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As in 2007 the first 3.5 cell superconducting radio frequency (SRF) gun was taken into operation, it turned out that the specified performance has not been achieved. However, to demonstrate the full potential of this new type of electron source, a second and slightly modified SRF gun II was built in collaboration with Thomas Jefferson National Accelerator Facility (TJNAF). We will report on commissioning and first results of the new gun, which includes in particular the characterization of the most important RF properties as well as their comparison with previous vertical test results.

At the ELBE accelerator a unique super-radiant THz source is currently under developement. It aims at delivering fourier-limited THz pulses with pulse energies of up to 100 microJ at reprates of up to 500 kHz (cw). This corresponds to transient electric elds in the GV/m regime or transient magnetic elds in the few T regime. First results from the commissioning are discussed.

In this paper, the feasibility of a large area exposure for the manufacturing of a NIL master (silicon wafer) dealing with a long writing time is shown. Fraunhofer CNT succeeded in a 355 h exposure with a variable shaped e-beam using a commercially available positive tone chemically amplified resist. The wafer has been evaluated in terms of resist contrast and stability, CD uniformity, linearity, pattern quality and defectivity. Electron beam tool parameters like Wehnelt voltage and stage temperature have been analyzed. Different writing strategies and concepts will be considered to optimize the exposure and minimize stitching error defects.

Histone modifications are crucial for the regulation of secondary metabolism in various filamentous fungi. Here we studied the involvement of histone deacetylases (HDACs) in secondary metabolism in the phytopathogenic fungus Fusarium fujikuroi, a known producer of several secondary metabolites including phytohormones, pigments and mycotoxins. Deletion of three Zn(2+)-dependent HDAC-encoding genes, ffhda1, ffhda2 and ffhda4, indicated that FfHda1 and FfHda2 regulate secondary metabolism, whereas FfHda4 is involved in developmental processes but dispensable for secondary metabolite production in F. fujikuroi. Single deletions of ffhda1 and ffhda2 resulted not only in an increase or decrease, but also in derepression of metabolite biosynthesis under normally repressing conditions. Moreover, double deletion of both genes ffhda1 and ffhda2 shows additive but also distinct phenotypes with regard to secondary metabolite biosynthesis and both genes are required for GA-induced bakanae disease on the preferred host-plant rice, as ΔΔffhda1/ffhda2 mutants resemble the uninfected control plant. Microarray analysis with a Δffhda1 mutant that has lost the major HDAC revealed differential expression of secondary metabolite gene clusters subsequently verified by a combination of chemical and biological approaches. These results indicate that HDACs are not only involved in gene silencing but also in activation of some genes. Chromatin immunoprecipitation with Δffhda1 revealed significant alterations in the acetylation state of secondary metabolite gene clusters compared to the wild type thereby providing insights into the regulatory mechanism on chromatin level. Altogether, manipulation of HDAC-encoding genes constitutes a powerful tool to control secondary metabolism in filamentous fungi.

International audience

Einleitung: Die akute Pankreatitis ist eine Erkrankung, die klinisch zum Teil fulminant verläuft. Trotz verbesserter intensivmedizinischer Therapieregime liegt die Letalität der hämorrhagisch-nekrotisierenden Verlaufsformen der akuten Pankreatitis immer noch zwischen 40% und 60%.[for full text, please go to the a.m. URL], 129. Kongress der Deutschen Gesellschaft für Chirurgie

Since 2005 the photocathode laboratory has been in operation at HZDR. The main goal is to prepare Cs2Te photocathodes for the SRF gun. A vacuum transport system with UHV is used to move the cathodes from preparation lab to accelerator hall. Up to now 34 Cs2Te photocathodes have been deposited and eight of them have been used in the SRF gun. Quantum efficiency (QE) of 1% and life time of months can be maintained during the gun operation. At the same time activities are directed towards new photocathode materials with high Q.E. for high current electron sources. Cs3Sb and GaN(Cs) photocathodes have been tested as new candidates, and the design of a preparation system for GaAs(Cs, O) is ongoing

BACKGROUND Although the indirect thrombin inhibitor heparin and the more potent direct inhibitor hirudin are useful in preventing thrombosis, a substantial opportunity remains for improving the thrombus selectivity of thrombin inhibitors. METHODS AND RESULTS To explore the effect of targeting an antithrombin to the surface of a clot, we covalently linked recombinant hirudin to the Fab' (or IgG) of a monoclonal antibody (59D8) that selectively binds to an epitope on fibrin that becomes exposed only after thrombin cleaves fibrinopeptide B. Antibody-coupled hirudin bound to an immobilized peptide of the fibrin beta-chain amino-terminal sequence and inhibited the peptidolytic activity of thrombin more efficiently than free hirudin. Thrombin inhibition dependent on binding to immobilized fibrin monomer was enhanced 1100-fold (P < .0001). Hirudin-59D8 Fab' was 10 times more effective than hirudin in inhibiting fibrin deposition on experimental clot surfaces in fibrinogen solution (P < .0001) and human plasma (P < .0001). The more effective inhibition of thrombin by the conjugate was supported by significantly diminished concentrations of fibrinopeptide A in the plasma supernatant of the clot (P = .0001). Inhibition of clotting by an uncoupled mixture of hirudin and 59D8 Fab' was indistinguishable from that by hirudin alone, indicating that the conjugate's greater inhibitory activity was due to the covalent linkage between antibody and hirudin. CONCLUSIONS Fibrin-targeted hirudin (in comparison with unmodified hirudin) significantly reduces fibrin deposition on the surface of experimental clots.

Lipoprotein(a) (Lp(a)) and plasminogen share a high degree of structural homology. Therefore it has been suggested that elevated levels of Lp(a) may inhibit the profibrinolytic activity at the cell surface and increase the risk of thrombosis by competitive inhibition of plasminogen. In the present study we evaluated whether high levels of Lp(a) affect thrombolytic therapy in patients with acute myocardial infarction. Forty-one patients with acute myocardial infarction were treated with a combination of recombinant tissue-type plasminogen activator and human single-chain urokinase-type plasminogen activator. Coronary patency was assessed angiographically 90 min after initiation of treatment. Thrombolysis was successful in 30 and unsuccessful in 11 patients. Patients with high Lp(a) levels (> 25 mg/dl) (n = 9) responded equally well to thrombolytic therapy (8 of 9, patency 89%) as did patients with normal or low levels of Lp(a) (22 of 32, patency 70%, difference P > 0.1). The results demonstrate that high levels of Lp(a) do not influence thrombolysis in patients with acute myocardial infarction when low-dose pharmacologic concentrations of recombinant tissue-type plasminogen activator and human single chain urokinase-type plasminogen activator are applied in combination.

Hintergrund: Die Inanspruchnahme ambulanter ärztlicher Versorgung ist in Deutschland im internationalen Vergleich hoch. In Deutschland beträgt die Zahl der Arztkontakte laut Gmünder Ersatzkasse 17,9/Jahr, während sie beispielsweise in Norwegen bei 4,6/Jahr liegt. Die kl[for full text, please go to the a.m. URL], 10. Deutscher Kongress für Versorgungsforschung; 18. GAA-Jahrestagung

To realize fast and efficient integrated circuits the interconnect system gains an increasing importance. In particular, this is the case for logic and processor circuits with up to 12 metallization layers. In order to optimize this technology and the according processes it is desirable to generate flexible test structures in small lot production. In opposition to standard optical lithography using masks, Electron Beam Direct Write (EBDW) lithography can rapidly deliver special test structures at low cost. Furthermore, critical dimensions of future technology nodes which are not yet manufacturable by standard optical lithography tools can be produced. In this paper we demonstrate the potential of the 50 kV variable shaped EBDW cluster for patterning of future back-end-of-line (BEOL) structures on full 200 mm wafers. The patterned wafers have been used to develop next generation copper damascene interconnect processes for critical dimensions down to 50 nm.

To study the performance of the ELBE RF-couplers until their limits a 1.3 GHz resonant ring driven by a 10 kW CW klystron (VKL7811St, CPI) has been built to operate a RF-coupler and RF-window test bench. The ring allows tests with RF power up to 100 kW in continuous wave (CW) mode and 200 kW in pulsed mode. Details of the resonant ring, the test bench design and results of the ELBE RF-coupler tests will be presented.

Two filamentous fungi, the white-rot fungus Trametes versicolor and the soil fungus and potential biocontrol organismTrichoderma harzianum, have been grown in pure and mixed cultures on low-N (0.4 mM) and high-N (4 mM) defined synthetic media to determine the activities of selected wood-degrading enzymes such as cellobiase, cellulase, laccase,and peroxidases. Growth characteristics and enzyme activities were examined for potential correlations. Such correlations would allow the use of simple enzyme assays for measuring biomass development and would facilitate predictions about competitiveness of species in mixed fungal cultures. Our results show that while laccase and Poly Red-478 peroxidase activities indicate survival of the decay fungus, none of the monitored extracellular enzymes can serve as a quantitative indicator for biomass accumulation. As expected, the level of available nitrogen affected the production of the enzymes monitored: in low-N media, specific cellobiase, specific cellulase, and peroxidase activities were enhanced, while laccase activities were reduced. Most importantly, laccase activities of Trametes versicolor, and to a smaller extent, cellobiase activities of both fungi, were significantly induced in mixed cultures of Trametes versicolor and Trichoderma harzianum. Key words: biocontrol, wood decay, laccase, peroxidases.

The RF-system of the superconducting electron linac ELBE (40 MeV, 1 mA CW) is in permanent operation since 2001, but it is not completely free of RF-trips. Experience gained within eight years of operation shows that the better the RF-components were conditioned the better is their electrical stability during long time operation. To be prepared for the planned ELBE upgrade with 16 kW of RF-power per cavity several test benches have been built to study the performance of RF-couplers and waveguide windows. In cooperation with Bruker BioSpin / France and CPI / USA the prototype of a 30 kW RF-amplifier based on an IOT had been tested with beam at ELBE. This paper gives an overview about tests of RF-components with increased RF-power at ELBE.

An SRF photoinjector has been successfully tested in FZD under the collaboration of BESSY, DESY, FZD, and MBI. In order to improve the gun cavity quality and thus reach a higher gradient, a new 3+1/2 superconducting cavity is being fabricated in cooperation with JLab. The modified cavity is made of large grain niobium, composed of one filter choke, one special designed half-cell (gun-cell) and three TESLA cavities. In this paper, the main updates of the new cavity design will be explained in detail. The deformation of the filter choke and the gun-cell, which is caused by pressure fluctuation in the He-line and also by the effect of the Lorentz force, will be minimized by stiffening between the filter choke and the gun-cell. Meanwhile, the cathode hole in the choke and gun-cell is enlarged for better rinsing. To simplify assembly, the NbTi pick-up will be welded directly on the wall of filter choke.

Using Monte Carlo codes, we follow the collisional evolution of clusters in a variety of scenarios. We consider the conditions under which a cluster of main-sequence stars may undergo rapid core collapse due to mass segregation, thus entering a phase of runaway collisions, forming a very massive star (VMS, M* > 1000Mo) through repeated collisions between single stars. Although collisional mass loss is accounted for realistically, we find that a VMS forms even in proto-galactic nuclei models with a high velocity dispersion (many 100 kms-1). Such a VMS may be a progenitor for an intermediate-mass black hole (M? >= 100Mo). In contrast, in galactic nuclei hosting a central massive black hole, collisions are found to be disruptive. The stars which are subject to collisions are progressively ground down by high-velocity collisions and a merger sequence appears impossible.

The partial waveguide resonator of the U100-FEL at FZ-Rossendorf and its peculiarities are ilustrated.