Utility of coronary artery calcium in refining 10-year ASCVD risk prediction using a Thai CV risk score

BackgroundCoronary artery calcium (CAC) scanning is a valuable additional tool for calculating the risk of cardiovascular (CV) events. We aimed to determine if a CAC score could improve performance of a Thai CV risk score in prediction of 10-year atherosclerotic cardiovascular disease (ASCVD) risk for asymptomatic patients with CV risk factors.MethodsThis was a retrospective cohort study that enrolled asymptomatic patients with CV risk factors who underwent CAC scans between 2005 and 2013. The patients were classified as low-, intermediate-, or high-risk (<10%, 10%–<20%, and ≥20%, respectively) of having ASCVD within 10-years based on a Thai CV risk score. In each patient, CAC score was considered as a categorical variable (0, 1–99, and ≥100) and natural-log variable to assess the risk of developing CV events (CV death, non-fatal MI, or non-fatal stroke). The C statistic and the net reclassification improvement (NRI) index were applied to assess whether CAC improved ASCVD risk prediction.ResultsA total of 6,964 patients were analyzed (mean age: 59.0 ± 8.4 years; 63.3% women). The majority of patients were classified as low- or intermediate-risk (75.3% and 20.5%, respectively), whereas only 4.2% were classified as high-risk. Nearly half (49.7%) of patients had a CAC score of zero (no calcifications detected), while 32.0% had scores of 1–99, and 18.3% of ≥100. In the low- and intermediate-risk groups, patients with a CAC ≥100 experienced higher rates of CV events, with hazard ratios (95% CI) of 1.95 (1.35, 2.81) and 3.04 (2.26, 4.10), respectively. Incorporation of ln(CAC + 1) into their Thai CV risk scores improved the C statistic from 0.703 (0.68, 0.72) to 0.716 (0.69, 0.74), and resulted in an NRI index of 0.06 (0.02, 0.10). To enhance the performance of the Thai CV risk score, a revision of the CV risk model was performed, incorporating ln(CAC + 1), which further increased the C statistic to 0.771 (0.755, 0.788).ConclusionThe addition of CAC to traditional risk factors improved CV risk stratification and ASCVD prediction. Whether this adjustment leads to a reduction in CV events and is cost-effective will require further assessment

Investigation of activated carbon/ethanol for low temperature adsorption cooling

Commercially available adsorption cooling systems use water/silica gel, water/zeolite and ammonia/ chloride salts working pairs. The water based pairs are limited to work above 0 °C due to the water high freezing temperature, while ammonia has the disadvantage of being toxic. Ethanol is a promising refrigerant due to its low freezing point (161 K), non-toxicity, zero ozone depletion and low global warming potential. Activated carbon (AC) is a porous material with high degree of porosity (500-3000 m2/g) that has been used in wide range of applications. Using Dynamic Vapour Sorption (DVS) test facility, this work characterizes the ethanol adsorption of eleven commercially available activated carbon materials for cooling at low temperature of - 15oC. DVS adsorption results show that Maxsorb has the best performance in terms of ethanol uptake and adsorption kinetics compared to the other tested materials. The Maxsorb/ethanol adsorption process has been numerically modeled using computational fluid dynamics (CFD) and simulation results are validated using the DVS experimental measurements. The validated CFD simulation of the adsorption process is used to predict the effects of adsorbent layer thickness and packing density on cycle uptake for evaporating temperature of -15oC. Simulation results show that as the thickness of the Maxsorb adsorbent layer increases, its uptake decreases. As for the packing density, the amount of ethanol adsorbed per plate increases with the packing density reaching maximum at 750 kg/m3. This work shows the potential of using Maxsorb/ethanol in producing low temperature cooling down to -15oC with specific cooling energy reaching 400kJ/kg

A state of the art of required techniques for employing activated carbon in renewable energy powered adsorption applications

This paper reviews, for the first time, the measurement adsorption characteristics techniques to facilitate optimal testing of the validity of adsorbent materials in adsorption applications. Thermo-physical properties, adsorption characteristics and modelling techniques are presented. The characterisation of material thermo-physical properties includes true and bulk densities, specific heat capacity, surface area, pore volume distribution and thermal conductivity. The adsorption characteristics were categorized into adsorption isotherms and kinetics including experimental and theoretical equations. A range of models used in the simulation of adsorption cooling systems is presented and discussed. The paper highlights the conditions for which each measurement technique is most suitable and the limitations of modelling techniques, which is a vital element in the robust assessment of the performance of adsorption cooling units

Inclusive development and international child rights organizations : good practices and challenges of SOGIESC and LGBTIQ+ inclusion in Thailand

The full abstract for this thesis is available in the body of the thesis, and will be available when the embargo expires.Applied Science, Faculty ofCommunity and Regional Planning (SCARP), School ofGraduat

Energy saving in sintering of porcelain stoneware tile manufacturing by using recycled glass and pottery stone as substitute materials

Commercial porcelain stoneware tiles are vitrified tiles (noted as C) that are composed of clay, feldspar, and quartz. They require high temperature sintering at 1230 °C that result in high energy costs. This study aimed to compare the energy consumption during sintering process of the porcelain stoneware tiles, which recycled glass and pottery stone were used in substitution of clay, feldspar, and quartz (noted as N). The sintering temperatures of the commercial (C) and the substituted (N) tiles were, respectively, at 1230 °C and 1050 °C. The physical, mechanical, and chemical properties of the N tiles were compared with those of the C tiles. As a result, the N tiles showed good properties according to several standards, such as water absorption of less than 0.1% (ISO 10545-3), linear shrinkage of less than 10% (ASTM C326), modulus of rupture of more than 40 N/mm2 (ISO 10545-4), and good resistance of chemicals (ISO 10545-13). The N tiles were in compliance with the ISO 13006:2012 (group BIa) Standard. In the sintering process, the energy consumption and CO2 emission of the N tiles were, respectively, 9191.24 kJ/kgProduct and 0.0782 kg CO2eq/kgProduct, while those of the C tiles were, respectively, 13304.84 kJ/kgProduct and 0.1132 kg CO2eq/kgProduct

Influence of Soda Pulping Variables on Properties of Pineapple ( Ananas comosus

Face-centered composite design (FCC) was used to study the effect of pulping variables: soda concentration (4-5 wt%), temperature (90–130°C), and pulping time (20–60 min) on the properties of pineapple leaf pulp and paper employing soda pulping. Studied pulp responses were screened yield and lignin content (kappa number). Paper properties, which include tensile index, burst index, and tear index, were also investigated. Effects of the pulping variables on the properties were statistically analyzed using Minitab 16. The optimum conditions to obtain the maximum tensile index were soda concentration of 4 wt%, pulping temperature of 105°C, and pulping time of 20 min. The predicted optimum conditions provided tensile index, burst index, tear index, screened yield, and kappa number of 44.13 kN·m/kg, 1.76 kPa·m2, 1.68 N·m2/kg, 21.29 wt%, and 28.12, respectively, and were experimentally confirmed