18 research outputs found
Partial Oxidation of Methane to Methanol on Cobalt Oxide-Modified Hierarchical ZSM-5
Conversion of methane to more reactive compounds such as methanol has drawn attention for many years. Hierarchical ZSM-5 zeolite has been used as support of metal oxide catalyst to facilitate the partial oxidation of methane to methanol. The NaZSM-5 zeolite was synthesized hydrothermally using double-template techniques, in which tetrapropylammonium hydroxide (TPAOH) and polydiallyldiammonium chloride (PDDA) were used as primary and secondary templates, respectively. HZSM-5 was prepared through multiple NH4+ exchange of NaZSM-5 followed by calcination. Co oxide-modified ZSM-5 (Co/NaZSM-5 and Co/HZSM-5) were prepared through impregnation method. Then, the zeolites were extensively characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), AAS, Fourier transform infrared (FTIR), 27Al solid-state NMR, microbalance, and surface area analysis. The catalytic test was performed in batch reactor, and the product was analyzed with GC-FID. Reaction condition and acidity of ZSM-5 as support catalyst were studied. As a result, when using Co/HZSM-5 as catalyst, percentage (%) yield of methanol was increased with longer reaction time. On the other hand, the percentage (%) yield decreased when Co/NaZSM-5 was employed. Introduction of trace amount of oxygen to the gas mixture showed different results. Furthermore, the prospect of synthesis of ZSM-5 using natural resources and using biogas are also explored
Metabolically-Healthy Obesity and Coronary Artery Calcification
ObjectivesThe purpose of this study was to compare the coronary artery calcium (CAC) scores of metabolically-healthy obese (MHO) and metabolically healthy normal-weight individuals in a large sample of apparently healthy men and women.BackgroundThe risk of cardiovascular disease among obese individuals without obesity-related metabolic abnormalities, referred to as MHO, is controversial.MethodsWe conducted a cross-sectional study of 14,828 metabolically-healthy adults with no known cardiovascular disease who underwent a health checkup examination that included estimation of CAC scores by cardiac tomography. Being metabolically healthy was defined as not having any metabolic syndrome component and having a homeostasis model assessment of insulin resistance <2.5.ResultsMHO individuals had a higher prevalence of coronary calcification than normal weight subjects. In multivariable-adjusted models, the CAC score ratio comparing MHO with normal-weight participants was 2.26 (95% confidence interval: 1.48 to 3.43). In mediation analyses, further adjustment for metabolic risk factors markedly attenuated this association, which was no longer statistically significant (CAC score ratio 1.24; 95% confidence interval: 0.79 to 1.96). These associations did not differ by clinically-relevant subgroups.ConclusionsMHO participants had a higher prevalence of subclinical coronary atherosclerosis than metabolically-healthy normal-weight participants, which supports the idea that MHO is not a harmless condition. This association, however, was mediated by metabolic risk factors at levels below those considered abnormal, which suggests that the label of metabolically healthy for obese subjects may be an artifact of the cutoff levels used in the definition of metabolic health
Life Course Evaluation of a Plant-Centered Diet and Risk of Type 2 Diabetes, Weight Gain, Cardiovascular Diseases, All-Cause Mortality, and Markers of Chronic Kidney Disease: The Coronary Artery Risk Development in Young Adults (CARDIA) Cohort
University of Minnesota Ph.D. dissertation. 2021. Major: Nutrition. Advisors: David Jacobs, Nicole Larson. 1 computer file (PDF); 206 pages.OBJECTIVE: To examine the association of plant-centered diet quality with risk of type 2 diabetes (T2D), weight gain, cardiovascular disease (CVD), all-cause mortality, and markers of chronic kidney disease (CKD)−estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (ACR).METHODS: Data from the Coronary Artery Risk Development in Young Adults (CARDIA) cohort were used. This US multicenter, community-based prospective study involved 5,115 Black and White men and women aged 18-30 years old at baseline assessment in 1985–1986 and followed through to 2018. Diet was assessed by an interviewer-administered, validated diet history questionnaire. Plant-centered diet quality was assessed using the A Priori Diet Quality Score (APDQS); higher index scores represent higher consumption of nutritionally-rich plant foods and limited consumption of high-fat meat products and unhealthy plant foods. Cox regression models were used to assess risk of T2D, CVD, and all-cause mortality, and linear regression models were used to examine change in body size, eGFR, ACR, and combination of eGFR and ACR.
RESULTS: For every 1–SD increase in the APDQS (over a 20-year period for T2D and a 13-year period for CVD), there was a reduction in subsequent risk of T2D (Hazard Ratio [HR]= 0.71; 95% CI: 0.59–0.86) and CVD (HR=0.75; 95% CI: 0.57–1.00), independent of the baseline APDQS. In addition, each 1–SD increase in the APDQS over 20 years was associated with concurrent changes in body mass index (-0.39±0.14 kg/m2; P=0.004), waist circumference (-0.90±0.27 cm; P <0.001), and body weight (-1.14±0.33 kg; P <0.001). The time-updated average APDQS was associated with lower risk of CVD (HR=0.80; 95% CI: 0.67–0.95), lower ln(ACR) (β±SE at Y30: -0.09±0.02 mg/g; P<0.001), higher eGFR (1.64±0.47 mL/min/1.73m2; P<0.001), and lower the combined markers (for ln(ACR) z-score - eGFR z-score: -0.19±0.03; P<0.001). However, there was a suggestive, but not statistically significant, inverse association between the APDQS and risk of all-cause mortality.
CONCLUSIONS: Consumption of a plant-centered, high-quality diet starting in young adulthood is associated with a lower risk of developing diet-related chronic disease by middle age
Simple Nutrient-Based Rules vs. a Nutritionally Rich Plant-Centered Diet in Prediction of Future Coronary Heart Disease and Stroke: Prospective Observational Study in the US
To better understand nutrition paradigm shift from nutrients to foods and dietary patterns, we compared associations of a nutrient-based blood cholesterol-lowering diet vs. a food-based plant-centered diet with risk of coronary heart disease (CHD) and stroke. Participants were 4701 adults aged 18–30 years and free of cardiovascular disease at baseline, followed for clinical events from 1985 and 86 to 2018. A plant-centered diet was represented by higher A Priori Diet Quality Score (APDQS). A blood cholesterol-lowering diet was represented by lower Keys Score. Proportional hazards regression was used to calculate hazard ratios (HR). Higher APDQS showed a nutrient-dense composition that is low in saturated fat but high in fiber, vitamins and minerals. Keys Score and APDQS changes were each inversely associated with concurrent plasma low-density lipoprotein cholesterol (LDL-C) change. Over follow-up, 116 CHD and 80 stroke events occurred. LDL-C predicted CHD, but not stroke. APDQS, but not Keys Score, predicted lower risk of CHD and of stroke. Adjusted HRs (95% CIs) for each 1-SD higher APDQS were 0.73 (0.55–0.96) for CHD and 0.70 (0.50–0.99) for stroke. Neither low dietary fat nor low dietary carbohydrate predicted these events. Our findings support the ongoing shift in diet messages for cardiovascular prevention
Gestational Diabetes Mellitus Is Associated with Differences in Human Milk Hormone and Cytokine Concentrations in a Fully Breastfeeding United States Cohort
It is unclear whether gestational diabetes mellitus (GDM) alters breast milk composition. We prospectively examined associations of GDM status with concentrations of six potentially bioactive elements (glucose, insulin, C-reactive protein (CRP), interleukin-6 (IL-6), leptin, and adiponectin) in human milk. These were measured at both 1 and 3 months postpartum in 189 fully breastfeeding women. Mixed-effects linear regression assessed GDM status-related differences in these milk bioactives, adjusting for demographics, maternal factors, and diet. At 1 and 3 months postpartum, milk CRP was higher (1.46 ± 0.31 ng/mL; p < 0.001 and 1.69 ± 0.31 ng/mL; p < 0.001) in women with GDM than in women without GDM, whereas milk glucose (−5.23 ± 2.22 mg/dL; p = 0.02 and −5.70 ± 2.22; p = 0.01) and milk insulin (−0.38 ± 0.17 μIU/mL; p = 0.03 and −0.53 ± 0.17; p = 0.003) were lower in women with GDM. These significant associations remained similar after additional adjustment for maternal weight status and its changes. No difference was found for milk IL-6, leptin, and adiponectin. There was no evidence of association between these milk bioactive compounds and 1 h non-fasting oral glucose challenge serum glucose in the women without GDM. This prospective study provides evidence that potentially bioactive elements of human milk composition are altered in women with GDM
The change of QRS duration after pulmonary valve replacement in patients with repaired tetralogy of Fallot and pulmonary regurgitation
Glycaemic index and glycaemic load in relation to risk of diabetes-related cancers: a meta-analysis
A Shift Toward a Plant-Centered Diet From Young to Middle Adulthood and Subsequent Risk of Type 2 Diabetes and Weight Gain: The Coronary Artery Risk Development in Young Adults (CARDIA) Study
ObjectiveTo examine the associations between change in plant-centered diet quality and type 2 diabetes risk and change in body size.Research design and methodsA prospective study conducted in the U.S. enrolled adults ages 18-30 years in 1985-1986 (examination year [Y0]) and followed them through 2015-2016. We analyzed the associations between change in plant-centered diet quality over 20 years (Y0-Y20) and diabetes (Y20-30; n = 2,534) and change (Y0-Y20 and Y20-30) in BMI, waist circumference (WC), and weight (n > 2,434). Plant-centered diet quality was measured using the A Priori Diet Quality Score (APDQS); a higher score favors nutritionally rich plant foods. Cox regression models were used to assess diabetes risk, and linear regression models were used to examine change in body size.ResultsDuring a mean follow-up of 9.3 (± 1.7) years, 206 case subjects with incident diabetes were observed. In multivariable analysis, participants with the largest increase in APDQS over 20 years had a 48% (95% CI 0.31-0.85; P trend < 0.001) lower risk of diabetes over the subsequent 10 years compared with participants whose score remained stable. Each 1-SD increment in APDQS over 20 years was associated with lower gains in BMI (-0.39 kg/m2; SE 0.14; P = 0.004), WC (-0.90 cm; SE 0.27; P < 0.001) and weight (-1.14 kg; SE 0.33; P < 0.001) during the same period, but not with subsequent changes.ConclusionsYoung adults who increased plant-centered diet quality had a lower diabetes risk and gained less weight by middle adulthood