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Charakterisierung von Subpopulationen Dendritischer Zellen und der Expression von C-Typ-Lektinrezeptoren in humanen Geweben mittels ImmunfluoreszenzmikroskopieEissing, Nathalie 06 September 2011 (has links)
Dendritische Zellen (DCs) sind befähigt, als potenteste Antigen-präsentierende Zelle anti¬genspezifische Immunantworten zu initiieren und zu regulieren. Mittels in vivo Antigen¬beladung von spezifischen DC-Subpopulationen mit rekombinanten Antigen-gekoppelten Antikörpern gegen C-Typ-Lektinrezeptoren konnte im Mausmodell erfolgreich adaptive zelluläre und humorale Immunantworten hervorgerufen werden. Im Menschen kann dieser Ansatz therapeutisch noch nicht zum Einsatz kommen, da DC-Subpopulationen im humanen Gewebe momentan nicht ausreichend charakterisiert sind. Im Rahmen dieser Arbeit wurden humane Gewebe auf das Vorhandensein der im peripheren Blut beschriebenen DC-Subpopulationen (mDC-1 DCs: CD11c+BDCA1+, mDC-2 DCs: CD11clowBDCA3+ und pDCs: CD11c-CD123+BDCA2+) und die Expression von C-Typ-Lektinrezeptoren (DC-SIGN, MMR, Langerin, DCIR und DEC205) mittels Immun¬fluoreszenz untersucht. Anhand der vorge¬gebenen Marker im peripheren Blut konnten alle drei DC-Subpopulationen in der Milz, Thymus und Tonsillen detektiert werden. Zusätzlich konnte hier erstmalig eine vierte CD11c-CD123-BDCA2+ pDC-2 DC-Subpopulation in der Milz beschrieben werden, deren Funktion derzeit noch näher untersucht wird. Im Thymus konnte CD26 nach FACS-Analysen von Gordon Heidkamp als spezifischer Marker für mDC-2 DCs identifiziert und dies in der vorliegenden Arbeit auch durch Immun¬fluores¬zenzaufnahmen von Gewebeschnitten verifi¬ziert werden. CD26 stellt damit erstmalig einen Marker dar, der erfolgreich als alternativer Marker für BDCA3, welcher unspezifisch an Thrombomodulin bindet, zur Identifikation von mDC-2 DCs in der Immunfluoreszenz von Thymusproben eingesetzt werden könnte. Die getesteten Anti¬körper XCR-1 (monoklonal) und Clec9a (polyklonal) hingegen erschienen in der Immun¬fluoreszenz sowie in FACS-Analysen (Gordon Heidkamp) nicht geeignet. Weiterhin wurde die Expression ausgewählter C-Typ-Lektinrezeptoren (MMR, Langerin, DCIR, DC-SIGN und DEC205) im vorhandenen Gewebe näher betrachtet. Nach Auswertung der Immun¬fluoreszenzen konnte eine weit verbreitete Expression der untersuchten C-Typ-Lektin¬rezeptoren in humaner Milz und Thymus gefunden werden. Einzig hDCIR war auf vereinzelten Zellen exprimiert, und Langerin im Thymus nicht detektierbar. Um nicht verfügbare monoklonale Antikörper gegen C-Typ-Lektinrezeptoren zu produzieren und später Antigene an diese koppeln zu können, sollten lösliche Proteine einiger C-Typ-Lektinrezeptoren (humanes und murines Clec9a, Dectin-1 und -2, Langerin) produziert werden. Dabei gelang es bereits, lösliche Proteine der C-Typ-Lektinrezeptoren von humanem und murinem Dectin-1 zu generieren und diese zur weiteren Antikör¬per¬produktion einzusetzen.
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Analyse und Optimierung der Webtechnik zur Realisierung von textilen Halbzeugen mit gestreckten Fadenlagen für die FaserverbundwerkstoffeKleicke, Roland 22 February 2018 (has links)
Die Entwicklung von Geweben mit gestreckten Fadenlagen ist Gegenstand aktueller Forschungen, die vielfach Sondermaschinen für ganz spezielle Anwendungen hervorbringen. Eine systematische Analyse und Optimierung der unter Berücksichtigung der Verbundeigenschaften existiert nach bekanntem Stand des Wissens nicht.
Ziel der Dissertation ist es, diese Lücke zu schließen und einen Beitrag zur Etablierung von Geweben mit gestreckten Fadenlagen in Faserverbundwerkstoffen zu leisten. Die Arbeit basiert zum Teil auf den Ergebnissen, die in der Zeit von 2006 – 2012 am Institut für Textilmaschinen und textile Hochleistungswerkstofftechnik der Technischen Universität Dresden im Rahmen verschiedener AiF und DFG Vorhaben entstanden sind. Weiterführende Überlegungen wurden 2015 – 2017 im Rahmen eines Promotionsstudiums an der Professur für Textile Technologien der Technischen Universität Chemnitz angefertigt.
Wie anhand konkreter Ausführungsbeispiele gezeigt wird, stößt das Weben insbesondere für Anwendungen im Faserverbundleichtbau an technologisch bedingte Grenzen. Es erfolgt zunächst eine Gegenüberstellung konventioneller Flächenbildungsverfahren und der Anforderungen seitens der Endanwender, insbesondere aus dem Bereich der Verbundwerkstoffindustrie, gleichermaßen. Daraus wird ein Anforderungsprofil für ein anforderungsgerechtes Flächenbildungsverfahren abgeleitet und konstruktive Lösungsvorschläge zu dessen Umsetzung aufgezeigt. / The development of non-crimped-fabrics (NCF) is subject of current research activities. These often led to special machines for very special applications. There is no systematic analysis and optimization of the properties of composites based on the state of the art.
The aim of this dissertation is to close this gap and to contribute to the establishment of woven NCF in fiber-reinforced composites. The work is based partially on the results obtained at the Institut für Textilmaschinen und textile Hochleistungswerkstofftechnik der Technischen Universität Dresden from 2006 to 2012 within the framework of various AiF and DFG projects. Further reflections were made between 2015 and 2017 as part of a doctoral study at the Chair of Textile Technologien der Technischen Universität Chemnitz.
As shown from examples of the design, weaving is reaching technological limits, especially for applications in composite construction. First of all, conventional surface formation methods are compared with the requirements of end users, especially from the composites industry. From this, a requirement profile is derived for a requirements-based surface formation process and constructive proposals for solutions for its implementation are identified.
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Evaluation of adhesive binders for the development of yarn bonding for new stitch-free non-crimp fabricsAl-Monsur, Md. Abdullah, Bardl, Georg, Cherif, Chokri 18 September 2019 (has links)
Non-crimp fabrics (NCFs), especially multi-axial warp-knitted fabrics, are used as reinforcement materials for fiberreinforced composites. The manufacturing of multi-axial warp-knitted fabrics by a conventional stitch bonding process to produce NCF has several disadvantages, such as filament damage, low production speed, yarn disorientation, etc. In order to overcome the existing limitations, the idea of using an adhesive binder to attach the fabric layers is a promising approach, so that the use of stitching yarns can be eliminated. The fundamental investigations presented in this paper show that the selection of the binder material has a major influence on the parameters of the textile products. Whereas the tested hotmelt adhesives offer a short curing time and a small but nevertheless sufficient bonding strength between bonded yarns, the tested reactive adhesives show a bonding strength up to 10 times higher, but at a considerably longer curing time. The reason for the different bonding strength is identified in the different penetration into the yarns. The experiments also show a significant influence of the fiber type and sizing, which needs to be taken into account when selecting fabric binders.
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Beiträge zur biomechanischen Charakterisierung faseriger BindegewebeSichting, Freddy 29 June 2016 (has links)
Im Mittelpunkt dieser kumulativ angefertigten Arbeit stehen fünf verschiedenartige biomechanische Untersuchungen faseriger Bindegewebe, welche in einer Gesamtschau zusammengeführt werden. Die einzelnen Beiträge setzen sich zusammen aus Untersuchungen zum Einfluss zellulärer Bestandteile auf die mechanischen Eigenschaften faseriger Bindegewebe und die Beeinflussung dieser Ergebnisse durch Messfehler, speziell am Beispiel des Materialschlupfs. Über diese beiden Beiträge wird eine Verbindung hergestellt zur rechnergestützten Simulation der Wirkung eines Beckenkompressionsgurts auf die Bänder des Beckenrings und dem Transmissionsverhalten faseriger Bindegewebe bei Zugbelastung. Im fünften Beitrag wird am Beispiel des Zusammenwirkens von Achillessehne, Fersenfettpolster und Plantarfaszie in vitro die Komplexität der Betrachtung faseriger Bindegewebe aufgezeigt. Die Zusammenführung der einzelnen Untersuchungen wird begleitet von der Frage, ob die bestehenden biomechanischen Untersuchungsansätze ausreichend sind, um ein umfassendes Verständnis zur funktionellen Bedeutung faseriger Bindegewebe aufbauen zu können.
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Exogenous modulation of embryonic tissue and stem cells to form nephronal structuresSebinger, David Daniel Raphael 26 April 2013 (has links)
Renal tissue engineering and regenerative medicine represent a significant clinical objective because of the very limited prospect of cure after classical kidney treatment. Thus, approaches to isolate, manipulate and reintegrate structures or stimulating the selfregenerative potential of renal tissue are of special interest. Such new strategies go back to knowledge and further outcome of developmental biological research. An understanding of extracellular matrix (ECM) structure and composition forms thereby a particularly significant aspect in comprehending the complex dynamics of tissue regeneration. Consequently the reconstruction of these structures offers beneficial options for advanced cell and tissue culture technology and tissue engineering. In an effort to investigate the influence of natural extracellular structures and components on embryonic stem cell and renal embryonic tissue, methodologies which allow the easy application of exogenous signals on tissue in vitro on the one hand and the straight forward evaluation of decellularization methods on the other hand, were developed. Both systems can be used to investigate and modulate behaviour of biological systems and represent novel interesting tools for tissue engineering. The novel technique for culturing tissue in vitro allows the growing of embryonic renal explants in very low volumes of medium and optimized observability, which makes it predestined for testing additives. In particular, this novel culture set up provides an ideal opportunity to investigate renal development and structure formation. Further studies indicated that the set is universally applicable on all kinds of (embryonic) tissue. Following hereon, more than 20 different ECM components were tested for their impact on kidney development under 116 different culture conditions, including different concentrations and being either bound to the substrate or dissolved in the culture medium. This allowed to study the role of ECM constituents on renal structure formation. In ongoing projects, kidney rudiments are exposed to aligned matrix fibrils and hydrogels with first promising results. The insights gained thereof gave rise to a basis for the rational application of exogenous signals in regenerative kidney therapies. Additionally new strategies for decellularization of whole murine adult kidneys were explored by applying different chemical agents. The obtained whole matrices were analysed for their degree of decellularization and their residual content and composition. In a new straight forward approach, a dependency of ECM decellularization efficiency to the different agents used for decellularization could be shown. Moreover the capability of the ECM isolated from whole adult kidneys to direct stem cell differentiation towards renal cell linage phenotypes was proved. The data obtained within this thesis give an innovative impetus to the design of biomaterial scaffolds with defined and distinct properties, offering exciting options for tissue engineering and regenerative kidney therapies by exogenous cues.:Table of Contents
LISTS OF FIGURES AND TABLES VI
ACKNOWLEDGEMENTS..................................................................................VII
ABSTRACT ............................................................................................................IX
NOMENCLATURE ................................................................................................X
1 INTRODUCTION...................................................................................................1
2 FUNDAMENTALS..................................................................................................2
2.1 KIDNEY DEVELOPMENT AND REGENERATION ...............................................................................2
2.1.1 Function of the kidney............................................................................................2
2.1.2 Development of the metanephric kidney ................................................................2
2.1.3 Selfregenerative potential of the kidney.................................................................5
2.2 THE EXTRACELLULAR MATRIX AS BIOLOGICAL SCAFFOLD ...............................................................6
2.2.1 Molecular composition of the ECM........................................................................7
2.2.1.1 An overview of the main ECM components..................................................................................8
2.2.2 Cell/tissue-matrix interactions.............................................................................12
2.2.2.1 Biochemical signals....................................................................................................................13
2.2.2.2 Mechanical signals......................................................................................................................14
2.2.2.3 Structural signals........................................................................................................................15
2.3 TISSUE ENGINEERING FOR THERAPEUTIC PURPOSES .....................................................................15
2.3.1 An overview of tissue engineering and regenerative medicine.............................15
2.3.2 Biomaterials for tissue engineering and regenerative medicine...........................18
2.3.2.1 Decellularization approach as tool to extract natural matrices....................................................19
2.3.3 Tissue engineering and regenerative medicine in kidney treatment.....................19
2.4 ORGAN AND TISSUE CULTURE AS TOOL FOR TISSUE ENGINEERING...................................................22
2.4.1 Common organ culture systems............................................................................24
3 OBJECTIVES AND MOTIVATION...................................................................25
4 RESULTS AND DISCUSSION............................................................................27
4.1 A NOVEL, LOW-VOLUME METHOD FOR ORGAN CULTURE OF EMBRYONIC KIDNEYS THAT ALLOWS
DEVELOPMENT OF CORTICO-MEDULLARY ANATOMICAL ORGANIZATION..............................................27
4.1.1 Additional evidences (to Appendix A) for stress reduction of kidney rudiments
cultured in the novel system than those grown in conventional organ culture.....28
4.1.2 Additional evidences (to Appendix A) for corticomedullary zonation and improved
development of kidney rudiments cultured in the novel system for a period of 12
days......................................................................................................................30
4.1.3 Additional evidences (to Appendix A) for the application of the glass based low
volume culture system for other organs................................................................32
4.2 ECM MODULATED EARLY KIDNEY DEVELOPMENT IN ORGAN CULTURE ...........................................34
4.3 ESTABLISHING AND EVALUATING DECELLULARIZATION TECHNIQUES TO ISOLATE WHOLE KIDNEY ECMS
FROM ADULT MURINE KIDNEYS................................................................................................37
4.4 THE ABILITY OF WHOLE DECELLULARIZED ECM CONSTRUCTS TO INFLUENCE MURINE EMBRYONIC STEM
CELL DIFFERENTIATION AND RENAL TISSUE BEHAVIOUR IN A NEW STRAIGHT FORWARD APPROACH..........38
iv
5 SUMMARY AND OUTLOOK.............................................................................39
5.1 SUMMARY..........................................................................................................................39
5.2 OUTLOOK...........................................................................................................................42
6 BIBLIOGRAPHY.................................................................................................49
7 APPENDICES..........................................................................................................I
7.1 APPENDIX A: A NOVEL, LOW-VOLUME METHOD FOR ORGAN CULTURE OF EMBRYONIC KIDNEYS
THAT ALLOWS DEVELOPMENT OF CORTICO-MEDULLARY ANATOMICAL ORGANIZATION......................I
7.2 APPENDIX B: ECM MODULATED EARLY KIDNEY DEVELOPMENT IN EMBRYONIC ORGAN CULTURE ....XIX
7.3 APPENDIX C: THE DEWAXED ECM: AN EASY METHOD TO ANALYZE CELL BEHAVIOUR ON
DECELLULARIZED EXTRACELLULAR MATRICES.......................................................................XLIV
7.4 PUBLICATIONS AND SCIENTIFIC CONTRIBUTIONS......................................................................LXV
7.5 SELBSTSTÄNDIGKEITSERKLÄRUNG......................................................................................LXIX
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Technology development of novel woven 3D cellular reinforcement for enhanced impact safety on the example of mineral-bonded compositesVõ, Duy Minh Phương 18 July 2024 (has links)
Concrete’s great vulnerability against impact demonstrates significant risks of injury for workers and occupants in all building types, especially existing concrete structures in which protection measures were not originally integrated. Beside the social and economic costs directly associated with impact accidents, the reconstruction or replacement of buildings damaged by impact negatively affects the environment and resources. In response to the increasing public concern for safety and sustainability, the DFG Research Training Group GRK 2250 is formed with the core aim to develop significant improvements in the impact resistance of existing concrete buildings by applying thin strengthening layers made of innovative mineral-bonded composites. The introduction of textile-based high-performance reinforcement is highly instrumental in realizing the required functions of thin mineral-bonded strengthening layers.
Novel impact-resistant 3D reinforcement is developed on the basis of the innovative 3D cellular weaving technology in this dissertation. Woven 3D cellular structures are characterized by outstanding and customizable mechanical characteristics, owning to the flexible incorporation of elements with different materials and geometries both in in-plane and out-of-plane directions. Based on a systematic and partly iterative development process, impact-resistant woven 3D cellular reinforcements containing impact-load-oriented elements and impact-appropriate material combination are successfully designed and optimized. On the one hand, a series of experiments are conducted to capture the working mechanism of woven 3D cellular structure in mineral-bonded composites loaded under impact, and to understand the effects of critical structure features. On the other hand, feasible weave patterns and effective technological solutions are worked out and implemented to enable a reliable and low-damage manufacturing process. Through a series of impact experiments, it can be strongly evidenced that the developed 3D cellular reinforcement pronouncedly enhances the load bearing capacity, ductility and energy dissipation of mineral-bonded composite undergoing impact, thus, remarkably enhances its impact resistance.
The development of impact-resistant woven 3D cellular reinforcements in this dissertation introduces a completely new and unique class of textile-based reinforcement for concrete, as well as mineral-bonded composites, with numerous benefits over the presently available reinforcing structures. A major advantage of the novel 3D cellular reinforcement is the capability to activate and exploit multiple energy dissipation mechanisms using both material and structure properties, through which remarkable impact resistance can be obtained. Thanks to a high degree of versatility and flexibility in material combination and structure design, in combination with a high degree of automation and flexibility of the weaving technology, impact-resistant woven 3D cellular reinforcement that is highly customized to specific impact scenarios can be produced with a significant time and cost efficiency. Furthermore, impact-resistant woven 3D cellular reinforcements possess an integral 3D architecture that ensures a high structure stability, allowing for a speedy casting process with a high placement-accuracy. On that basis, a reasonable production cost and a stable performance of designed functions can be obtained. The successful development of impact-resistant woven 3D cellular reinforcement essentially facilitates the successful creation of high-performance mineral-bonded strengthening layers, through the use of which the impact resistance of existing concrete structures, thus, their sustainable use, significantly enhances.:1 INTRODUCTION AND MOTIVATION 1
2 LITERATURE REVIEW 7
2.1 Fundamentals of concrete and reinforced concrete 7
2.1.1 Normal concrete 7
2.1.2 Structural concrete family 10
2.1.3 Steel reinforced concrete 11
2.1.4 Concrete and reinforced concrete under impact loading 14
2.1.5 Fiber-based reinforcing materials for concrete 18
2.1.6 Fiber reinforced concrete 21
2.1.7 Textile reinforced concrete 22
2.2 Two-dimensional textile concrete reinforcements 24
2.2.1 Welded metal wire mesh 24
2.2.2 Expanded metal mesh 25
2.2.3 Woven 2D reinforcing structures 25
2.2.4 Warp knitted 2D reinforcing structures 27
2.2.5 Stitched 2D reinforcing structures 28
2.2.6 Adhesively-bonded 2D reinforcing structures 29
2.2.7 Discussion of 2D reinforcing structures 30
2.3 Three-dimensional textile concrete reinforcements 33
2.3.1 Assembled 3D reinforcing structures 33
2.3.2 Woven 3D reinforcing structures 34
2.3.3 Warp knitted 3D reinforcing structures 35
2.3.4 Stitched 3D reinforcing structures 36
2.3.5 Adhesively-bonded 3D reinforcing structures 36
2.3.6 Discussion of available 3D reinforcing structures 36
2.4 Woven 3D cellular structures 37
2.5 Conclusion based on literature review 37
3 RESEARCH AIMS AND OBJECTIVES 39
4 PRELIMINARY INVESTIGATION INTO IMPACT BEHAVIOR OF MINERAL-BONDED COMPOSITE REINFORCED WITH WOVEN 3D CELLULAR STRUCTURE 41
4.1 Introduction 41
4.2 Materials under investigation 43
4.2.1 Reinforcement - Reference woven 3D cellular structure 3DWT Ref 43
4.2.2 Matrix - Fine-grained concrete Pagel TF10 44
4.2.3 Comparing reinforcement - Warp knitted 2D structure 2D BZT2 44
4.3 Specimen labeling 45
4.4 Methodology of small-scale plate impact test 46
4.4.1 Specimen preparation 46
4.4.2 Test setup 47
4.5 Preliminary small-scale plate impact test results 47
4.6 Summary and conclusion of preliminary investigation 58
4.7 Derivation of requirements and procedure for developing impact-resistant woven 3D cellular reinforcement 59
5 DEVELOPMENT OF STRUCTURE SYSTEMATICS FOR IMPACT-RESISTANT WOVEN 3D CELLULAR REINFORCEMENT 63
5.1 Fundamentals of woven 3D cellular structure 64
5.1.1 Conventional woven structure 64
5.1.2 Elements of woven 3D cellular structure 65
5.1.3 Formation principles of woven 3D cellular structure 66
5.1.4 Variation possibilities within woven 3D cellular structure 68
5.2 Design concept of mineral-bonded strengthening layers against impact 71
5.3 Requirements for impact-resistant woven 3D cellular reinforcement 73
5.4 Two-plane woven 3D cellular reinforcements 77
5.4.1 Two-plane woven 3D cellular reinforcements with biaxial grids 77
5.4.2 Two-plane woven 3D cellular reinforcements with triaxial grids 81
5.4.3 Two-plane woven 3D cellular reinforcements with quadriaxial grids 82
5.5 Three-plane 3D cellular reinforcements 83
5.6 Material variation 85
5.6.1 Double yarns 85
5.6.2 Hybrid yarns 86
5.7 Selected impact-resistant woven 3D cellular reinforcements for realization and investigation 86
6 DEVELOPMENT OF WEAVE PATTERN FOR IMPACT-RESISTANT WOVEN 3D CELLULAR REINFORCEMENT 89
6.1 Introduction 89
6.2 Two-plane reference structure 3DWT Ref 90
6.3 Two-plane double yarn structure 3DWT DbWi 92
6.4 Three-plane structure 3DWT DbLyr 93
6.5 Two-plane pyramid structure 3DWT Pyr 95
7 DEVELOPMENT OF TECHNOLOGICAL SOLUTIONS FOR THE MANUFACTURE OF IMPACT-RESISTANT WOVEN 3D CELLULAR REINFORCEMENT 101
7.1 3D cellular weaving technology 101
7.2 Manufacture of two-plane double yarn structure 3DWT-DbWi 107
7.3 Manufacture of three-plane structure 3DWT-DbLyr 108
7.4 Manufacture of two-plane pyramid structure 3DWT-Pyr 112
8 TENSILE BEHAVIOR OF SHCC CONTAINING IMPACT-RESISTANT WOVEN 3D CELLULAR REINFORCEMENT 117
8.1 Quasi-static tension tests 117
8.1.1 Specimen preparation 117
8.1.2 Test setup 118
8.1.3 Quasi-static tension test results 119
8.2 High-speed tension tests 126
8.2.1 Specimen preparation 126
8.2.2 Test setup 126
8.2.3 High-speed tension test results 127
9 ENHANCEMENT OF IMPACT-RESISTANT WOVEN 3D CELLULAR REINFORCEMENT 131
9.1 Concept of enhanced impact-resistant 3D cellular reinforcement 131
9.2 Weave pattern development of enhanced impact-resistant reinforcement 3DWT Pyr Hyb 134
9.3 Manufacture of enhanced impact-resistant reinforcement 3DWT Pyr Hyb 136
9.3.1 Material selection 136
9.3.2 Carbon rovings impregnation 142
9.3.3 Steel wires straightening and preshaping 142
9.3.4 Weaving and realized structure 143
10 PERFORMANCE OF MINERAL-BONDED STRENGTHENING LAYER WITH IMPACT-RESISTANT WOVEN 3D CELLULAR REINFORCEMENT 147
10.1 Tensile behavior of SHCC reinforced with 3DWT Pyr Hyb 147
10.1.1 Specimen preparation 147
10.1.2 Quasi-static tension test results 148
10.1.3 Dynamic tension test results 154
10.2 Impact behavior of SHCC reinforced with 3DWT Pyr Hyb 157
10.2.1 Materials under investigation 157
10.2.2 Small-scale plate impact test results 159
10.3 SHCC reinforced with 3DWT Pyr Hyb as strengthening layer on the impacted side of concrete core 169
10.4 Summary and conclusion of the performance investigation on mineral-bonded strengthening layer reinforced with 3DWT Pyr Hyb 173
11 CONCLUSIONS AND RECOMMENDATIONS 175
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Textile reinforcement structures for concrete construction applications––a reviewFriese, Danny, Scheurer, Martin, Hahn, Lars, Gries, Thomas, Cherif, Chokri 19 June 2023 (has links)
The use of non-metallic, textile reinforcement structures in place of steel reinforcement is a key component in making concrete constructions more sustainable and durable than they currently are. The reason for this is the corrosion resistance of textile reinforcements, which makes it possible to reduce the thickness of the concrete cover and at the same time extend the service life of concrete structures. This reduces the amount of cement required and thus also the emission of the greenhouse gas carbon dioxide. By means of textile manufacturing technologies, customized, load-adapted reinforcement topologies can be adjusted to the requirements of highly stressed and well-designed concrete components.
The objective of this paper is to give an overview of recent research literature dedicated to textile reinforcement structures that are already used for concrete applications in the construction industry as well as those currently under development. Therefore, textile reinforcement structures, which are divided into one-, two- and three-dimensional topologies, as well as common materials used for textile-reinforced concrete are reviewed. Most research has so far been devoted to two-dimensional textile reinforcement structures. Furthermore, novel approaches to the fabrication of textile reinforcement structures for concrete applications based on robotic yarn deposition technologies are addressed.:1.) Introduction
2.) Materials for textile reinforcement structures for construction applications
3.) Textile reinforcement structures for construction applications
4.) New developments in robot-supported manufacturing technologies for construction applications
5.) Conclusion
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Label‑free imaging flow cytometry for analysis and sorting of enzymatically dissociated tissuesHerbig, Maik, Tessmer, Karen, Nötzel, Martin, Nawaz, Ahsan Ahmad, Santos‑Ferreira, Tiago, Borsch, Oliver, Gasparini, Sylvia J., Guck, Jochen, Ader, Marius 16 May 2024 (has links)
Biomedical research relies on identification and isolation of specific cell types using molecular biomarkers and sorting methods such as fluorescence or magnetic activated cell sorting. Labelling processes potentially alter the cells’ properties and should be avoided, especially when purifying cells for clinical applications. A promising alternative is the label-free identification of cells based on physical properties. Sorting real-time deformability cytometry (soRT-DC) is a microfluidic technique for label-free analysis and sorting of single cells. In soRT-FDC, bright-field images of cells are analyzed by a deep neural net (DNN) to obtain a sorting decision, but sorting was so far only demonstrated for blood cells which show clear morphological differences and are naturally in suspension. Most cells, however, grow in tissues, requiring dissociation before cell sorting which is associated with challenges including changes in morphology, or presence of aggregates. Here, we introduce methods to improve robustness of analysis and sorting of single cells from nervous tissue and provide DNNs which can distinguish visually similar cells. We employ the DNN for image-based sorting to enrich photoreceptor cells from dissociated retina for transplantation into the mouse eye.
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Elucidation of isotropic and anisotropic shear elasticity of in vivo soft tissue using planar magnetic resonance elastographyPapazoglou, Sebastian 26 March 2010 (has links)
Die Magnetresonanzelastographie (MRE) stellt ein nichtinvasives Verfahren dar, welches die Bestimmung der in vivo Scherelastizität weicher Gewebe ermöglicht. Im Rahmen diese Arbeit wurden Methoden zur Bestimmung isotroper und anisotroper Scherelastizitäten anhand von MRE Wellenbildern entwickelt und evaluiert. Alle in dieser Arbeit vorgestellten Methoden basieren auf planarer MRE, d.h. auf der Aufnahme einer einzelnen Auslenkungskomponente innerhalb der Bildschicht. Dadurch wird die MRE erheblich beschleunigt. Allerdings stellen sich dadurch auch besondere Anforderungen an die Datenauswertung zur Bestimmung aussagekräftiger elastischer Kenngrößen. Anhand von planaren MRE-Experimenten an Gewebephantomen und menschlicher Skelettmuskulatur sowie mittels numerischer Simulation wird gezeigt, dass bei Beachtung weniger experimenteller Randbedingungen und einer darauf abgestimmten Datenauswertung, korrekte Elastizitäten ermittelt werden können. Ein besonderer Schwerpunkt der Arbeit liegt in der Analyse experimenteller Einflüsse wie Bildrauschen und -auflösung auf die ermittelten elastischen Kenngrößen. Des Weiteren werden Methoden zur Bestimmung anisotroper Elastizitäten sowie zur Analyse von Streueffekten im MRE-Wellenbild vorgestellt. Die behandelten Einflüsse auf die Amplituden und Wellenlängen im MRE-Bild, werden vergleichend diskutiert und zusammengefasst, um ein einfaches Verfahrensprotokoll zur Analyse experimenteller in vivo MRE-Daten zu entwickeln. Alle in dieser Arbeit verwendeten Methoden und Programme sind im Anhang zusammengefasst und auf Anforderung erhältlich. / Magnetic resonance elastography (MRE) is a noninvasive method that allows the determination of in vivo shear elasticity of soft tissues. In this thesis methods for the determination of isotropic and anisotropic shear elasticities from MRE wave data were developed and evaluated. All methods presented in this work are based on planar MRE, i.e. they are based on the measurement of a single displacement component in the image plane. This way measurement time in MRE is greatly reduced. However, this imposes specific requirements on data evaluation in order to determine significant elastic constants. On the basis of planar MRE experiments on tissue mimicking gels, human skeletal muscle and numerical simulations it is demonstrated that correct shear elasticities can be determined, taking into account a small set of experimental boundary conditions as well as the employment of complementary data evaluation strategies. This thesis is particularly focussed on the analysis of noise and image resolution on the determined elastic constants. Moreover, methods for determining anisotropic elasticity and analyzing shear wave scattering effects on MRE wave data are introduced. The investigated influences on wave amplitudes and wave lengths are compared and discussed to develop a simple measurement protocol for the evaluation of in vivo MRE data. All methods employed in this work are summarized in the appendix along with the corresponding computer code, which is available on demand.
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Identifizierung von Makrophagen-Subpopulationen und Gefäßen in Karzinomen des Gastrointestinaltraktes, des Respirationstraktes und des Urogenitalsystems mittels Gewebe-MikroarraysSickert, Denise 27 September 2005 (has links) (PDF)
Die vorliegende Arbeit beinhaltet umfangreiche histologische Untersuchungen an verschiedenen Tumoren bezüglich ihrer Infiltration durch Makrophagen-Subpopulationen, Granulozyten und Lymphozyten. Hierfür wurden 18 Gewebe-Mikroarrays mit jeweils 200 - 300 Tumorstanzen aus insgesamt 27 Organen des Gastrointestinaltraktes, des Urogenitaltraktes, des Respirationssystems und des endokrinen Systems angefertigt. Da alle Proben mit derselben Technik (Gewebe-Mikroarrays, Immunhiostochemie) ausgewertet wurden, bestand nun erstmalig die Möglichkeit eines direkten Vergleiches zwischen den verschiedenen Tumoren unterschiedlicher Organe. Für die immunhistochemischen Untersuchungen wurden fünf verschiedene Antikörper (anti-KP1, anti-PG-M1, anti-MRP8, anti-MRP14, anti-MRP8/14) eingesetzt. Die Antikörper gegen die Epitope PG-M1 und KP1 gelten als Pan-Makrophagen-Marker. Die Antikörper anti-MRP8, anti-MRP14 und anti-MRP8/14 gelten als Marker für entzündlich aktivierte Makrophagen. Diese Makrophagen wurden in einen aktiven inflammatorischen Typ (MRP14+, MRP8/14+), der proinflammatorische Zytokine wie TNF-a und Sauerstoffradikale bildet, und in einen chronisch inflammatorischen Typ (MRP8+) eingeteilt. Die Formation des MRP8/14-Heterodimers korreliert mit der zellulären Aktivierung wie z. B. mit der Aktivierung der NADPH-Oxidase. Es wurde beschrieben, dass diese Makrophagen auf Grund ihrer Eigenschaften eventuell die Tumorzellproliferation inhibieren und zytotoxische Wirkungen auf Tumorzellen ausüben können. Für die verschiedenen Tumorgewebe wurden höhere Makrophagendichten im Vergleich zum Normalgewebe und eine vergleichsweise geringe Dichte an MRP+ Makrophagen sowie signifikante Korrelationen zwischen den verschiedenen Makrophagen-Subpopulationen festgestellt. Die Dichte der Lymphozyten korrelierte negativ mit steigendem Tumorzellanteil und mit fortgeschrittenem Tumorstadium. Die Abnahme der Lymphozyten (Gastrointestinal- und Respirationstrakt) im Tumorgewebe im Vergleich zum tumorfreien Gewebe sowie die geringe Anzahl der potenziell tumoriziden MRP8/14+ Makrophagen lässt vermuten, dass die Immunantwort gegen den Tumor unterdrückt wird. Die positive Assoziation zwischen Makrophagen und Lymphozyten weist jedoch darauf hin, dass Makrophagen nicht am Rückgang der Lymphozyten beteiligt sind . Eine Korrelation der Makrophagen mit klinisch relevanten Parametern (pT-Stadium, UICC-Stadium, Lymphknotenmetastasen) zeigten ein voneinander abweichendes Infiltrationsmuster der CD68+ und MRP+ Makrophagen, was auf unterschiedliche Funktionen hinweist. Ferner liegen zahlreichen funktionelle Untersuchungsergebnisse anderer Arbeitsgruppen vor, welche darauf hinweisen, dass Makrophagen durch Hypoxie angezogen werden und im hypoxischen Tumorgewebe schließlich an der Neubildung von Blut- und Lymphgefäßen beteiligt sind. Um einen möglichen Zusammenhang zu zeigen, wurde mit den Antikörpern anti-CD31 und anti-CD34 die Gefäßdichte in Tumoren untersucht. Es zeigten sich zahlreiche positive Korrelationen zwischen Gefäßen und Makrophagen, jedoch konnte in den tumorfreien Geweben kein Zusammenhang zwischen beiden Größen gefunden werden. Das Vorkommen größerer Makrophagendichten in Tumoren mit wenig Nekrose als in Tumoren ohne Nekrose, die positive Korrelation zwischen der Anzahl der Gefäße und der Zahl der Makrophagen in Tumoren und die Unabhängigkeit von Makrophagen und Gefäßen im tumorfreien Gewebe legt die Vermutung nahe, dass TAM die Angiogenese begünstigen. Trotz vieler ähnlicher Charakteristika zwischen den Tumoren unterschiedlichen Ursprungsgewebes wurden auch Unterschiede festgestellt, die besonders die Anzahl der Makrophagen-Subpopulationen betreffen. Weitere Studien zur Aufklärung der Funktion unterschiedlicher Makrophagen-Subpopulationen (z. B. Immunsuppression, Neoangiogenese) sind notwendig, um deren Relevanz für das Tumorwachstum und die Tumorprogression aufzuklären.
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