Electron heat capacity and lattice properties of Americium

The temperature dependence of the electron heat capacity of americium is calculated using the concepts on the electronic structure and magnetic properties of this element. The Debye temperature, the thermal expansion coefficient, and the bulk modulus of americium are determined on the basis of the results of calculations and experimental data on heat capacity. © 2013 Pleiades Publishing, Ltd

Simultaneous determination of TBHQ and BHA on a MWNT-Brij® 35 modified electrode in micellar media

© 2015 The Royal Society of Chemistry. A voltammetric method for the simultaneous detection and quantification of tert-butylhydroquinone (TBHQ) and butylated hydroxyanisole (BHA) was developed using a multi-walled carbon nanotube (MWNT)-Brij® 35 modified glassy carbon electrode in Brij® 35 micellar medium. Significant improvements of TBHQ and BHA voltammetric characteristics were observed on the modified electrode. Electrochemical oxidation of TBHQ and BHA is a diffusion-controlled process that is confirmed by the linear dependence of peak currents on υ1/2 with R2 = 0.9983 and 0.9901, respectively, and involves two electrons corresponding to the formation of p-quinones. Under conditions of differential pulse voltammetry, a linear dynamic range of 1.0-1000 μmol L-1 for TBHQ and 0.50-7.50 and 10.0-750 μmol L-1 for BHA were obtained with the detection limits of 0.26 and 0.15 μmol L-1, respectively. The approach developed was successfully applied for the quantification of TBHQ and BHA in linseed oil samples with recoveries from 99% to 103% after a simple and rapid extraction with Brij® 35 micellar medium

Voltammetric determination of sterically hindered phenols in surfactant-based self-organized media

Tert-butylhydroquinone (TBHQ), butylhydroxyanisole (BHA), and butylhydroxytoluene (BHT) are irreversibly oxidized on a glassy-carbon electrode in a medium of acetonitrile-Britton-Robinson buffer solution (1: 9, pH 3.0) at 0.61, 0.79, and 1.1 V, respectively, to give quinones. Micellar media of Triton X100,Brij® 35, and sodium dodecyl sulfate affect their oxidation. The splitting and suppression of the oxidation steps for sterically hindered phenols (SHP) is observed in the presence of nonionic surfactants. Sodium dodecyl sulfate considerably enhances anodic currents and also shifts positive potentials to lower values. The conditions of the differential-pulse voltammetric determination of SHP in a 0.1 M sodium dodecyl sulfate supporting electrolyte are found. The calibration graphs are linear in the ranges 2.02-1010, 2.34-1170, and 6.15-615 μM and the detection limits (S/N = 3) are 0.23, 0.18, and 3.5 μM for TBHQ, BHA, and BHT, respectively. The possibility of determining SHP in TBHQ-BHT and BHA-BHT mixtures in wide ranges of component concentration is demonstrated. A method is developed for the extraction-voltammetric determination of BHT in vegetable oils. © 2014 Pleiades Publishing, Ltd

ОЦЕНКА ТЯЖЕСТИ БОЛЕЗНИ И ПОДБОРАДЕКВАТНОЙ ДОЗЫ БАЗИСНОЙ ТЕРАПИИМЕТОТРЕКСАТОМ У РЕБЕНКА С ЮВЕНИЛЬНЫМ ПОЛИАРТРИТОМ

The article presents a short review of the current notion of the leading role methotrexate in treatment of most clinical variants ofjuvenile idiopathic arthritis. The authors demonstrate that methotrexate is a “gold standard” of antirheumatic therapy and the key disease-modifying drug of pediatric rheumatology. The emphasis is laid on safety profile and advantages of parenteral administration thereof. The article presents follow-up of a clinical case involving use of dosage form of methotrexate in the dose of 15 mg/m per week for subcutaneous administration in a patient with polyarticular juvenile idiopathic arthritis featuring insufficient effectiveness and low tolerance of the oral drug. Prescription of methotrexate for subcutaneous administration helped to terminate progression of the disease and pain syndrome and improve function of the affected joints and the patient’s quality of life. В статье дан краткий обзор современных представлений о ведущем месте метотрексата в лечении большинства клинических вариантов ювенильного идиопатического артрита. Показано, что метотрексат ― «золотой стандарт» противоревматической терапии, ключевой болезньмодифицирующий препарат в педиатрической ревматологии. Сделан акцент на профиль его безопасности и преимущества парентерального способа введения. В статье представлено наблюдение клинического случая использования дозированной формы метотрексата в дозе 15 мг/м2 в нед для подкожного введения у пациента с полиартикулярным вариантом ювенильного идиопатического артрита с недостаточной эффективностью и плохой переносимостью перорального препарата. Назначение метотрексата для подкожного введения позволило остановить прогрессирование заболевания, купировать болевой синдром, улучшить функцию пораженных суставов и повысить качество жизни пациента.