Noninvasive in vivo tracking of mesenchymal stem cells and evaluation of cell therapeutic effects in a murine model using a clinical 3.0 T MRI

Cardiac cell therapy with mesenchymal stem cells (MSCs) represents a promising treatment approach for endstage heart failure. However, little is known about the underlying mechanisms and the fate of the transplanted cells. The objective of the presented work is to determine the feasibility of magnetic resonance imaging (MRI) and in vivo monitoring after transplantation into infarcted mouse hearts using a clinical 3.0 T MRI device. The labeling procedure of bone marrow-derived MSCs with micron-sized paramagnetic iron oxide particles (MPIOs) did not affect the viability of the cells and their cell type-defining properties when compared to unlabeled cells. Using a clinical 3.0 T MRI scanner equipped with a dedicated small animal solenoid coil, 105 labeled MSCs could be detected and localized in the mouse hearts for up to 4 weeks after intramyocardial transplantation. Weekly ECG-gated scans using T1-weighted sequences were performed, and left ventricular function was assessed. Histological analysis of hearts confirmed the survival of labeled MSCs in the target area up to 4 weeks after transplantation. In conclusion, in vivo tracking of labeled MSCs using a clinical 3.0 T MRI scanner is feasible. In combination with assessment of heart function, this technology allows the monitoring of the therapeutic efficacy of regenerative therapies in a small animal model. </jats:p

Ancient DNA identification of domestic animals used for leather objects in Central Asia during the Bronze Age

The arid climate of many regions within Central Asia often leads to excellent archaeological preservation, especially in sealed funerary contexts, allowing for ancient DNA analyses. While geneticists have looked at human remains, clothes, tools, and other burial objects are often neglected. In this paper, we present the results of an ancient DNA study on Bronze Age leather objects excavated from tombs of the Wupu cemetery in the Hami Oasis and Yanghai cemetery in the Turpan Oasis, both in Xinjiang Uyghur Autonomous Region of northwestern China. In addition to species identification of goat (Capra aegagrus/hircus), sheep (Ovis orientalis/aries), and cattle (Bos primigenius/taurus), mitochondrial haplogroups were determined for several samples. Our results show that Bronze Age domesticated goats and sheep from the Hami and Turpan oases possessed identical or closely related haplotypes to modern domestic animals of this area. The absence of leather produced from wild animals emphasizes the importance of animal husbandry in the cultures of Wupu and Yanghai

Untersuchungen zur Bewertung der Verarbeitbarkeit und des Umformverhaltens von textilen Multiaxialgelegen mit Hilfe von Standardprüfverfahren hinsichtlich des Einsatzes in kontinuierlich arbeitenden Formgebungsverfahren

This Bachelor’s Thesis deals with the drapability of multi-axial multiply fabrics during a continuously operating preforming process. In order to determine the material’s characteristics test methods used in clothing industry are transferred into technical textiles. The determined properties are compared to results from investigations of a preforming test rig. Finally, conclusions should give information whether a connection between the material’s characteristics and the drapability of fabrics during preforming exists or not. However, the preforming test rig is optimized with regard to a gentle processing

ADVANTAGES AND LIMITS OF NON-CRIMP-FABRIC-MATERIAL IN AUTOMATED PREFORMING FACILITIES WITH A NEW ROLL-FORMING PROCESS

The direct operating costs of aircraft are highly driven by the structural weight. To achieve lower structural weight the material of selected structures is changed from aluminum to lighter Carbon Fiber Reinforced Polymers (CFRP). To fulfill the high demand for new aircraft and thus high production rates, rapid processes for curved CFRP-frames are needed. The Resin Transfer Moulding (RTM) process has a high potential for fast and cost effective manufacturing of CFRP frames. Within the RTM-Process the preforming is one essential step for high quality components. A new preforming line developed at DLR using roll-forming techniques and Non-Crimp-Fabrics (NCF) provides a highly accurate fiber orientation along the complete length of the preform. This automated and continuous manufacturing process is characterized by draping NCF material with two roller stands rotating at different speeds. To use the full potential of the automation a thorough understanding of the material behavior is essential for an efficient and appropriate process. Within this paper the material parameters are further characterized by a newly developed draping test emulating the forming process. Parameters of different NCF-Materials were defined and compared to the automated manufacturing behavior. These parameters allow a higher feed rate thus leading to higher production rates

Untersuchung des Umformverhaltens von Multiaxialgelegehalbzeugen und Vergleich mit theoretischen Modellen bei der automatisierten Fertigung im Geschwindigkeitsdifferenzumform-Verfahren

In dieser Arbeit wird der Preforming-Prozess über eine Geschwindigkeitsdifferenzumformung von trockenem Multiaxialgelege untersucht. Ziel ist es, Aussagen über das Materialverhalten während der Umformung zu treffen bzw. dieses voraussagen zu können. Für die Beschreibung des Materialverhaltens wird ein geometrisches Modell basierend auf der Betrachtung von Geweben verwendet. In verschiedenen Versuchen, deren Umformprozess schrittweise komplexer wird, soll die Gültigkeit dieses Modells untersucht werden. Die Ergebnisse werden miteinander verglichen, um Zusammenhänge zwischen den einzelnen Versuchen und deren Umformprozessen zu finden

Low coherence interferometry in selective laser melting

© 2014 The Authors. Published by Elsevier B.V. Selective Laser Melting (SLM) is an additive layer manufacturing technology that offers several advantages compared to conventional methods of production such as an increased freedom of design and a toolless production suited for variable lot sizes. Despite these attractive aspects today's state of the art SLM machines lack a holistic process monitoring system that detects and records typical defects during production. A novel sensor concept based on the low coherence interferometry (LCI) was integrated into an SLM production setup. The sensor is mounted coaxially to the processing laser beam and is capable of sampling distances along the optical axis. Measurements during and between the processing of powder layers can reveal crucial topology information which is closely related to the final part quality. The overall potential of the sensor in terms of quality assurance and process control is being discussed. Furthermore fundamental experiments were performed to derive the performance of the system