The solubilities of nicotinic acid and nicotinamide in supercritical CO2 with a static-analytical method were determined at temperatures from 313.15K to 373.15K and over the pressure range from 5 to 30 MPa. Solid-liquid phase transitions were determined with a modified capillary method. Solubility increased with increasing pressure for both the investigated substances. The solubility data were correlated using four different density-based models: a good agreement between calculated and experimental data was confirmed. Solubility measurements were also preformed for the ternary system nicotinic acid-nicotinamide-CO2 with two different mass ratios. It was found that the composition of the mixture influences the solubilities of both components in CO2: the solubility of nicotinamide decreased 10-fold, and the solubility of nicotinic acid was up to 8 times higher than in the binary system.
Polyphenol antioxidants decrease the risk of atherosclerosis. The study aimed to evaluate prospectively in healthy young participants the effect of oral rosemary extracts (RE), consisting of diphenols, upon endothelial dysfunction (ED), preceding structural atherosclerosis. Nineteen healthy young volunteers were studied prospectively, who received oral RE (77.7 mg) for 21 days, consisting of active substances carnosol (0.97 mg), carnosic (8.60 mg) and rosmarinic acid (10.30 mg). Before and after RE treatment, the study evaluated fasting serum levels of plasminogen-activator-inhibitor-1 (PAI-1), vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), superoxide dismutase (SOD), glutathione peroxidase (GPX), fibrinogen, high-sensitivity capsular reactive protein (hs-CRP), tumor-necrosis factor alpha (TNF-alpha), the lipid profile and ED, characterized as flow-mediated dilatation (FMD) in the brachial artery of (4.5%, estimated by ultrasound measurements. After 21 days, any side effects were registered, the mean FMD increased nonsignificantly (6.51 +/- 5.96% vs 7.78 +/- 4.56%, p = 0.546) and ED decreased significantly (66.6% vs 16.6%, p = 0.040). Among the serum markers, only the mean PAI-1 level decreased significantly (4.25 +/- 1.46 U/mL vs 3.0 +/- 0.61 U/mL, p = 0.012) after 21-day RE supplementation. It is concluded that oral RE supplementation has the potential to improve serum PAI-1 activity and ED in young and healthy individuals.
A new adsorbent, silica aerogel modified with mercapto (-HS) functional group, was synthesized by standard sol-gel synthesis. Excellent properties of aerogels, obtained with the sol-gel synthesis, were preserved with supercritical drying with CO2. The adsorbent was characterized by FTIR, DSC and TG measurements, nitrogen physisorption and SEM. The ability of modified silica aerogel to remove Cu(II) and Hg(II) from aqueous solutions was assessed using batch adsorption technique under equilibrium conditions. The equilibrium data were fitted well by the Freundlich and Langmuir isotherm model.