Cerebral amyloid angiopathy (CAA) is characterized by the accumulation of the amyloid β (Aβ) protein in blood vessels and leads to hemorrhages, strokes, and dementia in elderly individuals. Recent reports have shown elevated copper levels colocalized with vascular amyloid in human CAA and Alzheimer's disease patients, which have been suggested to contribute to cytotoxicity through the formation of reactive oxygen species. Here, we treated a transgenic rat model of CAA (rTg-DI) with the copper-specific chelator, tetrathiomolybdate (TTM), via intraperitoneal (IP) administration for 6 months to determine if it could lower copper content in vascular amyloid deposits and modify CAA pathology. Results showed that TTM treatment led to elevated Aβ load in the hippocampus of the rTg-DI rats and increased microbleeds in the wild type (WT) animals. X-ray fluorescence microscopy was performed to image the distribution of copper and revealed a surprising increase in copper colocalized with Aβ aggregates in TTM-treated rTg-DI rats. Unexpectedly, we also found an increase in the copper content in unaffected vessels of both rTg-DI and WT animals. These results show that IP administration of TTM was ineffective in removing copper from vascular Aβ aggregates in vivo and increased the development of disease pathology in CAA.

We use the configuration of film boiling on a horizontal tube positioned in a stagnant pool of saturated diethyl carbonate (DEC, (C2H5O)2CO) to study DEC decomposition at temperatures up to 1500 K. The composition of bubbles that percolate through the liquid pool is measured and the results are used to infer the decomposition reactions. The results show that below tube temperatures of about 1100 K, the decomposition products are ethylene (C2H4), carbon dioxide (CO2), and ethanol (EtOH, C2H5OH) with a molar ratio nC2H4/nCO2∼1, which is consistent with a first-order decomposition process. At higher temperatures, nC2H4/nCO2 > 1 which is explained by an additional route to forming C2H4 from radicals in the system (created by EtOH decomposition) attacking DEC. The presence of H2, CO, CH4, and C2H6 in the product stream was noted at all temperatures examined with concentrations that increased from trace values at low temperatures to values comparable to the DEC unimolecular process at the highest temperatures. Formation of a carbon layer on the tube was observed but did not appear to influence the decomposition process. A scale analysis shows that the rate constant controls decomposition compared to the residence time, which has a weaker dependence on temperature.

This paper reports a study of ethanol pyrolysis (C2H5OH, EtOH) by film boiling at temperatures ranging from 600 to 1500 K. The reactor space is created in a self-assembled manner by first bringing EtOH to a boil on the surface of a horizontal tube submerged in a pool of EtOH and then increasing the power to the tube in steps to force transitioning the boiling regimes through nucleate boiling, the critical heat flux state, and finally film boiling. EtOH pyrolysis is found to yield hydrogen in the highest concentration followed by ethylene (C2H4), methane (CH4), and carbon monoxide (CO) in approximately equal proportions. Ethane (C2H6) and carbon dioxide (CO) concentrations were several orders of magnitude lower. The abundance of hydrogen was conjectured to be due to the absence of chemical inhibitors in the system. Reactions to explain formation of the product gases are suggested based on the chain nature of EtOH decomposition. Liquid sampling showed the presence of refluxed water along with acetaldehyde (CH3CHO) and trace quantities of formaldehyde (CH2O) and ethyl acetate (CH3COOC2H5). Evidence of heterogeneous surface reactions is postulated for tube temperatures below about 1000 K. The results are consistent with more conventional reactor designs, which establishes the potential for film boiling to serve as a simple and useful chemical processing technology.

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