BackgroundBody iron status has been implicated in atherosclerotic cardiovascular disease. The main hypothesis is that high iron status is associated with increased risk of atherosclerosis. We investigated the potential role of iron as an additional risk factor promoting atherosclerosis among beta-thalassemic patients.MethodsIn this cross-sectional study, the liver iron load was assessed by quantitative T2* MRI technique and intima-media thickness (IMT) of the common carotid artery by high-resolution ultrasound among 119 patients (62 male, 57 female) with beta-thalassemia (major and intermediate) whose age ranged from 10 to 50 years with a mean of 25.6 years. The patients were divided into three groups according to the severity of iron loading, obtained by T2*MRI technique: group I (normal), group II (mild) and group III (moderate and severe) iron load.For elimination of the effect of age on carotid IMT values, the patients also were divided into four age groups (10-19 y, 20-29 y, 30-39 y and 40-50 y). Mean carotid IMT based on the severity of iron loading were compared at different age groups, using one way ANOVA analysis for assessing the effect of iron loading on carotid IMT. Pearson's coefficient of correlation were used to assess the degree of correlation between studied variables (liver T2*, IMT, age).ResultsThere were significant differences in mean carotid IMT based on the severity of iron loading at different age groups, with P = 0.003 at 20-29 y, P = 0.006 at 30-39 y and p = 0.037 at 40-50 y. Age (p = 0.001) and liver T2*(p = 0.003) had significant correlation with mean carotid IMT independently.At the age group of 10-19 years, there were not significant differences in mean carotid IMT based on the liver iron loading (p = 0.661).No significant differences also are seen in mean carotid IMT between male and female (p = 0.41).ConclusionsThis study identified a relationship between body iron status and carotid IMT. This relationship support to the hypothesis of a link between body iron load and atherosclerosis.

In this study, the rice husk as a source of silica was used to synthesize the Al2O3/SiC composite via the self-propagation high-temperature synthesis (SHS) process. Then, the particle size of the synthesized product was reduced to the nanoscale using a planetary ball mill. Finally, different amounts (5, 10, and 15 wt.%) of Al2O3/SiC nanoparticles were incorporated into an epoxy resin in order to improve the mechanical properties and the dielectric strength of fabricated epoxy-based composites. The results indicated that the Al2O3/SiC composite was successfully synthesized by the SHS process from a mixture of the rice husk ash, Al, and carbon black powders as starting materials. The average size of the synthesized Al2O3/SiC particles decreased to 80 nm after 12-h ball milling. Also, the mechanical properties of the fabricated epoxy-based composite samples were improved with the addition of Al2O3/SiC nanoparticles in the investigated range in comparison with the pure epoxy sample. Additionally, the overall dielectric strength of the fabricated epoxy-based composites containing 5–15 wt.% of Al2O3/SiC nanoparticles was higher than that of the pure epoxy. These results were interpreted in terms of the synthesis mechanism of Al2O3/SiC composite via the SHS process, the rice husk ash structure, the interfacial bonding between the polymer chains and the surface of nanoparticles, and the insulation nature of the synthesized nanoparticles.

In this study, silica obtained from the rice husk was used to synthesis of Al2O3/SiC nanoparticles. For this reason, the ash obtained from the burning of the rice husk which contains more than 93 wt. % silica, aluminum and carbon powders with the molar ratios of 3:4:6 were mixed and then compacted into pellets by using a cylindrical die under a pressure 50MPa. In order to conduct the self-propagating high-temperature synthesis (SHS), the produced pellets were placed in an electrical furnace at 850°C under the argon gas atmosphere. Then, a planetary ball milling for 4 to 24h was used to decrease the particle size of the synthesized composite. The results of XRF, XRD, SEM and DLS investigations shown that the rice husk ash can be used to fabricate Al2O3/SiC nanoparticles with an average particle size of about 80 to 65nm via SHS process and ball-milling for 12 to 24h.

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