692 research outputs found
Characterization of rutile passivation layers formed on Magnéli-phase titanium oxide inert anodes
An ex situ characterization study has been performed on rutile passivation layers on inert anodes used for molten salt electrochemical studies. Rutile layer thicknesses were estimated using a number of ex situ methods, including laboratory and synchrotron X-ray diffraction and optical microscopy. The only phases in the anode detected by diffraction were the Magnéli phases (TinO2n-1, n = 5-6) of the unreacted anode and rutile (TiO2), which forms on electrolysis. These measurements validate a previously developed in situ energy-dispersive X-ray diffraction analysis technique [Scarlett, Madsen, Evans, Coelho, McGregor, Rowles, Lanyon & Urban (2009). J. Appl. Cryst. 42, 502-512]
Sample-displacement correction for whole-pattern profile fitting of powder diffraction data collected in capillary geometry
Abstract: Recent in situ experimentation at the Australian Synchrotron resulted in the nucleation and crystallization of material on the walls of the capillary reaction vessels. This lining of the capillary walls, without filling the bulk of the capillary volume, produced an artefact in the diffraction data due to sample displacement across the capillary. In effect, the experiment was examining simultaneously two samples displaced by equal and opposite amounts from the diffractometer centre. This was exaggerated by the fact that large-diameter (1 mm) capillaries had been used in order to increase the total sample volume and hence maximize the amount of material formed and examined. The effect of this displacement was to shift the diffraction peaks simultaneously to both lower and higher angles than their `ideal' positions, causing peak splitting in many instances. A model has been developed which considers the sample as being effectively two flat plate samples, thus allowing for correction through the use of sample displacement. An additional problem resulted from the oriented growth of the material on the capillary walls, producing preferred orientation in the observed data. The correction model can also be extended to model such anisotropic peak splitting caused by this preferential orientation of the crystallites on the capillary wall
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Age-related differences in breast cancer mortality according to race/ethnicity, insurance, and socioeconomic status.
BackgroundWe assessed breast cancer mortality in older versus younger women according to race/ethnicity, neighborhood socioeconomic status (nSES), and health insurance status.MethodsThe study included female breast cancer cases 18 years of age and older, diagnosed between 2005 and 2015 in the California Cancer Registry. Multivariable Cox proportional hazards modeling was used to generate hazard ratios (HR) of breast cancer specific deaths and 95% confidence intervals (CI) for older (60+ years) versus younger (< 60 years) patients separately by race/ethnicity, nSES, and health insurance status.ResultsRisk of dying from breast cancer was higher in older than younger patients after multivariable adjustment, which varied in magnitude by race/ethnicity (P-interaction< 0.0001). Comparing older to younger patients, higher mortality differences were shown for non-Hispanic White (HR = 1.43; 95% CI, 1.36-1.51) and Hispanic women (HR = 1.37; 95% CI, 1.26-1.50) and lower differences for non-Hispanic Blacks (HR = 1.17; 95% CI, 1.04-1.31) and Asians/Pacific Islanders (HR = 1.15; 95% CI, 1.02-1.31). HRs comparing older to younger patients varied by insurance status (P-interaction< 0.0001), with largest mortality differences observed for privately insured women (HR = 1.51; 95% CI, 1.43-1.59) and lowest in Medicaid/military/other public insurance (HR = 1.18; 95% CI, 1.10-1.26). No age differences were shown for uninsured women. HRs comparing older to younger patients were similar across nSES strata.ConclusionOur results provide evidence for the continued disparity in Black-White breast cancer mortality, which is magnified in younger women. Moreover, insurance status continues to play a role in breast cancer mortality, with uninsured women having the highest risk for breast cancer death, regardless of age
Dinuclear Copper(I) Complexes Supported by Bis‐Tridentate N‐Donor‐Ligands: Turning‐On Tyrosinase Activity
Four structurally related bis-tridentate N-donor ligands with either two secondary amine or two imine functions were synthesized, and the corresponding dicopper(I) complexes were investigated as catalysts for the tyrosinase-like conversion of 2,4-di-tert-butylphenol (DTBP-H) to 3,5-di-tert-butylquinone (DTBQ). Notably, the imine systems show evidence for both a μ-η2 : η2-peroxo-dicopper(II) species and catalytic conversion of DTBP-H to DTBQ. Moreover, kinetic studies indicate that a dinuclear copper-oxygen species is involved in the monooxygenation of DTBP-H. In contrast, the amine systems do not show monooxygenase activity. Comparison of the experimentally determined catalytic activities with DFT-optimized geometries of μ-η2 : η2-peroxo-dicopper(II) intermediates suggests that the ligand rigidity of the imine systems allows equatorial attack of the substrate and, thus, subsequent monooxygenation whereas this is not possible in the amine systems due to the fact that no free equatorial positions are available in the μ-peroxo intermediate
A Network of Physiological Interactions Modulating GI Homeostasis: Probiotics, Inflammasome, mTOR
The gastrointestinal surface is in constant interaction with various exogenous molecules. Exogenous components are discriminated in the GI context, as good, in case of nutrients and fibers, and bad, when they negatively affect host integrity. During this tolerogenic process, they also train the host’s immune system. The immune system is a morpho-physiologic unit driven by immune cells with the assistance of commensal organisms. Several species of commensal microorganisms have been used for centuries as probiotics due to their beneficial effects on human health. Lowering local levels of pro-inflammatory cytokines has a systemic effect, which is one of the fundamental characteristics associated with probiotics. Still, the primary mechanisms wiring those regulatory circuits as a unit remain unclear. Modulation of the innate immune system, via regulation of inflammasome assembly is emerging as a critical driver of this interaction. Stimulation of toll like receptors (TLR) and inner cell sensors like NLRP3 connect probiotics with essential host systems. In this context, the mTOR-regulated circuits, an intricate network modulating a cascade of protein phosphorylations, could be an important channel connecting host metabolism and probiotics crosstalk
A furnace and environmental cell for the in situ investigation of molten salt electrolysis using high-energy X-ray diffraction
This paper describes the design, construction and implementation of a relatively large controlled-atmosphere cell and furnace arrangement. The purpose of this equipment is to facilitate the in situ characterization of materials used in molten salt electrowinning cells, using high-energy X-ray scattering techniques such as synchrotron-based energy-dispersive X-ray diffraction. The applicability of this equipment is demonstrated by quantitative measurements of the phase composition of a model inert anode material, which were taken during an in situ study of an operational Fray-Farthing-Chen Cambridge electrowinning cell, featuring molten CaCl(2) as the electrolyte. The feasibility of adapting the cell design to investigate materials in other high-temperature environments is also discussed
Target Personification Influences the Positive Emotional Link Between Generating and Implementing Malevolently Creative Ideas
Research on malevolent creativity has rarely linked the generation of harmful ideas with their implementation (i.e., malevolent innovation). To explain why people might act upon their malevolently creative ideas, we drew on affective events theory. Specifically, given evidence that aggressive and creative thought events can elicit positive emotions, we argued that generating new and harmful ideas can evoke positive emotional states that make malevolent innovation a more desirable course of action. We first tested our mediational pathway in two studies with different malevolent creativity tasks. Finding only partial support for our predictions in Study 1 (N = 126), but full support in Study 2 (N = 296), we reflected on our study tasks and suspected that our mixed results may have occurred because the target of ideas in Study 2 embodied more human qualities than in Study 1. Thus, we integrated theory on target personification to see if assigning personhood to a target moderated the malevolent creativity-innovation pathway. We tested our updated model in Study 3 (N = 214) and found that the indirect effect of malevolent creativity on the desire to implement ideas (through positive emotions) was indeed conditional upon individuals’ personification of a target. Plain Language Summary
Little research has examined why and when people might act upon their malevolently creative (i.e., new and harmful) ideas. Given evidence that aggression and creativity can both arouse positive emotional states, it may be possible that forming malevolently creative ideas can make people feel more positively about implementing them later on. However, our research findings paint a more nuanced picture, suggesting that the emotional link between generating and implementing malevolently creative ideas only occurs when people see their targets as more human-like (i.e., they can assign personhood to their targets)
Household reporting of childhood respiratory health and air pollution in rural Alaska Native communities
Background. Air pollution is an important contributor to respiratory disease in children.
Objective. To examine associations between household reporting of childhood respiratory conditions and household characteristics related to air pollution in Alaska Native communities.
Design. In-home surveys were administered in 2 rural regions of Alaska. The 12-month prevalence of respiratory conditions was summarized by region and age. Odds ratios (ORs) were calculated to describe associations between respiratory health and household and air quality characteristics.
Results. Household-reported respiratory health data were collected for 561 children in 328 households. In 1 region, 33.6% of children aged/or bronchitis. Children with these conditions were 2 times more likely to live in a wood-heated home, but these findings were imprecise. Resident concern with mould was associated with elevated prevalence of respiratory infections in children (ORs 1.6–2.5), while reported wheezing was associated with 1 or more smokers living in the household. Reported asthma in 1 region (7.6%) was lower than national prevalence estimates.
Conclusions. Findings suggest that there may be preventable exposures, including wood smoke and mould that affect childhood respiratory disease in these rural areas. Additional research is needed to quantify particulate matter 2.5 microns in aerodynamic diameter or less and mould exposures in these communities, and to objectively evaluate childhood respiratory health
Quantification of passivation layer growth in inert anodes for molten salt electrochemistry by in situ energy-dispersive diffraction
An in situ energy-dispersive X-ray diffraction experiment was undertaken on operational titanium electrowinning cells to observe the formation of rutile (TiO2) passivation layers on Magnéli-phase (TinO2n-1; n = 4-6) anodes and thus determine the relationship between passivation layer formation and electrolysis time. Quantitative phase analysis of the energy-dispersive data was undertaken using a crystal-structure-based Rietveld refinement. Layer formation was successfully observed and it was found that the rate of increase in layer thickness decreased with time, rather than remaining constant as observed in previous studies. The limiting step in rutile formation is thought to be the rate of solid-state diffusion of oxygen within the anode structure
Expurgated random-coding ensembles: Exponents, refinements, and connections
This paper studies expurgated random-coding bounds and exponents with a given (possibly suboptimal) decoding rule. Variations of Gallager’s analysis are presented, yielding new asymptotic and non-asymptotic bounds on the error probability for an arbitrary codeword distribution. A simple non-asymptotic bound is shown to attain an exponent which coincides with that of Csiszár and Körner for discrete alphabets, while also remaining valid for continuous alphabets. The method of type class enumeration is studied for both discrete and continuous alphabets, and it is shown that this approach yields improved exponents for some codeword distributions. A refined analysis of expurgated i.i.d. random prefactor, thus improving on Gallager’s O(1) prefactor. coding is given which yields an exponent with a O ( 1 √n I
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