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Als ein komplexes Feld lässt sich das Thema Internationalisierung der Hochschulen nach Kehm (2003, S. 8 f.) auf mehreren Bezugsebenen verorten:
- Internationalisierung von Studium und Lehre. Hier geht es um die Entwicklung von interkultureller Kompetenz der Beteiligten, um neue Ansätze in der Lehre sowie um Fragen der Qualität.
- Herstellung international transparenter und kompatibler Strukturen und Standards. Damit sind die Umstellungen von Studienprogrammen auf gestufte Abschlüsse, qualitative Vergleichbarkeit von Studienleistungen und Akkreditierung von Studiengängen gemeint.
- Anpassungen in der Organisation der Hochschulen. Es handelt sich hierbei um die Umstrukturierungen von Akademischen Auslandsämtern und die Einführung einer Leitungsfunktion für Internationale Angelegenheiten.
- Internationalisierung des Politikfeldes Hochschulen. Hiermit sind die externen Einwirkungen auf die nationale Bildungspolitik gemeint, beispielsweise durch Organisationen wie OECD, UNESCO, World Bank und Europäische Union mit ihren jeweils „eigenen Definitionen der Funktionen von Hochschulen und der Ziele von Hochschulbildung“ (Kehm 2003, S. 9).
Mit diesen Ebenen der Internationalisierung kommen die Lehrenden in unterschiedlicher Intensität in Berührung.
Motivated by findings of new mineral related water sources for organisms under extremely dry conditions on Earth we studied in an interdisciplinary approach the water sorption behaviour of halite, soil component and terrestrial Nostoc commune biofilm under Mars relevant environmental conditions. Physicochemical methods served for the determination of water sorption equilibrium data and survival of heterotrophic bacteria in biofilm samples with different water contents was assured by recultivation. Deliquescence of halite provides liquid water at temperatures <273 K and may serve as water source on Mars during the morning stabilized by the CO2 atmosphere for a few hours. The protecting biofilm of N. commune is rather hygroscopic and tends to store water at lower humidity values. Survival tests showed that a large proportion of the Alphaproteobacteria dominated microbiota associated to N. commune is very desiccation tolerant and water uptake from saturated NaCl solutions (either by direct uptake of brine or adsorption of humidity) did not enhance recultivability in long-time desiccated samples. Still, a minor part can grow under highly saline conditions. However, the salinity level, although unfavourable for the host organism, might be for parts of the heterotrophic microbiota no serious hindrance for growing in salty Mars-like environments.
We quantitatively studied the hydration and dehydration behaviour of the three astrobiological model lichens Xanthoria elegans, Buellia frigida and Circinaria gyrosa by thermoanalysis and gravimetric isotherm measurements under close-to-Martian environmental conditions in terms of low temperature and low pressure. Additionally, the impact of UVC exposure on the isolated symbionts of B. frigida and X. elegans was studied by thermoanalysis and mass spectrometry as well as by gravimetric isotherm measurements. The thermal analysis revealed whewellite as a component of C. gyrosa which was not found in B. frigida and X. elegans. Neither the water retention nor the thermal behaviour of symbionts changed when irradiated with UVC under dry conditions. On the other hand, UVC irradiation of the wet mycobiont of B. frigida had a distinct impact on the hydration/dehydration ability which was not observed for the mycobiont of X. elegans. Possibly the melanin of B. frigida's mycobiont, that is not present in X. elegans, or a specifically damaged acetamido group of the chitin of B. frigida may be the sources of additional UVC-induced sorption sites for water associated with the UVC exposure.
Recent developments in optical biosensors based on integrated photonic devices are reviewed with a special emphasis on silicon-on-insulator ring resonators. The review is mainly devoted to the following aspects: (1) Principles of sensing mechanism, (2) sensor design, (3) biofunctionalization procedures for specific molecule detection and (4) system integration and measurement set-ups. The inherent challenges of implementing photonics-based biosensors to meet specific requirements of applications in medicine, food analysis, and environmental monitoring are discussed.
Comparative Study of Nano-Slot Silicon Waveguides Covered by Dye Doped and Undoped Polymer Cladding
(2019)
Nonlinear optical dyes doped in optical polymer matrices are widely used for electro-optical devices. Linear optical properties change with dye concentration, which leads to a change in modal properties, especially in nano-structured integrated waveguides such as silicon slot-waveguides. Here, we investigate the influence of a nonlinear optical dye on the performance of a silicon-organic hybrid slot-waveguide. A simulation study of the modal and optical confinement properties is carried out and dependence of the structural parameters of the slot-waveguide and the organic cladding material is taken into account. As cladding material, a guest-host polymer system is employed comprising the nonlinear optical dye Disperse Red 1 (DR1) doped in a poly[methyl methacrylate] (PMMA) matrix. The refractive indices of doped and undoped PMMA were deduced from ellipsometric data. We present a guideline for an optimized slot-waveguide design for the fabrication in silicon-on-insulator technology giving rise to scalable, high-performance integrated electro-optical modulators.
During the last years, various approaches on an individualized drug therapy for benign cells have been researched. However, due to the complex topic a universal approach has not been found up until this point. Commonly, the effect of cytotoxic drugs on benign cells is in most cases the same compared to regular cells while the actual effect on patient still can't be predicted. In order to reduce unwanted side effects or unspecific drug reactions a test system for patients which allows to analyse the interaction between cytotoxic agents and the targeted cells is needed. Furthermore, this should also include an adequate measurement system which is capable to work in a natural environment and without any additional preparation. In terms of this work, a first proof of concept with different benign cells and cytotoxic agents is presented while monitoring the obtained displacement using electronic speckle pattern interferometry (ESPI).
The isoquinoline quaternary alkaloid Berberine possesses a variety of pharmacological properties that suggests its promising application for an anticancer delivery system design utilizing its ability to intercalate DNA.In the current work we have investigated the effects of Berberine on the human T-cell leukemia cell line in vitro.Fluorescent microscopy of leukemic cells revealed Berberine nuclear localization. The results showed that Berberine inhibited leukemic cell growth in a time-and dose-dependent manner, that was associated with reactive oxygen species production intensification and caspase 3/7 activity increase with followed apoptosis induction.Berberine was used as a toxic and phototoxic agent for triple system synthesis along with DNA as a carrier and nanosilver as a plasmonic accelerator of Berberine electronic transitions and high energy emission absorbent centers.The proposed method allows to obtain the complex of DNA with Berberine molecules and silver nanopoarticles. The optical properties of free components as well as their various combinations, including the final triple system DNA-Nanosilver-Berberine, were investigated. Obtained results support the possibility to use the triple system DNA-Nanosilver-Berberine as an alternative therapeutic agent for cancer treatment.
Konventionelle Fertigungsstrategien werden künftig zunehmend durch komplexe cyberphysische Produktionssysteme (CPPS) ersetzt. Es entstehen durchgehend verbundene Wertschöpfungsnetzwerke mit großer Informationsdichte, die den Menschen mit einer signifikant gestiegenen Datenmenge konfrontieren, auf deren Basis er agieren muss. Daher nimmt die Mensch-Maschine-Schnittstelle einen wichtigen Stellenwert innerhalb des Produktionsprozesses ein, wobei sich neuartige Visualisierungsverfahren wie Augmented Reality (AR) vielversprechend zeigen. Für entsprechende Anwendungen bedarf es einer durchgängigen Kommunikation aus dem Feld bis hin zur Applikation. Der Artikel beschreibt, wie existierende Kommunikationsstandards dafür nutzbar gemacht werden können und zeigt eine beispielhafte Umsetzung. Zudem wird eine Kommunikationsarchitektur vorgeschlagen, die auf Grundlage der Verwaltungsschale den interoperablen Informationsaustausch zwischen physischen und virtuellen Entitäten ermöglicht.
Recent progress in nanobiotechnology has attracted interest to a biomedical application of the carbon nanostructure C60 fullerene since it possesses a unique structure and versatile biological activity. C60 fullerene potential application in the frame of cancer photodynamic therapy (PDT) relies on rapid development of new light sources as well as on better understanding of the fullerene interaction with cells.
The aim of this study was to analyze C60 fullerene effects on human leukemic cells (CCRF-CEM) in combination with high power single chip light-emitting diodes (LEDs) light irradiation of different wavelengths: ultraviolet (UV, 365 nm), violet (405 nm), green (515 nm) and red (632 nm). The time-dependent accumulation of fullerene C60 in CCRF-CEM cells up to 250 ng/106 cells at 24 h with predominant localization within mitochondria was demonstrated with immunocytochemical staining and liquid chromatography mass spectrometry. In a cell viability assay we studied photoexcitation of the accumulated C60 nanostructures with ultraviolet or violet LEDs and could prove that significant phototoxic effects did arise. A less pronounced C60 fullerene phototoxic effect was observed after irradiation with green, and no effect was detected with red light. A C60 fullerene photoactivation with violet light induced substantial ROS generation and apoptotic cell death, confirmed by caspase3/7 activation and plasma membrane phosphatidylserine externalization. Our work proved C60 fullerene ability to induce apoptosis of leukemic cells after photoexcitation with high power single chip 405 nm LED as a light source. This underlined the potential for application of C60 nanostructure as a photosensitizer for anticancer therapy.
Silicon-on-Insulator Slot Waveguides: Theory and Applications in Electro-Optics and Optical Sensing
(2018)
This chapter deals with the basic concept of silicon-on-insulator (SOI) slot waveguides,including slot waveguide theory, fabrication steps, and applications. First, in the theorysection, a modal field expression and the characteristic equation is derived, which is alsovalid for higher-order modes. SOI slot waveguide structures are simulated and character-istic values like the effective refractive indices and the field confinement factors are deter-mined. The fabrication section describes typical SOI fabrication steps and the limits ofcurrent fabrication techniques. Additionally, developments regarding loss reduction inSOI slot waveguides are given from the fabrication point of view. This is followed by thetheory and practice of slot waveguide based electro-optical modulators. Here, the SOI slotwaveguide is embedded in an organic nonlinear optical material in order to achieverecord-low voltage-length products. In the field of optical sensors, it is shown that slotwaveguides enable remarkable waveguide sensitivity for both refractive index sensingand surface sensing.