Structure and transport properties of La0.5Sr0.5 (-) xCaxFeO3 (-) (delta)

Effects of calcium doping on the structure, dimensional stability, and mixed oxygen-ion and electron conductivity of perovskite-like La0.5Sr0.5 - xCaxFeO3 - delta(x = 0-0.3) were studied in light of potential membrane applications. The incorporation of relatively small Ca2+ cations into the lanthanum-strontium ferrite lattice decreases unit cell volume, oxygen nonstoichiometry variations and chemical contribution to the thermal expansion in air. These changes correlate with rising tendency to local oxygen-vacancy ordering and the formation of nano-sized domains with the brownmillerite and LaCa2Fe3O8-type lattices, as revealed by electron diffraction. The resultant vacancy trapping, changing domain structure and enlargement of the interfacial boundary area lead to non-linear relationships between the partial ion conductivity and cation composition, while the apparent activation energy for ion transport at temperatures below 900 degrees C remains almost constant, 0.6-0.7 eV. The n-type electron contribution to the total conductivity, measured in the oxygen pressure range 10(-20)-0.5 atm at 700-950 degrees C, is also essentially independent of the calcium concentration. (C) 2013 Elsevier B.V. All rights reserved

COMPARISON OF THERAPIES BASED ON CARVEDILOL AND METOPROLOL IN HYPERTENSIVE PATIENTS WITH OVERWEIGHT OR OBESITY. THE FIRST RESULTS OF CAMELLIA TRIAL

Aim. To evaluate antihypertensive and metabolic effects of the therapy based on carvedilol (C) in comparison with metoprolol (M) in hypertensive patients with overweight or obesity.Material and methods. 320 patients were involved in multicenter, randomized open parallel study. One part of the patients received C 12,5 mg BID (Vedicardol, “Sintez”), another part – M 25 mg/day BID. Doubling dose of β-blockers (BB) and switching patients to combined therapy with AML 5-10 mg OD (Amlorus, “Sintez”) and hydrochlorothiazide (HCT) 12,5-25 mg OD was performed if necessary. The study duration was 24 weeks.Results. Significant reduction of systolic and diastolic blood pressure was revealed in both groups, there was no difference between groups (р=0,88 and p=0,61 respectively). Switching patients to combined therapy with AML and HCT was made more often in M group than in C group (p&gt;0,05). Prescription of BB resulted in significant reduction of the heart rate, there was no difference between groups (p=0,61). 96,2% patients of group C and 95,5% of group M reached target levels of BP. Significant reduction of glucose (p&lt;0,01) and uric acid levels were registered in group C as well as tendency to lowering of total cholesterol (TC) and low density lipoprotein cholesterol (LDLC) levels. 34 adverse effects were registered during observation period: 24 in group C and 10 in group M (p&gt;0.05), half of them were not related to BB taking.Conclusion: Controlled antihypertensive therapy, based on С and M, allows reaching target levels of BP in majority of patients with overweight or obesity. Switching to combined therapy was made more seldom in group of С than in M group. Both drugs demonstrated metabolic neutrality, however significant lowering of glucose and uric acid levels and tendency to lowering of TC an LDLC levels was observed only in group С.</p