Densification during hot-pressing of carbon nanotube–metal–magnesium aluminate spinel nanocomposites

The densification by hot-pressing of ceramic–matrix composites containing a dispersion of carbon nanotubes (CNT), mostly single-walled, is studied for the first time. Fifteen different CNT–Co/Mo–MgAl2O4 composite powders containing between 1.2 and 16.7 vol.% CNT were prepared by catalytic chemical vapour deposition. The in situ growth of CNT within the oxide powder made it possible to obtain a highly homogeneous distribution of CNT. Low contents of CNT (up to 5 vol.%) are beneficial for the first shrinkage step (up to 1100 ◦C), dominated by the rearrangement process, while higher contents are detrimental. At higher temperatures (1100–1300 ◦C), CNT clearly inhibit the shrinkage, and this detrimental effect regularly increases with the CNT content. Several explanations are proposed, in relation with the particular mechanical properties of CNT and their highly connected web-like distribution within the material

Stürze bei Schwindel- und Gleichgewichtserkrankungen

Das Ziel der vorliegenden Dissertation war es, zunächst das krankheitsspezifische Sturzrisiko bei Schwindel- und Gleichgewichtsstörungen zu ermitteln und daraufhin die Gangstabilität als potentiellen Sturzrisikomarker in den Erkrankungsgruppen mit erhöhter Sturzgefährdung zu untersuchen. Parallel dazu wurde ein spezifisches Gangtraining für Patienten mit Morbus Parkinson, bei denen eine starke Disposition für Stürze bereits durch umfangreiche Forschungsarbeiten bekannt ist, entwickelt und evaluiert. Das Sturzrisiko zeigte sich bei Erkrankungen des Kleinhirns und der Basalganglien stark und bei peripheren Störungen, wie vestibulären Dysfunktionen und Polyneuropathie, moderat ausgeprägt. Dementsprechend waren diese Patienten auch von Angst vor Stürzen betroffen. Patienten mit funktionellen Schwindelbeschwerden berichteten ebenfalls unter Sturzbedenken zu leiden, obwohl das Sturzrisiko im Vergleich zur Kontrollgruppe nicht erhöht war. Bestimmte Gangabweichungen, insbesondere eine erhöhte Variabilität des Gangmusters, stellen Risikofaktoren für das Auftreten von Stürzen in der älteren Bevölkerung dar. Aus diesem Grund wurde eine Studienserie durchgeführt, innerhalb derer die Gangstabilität bei Patienten mit bilateraler Vestibulopathie, Polyneuropathie, Downbeat Nystagmus Syndrom und zerebellärer Ataxie quantifiziert wurde. Bei allen Krankheitsbildern war die Gangvariabilität bei langsamer Ganggeschwindigkeit gesteigert. Bei Patienten mit zerebellärer Ataxie zeigte sie sich zusätzlich bei schneller Ganggeschwindigkeit erhöht. Der Zusammenhang zwischen Gangvariabilität und Sturzhistorie wurde bis dato bei Patienten mit zerebellärer Ataxie überprüft. Eine gesteigerte Gangvariabilität bei langsamer Ganggeschwindigkeit ging mit einer hohen Sturzfrequenz einher, während eine erhöhte Gangvariabilität bei schneller Ganggeschwindigkeit mit einem hohen Ataxie-Schweregrad assoziiert war. Die Messung der Schritt- zu-Schritt-Fluktuation bei langsamem Gehen eignet sich daher für die Einschätzung des individuellen Sturzrisikos bei zerebellären Patienten. Basierend auf der aktuellen Studienlage zur Gangrehabilitation bei Morbus Parkinson wurde eine kombinierte Therapie aus Laufbandtraining und visuellen Schrittvorgaben entwickelt und in einer Pilotstudie mit 23 mittel- bis hochgradig betroffenen Patienten untersucht. Der Trainingserfolg zeigte sich vor allem durch ein verbessertes Ergebnis im Timed Up and Go Test. Dies bedeutet nicht nur eine Besserung der funktionellen Gehfähigkeit, sondern spricht gleichzeitig für eine Reduktion des individuellen Sturzrisikos

Molecular dynamics-based approaches for enhanced sampling of long-time, large-scale conformational changes in biomolecules

The rugged energy landscape of biomolecules together with shortcomings of traditional molecular dynamics (MD) simulations require specialized methods for capturing large-scale, long-time configurational changes along with chemical dynamics behavior. In this report, MD-based methods for biomolecules are surveyed, involving modification of the potential, simulation protocol, or algorithm as well as global reformulations. While many of these methods are successful at probing the thermally accessible configuration space at the expense of altered kinetics, more sophisticated approaches like transition path sampling or Markov chain models are required to obtain mechanistic information, reaction pathways, and/or reaction rates. Divide-and-conquer methods for sampling and for piecing together reaction rate information are especially suitable for readily available computer cluster networks. Successful applications to biomolecules remain a challenge

Patient Empowerment in Modern Medicine: A Personal Account of Endometriosis and Being an Equal Partner in My Healthcare

This work outlines my personal experience with a diagnosis of stage three endometriosis and partial oophorectomy surgery along with the subsequent medical opinions I received by my primary OB/GYN and other doctors. This thesis seeks to discuss the issues surrounding patient empowerment, and specifically, laws that support patients in their exploration of the truths behind their conditions and the importance of self-education in order to be better equipped in conversations with their physicians. The work includes testimonials from women about their levels of knowledge into their own medical needs upon the time of their prescription to pharmaceutical medications, and how patients can improve their healthcare through utilizing pharmacist opinion. Readers should take away tools and best practices for securing a better patient outcome through their empowerment and education of this topi

Radical Feminism: Sisterhood and Similarity

The American radical feminist movement (1967-1975) exhibited in its theory a tension between two opposing ideas. Radical feminists believed men and women were similar and equal by nature,and they challenged social institutions which promoted differences between the sexes. They also created a movement for women only.The tension between gender similarity and sisterhood characterizes radical feminist theory and caused the end of the movement

Investigating the role of RGC-32 in cell cycle disruption by EBV EBNA 3C

Epstein-Barr virus (EBV) immortalises resting B-lymphocyctes and is associated with a diverse range of cancers and establishes a persistent, latent infection in >90% of the world-wide population. Epstein-Barr virus nuclear antigen (EBNA) 3C is one of only six EBV latent proteins that are crucial for B-cell transformation. EBNA3C is known to disrupt cell-cycle control and to progress phase transition at G1/S and G2/M under conditions where cells should growth arrest, but the mechanism by which EBNA3C does this has not been fully determined. The cell-cycle regulator response gene to complement (RGC) 32 was found to be upregulated in EBNA3C-expressing cells in microarray experiments carried out previously. RGC-32 is involved in cell-cycle activation and also plays a role in G1/S and G2/M transition. I have shown that both EBNA3C-expressing cell-lines with upregulated RGC-32 and cell-lines overexpressing RGC-32 alone displayed disrupted G2/M checkpoint control indicating that EBNA3C may overcome cell-cycle control by upregulation of RGC-32. I also confirmed that RGC-32 increases the in vitro kinase activity of CDK1, the key mitotic kinase essential for G2/M transition. Surprisingly, my data showed that EBNA3C only activated RGC- 32 transcription in reporter assays at a very low-level, but stabilised the RGC-32 mRNA. Further studies investigating the differential expression of RGC-32 in EBVpositive and negative cells demonstrated that RGC-32 is upregulated in LCLs and tumour (Burkitt’s lymphoma) cell-lines expressing the full panel of latent genes, but intriguingly highly expressed in Burkitt’s lymphoma cell-lines expressing only EBNA 1. I found that this expression pattern correlated with expression of the RUNX1 transcription factor. Reporter assays revealed that RUNX1 was able to activate the RGC-32 promoter. Together, this data indicates a new mechanism by which EBNA 3C can disrupt the G2/M checkpoint and highlights a link between RUNX1 and RGC-32 expression in B-cells