, again based on the word type pattern, are proposed for selecting optimal single arrays. Useful optimal COAs, PSAs, and ESAs are constructed and tabulated as convenient references for experimenters in practice.     

Evaluierung und Optimierung einer doppelschaligen Fassade mit Hilfe von Simulationen

Bei großflächig verglasten, mehrgeschossigen Bürogebäuden liegen doppelschalige, hinterlüftete Glasfassaden nach wie vor im gestalterischen Trend. Die Konstruktionsdetails der Fassade haben einen erheblichen Einfluss auf die sommerliche Überhitzung der Luft im Fassadenzwischenraum (FZR), in dem auch der Sonnenschutz platziert ist. Es empfiehlt sich daher, die Details einer doppelschaligen Fassade im Hinblick auf die sommerlichen Temperaturverhältnisse zu optimieren. Die üblichen Methoden einer standardmäßigen bauphysikalischen Planung sind für eine derartige Optimierung nur sehr bedingt verwendbar. Im vorliegenden Beitrag wird anhand des Projektes Neues K & H Bank‐Gebäude in Budapest exemplarisch aufgezeigt, wie mit Hilfe von moderner Simulationstechnik die Ausbildung einer doppelschaligen Fassade evaluiert und anschließend optimiert werden kann. Evaluation and optimization of a double skin façade with the help of computational simulations. Natural ventilated double skin façades still prove to be trendy design choices for multi‐story office buildings with large glazed surfaces. The construction design details of these façades have a significant impact on the summer overheating of the air in the façade cavity, in which the shading is positioned also. Therefore it is recommended to investigate and optimize the parameters of the double skin façade concerning the summer temperature conditions. The usual methods of standard building physical planning have limited application possibilities for optimizing these kinds of systems. Therefore in the following article through the example of the K°&°H Bank, Budapest, we are going to explain how the modern simulation techniques can support the constructional design of double skin façades first by evaluation, then subsequently, by optimization.