Pericardial adipose tissue, cardiac structures, and cardiovascular risk factors in school-age children

Aims We examined the associations of pericardial adipose tissue with cardiac structures and cardiovascular risk factors in children.Methods and results We performed a cross-sectional analysis in a population-based cohort study among 2892 children aged 10 years (2404 normal weight and 488 overweight/obese). Pericardial adipose tissue mass was estimated by magnetic resonance imaging (MRI) and indexed on height 3 . Left ventricular mass (LVM) and left ventricular mass-to-volume ratio (LMVR) were estimated by cardiac MRI. Cardiovascular risk factors included android adipose tissue percentage obtained by Dual-energy X-ray absorptiometry, blood pressure and glucose, insulin, cholesterol, and triglycerides concentrations. Adverse outcomes were defined as values above the 75 percentile. Median pericardial adipose tissue index was 3.6 (95% range 1.6-7.1) among normal weight and 4.7 (95% range 2.0-8.9) among overweight children. A one standard deviation (1 SD) higher pericardial adipose tissue index was associated with higher LMVR [0.06 standard deviation scores, 95% confidence interval (CI) 0.02-0.09], increased odds of high android adipose tissue [odd ratio (OR) 2.08, 95% CI 1.89-2.29], high insulin concentrations (OR 1.17, 95% CI 1.06-1.30), an atherogenic lipid profile (OR 1.22, 95% CI 1.11-1.33), and clustering of cardiovascular risk factors (OR 1.56, 95% CI 1.36-1.79). Pericardial adipose tissue index was not associated with LVM, blood pressure, and glucose concentrations. The associations showed largely the same directions but tended to be weaker among normal weight than among overweight children.Conclusion Pericardial adipose tissue is associated with cardiac adaptations and cardiovascular risk factors already in childhood in both normal weight and overweight children.Developmen

Adjustment for time-invariant and time-varying confounders in ‘unexplained residuals’ models for longitudinal data within a causal framework and associated challenges

‘Unexplained residuals’ models have been used within lifecourse epidemiology to model an exposure measured longitudinally at several time points in relation to a distal outcome. It has been claimed that these models have several advantages, including: the ability to estimate multiple total causal effects in a single model, and additional insight into the effect on the outcome of greater-than-expected increases in the exposure compared to traditional regression methods. We evaluate these properties and prove mathematically how adjustment for confounding variables must be made within this modelling framework. Importantly, we explicitly place unexplained residual models in a causal framework using directed acyclic graphs. This allows for theoretical justification of appropriate confounder adjustment and provides a framework for extending our results to more complex scenarios than those examined in this paper. We also discuss several interpretational issues relating to unexplained residual models within a causal framework. We argue that unexplained residual models offer no additional insights compared to traditional regression methods, and, in fact, are more challenging to implement; moreover, they artificially reduce estimated standard errors. Consequently, we conclude that unexplained residual models, if used, must be implemented with great care

Birth weight, cardiometabolic risk factors and effect modification of physical activity in children and adolescents: pooled data from 12 international studies

Abstract: Objectives: Low and high birth weight is associated with higher levels of cardiometabolic risk factors and adiposity in children and adolescents, and increases the risk of cardiovascular diseases, obesity, and early mortality later in life. Moderate-to-vigorous physical activity (MVPA) is associated with lower cardiometabolic risk factors and may mitigate the detrimental consequences of high or low birth weight. Thus, we examined whether MVPA modified the associations between birth weight and cardiometabolic risk factors in children and adolescents. Methods: We used pooled individual data from 12 cohort- or cross-sectional studies including 9,100 children and adolescents. Birth weight was measured at birth or maternally reported retrospectively. Device-measured physical activity (PA) and cardiometabolic risk factors were measured in childhood or adolescence. We tested for associations between birth weight, MVPA, and cardiometabolic risk factors using multilevel linear regression, including study as a random factor. We tested for interaction between birth weight and MVPA by introducing the interaction term in the models (birth weight x MVPA). Results: Most of the associations between birth weight (kg) and cardiometabolic risk factors were not modified by MVPA (min/day), except between birth weight and waist circumference (cm) in children (p = 0.005) and HDL-cholesterol (mmol/l) in adolescents (p = 0.040). Sensitivity analyses suggested that some of the associations were modified by VPA, i.e., the associations between birth weight and diastolic blood pressure (mmHg) in children (p = 0.009) and LDL- cholesterol (mmol/l) (p = 0.009) and triglycerides (mmol/l) in adolescents (p = 0.028). Conclusion: MVPA appears not to consistently modify the associations between low birth weight and cardiometabolic risk. In contrast, MVPA may mitigate the association between higher birth weight and higher waist circumference in children. MVPA is consistently associated with a lower cardiometabolic risk across the birth weight spectrum. Optimal prenatal growth and subsequent PA are both important in relation to cardiometabolic health in children and adolescents

Effect of ceria and strontia over Ru/Mn/Al2O3 catalyst: catalytic methanation, physicochemical and mechanistic studies

The 65 wt% of ceria and strontia based catalysts prepared by impregnation with RuMn/Al2O3 were tested on its CO2 methanation reaction under reducing pretreatment at 300 °C. The result obtained revealed that the addition of Ce to RuMn/Al2O3 has a positive effect on the activity and catalyst stability compared to the Sr containing catalyst. The CO2 conversion over Ru/Mn/Ce-65/Al2O3 achieved 97.73% with 91.31% of methane formation at a reaction temperature of 200 °C while, 73.10% conversion over Ru/Mn/Sr-65/Al2O3 catalyst with 44.58% of methane yielded at reaction temperature of 210 °C. The characterization results obtained suggest that the CeO2, SrO2, RuO2, Mn2O3 and orthorhombic Al2O3 were the active species for both catalysts while, the presence of spinel compound, Sr4(Ru2O9) caused the reducibility and basicity of Ru/Mn/Sr-65/Al2O3 catalyst decreased hence reduced the catalytic activity eventually. The mechanistic study showed it was depended on the type of catalysts as the CO2 adsorbed on the Sr based catalyst tended to form monodentate carbonate at the initial state before forming the formate species when it was hydrogenated and finally releasing the methane. Meanwhile, the methane formation on Ce based catalyst involved the initially adsorption and dissociation of CO2 into C and O adsorbed species before reacting with the adsorbed H2 to form methane gas

CO2/H2 methanation technology of strontia based catalyst: physicochemical and optimisation studies by Box–Behnken design

Catalytic methanation is a fascinating method in converting the carbon dioxide gas from power plant flue gases into the valuable product of methane gas. It can be of great benefit to the environment and the national economy since the production of methane gas can be used as a fuel to run the turbine for electricity generation in power plant system or to run automobile vehicles. As such, catalytic methanation technology is able to reduce the emission of this greenhouse gas to atmosphere. Strontia based catalyst impregnated with Ru/Mn/Al2O3 was developed in this study. The optimum conditions over 10 g of Ru/Mn/Sr/Al2O3 catalyst were achieved with 65 wt% of based loading and calcined at 1000 °C for 5 h which gave 73.10% carbon dioxide conversion with 43.58% of methane at reaction temperature of 210 °C. The value was closely agreed with the predicted result obtained by Response Surface Methodology (RSM) which achieved 72.41% conversion. The higher carbon dioxide conversion was due to the higher reducibility and basicity of the catalyst surface as well as the higher surface area of 83.27 m2/g. The polycrystalline structure obtained from X-Ray Diffraction analysis showed a mixture of smaller (rod shape < 12 nm) and bigger (square sheet shape ∼130 nm) crystallite particles of alumina (Al2O3), strontia (SrO2), tetrastrontium diruthenate (Sr4(Ru2O9)), manganese (II,III) oxide (Mn3O4) and ruthenium oxide (RuO2). The active sites responsible for the higher carbon dioxide activity were SrO2 and RuO2

Physicochemical characteristics of cu/zn/g-al2o3 catalyst and its mechanistic study in transesterification for biodiesel production

A series of novel mixed metal oxide catalysts with the incorporation of copper as a dopant supported on zinc-alumina (Cu/Zn/γ-Al2O3) for biodiesel production have been synthesized and characterized. ZnO is a solid base catalyst, but its weak surface basic properties have limited the usage of ZnO in the transesterification reaction of refined used cooking oil to biodiesel. To further improve the catalytic activity, the copper dopant was loaded by the wetness impregnation method. Cu/Zn/γ-Al2O3 catalyst of 10:90 wt% dopant-to-based (ZnO) ratio with calcination at 800 °C exhibited the highest biodiesel yield (89.5%) at optimum reaction conditions (65 °C, 10 wt% catalyst loading, 1:20 oil-to-methanol mol ratio and 2 h reaction time). The N2 adsorption-desorption and CO2-temperature programmed desorption analyses indicated that the material possessed a high surface area (149 m2/g) and high basicity (3.7424 mmol/g). The mechanistic study confirmed the catalytic reaction followed the Langmuir-Hinshelwood (LH) model, which involves the initial adsorption of reactants molecules on active sites of the catalyst surface

Associations of Fetal and Infant Weight Change With General, Visceral, and Organ Adiposity at School Age

IMPORTANCE Both fetal and infant growth influence obesity later in life. The association of longitudinal fetal and infant growth patterns with organ fat is unknown. OBJECTIVE To examine the associations of fetal and infant weight change with general, visceral, and organ adiposity at school age. DESIGN, SETTING, AND PARTICIPANTS This cohort study was embedded in the Generation R Study, a population-based prospective cohort study in Rotterdam, the Netherlands. Pregnant women with a delivery date between April 2002 and January 2006 were eligible to participate. Follow-up measurements were performed for 3205 children. Data analysis of this population was performed from July 26, 2018, to February 7, 2019. EXPOSURES Fetal weight was estimated in the second and third trimester of pregnancy. Infant weight was measured at 6, 12, and 24 months. Fetal and infant weight acceleration or deceleration were defined as a change in standard deviation scores greater than 0.67 between 2 ages. MAIN OUTCOMES AND MEASURES Visceral fat index, pericardial fat index, and liver fat fraction were measured by magnetic resonance imaging. RESULTS The sample consisted of 3205 children (1632 girls [50.9%]; mean [SD] age, 9.8 [0.3] years). Children born small for gestational age had the lowest median body mass index compared with children born appropriate for gestational age and large for gestational age (16.4 [90% range, 14.1-23.6] vs 16.9 [90% range, 14.4-22.8] vs 17.4 [90% range, 14.9-22.7]). Compared with children with normal fetal and infant growth (533 of 2370 [22.5%]), those with fetal weight deceleration followed by infant weight acceleration (263 of 2370 [11.1%]) had the highest visceral fat index (standard deviation scores, 0.18; 95% CI, 0.03-0.33; P = .02) and liver fat fraction (standard deviation scores, 0.34; 95% CI, 0.20-0.48; P < .001). CONCLUSIONS AND RELEVANCE Fetal and infant weight change patterns were both associated with childhood body fat, but weight change patterns in infancy tended to have larger effects. Fetal growth restriction followed by infant growth acceleration was associated with increased visceral and liver fat

Catalytic methanation over nanoparticle heterostructure of Ru/Fe/Ce/y-Al2O3 catalyst: performance and characterisation

A novel trimetal-oxides (Ru/Fe/Ce) supported on γ-Al2O3 catalyst was synthesised by simple impregnation method and the activity was investigated at atmospheric pressure. The results showed that Ru/Fe/Ce (5:10:85)/γ-Al2O3 catalyst calcined at 1000 °C for 5 h was effective and gave a 97.20% of CO2 conversion at 275 °C with 93.5% of CH4 formation. The catalyst possesses medium-strength basic sites with the best reduction temperature of <200 °C. The mesoporous structure was covered with small, dispersed particles of spherical in shape. The catalyst is formed by nanoparticles below 10 nm with a surface area of 51 m2/g. The physicochemical analyses showed that the active sites of the potential catalyst Ru/Fe/Ce (5:10:85)/γ-Al2O3 are RuO2 (tetragonal), Fe2O3 (rhombohedral), γ-Al2O3 (cubic), and CeO2 (cubic), with a good distribution on the catalyst surface

Biodiesel production from refined used cooking oil using co-metal oxide catalyzed transesterification

The world is challenged with depletion of non-renewable fossil fuel and environmental pollution. Thus, this research was emphasized on converting refined used cooking oil to safer and low toxicity biodiesel by base-catalyzed transesterification reaction. Alumina supported magnesium, calcium, strontium and barium oxide-based catalysts with iron as its dopant were optimized according to various calcination temperatures and iron loadings. The optimum conditions over potential catalyst was achieved with 20 wt% of Fe loading for Fe/Ba/Al2O3 catalyst calcined at 800 °C which gave the maximum biodiesel production of 84.02%. Characterization of catalyst carried out by XRD showed that the 20Fe:80Ba/Al2O3 catalyst calcined at 800 °C had a polycrystalline structure with high BET surface area (133.59 m2/g) while FESEM analysis displayed a morphology of uniform plate-like shape grains with fine particles in the range of 55–60 nm. CO2-TPD results showed that the catalyst exhibited highest basicity of 2.5854 mmol/g, while TGA analysis proved that 800 °C was the optimum calcination temperature. The transesterification process of refined used cooking oil to produce high yield biodiesel was effectively attained using 20Fe:80Ba/Al2O3 catalyst