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The magnetic diagnostics foreseen for the Wendelstein 7-X (W7-X) stellarator are diamagnetic loops to measure the plasma energy, Rogowski coils to measure the toroidal plasma current, saddle coils to measure the Pfirsch–Schluter currents, segmented Rogowski coils (poloidal magnetic field probes) to add information on the distribution of the plasma current density, and Mirnov coils to observe magnetohydrodynamic modes. All these magnetic field sensors were designed as classical pick-up coils, after the time integration of induced signals for 1/2 hour had been successfully demonstrated. The long-pulse operation planned for W7-X causes nevertheless significant challenges to the design of these diagnostics, in particular for the components located inside the plasma vessel, which may be exposed to high levels of microwave (electron cyclotron resonance) stray radiation and thermal radiation. This article focuses on the tests and modelling performed during the development of the magnetic diagnostics and on the design solutions adopted to meet the conflicting requirements. All pick-up coils foreseen for the initial operation phase of W7-X and their signal cable sections inside the plasma vessel and the cryostat are now installed, and their electronics and data acquisition are under preparation.

The main heating system of W7-X will be a 10 MW, 140 GHz ECRH. It is expected that the non-absorbed ECRH power will be up to 1 MW. Multiple reflections of the ECRH beam result in a nearly isotropic radiation background. The non-absorbed ECRH power has to be considered as an additional thermal load of microwave stray radiation for all W7-X in-vessel components. Several in-vessel diagnostics, especially magnetic diagnostics, partly consist of microwave absorbing materials. The microwave stray radiation could damage these components or, by evaporation due to overheating, perturb the operation of W7-X. Usually these diagnostics are protected against direct plasma radiation and are thermally connected to actively cooled structures. Nevertheless, ECRH stray radiation can cause a critical temperature increase. We present examples of ECRH stray radiation protection by metallic housing. The use of such housing may be in conflict with vacuum compatibility and in particular for magnetic diagnostics, with the requirement to avoid eddy currents limiting the time resolution of magnetic measurements. Details are given on the protection against ECRH stray radiation as well as on thermal connection concepts. Acceptance tests are presented on full-scale mockups.

Die wissenschaftlich-technischen Arbeitsziele dieses vom Bundesministerium fur Wirtschaft (BMWi) geforderten Projektes wurden in funf Teilen erarbeitet. Die einzelnen Themen resultieren aus aktuellen Fragestellungen; sie haben dennoch einen allgemein anwendbaren Charakter. Das Konsortium hat die folgenden Teilprojekte bearbeitet: (1) Aufbau einer Messtechnik zur Bestimmung energetischer und lichttechnischer Kennzahlen von Tageslichtbauteilen mit einem round robin test, an dem drei Institute beteiligt waren. (2) Realisierung eines detaillierten Bewertungs- und Nachweisverfahrens fur die Tageslichtversorgung von Innenraumen in unterschiedlichen Klimazonen. (3) Fur die Beleuchtungskontrolle privater Lebensraume wurde ein “Powerline Carrier Communication“-System evaluiert und die Vorteile gegenuber einem Funkubertragungssystem herausgearbeitet. (4) In einem Pflegeheim wurden quantitative Untersuchungen zum Wohlbefinden, zur Erfullung von Sehaufgaben und zur Eignung zur Melatoninsuppression bei verschiedenen Szenarien der Allgemeinbeleuchtung mit zwei unterschiedlichen Farbtemperaturen der eingesetzten Lampen (“warmweises Licht“ mit TCP = 3000 K und “kaltweises Tageslicht“ mit TCP = 6500 K) und vertikalen Beleuchtungsstarken an den Augen der Probanden zwischen 100 lx und 700 lx durchgefuhrt. (5) Fur zwei Schulgebaude in Berlin wurde der Endenergiebedarf der Bestandsanlage, des Referenzgebaudes sowie der Neuplanung ermittelt. Dabei wurde in beiden Beispielen deutlich, dass die Bestandsanlage im Bereich der Beleuchtung den zulassigen Wert nach EnEV 2009 mitunter weit uberschreitet. Eine gute Neuplanung hingegen kann den maximal zulassigen Wert deutlich unterschreiten. Diese Untersuchungen wurden von einem einjahrigen Monitoring des Energieumsatzes begleitet. Eine Querschnittsanalyse uber 48 Schulen mit insgesamt 86 Gebauden zeigt unter anderem einen erheblichen Sanierungsbedarf bei Schulgebauden, die vor 1990 errichtet wurden. Energy optimised lighting in buildings with simultaneous improvement of quality of life by daylight utilisation and innovative lamps and ballast techniques. The scientific and technical goals of this project were developed in five parts. The individual topics arising from current issues, they still have a generally applicable nature. The consortium has worked on the following subprojects: (1) Development of a measurement technique to determine energy and photometric key figures of daylight components with a round robin test with three institutes. (2) Implementation of a detailed evaluation and documentation process for daylighting of interior spaces in different climate zones. (3) For lighting control in private living areas a “Power Line Carrier Communication” system has been evaluated and the advantages of a wireless transmission system were identified. (4) In a home for elderly quantitative studies on the well-being, for the fulfillment of visual tasks and the capability of melatonin suppression at different scenarios of general lighting with two different color temperatures of lamps (“warm white” with TCP = 3000 K and “cold white daylight” with TCP = 6500 K) and vertical illuminance at the eyes of the subjects between 100 lx and 700 lx were performed. (5) For two school buildings in Berlin, the final energy consumption of the existing lighting system, the reference building and a re-planning were determined. It became clear in both examples that the existing lighting system exceeds the permitted value (EnEV 2009) by far. A good redesign, however, can be significantly less than the maximum allowed value. These studies were accompanied by a one-year monitoring of energy consumption. A cross-sectional analysis of 48 schools with a total of 86 buildings shows a substantial need for renovation of school buildings that were built before 1990.

Experimental and theoretical investigations have demonstrated that a quasi-two-dimensional electron gas (q-2DEG) can form at the interface between two insulators: non-polar SrTiO3 and polar LaTiO3 (ref. 2), LaAlO3 (refs 3-5), KTaO3 (ref. 7) or LaVO3 (ref. 6). Electronically, the situation is analogous to the q-2DEGs formed in semiconductor heterostructures by modulation doping. LaAlO3/SrTiO3 heterostructures have recently been shown to exhibit a hysteretic electric-field-induced metal-insulator quantum phase transition for LaAlO3 thicknesses of 3 unit cells. Here, we report the creation and erasure of nanoscale conducting regions at the interface between two insulating oxides, LaAlO3 and SrTiO3. Using voltages applied by a conducting atomic force microscope (AFM) probe, the buried LaAlO3/SrTiO3 interface is locally and reversibly switched between insulating and conducting states. Persistent field effects are observed using the AFM probe as a gate. Patterning of conducting lines with widths of approximately 3 nm, as well as arrays of conducting islands with densities >10(14) inch(-2), is demonstrated. The patterned structures are stable for >24 h at room temperature.

The interleukin-6 (IL-6) receptor complex comprises the IL-6 receptor (IL-6R, gp80) and the signal transducer gp130. Binding of IL-6 to its receptor results in dimerization of gp130, activation of the Jak/STAT pathway, and in a down-regulation of IL-6 binding sites by endocytosis. The STAT activation after stimulation is transient, being maximal after 15–30 min and disappearing after 60–90 min. The mechanism which leads to the termination of the signal is still unknown.In this paper we have studied whether the down-modulation of the STAT signal requires the endocytosis of the receptor complex. Our results suggest that the desensitization of the IL-6 signal is not due to internalization of the receptor complex but requires de novo protein synthesis.

The transmembrane protein gp130 is the common signalling receptor subunit for the interleukin-6 (IL-6)-type cytokines. It has recently been shown that the cytoplasmic domain of gp130 contains a dileucine internalization motif and that endocytosis of gp130 occurs signal-independent. Here, we have studied whether gp130 itself undergoes constitutive internalization or whether its endocytosis is stimulated by formation of the IL-6/IL-6R/gp130 complex. Using two different assays, we found that gp130 is internalized independent from IL-6/IL-6R stimulation. In addition, we show that gp130 is constitutively associated with the cell surface adaptor complex AP-2. Our findings strongly suggest endocytosis of gp130 to be constitutive.

s Long pulse operation considerably increases the thermal load on in-vessel components. Diagnostic front-ends formerly employed at short pulse machines therefore have to be considerably re-designed for installation in the stellarator W7-X that is currently being built at Greifswald, Germany. The strategy applied to cope with the thermal load is threefold: to reduce the influx of heat on the component, to conduct the heat inside the component to suitable heat sinks and to choose suitable materials for sensitive components. The first is achieved by the shielding against microwave stray radiation, plasma radiation, thermal radiation and particle fluxes and by absorbing residual microwave stray radiation in the immediate vicinity of sensitive components. The second task, suitable heat conduction, enforces severe restrictions on the use of any thin parts like foils or meshes. Thirdly, in order for a component to survive the residual loads, materials must be chosen that absorb only a small fraction of the microwave stray radiation flux, conduct heat well enough, and survive high temperatures and large temperature gradients. Examples are provided from bolometry, magnetic diagnostics, soft X-ray diagnostics and Thomson scattering. Measurements of microwave stray radiation effects are presented, in particular the effectiveness of several shielding concepts.

With infrared ellipsometry and transport measurements we investigated the electrons at the interface between ${\mathrm{LaAlO}}_{3}$ and ${\mathrm{SrTiO}}_{3}$. We obtained a sheet carrier concentration of ${N}_{\mathrm{s}}\ensuremath{\approx}5--9\ifmmode\times\else\texttimes\fi{}{10}^{13}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$, an effective mass of ${m}^{*}=3.2\ifmmode\pm\else\textpm\fi{}0.4{m}_{e}$, and a strongly frequency dependent mobility. The latter are similar as in bulk ${\mathrm{SrTi}}_{1\ensuremath{-}x}{\mathrm{Nb}}_{x}{\mathrm{O}}_{3}$ and therefore suggestive of polaronic correlations. We also determined the vertical concentration profile which has a strongly asymmetric shape with a rapid initial decay over the first 2 nm and a pronounced tail that extends to about 11 nm.

The so-called ``polar catastrophe,'' a sudden electronic reconstruction taking place to compensate for the interfacial ionic polar discontinuity, is currently considered as a likely factor to explain the surprising conductivity of the interface between the insulators ${\text{LaAlO}}_{3}$ and ${\text{SrTiO}}_{3}$. We applied optical second harmonic generation, a technique that a priori can detect both mobile and localized interfacial electrons, to investigating the electronic polar reconstructions taking place at the interface. As the ${\text{LaAlO}}_{3}$ film thickness is increased, we identify two abrupt electronic rearrangements: the first takes place at a thickness of 3 unit cells, in the insulating state; the second occurs at a thickness of 4--6 unit cells, i.e., just above the threshold for which the samples become conducting. Two possible physical scenarios behind these observations are proposed. The first is based on an electronic transfer into localized electronic states at the interface that acts as a precursor of the conductivity onset. In the second scenario, the signal variations are attributed to the strong ionic relaxations taking place in the ${\text{LaAlO}}_{3}$ layer.

The conducting interface of ${\mathrm{LaAlO}}_{3}/{\mathrm{SrTiO}}_{3}$ heterostructures has been studied by hard x-ray photoelectron spectroscopy. From the Ti $2p$ signal and its angle dependence we derive that the thickness of the electron gas is much smaller than the probing depth of 4 nm and that the carrier densities vary with increasing number of ${\mathrm{LaAlO}}_{3}$ overlayers. Our results point to an electronic reconstruction in the ${\mathrm{LaAlO}}_{3}$ overlayer as the driving mechanism for the conducting interface and corroborate the recent interpretation of the superconducting ground state as being of the Berezinskii-Kosterlitz-Thouless type.

We report experimental investigations of the effects of microstructural defects and of disorder on the properties of 2D electron gases at oxide interfaces. The cross section for scattering of electrons at dislocations in LaAlO(3)/SrTiO(3) interfaces has been measured and found to equal approximately 5 nm. Our experiments reveal that the transport properties of these electron gases are strongly influenced by scattering at dislocation cores.

Intrinsic functionalities of complex oxides like ferroelectricity, magnetism, superconductivity or multiferroic behaviour can be combined in electronic devices based on epitaxially grown heterostructures. Searching for new materials with special properties in nanoscience implies also the control of interfaces down to the atomic level.

In this Comment we clarify the misconceptions expressed by Panguluri et al. [R. P. Panguluri, T. S. Santos, E. Negusse, J. Dvorak, Y. Idzerda, J. S. Moodera, and B. Nadgorny, Phys. Rev. B 78, 125307 (2008)] regarding the experimental procedures and data interpretation used in our work [A. Schmehl, V. Vaithyanathan, A. Herrnberger, S. Thiel, C. Richter, M. Liberati, T. Heeg, M. Rockerath, L. F. Kourkoutis, S. Muhlbauer, P. Boni, D. A. Muller, Y. Barash, J. Schubert, Y. Idzerda, J. Mannhart, and D. G. Schlom, Nature Mater. 6, 882 (2007)]. We show that our experimental procedures and resulting data are direct consequences of the materials and sample geometries we used and demonstrate that our carefully chosen approach has advantages over the techniques used in the criticizing publication.

Electronic confinement at nanoscale dimensions remains a central means of science and technology. We demonstrate nanoscale lateral confinement of a quasi–two-dimensional electron gas at a lanthanum aluminate–strontium titanate interface. Control of this confinement using an atomic force microscope lithography technique enabled us to create tunnel junctions and field-effect transistors with characteristic dimensions as small as 2 nanometers. These electronic devices can be modified or erased without the need for complex lithographic procedures. Our on-demand nanoelectronics fabrication platform has the potential for widespread technological application.

At interfaces between complex oxides, electronic systems with unusual electronic properties can be generated. We report on superconductivity in the electron gas formed at the interface between two insulating dielectric perovskite oxides, LaAlO 3 and SrTiO 3 . The behavior of the electron gas is that of a two-dimensional superconductor, confined to a thin sheet at the interface. The superconducting transition temperature of ≅ 200 millikelvin provides a strict upper limit to the thickness of the superconducting layer of ≅ 10 nanometers.

Doped EuO is an attractive material for the fabrication of proof-of-concept spintronic devices. Yet for decades its use has been hindered by its instability in air and the difficulty of preparing and patterning high-quality thin films. Here, we establish EuO as the pre-eminent material for the direct integration of a carrier-concentration-matched half-metal with the long-spin-lifetime semiconductors silicon and GaN, using methods that transcend these difficulties. Andreev reflection measurements reveal that the spin polarization in doped epitaxial EuO films exceeds 90%, demonstrating that EuO is a half-metal even when highly doped. Furthermore, EuO is epitaxially integrated with silicon and GaN. These results demonstrate the high potential of EuO for spintronic devices.

We report on a large electric-field response of quasi–two-dimensional electron gases generated at interfaces in epitaxial heterostructures grown from insulating oxides. These device structures are characterized by doping layers that are spatially separated from high-mobility quasi–two-dimensional electron gases and therefore present an oxide analog to semiconducting high–electron mobility transistors. By applying a gate voltage, the conductivity of the electron gases can be modulated through a quantum phase transition from an insulating to a metallic state.

Matriptase, also known as membrane-type-serine-protease 1 (MT-SP 1), is a type II transmembrane serine protease involved in the activation of the precursor form of hepatocyte growth factor/scatter factor (pro-HGF/SF). Since HGF/SF is a well-known extracellular signal, which plays a key role in the control of invasive growth, we investigated the effects of matriptase inhibition in cell lines derived from colon (DLD-1) or prostate (PC-3) carcinomas. Biochemical analysis showed that matriptase was very efficient in the proteolytic conversion of the inactive HGF/SF precursor into HGF/SF. Inhibition of endogenous matriptase synthesis in DLD-1 or PC-3 cells by specific small interfering RNAs impaired the conversion of pro-HGF/SF into HGF/SF at the cell surface and inhibited cell scattering upon pro-HGF/SF stimulation. The same effect was observed after treatment of these cells with matriptase inhibitors of the 3-amidinophenylalanine-type, CJ-697 or CJ-730. Inhibition of matriptase significantly reduced invasion of the extracellular matrix as well. Interestingly, this reduction was observed even in the presence of pre-activated HGF/SF. It is concluded that matriptase plays a dual-role in the events unleashing the invasive phenotype, one 'upstream' from the HGF/SF signalling cascade and one 'downstream', most likely at the level of the plasminogen activation system. These data provide a proof of concept for the targeting of matriptase in the search for anti-invasive drugs.

A screw dislocation network at the low-angle SrTiO3/Nb:SrTiO3 twist grain boundary has been analyzed by annular dark field (ADF) imaging and spatially resolved electron energy loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM). The cores of one set of dislocations running parallel to the beam direction appear dark in the ADF STEM images. EELS on the dislocation core reveals a reduced Sr/Ti ratio compared to the bulk suggesting Sr-deficient cores. The second set of dislocations, orthogonal to the latter, is imaged by its strain field using low-angle annular dark field (LAADF) imaging. Multislice image simulations suggest channeling of the electron probe on the atomic columns for small tilts, theta < 1 degree, where the Sr columns act as beam guides. Only for larger tilts is the channeling effect strongly reduced and the fringe contrast approaches the value predicted by a purely incoherent imaging model. Ti-L(2,3) EELS across the dislocation core shows an asymmetry between the EELS and the ADF signal which cannot be explained by the geometry or beam broadening. This asymmetry might be explained by an effective nonlocal potential representing inelastic scattering in EELS.

Seit der Entdeckung der Hochtemperatur-Supraleitung im Jahr 1986 werden kristalline Schichten aus komplexen Oxiden intensiv erforscht. Diese Materialien zeigen neuartige und bisweilen unerwartete physikalische Eigenschaften, die zukunftige elektronische Schaltkreise revolutionieren konnten. Ein aktuelles Beispiel ist die Doppelschicht der Isolatoren Lanthanaluminat (LaAlO3) und Strontiumtitanat (SrTiO3) (Abbildung 1), an deren Grenzflache sich erstaunlicherweise ein zweidimensionales Elektronengas bildet, das bei tiefen Temperaturen sogar supraleitend wird.

Peptide libraries on cellulose paper have proven to be valuable tools for the a priori determination of substrate specificities of cyclic AMP- and cyclic GMP-dependent protein kinases (cAMP-kinase and cGMP-kinase) on the basis of octa-peptide sequences. Here, we report the extension of our peptide library screens to 12-mer and 14-mer peptide sequences, resulting in highly cGMP-kinase Ialpha selective peptides. The sequences TQAKRKKSLAMA-amide and TQAKRKKSLAMFLR-amide, with Km values for cGMP-kinase Ialpha of 0.7 and 0.26 microM and Vmax values of 11.5 and 10.9 micromol/min/mg, respectively, display a high specificity for this enzyme. Furthermore, replacing the phosphate acceptor residue serine with alanine in TQAKRKKSLAMA-amide resulted in the highly cGMP-kinase Ialpha selective inhibitor peptide TQAKRKKALAMA-amide, with inhibitor constants for cGMP-kinase Ialpha and cAMP-kinase of 7.5 microM and 750 microM, respectively. Selective cGMP-kinase inhibitors have the potential to play an important role in the elucidation of the distinct cellular functions of cGMP-kinase separate from those activated by cAMP-kinases, and, therefore, may play an important role as pharmaceutical targets. Molecular docking experiments of the most cGMP-kinase selective sequences on a molecular model of the catalytic domain of cGMP-kinase Ialpha suggest that they adopt unique conformations, which differ significantly from those observed for the cAMP-kinase-specific inhibitor PKI(5-24). Our results suggest that despite their structural similarities, cAMP-kinase and cGMP-kinase use distinct peptide substrate and inhibitor conformations, which could account for their unique substrate specificities. These findings are further supported by cAMP- and cGMP-kinase-selective inhibitor analogs with (D)-Ala residues at the inhibitory positions.

Leukaemia inhibitory factor (LIF) signals via a heterodimeric receptor complex comprised of the LIF receptor (LIFR) and the interleukin (IL)-6 signal transducer gp130. Upon binding to its cognate receptor LIF is internalized. In this study, we show that the LIFR is endocytosed independently of gp130. By using a heterochimaeric receptor system we identified a dileucine-based internalization motif within the cytoplasmic domain of the LIFR. Our findings suggest that a heterodimeric LIFR/gp130 complex and homodimeric gp130/gp130 complex are endocytosed via distinct internalization signals.

Signalling receptors often undergo receptor-mediated endocytosis. In many cases this internalization is stimulated by ligand binding and activation of intrinsic receptor tyrosine kinases, resulting in a receptor down-regulation. We have analysed whether internalization of the interleukin 6 signal transducer gp130 is dependent on the activation of receptor-associated Jak kinases. By using a chimaeric receptor system we found that receptor mutants that lack box1 and therefore are not capable of activating Jak and signal transducer and activator of transcription (STAT) proteins are still endocytosed efficiently. A chimaeric receptor with the recently identified dileucine internalization motif being replaced by two alanine residues was not efficiently internalized but still capable of recruiting STATs. Furthermore an antagonistic antibody that inhibits the signalling of all interleukin-6-type cytokines via gp130 was internalized as efficiently as an agonistic one that activates the Jak/STAT pathway. Our findings suggest that the endocytosis of gp130 is signal-independent.

Submicron wide structures of conducting quasi-two-dimensional electron gases generated at SrTiO3∕LaAlO3 interfaces have successfully been patterned by modulating the thickness of the LaAlO3 layers with unit cell resolution. This technique allows the authors to structure the electron gases without exposing them to the environment and without incorporating other materials at the edges. The structured electron gases have resistances of ≈200Ω∕◻ (4.2K) and mobilities of ≈700cm2∕Vs (4.2K), while the resistances of the areas patterned to be insulating exceed 1010Ω∕◻.

The critical current density of grain boundaries and grains in Y1−xCaxBa2Cu3O7−δ films has been measured in magnetic fields up to 10T. As a function of temperature the critical current densities across 8° [001]-tilt boundaries display a maximum at ≈15–20K for 0.04⩽x⩽0.2 and fields of several teslas. Opposite to the behavior of large angle grain boundaries, calcium doping is found not to enhance the critical current densities of low angle grain boundaries (θ⩽8°).

Die fur das KWV-gesteuerte Biegeverfahren notwendige Kraftmessung eroffnet die Moglichkeit, beim Richten durch Beurteilung des KWV uber die Geometrie hinausgehende Qualitatsmerkmale des Werkstucks zu erfassen. Der generelle KWV gibt Auskunft uber Steifigkeit und Festigkeit des Werkstucks in der Richtung der Beanspruchung. Beim Richten durch Fugen entstandener Werkstucke werden Steifigkeit und Festigkeit durch im Kraftflus liegende Fugestellen beeinflust. Mangelhafte Ausfuhrung solcher Fugestellen vermindert Steifigkeit und Festigkeit. Eine verminderte Festigkeit bei korrekter Steifigkeit gibt eine direkte Aussage uber die Festigkeit des Werkstoffs. Bei in der Festigkeit stark streuenden Werkstoffen kann diese Kontrolle fur die Qualitat des Werkstucks von entscheidender Bedeutung sein. Im Falle durch Lagerung aushartender Aluminiumlegierungen ergibt sich dadurch etwa eine Kontrolle des Auslagerungszustandes.

Es sollen die Moglichkeiten zur Beherrschung des II. Grundproblems des Richtens behandelt werden. Wie in der Einleitung beschrieben, besteht bei den meisten Werkstucken mit mehreren Richtstellen das Problem, das die Verformungen der einzelnen Richtstellen voneinander abhangig sind. Um von der Automatisierung einer Richtaufgabe eine moglichst grose Wirkung zu erhalten, ist es notwendig, diese Abhangigkeiten zu erfassen und so zu verarbeiten, das das iterative Vorgehen weitgehend vermieden wird. Ziel ist es, folgendes Vorgehen zu ermoglichen: Messen aller Abweichungen, Berechnen aller erforderlichen Formanderungen unter Berucksichtigung der Abhangigkeiten, Gezielte Durchfuhrung der Formanderungen.

In diesem Kapitel werden Losungsmoglichkeiten fur das I. Grundproblem des Richtens behandelt. Dafur ergeben sich zwei grundverschiedene Varianten: 1. die Vorgabe des Weges der Umformeinheit (des Pressenstos-sels) aus Erfahrungswerten, weggesteuertes Biegerichten genannt. 2. die adaptive Steuerung des Biegevorgangs durch den aktuellen Kraft-Weg-Verlauf (KWV).