Size controlled green synthesis of gold nanoparticles using Coffea arabica seed extract and their catalytic performance in 4-nitrophenol reduction

Well crystalline gold nanoparticles (AuNPs) of different sizes were fabricated using sundried Coffea arabica seed (CAS) extract at room temperature by controlling the pH of the green extract. The size, shape and crystallinity of the nanoparticles have been studied using electron microscopy and X-ray diffraction. The presence of phenolic groups (revealed through FT-IR studies) from the CAS extract are responsible both for the reduction of Au ions and stabilization of the formed AuNPs. The efficiency of the CAS extract mediated green synthesis technique for the production of AuNPs has been compared to the conventional chemical Turkevich technique, which not only uses a toxic reductant such as NaBH₄, but also operates around the boiling point of water. It has been observed that the CAS extract mediated synthesis process produces relatively bigger AuNPs at similar pH values of the reaction mixture in comparison to the AuNPs produced in the Turkevich process. Although the AuNPs synthesized using CAS extract are relatively larger and polydisperse in nature, their catalytic efficiencies for the degradation of an aromatic nitro compound (4-nitrophenol) are found to be comparable to the chemically fabricated AuNPs. Probable mechanisms associated with the formation of AuNPs and their size control in the CAS extract mediated green synthesis process have been discussed.

Size dependent catalytic activity of AuNPs synthesized at room temperature from Coffea arabica seed extract.     

Successful catheter ablation of ventricular tachycardia originating from the idiopathic saccular apical left ventricular aneurysm

Left ventricular (LV) aneurysm has been recognized to frequently become a substrate of ventricular tachyarrhythmias. We report a case of a 66-year-old woman with symptomatic sustained monomorphic ventricular tachycardia (SMVT) originating from saccular apical LV aneurysm without definite underlying diseases. We performed catheter ablation using electroanatomical and conventional bipolar potential mapping. During SMVT, we found an area of fragmented potential -40 ms preceding the earliest wide QRS complex in the area of the apical LV aneurysm. Radiofrequency applications were delivered to this area. Since then, SMVT was no longer inducible by programmed electrical stimulation. The patient has remained free of VT recurrences during a subsequent 12-month follow-up period.     

Precursors of arteriosclerosis in childhood. Protocol and firsts results concerning plasma lipids and carbohydrate tolerance in 520 school children at Pordenone (Italy) (author's transl)]

The cardiological centers of Pordenone and Cittadella (Italy) organized by the Institute of Clinica Medica II of Padua University, have carried out a study on the "Precursors of arteriosclerosis in children", according to a WHO protocol. In this paper some results of the Pordenone study are reported, concerning serum cholesterol (TC), triglycerides (TG) and blood glucose 1 h after 1 g/Kg glucose per os. 520 school children, males and females, aged 6, 9, 12, 15 years, entered the study. Mean serum TC resulted significantly higher at age 12 as compared to the other age classes. Serum TG progressively increased with age. Mean serum TC and TG in our italian children and adolescents were silimar to those reported in studies from other countries. Blood glucose resulted significantly higher in children than in adolescents. The distribution of the blood glucose values was bimodal. After having arbitrarily fixed cut-off points for serum TC, TG and blood glucose, the prevalence of hyperlipidemia and hyperglycemia was determined. The prevalence figures have shown that at the pediatric age it is possible to identify subjects at "risk" of developing arteriosclerosis.     

Comparison of effectiveness of thyrotropin-suppressive doses of d- and l-thyroxine in treatment of hypercholesterolemia

In an attempt to compare the cholesterol-lowering effects of equivalent doses of d- and l-thyroxine, 10 euthyroid, hypercholesterolemic subjects were treated with graded doses of each medication in a cross-over design using thyrotropin suppression following thyrotropin-releasing hormone administration as the end-point. The mean thyrotropin-suppressive dose of d-thyroxine was 2.4 ± 0.66 mg per day, which resulted in mean reductions of 10 percent in total plasma cholesterol, 10 percent in plasma low-density lipoprotein cholesterol, and 11 percent in plasma high-density lipoprotein cholesterol. The mean thyrotropin-suppressive dose of l-thyroxine was 135 ± 46 μg per day, which resulted in mean reductions of 7 percent in total plasma cholesterol, 6 percent in plasma low-density lipoprotein cholesterol, and 14 percent in plasma high-density lipoprotein cholesterol. The reductions in total, low-density, and high-density cholesterol achieved with d-thyroxine were not significantly different from those achieved with l-thyroxine. Neither medication produced a significant increase in heart rate or ventricular ectopy as determined by Holter monitoring. These data do not support the belief that d-thyroxine has a preferential cholesterol-lowering effect in humans when compared with equivalent doses of l-thyroxine. In addition, both d- and l-thyroxine reduced plasma high-density lipoprotein cholesterol.