Cell-Free Synthesis of Selenoproteins in High Yield and Purity for Selective Protein Tagging

The selenol group of selenocysteine is much more nucleophilic than the thiol group of cysteine. Selenocysteine residues in proteins thus offer reactive points for rapid post-translational modification. Herein, we show that selenoproteins can be expressed in high yield and purity by cell-free protein synthesis by global substitution of cysteine by selenocysteine. Complete alkylation of solvent-exposed selenocysteine residues was achieved in 10 minutes with 4-chloromethylene dipicolinic acid (4Cl-MDPA) under conditions that left cysteine residues unchanged even after overnight incubation. Gd^III−Gd^III distances measured by double electron–electron resonance (DEER) experiments of maltose binding protein (MBP) containing two selenocysteine residues tagged with 4Cl-MDPA-Gd^III were indistinguishable from Gd^III−Gd^III distances measured of MBP containing cysteine reacted with 4Br-MDPA tags.     

Second-harmonic generation in GaAs-based quantum-cascade lasers grown on <100> substrates

Emission of coherent light at 5.1 /spl mu/m wavelength from GaAs-based quantum cascade lasers is reported. This was achieved by integrating nonlinear cascades with large second-order susceptibility in the active regions of the laser.     

Evaluation of a supermarket twin-checkout involving forward and backward operation

Cashier workplaces recently put into service in self-service shops of a retail company provide a face-to-face position of two cashiers. These twin-checkouts involve both traditional goods handling from the front to the rear as well as a reverse technique - i e, forward operation from behind. By means of different methods they have been analysed from an ergonomics point of view and evaluated in respect of operators' workload resulting from the specific layout. The results support the conclusion that the new 'backward' system and twin-checkouts are not inferior to traditional single checkouts. On the contrary, a working technique where the arm moves from behind to the front involves a better approach to accounting for physiological characteristics and obviously allows a better fitting of the task of operators.     

Die Mikroflora des Sauerteiges

Zusammenfassung Es wurden Untersuchungen angestellt über die Mikroflora von 26 Weizensauerteigen für die Panettone- und Weizenbrotherstellung aus Bäckereien in Italien, der Schweiz, Deutschland und Schweden. Die Sauerteige wurden teils mit einem Spontansauer angestellt, teils mit einem reifen Weizensauer (masa madre), der bereits über längere Zeit fortgeführt wurde. Die Mikroflora der Sauerteige (pH 4,4 bis 3,8, Säuregrad 6,3 bis 22,4) setzte sich aus 2,5 × 10⁵ bis 3 × 10⁹ Lactobacillun/g und 1 × 10³ bis 4,5 × 10⁷ Hefen/g zusammen. Es wurden insgesamt 388 Isolate gewonnen und als Vertreter der GattungLactobacillus identifiziert. In Weizensauerteigen, die mit einem Spontansauer angestellt wurden, traten vornehmlich homofermentativeLactobacillus-Species auf (Lactobacillus plantarum, L. casei, L. farciminis, L. homohiochii), nebenL. brevis, L. hildegardii und einigen anderen heterofermentativen Spezies. Die Sauerteigbakterien des mit einem masa madre angestellten Weizensauerteig erwiesen sich insbesondere alsLactobacillus brevis ssp.lindneri resp.L. sanfrancisco, nebenL. brevis, L. hildegardii undL. viridescens. Daneben kamen in den Weizensauerteigen zu mehr oder minder hohen AnteilenStreptococcus spp. vor. Bei den im Weizensauerteig auftretenden Hefen handelt es sich umSaccharomyces cerevisiae, nebenS. servazzi undCandida milleri.

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The microflora of sourdoughXXII. Communication: The lactobacillus species of wheat sourdough

Summary We investigated the microflora of 26 wheat sourdoughs which are used for the production of panettone and wheat bread in bakeries in Italy, Switzerland, Germany and Sweden. The sourdoughs were started in part with a ripe wheat sour (masa madre) which had been propagated for a long time. The microflora of the wheat sourdough (pH 4.4 to 3.8; acidity 6.3 to 22.4) consisted of 2 × 10⁵ to 3 × 10⁹ lactobacilli/g and 1 × 10³ to 4.5 to 10⁷ yeasts/g. We obtained 388 isolates; all belonging to the genusLactobacillus. In wheat sourdoughs which were started with a spontaneous sour homofermentativelactobacilli (Lactobacillus plantarum, L. casei, L. farciminis, L. homohiochii) are mainly found and alsoLactobacillus brevis, L. hildegardii and some other heterofermentative species. The main sourdough bacteria of wheat sourdoughs which were prepared with a masa madre were identified asLactobacillus brevis ssp.lindneri resp.L. sanfrancisco, which were present in addition toL. brevis, L. hildegardii, andL. viridescens. We also found varying numbers ofStreptococcus spp. in the wheat sourdoughs. The yeasts which we identified wereSaccharomyces cerevisiae, S. servazzi andCandida milleri.

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Nr. 5475 der Veröffentlichung der Bundesforschungsanstalt für Getreide- und Kartoffelverarbeitung, Detmold     

Iron(II)‐based catalysts for ethene oligomerization

The synthesis of iron(II) complexes with various tridentate di(imino)pyridine ligands and their potential as ethene oligomerization catalysts are described. The ligands are characterized by ¹H‐ and ¹³C‐NMR spectroscopy and the complexes only by mass spectrometry due to their paramagnetism. After activation either with methylalumoxane (MAO) or with a heterogeneous cocatalyst consisting of partially hydrolyzed trimethylaluminum and silica gel, the prepared complexes proved to be good catalysts for the oligomerization of ethene. 1‐Octene, 1‐hexene, and 1‐decene were the major products, formed in very high isomeric purity (99.9 %). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 476–482, 2003     

When Disaster Strikes

The importance of securing data against the threat of natural disasters i s something most MIS managers don't realize until it's too late. This column describes how two fires and an earthquake adversely affected several companies that were unprepared, or only partially prepared, for such disasters. It also discusses disaster recovery measures some MIS executives believe their companies should strengthen not only to protect the data center but to reduce their employees risk of losing valuable informa- tion from office files.     

Universal Remote Console-based next-generation accessible television

This paper presents a new approach to make current and future television universally accessible. The proposed approach provides a means of universal accessibility both for remotely operating the TV set and for interacting with online services delivered through the TV. This proposal is based on the ISO/IEC 24752 “Universal Remote Console” (URC) standard. This standard defines an abstract user interface layer called the “user interface socket” and allows the development of pluggable (plug-in) user interfaces for any type of user and any control device. The proposed approach lays the foundation for the development of advanced user interfaces that can be interacted within various modalities. Different prototypes have been developed based on this approach and tested with end users. The user tests have shown this approach to be a viable option for the proposed scenarios. Based on the experience gathered with the prototypes, recommendations and implementation options are suggested for commercial adoption.     

Highly efficient switched‐mode transmitter using a current mode class‐D RF amplifier

This article presents a switched‐mode transmitter architecture using a current mode class‐D (CMCD) amplifier. To achieve high average efficiency for a modulated signal the envelope of the complex baseband signal is transformed into pulses such that the CMCD amplifier is operated either at its peak efficiency or completely switched off. The CMCD amplifier has been designed based on single‐tone active harmonic load‐pull measurements to achieve a power‐added efficiency (PAE) of 61.5% with 25 W output power at 900 MHz using LDMOS FETs. Removing the losses of the demodulation filter and of the amplifier a 10% higher efficiency than in an ideal class‐B amplifier can be obtained for burst‐mode operation with a peak‐to‐average power ratio of 10 dB. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010.     

ID-Services: an RFID middleware architecture for mobile applications

The use of RFID middleware to support application development for and integration of RFID hardware into information systems has become quite common in RFID applications where reader devices remain stationary, which currently represents the largest part of all RFID applications in use. Another field for applying RFID technology which is offering a huge set of novel possibilities and applications are mobile applications, where readers are no longer fixed. In order to address the specific issues of mobile RFID-enabled applications and to support developers in rapid application development, we present ID-Services, an architecture for an RFID middleware that is designed to support mobile applications. The ID-Services approach has been used to implement MoVIS (Mobile Visitor Information System), a mobile application which allows museum visitors to request individually adapted multimedia information about exhibits in an intuitive way.