Halterungsvorrichtung fuer im wesentlichen zylindrische Bauteile mit Kragen, insbesondere Flanschbauteile

Eine Halterungsvorrichtung (1) fuer im wesentlichen zylindrische Bauteile (24) mit Kragen (25), insbesondere Flanschbauteile der Vakuumtechnik, verfuegt ueber eine Grundplatte (5) und konzentrische Halterungsringe (6). Jeder Halterungsring (6) ist in mindestens zwei Teilringe (7) unterteilt und jeder Teilring (7) weist eine Hinterschneidung in seiner Auflageoberflaeche und eine Nase in seiner Aufliegeoberflaeche auf, deren Winkelsegmente kleiner als 180 oder gleich sind. Weiterhin verfuegt jeder Teilring (7) ueber ein Sackloch zur verdrehsicheren Halterung des Bauteils (24)

X-ray photoelectron spectroscopy study of the chemical interaction at the Pd/SiC interface

U.S. Department of Energy [FG07-01AL67358, DE-FC07-06ID14781]In order to study the chemical interaction during interface formation between Pd and SiC, Pd layers of various thicknesses were deposited on structurally disordered SiC surfaces at 800 degrees C. The Pd/SiC interface, which plays a crucial role for many applications such as high power electronic devices and tristructural-isotropic (TRISO) nuclear fuels, was studied in situ by x-ray photoelectron spectroscopy. We find that after Pd deposition, Si-C and Si-Si bonds are broken in favor of the formation of not only Pd-Si but also Pd-C bonds. In addition, various silicon oxycarbide bonds are observed at the SiC surface and the Pd/SiC interface. These results are not only of relevance for the long-term stability of TRISO fuels but also for a variety of other applications, including Schottky-barrier-type contacts in electronic devices. (C) 2010 American Institute of Physics. [doi:10.1063/1.3500374

Design, synthesis, and evaluation of cisplatin-containing EGFR targeting bioconjugates as potential therapeutic agents for brain tumors

Rolf F Barth,1 Gong Wu,1 W Hans Meisen,2 Robin J Nakkula,1 Weilian Yang,1 Tianyao Huo,1 David A Kellough,1 Pravin Kaumaya,3–5 Claudia Turro,6 Lawrence M Agius,7 Balveen Kaur2 1Department of Pathology, 2Department of Neurological Surgery, 3Department of Obstetrics and Gynecology, 4Department of Molecular and Cellular Biochemistry, 5Department of Microbiology, 6Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA; 7Department of Pathology, Mater Dei Hospital, University of Malta Medical School, Msida, Malta Abstract: The aim of this study was to evaluate four different platinated bioconjugates containing a cisplatin (cis-diamminedichloroplatinum [cis-DDP]) fragment and epidermal growth factor receptor (EGFR)-targeting moieties as potential therapeutic agents for the treatment of brain tumors using a human EGFR-expressing transfectant of the F98 rat glioma (F98EGFR) to assess their efficacy. The first two bioconjugates employed the monoclonal antibody cetuximab (C225 or Erbitux®) as the targeting moiety, and the second two used genetically engineered EGF peptides. C225-G5-Pt was produced by reacting cis-DDP with a fifth-generation polyamidoamine dendrimer (G5) and then linking it to C225 by means of two heterobifunctional reagents. The second bioconjugate (C225-PG-Pt) employed the same methodology except that polyglutamic acid was used as the carrier. The third and fourth bioconjugates used two different EGF peptides, PEP382 and PEP455, with direct coordination to the Pt center of the cis-DDP fragment. In vivo studies with C225-G5-Pt failed to demonstrate therapeutic activity following intracerebral (ic) convection-enhanced delivery (CED) to F98EGFR glioma-bearing rats. The second bioconjugate, C225-PG-Pt, failed to show in vitro cytotoxicity. Furthermore, because of its high molecular weight, we decided that lower molecular weight peptides might provide better targeting and microdistribution within the tumor. Both PEP382-Pt and PEP455-Pt bioconjugates were cytotoxic in vitro and, based on this, a pilot study was initiated using PEP455-Pt. The end point for this study was tumor size at 6 weeks following tumor cell implantation and 4 weeks following ic CED of PEP455-Pt to F98 glioma-bearing rats. Neuropathologic examination revealed that five of seven rats were either tumor-free or only had microscopic tumors at 42 days following tumor implantation compared to a mean survival time of 20.5 and 26.3 days for untreated controls. In conclusion, we have succeeded in reformatting the toxicity profile of cis-DDP and demonstrated the therapeutic efficacy of the PEP455-Pt bioconjugate in F98 glioma-bearing rats. Keywords: cisplatin, F98EGFR rat glioma, molecular targets, peptides, monoclonal antibodie