University of Ioannina

About: University of Ioannina is a education organization based out in Ioannina, Greece. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 7654 authors who have published 20594 publications receiving 671560 citations. The organization is also known as: Panepistimio Ioanninon.

Effects of fibrates on serum metabolic parameters.

Abstract: Fibric acid derivatives are a class of hypolipidaemic drugs used in the treatment of patients with hypertriglyceridaemia, mixed hyperlipidaemia and diabetic dyslipidaemia. Fibrate therapy results in a significant decrease in serum triglycerides and an increase in high-density lipoprotein (HDL) cholesterol levels. The latest drugs of this class are also effective in lowering low-density (LDL) cholesterol levels and can change the distribution of LDL towards higher and larger particles. The effects of fibrates on lipid metabolism are mostly mediated through the activation of peroxisome proliferator-activated receptors (PPARalpha). A number of angiographic and clinical trials have confirmed that fibrates can slow the progression of atherosclerotic disease and decrease cardiovascular morbidity and mortality. Recently published data suggest that the ability of fibrates to prevent atherosclerosis is not related only to their hypolipidaemic effects but also to other 'pleiotropic effects', such as their anti-inflammatory, antioxidant and antithrombotic effects, as well as their ability to improve endothelial function. Interestingly, fibrates may favourably influence the thrombotic/fibrinolytic system. In fact, most of these drugs can significantly decrease plasma fibrinogen levels and inhibit tissue factor expression and activity in human monocytes and macrophages. Some studies have shown that fibrates can improve carbohydrate metabolism in patients with dyslipidaemia, including diabetic patients. Among fibrates only fenofibrate can significantly decrease serum uric acid levels by increasing renal urate excretion. Fibrates, with the possible exception of gemfibrozil, can significantly increase serum creatinine and homocysteine levels. Finally, a reduction in serum alkaline phosphatase and gamma glutamyltranspeptidase (gammaGT) activity is a well-documented effect of therapy with fibrates. The fibrates are generally well-tolerated drugs with few side-effects. The most important side-effect is myositis, which is observed in patients with impaired renal function or when statins are given concomitantly.

Conductive nitrides: Growth principles, optical and electronic properties, and their perspectives in photonics and plasmonics

Abstract: The nitrides of most of the group IVb-Vb-VIb transition metals (TiN, ZrN, HfN, VN, NbN, TaN, MoN, WN) constitute the unique category of conductive ceramics. Having substantial electronic conductivity, exceptionally high melting points and covering a wide range of work function values, they were considered for a variety of electronic applications, which include diffusion barriers in metallizations of integrated circuits, Ohmic contacts on compound semiconductors, and thin film resistors, since early eighties. Among them, TiN and ZrN are recently emerging as significant candidates for plasmonic applications. So the possible plasmonic activity of the rest of transition metal nitrides (TMN) emerges as an important open question. In this work, we exhaustively review the experimental and computational (mostly ab initio) works in the literature dealing with the optical properties and electronic structure of TMN spanning over three decades of time and employing all the available growth techniques. We critically evaluate the optical properties of all TMN and we model their predicted plasmonic response. Hence, we provide a solid understanding of the intrinsic (e.g. the valence electron configuration of the constituent metal) and extrinsic (e.g. point defects and microstructure) factors that dictate the plasmonic performance. Based on the reported optical spectra, we evaluate the quality factors for surface plasmon polariton and localized surface plasmon for various TMN and critically compare them to each other. We demonstrate that, indeed TiN and ZrN along with HfN are the most well-performing plasmonic materials in the visible range, while VN and NbN may be viable alternatives for plasmonic devices in the blue, violet and near UV ranges, albeit in expense of increased electronic loss. Furthermore, we consider the alloyed ternary TMN and by critical evaluation and comparison of the reported experimental and computational works, we identify the emerging optimal tunable plasmonic conductors among the immense number of alloying combinations.

Atorvastatin Preferentially Reduces LDL-Associated Platelet-Activating Factor Acetylhydrolase Activity in Dyslipidemias of Type IIA and Type IIB

Abstract: Human plasma platelet-activating factor acetylhydrolase (PAF-AH) is a phospholipase A(2) that is primarily associated with low density lipoprotein (LDL). PAF-AH activity has also been found in high density lipoprotein (HDL), although it has recently been indicated that there is no PAF-AH protein in HDL. Plasma paraoxonase 1 (PON1) is an HDL-associated esterase, which also exhibits PAF-AH-like activity. The effect of atorvastatin (20 mg per day for 4 months) on PAF-AH and PON1 activities in patients with dyslipidemia of type IIA (n=55) or type IIB (n=21) was studied. In both patient groups, atorvastatin significantly reduced plasma PAF-AH activity because of the decrease in LDL plasma levels and the preferential decrease in PAF-AH activity on dense LDL subfractions (LDL-4 and LDL-5). Drug therapy did not affect HDL-associated PAF-AH activity or serum PON1 activities toward paraoxon and phenylacetate in either patient group. However, because of the reduction in LDL cholesterol levels, the ratios of HDL-associated PAF-AH and serum PON1 activities to LDL cholesterol levels were significantly increased after drug administration. The reduction of the LDL-associated PAF-AH activity and the elevation in the ratios of HDL-associated PAF-AH and PON1 activities to LDL plasma levels may represent a new dimension in the antiatherogenic effect of atorvastatin.

Lipoprotein-Associated Phospholipase A2 Activity Is a Marker of Small, Dense LDL Particles in Human Plasma

Abstract: Background: Recent clinical studies showed that lipoprotein-associated phospholipase A2 (Lp-PLA2) is a predictor for incident atherosclerotic disease. We have previously shown that among the LDL subfractions, Lp-PLA2 activity is preferentially associated with the atherogenic small, dense (sdLDL) particles in vitro. We investigated whether Lp-PLA2 could be a marker of sdLDL in human plasma. Methods: One hundred and seventy-six individuals participated in the study. LDL subclass analysis was performed by polyacrylamide gel electrophoresis. Lp-PLA2 activity and mass were determined in total plasma and in apolipoprotein B-depleted plasma (HDL-Lp-PLA2). Non–HDL-Lp-PLA2 activity and mass were calculated by subtracting the HDL-Lp-PLA2 from total plasma Lp-PLA2. Results: On the basis of the LDL subclass analysis, participants were categorized into phenotype A and non-A (total cholesterol mass of the sdLDL subfractions ≤0.155 and >0.155 mmol/L, respectively). Unlike total plasma Lp-PLA2 mass, total plasma Lp-PLA2 activity and non–HDL-Lp-PLA2 activity and mass were significantly higher in persons with phenotype non-A compared with persons with phenotype A, whereas HDL-Lp-PLA2 activity and mass were lower in persons with phenotype non-A compared with phenotype A. Total plasma activity and non–HDL-Lp-PLA2 activity and mass, but not Lp-PLA2 mass, were correlated with sdLDL-cholesterol mass, proportion, and mean LDL particle size. In multiple regression analysis, total plasma and non–HDL-Lp-PLA2 activities were the second best predictors of the presence of sdLDL particles in human plasma after serum triglyceride concentrations. At serum triglyceride concentrations >1.356 mmol/L, total plasma and non–HDL-Lp-PLA2 activity added significantly to the prediction of the presence of sdLDL in plasma. Conclusions: Lp-PLA2 activity, but not the enzyme mass, is a marker of sdLDL in human plasma.

Preparation, characterization and investigation of catalytic activity for NO+CO reaction of LaMnO3 and LaFeO3 perovskites prepared via microemulsion method

Abstract: Two typical perovskites LaMnO3 and LaFeO3 have been successfully prepared via microemulsion method both in the reverse and bicontinuous state. Pure perovskite crystal phases are achieved at final calcinations temperature of 800 °C. The specific surface areas (Sp) of the obtained materials were 24 and 12 m2 g−1 for the LaMnO3 prepared via reverse and bicontinuous phase and while the corresponding Sp for LaFeO3 were 30 and 14 m2 g−1. SEM images have shown that perovskites developed via reverse micelles have smaller particle size than those developed via the bicontinuous phase. The perovskites were tested for NO+CO reaction and exhibited higher catalytic activity than similar materials prepared via the ceramic method. The reactants NO and CO react in a 2:1 ratio at low temperature but they convert in a 1:1 ratio at high temperatures. From the kinetic analysis the heat of NO adsorption is estimated. In the case of manganese-containing materials except for the Sp, the percentage of Mn3+OMn4+ pairs seems to be another critical factor which influences the catalytic activity.