How does obesity influence the risk of vertebral fracture? Findings from the UK Biobank participants

Obesity and osteoporotic-related fractures are two common public health problems, although it is unclear how obesity affects the risk of vertebral fractures. The purpose of this study was to examine the association between different measures of obesity and the risk of vertebral fracture, and to establish the various clinical factors that can predict such risk. We analysed the data obtained from 502,543 participants in the UK Biobank (229,138 men and 273,405 women) who were aged 40-69 years. Imaging information was available in a subset of this cohort (5,189 participants, 2,473 men and 2,716 women). We further examined how bone mineral density (BMD) and geometry of the vertebrae were related to body fat measures. It was shown that a larger waist circumference, but not body mass index (BMI), was associated with an increase in fracture risk in men, but in women, neither BMI nor waist circumference affected the risk. Trunk fat mass, visceral adipose tissue (VAT) mass and limb fat mass were negatively associated with vertebral body BMD and geometry in men and women. BMD and geometry are related to the vertebral strength, but may not be directly related to the risk of fractures which are also influenced by other factors. The binary logistic regression equation established in this study may be useful to clinicians for prediction of vertebral fracture risks, and may provide further information to supplement FRAX which assesses general fracture risks

Characterization of SO\u3csub\u3e2\u3c/sub\u3e-Poisoned Ceria-Zirconia Mixed Oxides

CeO2, ZrO2, and a series of CexZr1-xO2 catalysts with 1 wt% Pd were exposed to fixed exposures of SO2 under oxidizing environments and then characterized by FTIR, pulse-reactor studies with CO and O2, and temperature-programmed desorption (TPD). For exposures above 473 K, sulfates were formed on all of the materials; however, the results are consistent with the formation of bulk sulfates on CeO2 and only surface sulfates on ZrO2. For the mixed oxides, the quantity of sulfates formed at 673 K increased linearly with the Ce content. In TPD, the sulfates on ZrO2 were stable to higher temperatures than those formed on CeO2, which decomposed in a well-defined peak between 900 and 1050 K. The sulfates on both oxides were reduced by CO above 750 K. Even though XRD patterns for the mixed oxide were significantly different from that of the physical mixture, the TPD and pulse-reactor results were similar to what would be expected for physical mixtures of CeO2 and ZrO2, suggesting that sulfate species are associated with individual metal cations. Finally, pulse-reactor studies with CO and O2 at 873 K show that the sulfates can be reversibly reduced and oxidized on both CeO2 and ZrO2, so that sulfur poisoning gives rise to an apparent increase in oxygen storage, demonstrating that this method is not acceptable for measurement of this quantity

A Mechanistic Study of Sulfur Poisoning of the Water-Gas-Shift Reaction Over Pd/Ceria

The effect of sulfur on the water-gas-shift (WGS) activity of Pd/ceria catalysts has been studied using steady-state rate measurements, pulse-reactor studies, and FTIR. After exposing Pd/ceria to SO2 at 673 K in an oxidizing environment, the WGS rates dropped to a value close to that observed on Pd/alumina. Both pulse-reactor and FTIR measurements showed that cerium sulfates can be readily reduced by CO and re-oxidized by O2 at 723 K; however, unlike reduced ceria, the Ce2O2S formed by reduction of the sulfates cannot be re-oxidized by H2O or CO2. The implications of these measurements for understanding oxygen-storage capacity (OSC) of three-way catalysts are discussed

An investigation of NO\u3csub\u3ex \u3c/sub\u3estorage on Pt–BaO–Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e

A series of samples containing 5-wt% or 20-wt% BaO on γ-Al2O3 with different loadings of Pt were prepared and examined for their NO2 adsorption properties using temperature programmed desorption (TPD), temperature programmed reduction (TPR), and x-ray diffraction (XRD). For calcination at 873 K or above, BaO/Al2O3 formed BaAl2O4. While carbonates were found to be unstable on the aluminate phase, NO2 reacted with the aluminate to form bulk Ba(NO3)2 and Al2O3, even at room temperature. With BaO/Al2O3, reaction to form the nitrate required slightly higher temperatures because of the need to displace CO2; however, pulsing NO2 over pure Ba(CO3) showed rapid reaction to form CO2 and NO in the gas phase, along with Ba(NO3)2, at 673 K. The decomposition temperature for Ba(NO3)2 shifted by more than 100 degrees when TPD was carried out in vacuum rather than in a carrier gas, showing that re-equilibration with the gas phase is important in the decomposition process. The addition of Pt had a minimal effect on the thermal stability of the nitrates but was essential for the reduction of the nitrate in H2. Since a relatively small amount of Pt was sufficient to cause the complete reduction of the Ba(NO3)2 phase at temperatures below 400 K, it appears that the nitrates must be extremely mobile within the Ba-containing phase. Finally, trapping studies of NO2 at 573 K, with or without 10% CO2 in the gas phase, showed no measurable difference between BaO/Al2O3 and BaAl2O4, with or without CO2

Deactivation of the Water-Gas-Shift Activity of Pd/Ceria by Mo

The effect of surface Mo on the water-gas-shift (WGS) activity of Pd/ceria was studied. A series of 1-wt% Pd catalysts, with varying Mo content, were prepared from supports obtained by aqueous impregnation of (NH4)2MoO4 onto ceria. Rates were found to decrease linearly with Mo coverage up to 1.8 Mo/nm2 and were 10% of that on Pd/ceria after the addition of this amount of Mo. TPD studies with 2-propanol on the Mo-containing ceria demonstrate a relationship between the loss of WGS activity and ceria sites that decompose the alcohol to propene and water. FTIR measurements suggest that Mo ions exchange with surface hydroxyls on ceria and that carbonates are not formed on ceria surfaces that have 1.8 Mo/nm2. The results from CO-O2 pulse measurements suggest that the Mo-containing surface is much harder to reduce than pure ceria. Raman spectra of the Mo-containing ceria show features associated with molybdena only for Mo coverages greater than 1.8 Mo/nm2. The implications of these results for understanding WGS activity on Pd/ceria are discussed

Stage effects of negative emotion on spatial and verbal working memory

Background: The effects of negative emotion on different processing periods in spatial and verbal working memory (WM) and the possible brain mechanism of the interaction between negative emotion and WM were explored using a high-time resolution event-related potential (ERP) technique and time-locked delayed matching-to-sample task (DMST)