435 research outputs found
Directing the mechanism of CO2 reduction by a Mn catalyst through surface immobilization
Immobilization of a Mn polypyridyl CO2 reduction electrocatalyst on nanocrystalline TiO2 electrodes
yields an active heterogeneous system and also significantly triggers a change in voltammetric and
catalytic behaviour, relative to in solution. A combination of spectroelectrochemical techniques are
presented here to elucidate the mechanism of the immobilised catalyst in-situ
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Accounting for changing temperature patterns increases historical estimates of climate sensitivity
Eight atmospheric general circulation models (AGCMs) are forced with observed historical (1871â2010) monthly sea surface temperature and sea ice variations using the Atmospheric Model Intercomparison Project II data set. The AGCMs therefore have a similar temperature pattern and trend to that of observed historical climate change. The AGCMs simulate a spread in climate feedback similar to that seen in coupled simulations of the response to CO2 quadrupling. However, the feedbacks are robustly more stabilizing and the effective climate sensitivity (EffCS) smaller. This is due to a pattern effect, whereby the pattern of observed historical sea surface temperature change gives rise to more negative cloud and longwave clearâsky feedbacks. Assuming the patterns of longâterm temperature change simulated by models, and the radiative response to them, are credible; this implies that existing constraints on EffCS from historical energy budget variations give values that are too low and overly constrained, particularly at the upper end. For example, the pattern effect increases the longâterm Otto et al. (2013, https://doi.org/10.1038/ngeo1836) EffCS median and 5â95% confidence interval from 1.9 K (0.9â5.0 K) to 3.2 K (1.5â8.1 K
Higher baseline inflammatory marker levels predict greater cognitive decline in older people with type 2 diabetes:year 10 follow-up of the Edinburgh Type 2 Diabetes Study
AIMS/HYPOTHESIS: We aimed to determine the longitudinal association of circulating markers of systemic inflammation with subsequent long-term cognitive change in older people with type 2 diabetes. METHODS: The Edinburgh Type 2 Diabetes Study is a prospective cohort study of 1066 adults aged 60 to 75 years with type 2 diabetes. Baseline data included C-reactive protein, IL-6, TNF-α fibrinogen and neuropsychological testing on major cognitive domains. Cognitive testing was repeated after 10 years in 581 participants. A general cognitive ability score was derived from the battery of seven individual cognitive tests using principal component analysis. Linear regression was used to determine longitudinal associations between baseline inflammatory markers and cognitive outcomes at follow-up, with baseline cognitive test results included as covariables to model cognitive change over time. RESULTS: Following adjustment for age, sex and baseline general cognitive ability, higher baseline fibrinogen and IL-6 were associated with greater decline in general cognitive ability (standardised ÎČsâ=ââ0.059, p=0.032 and â0.064, p=0.018, respectively). These associations lost statistical significance after adjustment for baseline vascular and diabetes-related covariables. When assessing associations with individual cognitive tests, higher IL-6 was associated with greater decline in tests of executive function and abstract reasoning (standardised ÎČsâ=â0.095, p=0.006 and â0.127, p=0.001, respectively). Similarly, raised fibrinogen and C-reactive protein levels were associated with greater decline in processing speed (standardised ÎČsâ=ââ0.115, p=0.001 and â0.111, p=0.001, respectively). These associations remained statistically significant after adjustment for the diabetes- and vascular-related risk factors. CONCLUSIONS/INTERPRETATION: Higher baseline levels of inflammatory markers, including plasma IL-6, fibrinogen and C-reactive protein, were associated with subsequent cognitive decline in older people with type 2 diabetes. At least some of this association appeared to be specific to certain cognitive domains and to be independent of vascular and diabetes-related risk factors. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains peer-reviewed but unedited supplementary material available at 10.1007/s00125-021-05634-w
The relationship between alignment, function and loading in total knee replacement : in-vivo analysis of a unique patient population
The purpose of this study was to quantify the effect of total knee replacement (TKR) alignment on in-vivo knee function and loading in a unique patient cohort who have been identified as having a high rate of component mal-alignment. Post-TKR (82.4 ± 6.7 months), gait analysis was performed on 25 patients (27 knees), to calculate knee kinematics and kinetics. For a step activity, video fluoroscopic analysis quantified in-vivo implant kinematics. Frontal plane lower-limb alignment was defined by the Hip-Knee-Ankle angle (HKA) measured on long leg static X-rays. Transverse plane component rotation was calculated from computed tomography scans. Sagittal plane alignment was defined by measuring the flexion angle of the femoral component and the posterior tibial slope angle (PTSA). For gait analysis, a more varus HKA correlated with increased peak and dynamic joint kinetics, predicting 47.6% of Knee Adduction Angular Impulse variance. For the step activity, during step-up and single leg loaded, higher PTSA correlated with a posterior shift in medial compartment Anterior-Posterior (AP) translation. During step-down, higher PTSA correlated with reduced lateral compartment AP translation with a posterior shift in AP translation in both compartments. A more varus HKA correlated with a more posterior medial AP translation and inter-component rotation was related to transverse plan range of motion. This in-vivo study found that frontal plane lower-limb alignment had a significant effect on joint forces during gait but had minimal influence on in-vivo implant kinematics for step activity. PTSA was found to influence in-vivo TKR translations and is therefore an important surgical factor
Nitrogen Production in Starburst Galaxies Detected by GALEX
We investigate the production of nitrogen in star-forming galaxies with ultraviolet (UV) radiation detected by the Galaxy Evolution Explorer Satellite (GALEX). We use a sample of 8745 GALEX emission-line galaxies matched to the Sloan Digital Sky Survey (SDSS) spectroscopic sample. We derive both gas-phase oxygen and nitrogen abundances for the sample and apply stellar population synthesis models to derive stellar masses and star formation histories of the galaxies. We compare oxygen abundances derived using three different diagnostics. We derive the specific star formation rates of the galaxies by modeling the seven-band GALEX+SDSS photometry. We find that galaxies that have log (SFR/M_*) âł â 10.0 typically have values of log (N/O) ~ 0.05 dex less than galaxies with log (SFR/M_*) ⟠â 10.0 and similar oxygen abundances
Zero-Gap Bipolar Membrane Electrolyzer for Carbon DioxideReduction Using Acid-Tolerant Molecular Electrocatalysts
[Image: see text] The scaling-up of electrochemical CO(2) reduction requires circumventing the CO(2) loss as carbonates under alkaline conditions. Zero-gap cell configurations with a reverse-bias bipolar membrane (BPM) represent a possible solution, but the catalyst layer in direct contact with the acidic environment of a BPM usually leads to H(2) evolution dominating. Here we show that using acid-tolerant Ni molecular electrocatalysts selective (>60%) CO(2) reduction can be achieved in a zero-gap BPM device using a pure water and CO(2) feed. At a higher current density (100 mA cm(â2)), CO selectivity decreases, but was still >30%, due to reversible product inhibition. This study demonstrates the importance of developing acid-tolerant catalysts for use in large-scale CO(2) reduction devices
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