Indicators of humoral regulation of the circulatory system in obese patients

Objectives to study the indicators of humoral regulation of circulatory system in obese patients as the predictors of CHF development. Materials and methods.Two groups of 40 patients were formed: the first group consisted of patients with I or II grades obesity with BMI of up to 40 kg/m2, the second group included patients with grade III obesity with BMI of over 40 kg/m2. None of the selected patients had a history of cardiovascular events. The concentration value of renin-angiotensin-aldosterone system components and level of N-terminal pro B-type natriuretic peptide (NT-pro-BNP) was determined. Results.Aldosterone level in grade III obese patients was close to normal upper border: 58.9 [54.9; 73.8] pg/ml (normal range is 1060 pg/ml), while in patients with grade III obesity it was 79.5 [64.5; 90.1], which is 25.9% higher than in patients of the first group and 24.5% higher above the normal level (p 0.05). These two groups was significantly different not only in average plasma aldosterone level, but in absolute number of patients with hyperaldosteronism, whose number accounted for 46.2% in grades I or II obese patients and 85.7% among patients with grade III obesity. Plasma renin level and angiotensin II levels in both groups was within the normal range. NT-proBNP level in the first group was 23.7 [10.6; 23.6] pg/ml, in the second group 138.0 [121.5; 145.9] pg/ml, which is 5.8 times higher (p = 0.001). In both groups of patients, the correlation analysis showed that aldosterone and NT-proBNP levels are closely related (r = 0.74, p 0.05). Conclusion.This study suggests that aldosterone level can be used as a predictor of HF

A facile synthetic route to convert Tb(III) complexes of novel tetra-1,3-diketone calix[4]resorcinarene into hydrophilic luminescent colloids

The work presents the synthesis of a novel calix[4]resorcinarene cavitand bearing four 1,3-diketone groups at the upper rim and its complex formation with Tb(iii) ions in DMF and DMSO solutions. Electrospray ionization mass spectra, 1H NMR, UV-Vis and luminescence spectra indicate a long (three hours at least) equilibration time for the complex formation between the cavitand and Tb(iii) in alkaline DMF and DMSO solutions. These results are explained by the restricted keto-enol conversion, resulting from the steric hindrance effect of the methylenedioxy-groups linking the benzene rings within the cavitand framework. A facile synthetic route to convert luminescent Tb(iii) complexes of various stoichiometries into luminescent hydrophilic colloids is disclosed in this work. The route is based on the reprecipitation of the Tb(iii) complexes from DMF to aqueous solutions with further polyelectrolyte deposition without prior separation of the luminescent complexes. The luminescent colloids exhibit high stability over time and in buffer systems, which is a prerequisite for their applicability in analysis and biolabeling. © the Partner Organisations 2014

Water transverse relaxation rates in aqueous dispersions of superparamagnetic iron oxide nanoclusters with diverse hydrophilic coating

The article introduces transverse relaxation rates of water protons in the aqueous hydrophilic colloids synthesized on the basis of the oleate-coated iron oxide nanoparticles (17. nm) with non-ionic and cationic surfactants, triblock copolymers, polyethyleneimine (PEI) and 4,5-dihydroxybenzene-1,3-disulfoacid disodium salt (Tiron) as hydrophilic components. The IR spectroscopy, atomic force and transmission electron microscopy, along with dynamic light scattering data were obtained to evaluate the content of the hydrophilic coating, the clustering of iron oxide nanoparticles within the hydrophilic covering and the aggregation of hydrophilic nanoclusters. The analysis of the obtained results together with transverse relaxation rates under various concentration, counter-ion and temperature conditions reveals the particular importance of the water molecules diffusion in the outer hydrophilic layer versus the nearest to the iron oxide core layer. The obtained results reveal the counter ion binding with the charged hydrophilic iron oxide colloids as a route to affect the water transverse relaxation rates by biorelevant anionic substrates such as adenosine triphosphates. © 2013 Elsevier B.V

НАПРЯЖЕННОСТЬ ЭЛЕКТРИЧЕСКОГО ПОЛЯ В БАРЬЕРНОМ СЛОЕ ПОРИСТОГО ОКСИДА АЛЮМИНИЯ ПРИ АНОДИРОВАНИИ

The electric field strength calculations inside porous alumina barrier layer during electrochemical anodizing in aqueous solutions of oxalic acid at a forming voltage of 90 to 250 V have been performed. The configuration of porous alumina cells with a porosity from 1 to 10 % have been used as the input data for calculations. It is found that the value of electric field strength inside porous alumina reaches 1010-1011 V/m. New phenomena and effects, appeared during alumina anodizing process with high forming voltages, have been analyzed.Представлены результаты расчета электрического поля в пористом оксиде алюминия при электрохимическом анодировании в электролитах на основе водных растворов щавелевой кислоты при напряжениях от 90 до 250 В. Для расчета использовались конфигурации ячеек пористых оксидов алюминия с пористостью от 1 до 10 %. Рассмотрены новые явления и эффекты, возникающие в процессе пористого анодирования алюминия при высоких напряжениях, когда напряженность электрического поля внутри пористого оксида алюминия достигает величин 1010-1011 В/м

JOULE HEAT CALCULATION IN POROUS ALUMINA BARRIER LAYER DURING ELECTROCHEMICAL ANODIZING PROCESS

Heat-segregation calculations inside porous alumina barrier layer have been performed. It is shown that Joule heat on pore bottom surface is four orders of magnitude greater than in other porous oxide areas. This effect leads to local heating of this areas and microplasma formations during anodizing process. The recommendations about the heat dissipation efficiency increasing in order to improve the uniformity of the structures have been advised

Porous Silicon Avalanche LEDs and their Applications in Optoelectronics and Information Displays

The use of silicon based light emitting diodes may completely solve the problem of low compatibility of optoelectronics elements and silicon chip. At present time the most suitable kinds of Si-LEDs are monocrystal and porous silicon avalanche LEDs. They have advantages such as long operation lifetime (>10000 hours), continuous spectrum, which allows to filter RGB colors, operation voltages (<12 V), extremely sharp voltage-current characteristic, nanosecond response time, and high high operation current densities (up to 8000 A/cm$\text{}^{2}$ in pulse mode). Rather low energy efficiency (<1%) is not so significant for near to eyes (NTE) microdisplays. These advantages open a way to design a high performance and cost effective passive addressed microdisplays

Fabrication of photoluminescent amorphous pillar silicon structures

Fabrication of amorphous pillar silicon structures showing visible photoluminescence (PL) by naked eye is reported. Some attempts involving silicon etching processes were previously performed by other authors, but PL from the resulting pillar structures was never observed. The pillar silicon structures were grown by Plasma Enhanced Chemical Vapour Deposition (PECVD) of hydrogenated amorphous silicon (α-Si:H) over the surface of porous aluminum oxide films, previously formed by anodization process. Alumina pore dimensions varied between 4-200 nm, depending on the parameters of the anodization process. The size of the grown α-Si:H pillars was quite homogeneous and could be tightly controlled by the anodization conditions. Immediately after PECVD process, PL from the pillar structure was very weak and not visible by naked eye, but after a short electrochemical treatment in 1% wt HF at 2 mA/cm2 it became quite bright and visible at normal daylight. A red shift, very similar to the one shown by porous silicon formed on monocrystalline substrates, was observed during samples drying after the electrochemical treatment

РАСЧЕТ ДЖОУЛЕВА ТЕПЛА ВНУТРИ БАРЬЕРНОГО СЛОЯ ПОРИСТОГО ОКСИДА АЛЮМИНИЯ ПРИ ЭЛЕКТРОХИМИЧЕСКОМ АНОДИРОВАНИИ

Heat-segregation calculations inside porous alumina barrier layer have been performed. It is shown that Joule heat on pore bottom surface is four orders of magnitude greater than in other porous oxide areas. This effect leads to local heating of this areas and microplasma formations during anodizing process. The recommendations about the heat dissipation efficiency increasing in order to improve the uniformity of the structures have been advised.Обсуждается выделение джоулева тепла в ходе процесса электрохимического анодирования алюминия в электролитах на основе водных растворов серной и щавелевой кислот. Разработаны модель, алгоритм и проведен расчет тепловой мощности, выделенной в единице объема барьерного слоя оксида алюминия с различной пористостью пленки. Установлено, что при низкой пористости исследуемых структур тепловыделение в области границы дна поры значительно превышает тепловыделение в других областях пористого оксида, что приводит к локальному разогреву этих мест и появлению микроплазменных образований во время процесса анодирования. Приведены рекомендации по увеличению эффективности теплоотвода, позволяющие улучшить равномерность формируемых пористых пленок