Increased Prostaglandin Response to Oxytocin in Ewes Fed a Diet High in Omega-6 Polyunsaturated Fatty Acids

Diets high in omega-6 polyunsaturated fatty acids (n-6) are associated with increased prostaglandin F_2α (PGF_2α) synthesis in cattle, however, the specific effects on the potential prostaglandin response to an oxytocin challenge in sheep have not been reported. The aim of the current study was to determine whether oxytocin-stimulated PGF_2α was significantly increased when ewes were fed a diet high in n-6 compared with a control diet low in n-6. Merino x Border Leicester ewes (n = 30) received one of two dietary treatments, either high in n-6 (70 % oat grain) or low in n-6 (control diet, 100 % cereal/legume silage). Ewes consumed the diets for 44 days prior to two consecutive oxytocin challenges. Plasma n-6 and PGF_2α metabolite (PGFM) concentrations following oxytocin challenge were greater (P < 0.05) when ewes were fed a diet high in n-6 compared with the control diet. A higher availability of n-6 may have lead to an increased in vivo synthesis of PGF_2α, however, further research is required to determine the exact mechanisms involved.     

Investigation of doped-gadolinium zirconate nanomaterials for high-temperature hydrogen sensor applications

The incorporation of selective nanomaterials, such as common metal oxide semiconductor compositions, into resistive-type gas sensors has been shown by many researchers to lead to very high sensitivities and response rates, especially for micro-sized chemical sensors for room-temperature applications. The same strategy utilizing sensing nanomaterials has not been demonstrated for high-temperature sensors due to the intrinsic instability of typical metal oxide semiconductor nanomaterials at temperatures >500 °C. Within this work, doped Gd₂Zr₂O₇ (GZO) nanomaterial compositions were investigated for H₂ resistive-type sensors for applications between 600 and 1000 °C. This paper investigates the mechanism of H₂ sensing for doped GZO nanomaterials and SnO₂/GZO nanocomposites at the elevated temperatures. By integrating 10 vol.% nano-SnO₂ into yttrium-doped GZO nanomaterials, a sensitivity of 4.15 % was retained for 4000 ppm H₂ levels with a low signal drift of 0.42 %/h at 1000 °C in a 20 % O₂/N₂ gas stream. The signal drift was reduced by more than half of that compared to pure nano-SnO₂ at the same conditions. The nano-GZO limited the grain growth of the nano-SnO₂ particles and also prevented the nano-SnO₂ from fully reducing to Sn at high temperatures in a low oxygen atmosphere. It is among the first resistive-type sensors operating at 1000 °C with sensing times of <5 min. This demonstration provided an example of a strategy of combining traditional metal oxide semiconductor and refractory nanomaterial compositions to form sensing nanocomposites with new sensing mechanisms, as well as, enhanced chemical and microstructural stabilities in high-temperature environments.     

Examining cognitive function across the lifespan using a mobile application

Many studies conducted in a laboratory or university setting are limited by funding, personnel, space, and time constraints. In the present study, we introduce a method of data collection using a mobile application that circumvents these typical experiment administration issues. Using the application, we examined cross-sectional age differences in cognitive function. We obtained data from more than 15,000 participants and replicated specific patterns of age-related differences in cognition. Using a subset of these participants, we also examined the processing speed account of age-related cognitive differences, and the association of exercise and leisure activity with cognitive function across the lifespan. We discuss the relative advantages and disadvantages of data collection with a mobile application, and provide recommendations for the use of this method in research.     

Online monitoring of the thermal degradation of POM during melt extrusion

Because of its high stiffness, chemical resistance, and low viscosity, Poly (oxymethylene) (POM) is of high relevance for technical applications. The thermal degradation of POM during processing affects its final properties and decreases the long‐term stability. The degradation is indicated by the emission of formaldehyde (FA) gas. The aim of this study is to monitor the thermal degradation of POM online, during the melt extrusion in a co‐rotating twin screw extruder (TSE). The effect of the processing conditions on the thermal stabilisation of the POM is observed by FA emission and online viscosity measurements. The effect of processing conditions on the compounding of POM with two different FA scavengers is also studied. Fourier transform infrared (FTIR) spectroscopy is used for the online measurement of FA gas and acetyl acetone colour measurement for the offline characterisation. The online viscosity is measured by passing the melt through a slit die at constant volume flow rate. An enhanced thermal degradation is found with decreasing throughput and increasing screw speed. A good correlation between the online viscosity and offline FA measurement is observed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Oriented Multiwalled Organic–Co(OH)2 Nanotubes for Energy Storage

In energy storage materials, large surface areas and oriented structures are key architecture design features for improving performance through enhanced electrolyte access and efficient electron conduction pathways. Layered hydroxides provide a tunable materials platform with opportunities for achieving such nanostructures via bottom‐up syntheses. These nanostructures, however, can degrade in the presence of the alkaline electrolytes required for their redox‐based energy storage. A layered Co(OH)₂–organic hybrid material that forms a hierarchical structure consisting of micrometer‐long, 30 nm diameter tubes with concentric curved layers of Co(OH)₂ and 1‐pyrenebutyric acid is reported. The nanotubular structure offers high surface area as well as macroscopic orientation perpendicular to the substrate for efficient electron transfer. Using a comparison with flat films of the same composition, it is demonstrated that the superior performance of the nanotubular films is the result of a large accessible surface area for redox activity. It is found that the organic molecules used to template nanotubular growth also impart stability to the hybrid when present in the alkaline environments necessary for redox function.