7 research outputs found

    Wood Fibre Materials on Hot Sounding Rocket Structures

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    Throughout the history of aviation as well as space flight, wooden materials played a major role in the construction of primary as well as secondary structures. Being one of the first construction materials used in that field, it does not only offer low density and good relative strength properties, but also easy handling, simple production processes, low costs and last but not least a green, renewable resource. With its unique characteristics the worlds lightest and biggest aviation vehicles heavier than air were created. Because of its relatively low thermal conductivity and good ablative behaviour wooden materials are taken into consideration for the use of hot structures such as the leading edges of sounding rocket stabilising fins. As a mandatory and thus flight critical structure of ballistic flying vehicles, fins need to be aerodynamically effective, lightweight, stiff and heat resistant on its foremost front end, where high temperatures may arise from fluid stagnation and friction. In order to gain a deeper understanding and assess the usability of modern wood fibre materials being appropriate in that field jointly, a cooperation with the Technische UniversitÀt Dresden (TUD) and the German Aerospace Center (DLR) has been established. This paper describes the motivation of the research as well as the structural application with its functionality and boundary conditions. The choice of materials and its rationale for selection in combination with various screening test results are the core of this research. First impacts on the componentsŽ design and an outlook for future research conclude this paper

    Bio-based ablative thermal protection materials for space application

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    In the context of a growing bioeconomy, green renewable resources are of interest for the space industry. Because of its relatively low density, low thermal conductivity, easy handling and good ablative behaviour bio- and wood-based materials are taken into consideration for the use as a thermal protection system (TPS) material on hot structures such as the leading edges of stabilising fins, fairings, nose cones and other TPS applications. As a mandatory and thus flight critical structure of launch vehicles, these parts need to be aerodynamically effective, lightweight, stiff and heat resistant on its foremost front end, where high temperatures may arise from gas kinetic effects. In order to gain a deeper understanding and assess the applicability of modern bio- and wood-based materials, a systematic literature and patent analysis of bio- and wood-based materials in spaceflight has been conducted as a starting point for the research. To set a framework for the application of a bio-based material in space, functionality and boundary conditions have been analysed and form requirements for the development of the bio-based TPS material. Further, prototype materials with varying ingredients of natural fibres, binders and additives have been developed and characterised by a thermogravimetric analysis (TGA) to determine their general suitability as a TPS material. The materials have been additionally screened in more detail via the analyses of bulk density, thermal conductivity and specific heat capacity. Measurements under real environmental conditions in a plasma channel were carried out for further investigation and form the core of this work. With the defined requirements and results from screening tests and plasma channel tests a selection of the best-performing prototype material could be made. First impacts on launch vehicle’s design and an outlook for future research on bio-based TPS conclude this contribution

    The First European Interdisciplinary Ewing Sarcoma Research Summit

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    The European Network for Cancer Research in Children and Adolescents (ENCCA) provides an interaction platform for stakeholders in research and care of children with cancer. Among ENCCA objectives is the establishment of biology-based prioritization mechanisms for the selection of innovative targets, drugs, and prognostic markers for validation in clinical trials. Specifically for sarcomas, there is a burning need for novel treatment options, since current chemotherapeutic treatment protocols have met their limits. This is most obvious for metastatic Ewing sarcoma (ES), where long term survival rates are still below 20%. Despite significant progress in our understanding of ES biology, clinical translation of promising laboratory results has not yet taken place due to fragmentation of research and lack of an institutionalized discussion forum. To fill this gap, ENCCA assembled 30 European expert scientists and five North American opinion leaders in December 2011 to exchange thoughts and discuss the state of the art in ES research and latest results from the bench, and to propose biological studies and novel promising therapeutics for the upcoming European EWING2008 and EWING2012 clinical trials

    Genomweites Expressionsprofil skelettaler Tumore und funktionelle Analyse der Ephrine und CD52 in Osteosarkomen und Riesenzelltumoren

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    Knochentumore stellen mit nur 0,2% aller menschlichen Tumore sehr seltene primĂ€re Neoplasien des skelettalen Systems dar. Diese Dissertation beschreibt die genomweite Microarray Analyse von Osteosarkomen und Riesenzelltumoren. Mit einer Microarray Analyse von konventionellen und metastatischen Osteosarkom-Geweben verglichen zu einer Osteoblasten-PrimĂ€rkultur (HOBc) wurden Gene ermittelt, die im Prozess der Entstehung und Entwicklung sowie im Verlauf der Metastasierung von Osteosarkomen eine Rolle spielen könnten. EFNA1, EphA2, EphA3 und EFNB2 wiesen sehr hohe relative Expressionswerte und eine deutliche Aufregulierung in den Osteosarkomen im Vergleich zu HOBc auf. Mittels RT-PCR und immunhistochemischer FĂ€rbung wurde die Expression von EFNA1, EFNA2, EFNB1, EFNB3, EphA1 und EphA2 validiert. Da die deutliche Aufregulation von EphA2 und EFNA1 im Osteosarkom bestĂ€tigt werden konnte, wurden beide Ephrine funktionell untersucht. EphA2 wird in Osteosarkom-Zellen durch seinen Liganden EFNA1 Zeit- und Dosis-abhĂ€ngig internalisiert und vermutlich degradiert. Die Stimulierung des EphA2 Rezeptors durch EFNA1/Fc fĂŒhrt zu einer Aktivierung von Mek, Erk und den Transkriptionsfaktoren Elk1 und cJun. In Wachstumsassays wurde eine signifikant erhöhte Proliferation der stark EphA2 exprimierenden MNNG/HOS Osteosarkom-Zellen durch EFNA1/Fc beobachtet. Diese Resultate zeigen, dass die Überexpression von EphA2 und EFNA1 im Osteosarkom eine Rolle wĂ€hrend der osteogenen Tumorgenese spielen. Interessanterweise scheinen EphA2 und EFNA1 direkte Zielgene des Mek/Erk-Signalweges zu sein. Wir vermuten einen positiven „feedback-loop“, der die EphA2-Expression ĂŒber die Aktivierung des Ras/Erk-Signalweges reguliert. Mittels Microarray Analyse wurden auch primĂ€re und rezidivierende Riesenzelltumor-Gewebe analysiert. Riesenzelltumore sind osteolytische Neoplasien mit einem variablen Grad der AggressivitĂ€t. Durch diese molekulare Charakterisierung konnten neue Gene (AMFR, CD52, Claudin7, EphA1 und FGFR3) als differentiell exprimiert detektiert werden. Sie wurden bisher noch nicht mit Riesenzelltumoren assoziiert und spielen vermutlich eine Rolle in der Tumorprogression. Weitere Analysen grĂ¶ĂŸerer Patientenkollektive sowie funktionelle Studien sind notwendig, um interessante Gene wie AMFR, Cathepsin L, Claudin7, EphA1, FGFR3, Jun und MMP13 weiter zu untersuchen, und um ihre mögliche Beteiligung an Entstehung und Entwicklung von Riesenzelltumoren zu verfestigen. Im Rahmen dieser Arbeit wurde erstmals die extrazellulĂ€re und intrazellulĂ€re Expression von CD52 in mesenchymalen Tumoren beschrieben. Die unterschiedlichen Expressionsmuster von CD52 in den Microarray Analysen der Riesenzelltumore und Osteosarkome veranlassten uns, CD52 nĂ€her zu analysieren. Wir bestĂ€tigten die in vivo und in vitro Expression von CD52 in Osteosarkomen, Chondrosarkomen und Riesenzelltumoren sowie in weiteren benignen und malignen skelettalen EntitĂ€ten verglichen zu deren nicht-neoplastischen GegenstĂŒcken. Generell wiesen die malignen Tumore eine höhere Expression verglichen mit den benignen EntitĂ€ten auf, was eine Rolle des CD52-Antigens bei der Entwicklung von Knochentumoren vermuten lĂ€sst. Weiterhin zeigte unsere Analyse erstmals, dass der derzeit bei der chronisch lymphatischen LeukĂ€mie eingesetzte CAMPATH-1H-Antikörper auch in der Lage ist, die Proliferation von MNNG/HOS Osteosarkom-Zellen Komplement- und Antikörper-vermittelt zu reduzieren.Bone tumors are rare neoplasms of the skeletal system amounting to only 0.2% of the overall human tumor burden. This dissertation describes a genome wide microarray analysis of osteosarcoma and giant cell tumor of the bone as well as a functional analysis of ephrins in osteosarcoma cell lines. We used a microarray analysis to detect genes differentially expressed between a normal bone osteoblast primary culture (HOBc) and primary and metastatic osteosarcoma tissue. For EFNA1, EphA2, EphA3 and EFNB2 an increased expression was detected in the osteosarcoma tissue samples compared to HOBc. The study verified the increased expression of EFNA1 and EphA2 through RT-PCR and immunohistochemical staining in human osteosarcomas and so the effects of their interaction in osteosarcoma cell lines were analyzed. We observed time- and dosedependent suppression of EphA2 expression via internalisation and degradation in osteosarcoma cell lines through the EFNA1 ligand. The stimulation of the EphA2 receptor by EFNA1/Fc led to an activation of Mek and Erk. In addition, this stimulation resulted in an activation of the transcription factors Elk1 and cJun. In MTT-assays a significantly higher proliferation of high expressing EphA2 MNNG/HOS osteosarcoma cells was observed by ligand-treatment. Our results show that EphA2 and EFNA1 are overexpressed in osteosarcomas suggesting a role of the EphA2 receptor during osteogenic tumorigenesis. We further showed that EphA2 and EFNA1 are targets of the Mek/Erk pathway. We suggest that a possible positive feedback loop regulates EphA2-expression through the activation of Mek/Erk activity. Further one, a molecular characterization of primary and relapse giant cell tumor tissue (GCT) was performed via microarray hybridization. GCTs are osteolytic neoplasms with variable degrees of aggressiveness. We established gene expression profiles and discovered a number of new genes (AMFR, CD52, Claudin7, EphA1 and FGFR3) that have not been described in GCTs before. Further studies and functional analyses are necessary in order to verify genes like AMFR, Cathepsin L, Claudin7, EphA1, FGFR3, Jun and MMP13 that may be involved in the progression of the GCTs and to identify potential targets for future therapy. In this study we described for the first time the extracellular and intracellular expression of CD52 in mesenchymal tumors. We confirmed the expression of the CD52 mRNA and protein both in vivo and in vitro of osteosarcomas, chondrosarcomas, GCTs and other benign and malign skeletal tumors compared to their non-neoplastic counterpart. In general, the malignant tumors showed a higher CD52-expression compared to the benign entities suggesting a role in the progression of bone tumors. Our results obtained in osteosarcoma MNNG/HOS cells showed that CAMPATH-1H, a CD52 antibody currently used in the treatment of chronic lymphatic leukaemia, led to a complement- and antibody-dependent reduction of viable osteosarcoma cells

    Familial chilblain lupus due to a gain-of-function mutation in STING

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    Objectives Familial chilblain lupus is a monogenic form of cutaneous lupus erythematosus caused by loss-of-function mutations in the nucleases TREX1 or SAMHD1. In a family without TREX1 or SAMHD1 mutation, we sought to determine the causative gene and the underlying disease pathology. Methods Exome sequencing was used for disease gene identification. Structural analysis was performed by homology modelling and docking simulations. Type I interferon (IFN) activation was assessed in cells transfected with STING cDNA using an IFN-Ăą reporter and Western blotting. IFN signatures in patient blood in response to tofacitinib treatment were measured by RT-PCR of IFN-stimulated genes. Results In a multigenerational family with five members affected with chilblain lupus, we identified a heterozygous mutation of STING, a signalling molecule in the cytosolic DNA sensing pathway. Structural and functional analyses indicate that mutant STING enhances homodimerisation in the absence of its ligand cGAMP resulting in constitutive type I IFN activation. Treatment of two affected family members with the Janus kinase ( JAK) inhibitor tofacitinib led to a marked suppression of the IFN signature. Conclusions A heterozygous gain-of-function mutation in STING can cause familial chilblain lupus. These findings expand the genetic spectrum of type I IFNdependent disorders and suggest that JAK inhibition may be of therapeutic value.Fil: König, Nadja. Technische UniversitĂ€t Dresden; AlemaniaFil: Fiehn, Christoph. Acura Akutklinik FĂŒr Rheumatologie Baden-baden; AlemaniaFil: Wolf, Christine. Technische UniversitĂ€t Dresden; AlemaniaFil: Schuster, Max. Technische UniversitĂ€t Dresden; AlemaniaFil: Cura Costa, Emanuel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicos; ArgentinaFil: TĂŒngler, Victoria. Technische UniversitĂ€t Dresden; AlemaniaFil: Alvarez, Hugo Ariel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicos; ArgentinaFil: Chara, Osvaldo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicos; ArgentinaFil: Engel, Kerstin. Technische UniversitĂ€t Dresden; AlemaniaFil: Goldbach Mansky, Raphaela. Technische UniversitĂ€t Dresden; AlemaniaFil: GĂŒnther, Claudia. National Institutes of Health; Estados UnidosFil: Lee Kirsch, Min Ae. Technische UniversitĂ€t Dresden; Alemani

    12. Literaturverzeichnis

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