The Study and Application of Carbon Nanotube Film Heaters for Space Applications

The purpose of this research was to examine the feasibility of using Carbon Nanotube (CNT) sheets as thin film heaters for space applications. The ability to maintain the temperature of space components has a direct impact on a space vehicle\u27s operation and longevity. Currently etched foil heaters are used to heat satellite batteries. Battery heaters are the focus of this research. However, as this study will show, they have limitations and are susceptible to failure. CNT sheets have many beneficial properties and show potential in replacing the etched foil design. In this study test specimens were created by forming laminate test articles comprised of CNT sheets and an adhesive Kapton® substrate material. These test articles were subjected to a series of tests both in atmosphere and in vacuum. Comparative tests were done on etched foil heaters and specimens made from a new polyimide material from Dupont™. As a secondary study, the effects of CNT grain orientation on heat generation capability was included. It was found that while the CNT articles were not as power efficient as the etched foil design, in the configurations tested, they offered a much higher maximum temperature, a faster response time (how fast the specimens heated up), and mitigated the potential for total heater failure. With respect to the grain orientation study, it was found that using commercial off the shelf (COTS) CNT sheets resulted in no significant change in thermal properties for specimens of the size used in these tests. In conclusion, CNT thin film heaters proved to be a viable alternative to current battery heater technology

In situ measurement of bovine serum albumin interaction with gold nanospheres

Here we present in situ observations of adsorption of bovine serum albumin (BSA) on citratestabilized gold nanospheres. We implemented scattering correlation spectroscopy as a tool to quantify changes in the nanoparticle Brownian motion resulting from BSA adsorption onto the nanoparticle surface. Protein binding was observed as an increase in the nanoparticle hydrodynamic radius. Our results indicate the formation of a protein monolayer at similar albumin concentrations as those found in human blood. Additionally, by monitoring the frequency and intensity of individual scattering events caused by single gold nanoparticles passing the observation volume, we found that BSA did not induce colloidal aggregation, a relevant result from the toxicological viewpoint. Moreover, to elucidate the thermodynamics of the gold nanoparticle-BSA association, we measured an adsorption isotherm which was best described by an anti-cooperative binding model. The number of binding sites based on this model was consistent with a BSA monolayer in its native state. In contrast, experiments using poly-ethylene glycol capped gold nanoparticles revealed no evidence for adsorption of BSA

Application of isothermal titration calorimetry in evaluation of protein–nanoparticle interactions

Nanoparticles (NPs) offer a number of advantages over small organic molecules for controlling protein behaviour inside the cell. Protein binding to the surface of NPs depends on their surface characteristics, composition and method of preparation (Mandal et al. in J Hazard Mater 248–249:238–245, 2013). It is important to understand the binding affinities, stoichiometries and thermodynamical parameters of NP–protein interactions in order to see which interaction will have toxic and hazardous consequences and thus to prevent it. On the other side, because proteins are on the brink of stability, they may experience interactions with some types of NPs that are strong enough to cause denaturation or significantly change their conformations with concomitant loss of their biological function. Structural changes in the protein may cause exposure of new antigenic sites, “cryptic” peptide epitopes, potentially triggering an immune response which can promote autoimmune disease (Treuel et al. in ACS Nano 8(1):503–513, 2014). Mechanistic details of protein structural changes at NP surface have still remained elusive. Understanding the formation and persistence of the protein corona is critical issue; however, there are no many analytical methods which could provide detailed information about the NP–protein interaction characteristics and about protein structural changes caused by interactions with nanoparticles. The article reviews recent studies in NP–protein interactions research and application of isothermal titration calorimetry (ITC) in this research. The study of protein structural changes upon adsorption on nanoparticle surface and application of ITC in these studies is emphasized. The data illustrate that ITC is a versatile tool for evaluation of interactions between NPs and proteins. When coupled with other analytical methods, it is important analytical tool for monitoring conformational changes in proteins

Urbane Resilienz gegenüber extremen Wetterereignissen: Gemeinsamer Verbundabschlussbericht des Forschungsprojektes ExTrass

Das Projekt ExTrass hatte zwei Ziele: Das erste Ziel war es, Klimaresilienz in den drei Fallstudienstädten Potsdam, Remscheid und Würzburg messbar zu stärken. Das zweite Ziel war es, Transferpotenziale zwischen Groß- und Mittelstädten in Deutschland zu identifizieren und besser nutzbar zu machen, sodass die Wirkung von Pilotvorhaben über die direkt involvierten Städte hinausgehen kann. Dies sollte in enger Zusammenarbeit mit den Stadtverwaltungen sowie zivilgesellschaftlichen Akteur:innen des Katastrophenschutzes erfolgen. Dabei standen folgende Leitfragen im Fokus: • Wie verbreitet sind Klimaanpassungsaktivitäten in Großstädten und größeren kreisfreien Mittelstädten in Deutschland? • Welche hemmenden und begünstigenden Faktoren beeinflussen die Klimaanpassung? • Welche Maßnahmen der Klimaanpassung werden tatsächlich umgesetzt, und wie kann die Umsetzung verbessert werden? Was behindert? • Inwiefern lassen sich Beispiele guter Praxis auf andere Städte übertragen, adaptieren oder weiterentwickeln

MYT1L mutations cause intellectual disability and variable obesity by dysregulating gene expression and development of the neuroendocrine hypothalamus

Deletions at chromosome 2p25.3 are associated with a syndrome consisting of intellectual disability and obesity. The smallest region of overlap for deletions at 2p25.3 contains PXDN and MYT1L. MYT1L is expressed only within the brain in humans. We hypothesized that single nucleotide variants (SNVs) in MYT1L would cause a phenotype resembling deletion at 2p25.3. To examine this we sought MYT1L SNVs in exome sequencing data from 4, 296 parent-child trios. Further variants were identified through a genematcher-facilitated collaboration. We report 9 patients with MYT1L SNVs (4 loss of function and 5 missense). The phenotype of SNV carriers overlapped with that of 2p25.3 deletion carriers. To identify the transcriptomic consequences of MYT1L loss of function we used CRISPR-Cas9 to create a knockout cell line. Gene Ontology analysis in knockout cells demonstrated altered expression of genes that regulate gene expression and that are localized to the nucleus. These differentially expressed genes were enriched for OMIM disease ontology terms “mental retardation”. To study the developmental effects of MYT1L loss of function we created a zebrafish knockdown using morpholinos. Knockdown zebrafish manifested loss of oxytocin expression in the preoptic neuroendocrine area. This study demonstrates that MYT1L variants are associated with syndromic obesity in humans. The mechanism is related to dysregulated expression of neurodevelopmental genes and altered development of the neuroendocrine hypothalamus