Voltammetric determination of curcumin in spices

Curcumin is oxidized on a glassy carbon electrode in 0.1 M LiClO 4 in ethanol at the potential 0.74 V. The calibration graph is linear in the range 9.9 × 10 -6-1.07 × 10 -4 M curcumin; the detection limit is 4.1 × 10 -6 M. Curcumin is determined in model solutions. The relative standard deviation does not exceed 0.05. A procedure is proposed for the voltammetric determination of curcumin in spices. It was shown that single extraction by ethanol quantitatively recovers curcumin from spices. © 2012 Pleiades Publishing, Inc

How the unequal spacing of the spectrum of a three-level system affects the formation of a stimulated photon echo

This paper discusses the correlation of inhomogeneous broadening at various frequency transitions in three-level systems and how it affects the intensity of the stimulated-photon-echo response. It is shown that the correlation coefficient of inhomogeneous broadening at two different energy transitions and the response intensity of the stimulated photon echo depends on the random interaction parameter m of an optical electron with the local field, which in turn depends on the unequal-spacing parameter of the spectrum of the system. © 2013 Optical Society of America

Determination of Optimum Conditions for Reproducing Information in Optical Echo Processors

We consider correlations between the temporal profile of stimulated photon echo and the temporal form of the object laser pulse. We find that the information measure is a good criterion in choosing optimum conditions for reproducing information in optical echo processors. We show that the reproducibility of information in the stimulated photon-echo response in this regime depends on the object-pulse area. © 2013 Springer Science+Business Media New York

Differential Pulse Voltammetric Assay of Coffee Antioxidant Capacity with MWNT-Modified Electrode

Multi-walled carbon nanotube-modified glassy carbon electrode (GCE) has shown electrocatalytic activity toward electrochemical oxidation of hydroxycinnamic acids (chlorogenic, caffeic, p-coumaric and ferulic), i.e. decrease of the overpotential on 0.1-0.29 V and two- to threefold increase of oxidation currents in comparison with bare GCE under conditions of cyclic voltammetry. Oxidation of compounds under investigation is a diffusion-controlled process that is confirmed by linear dependence of peak currents on the v1/2 (R2 = 0.9944-0.9998) and peak potentials on the logarithm of v(R2 = 0.9805-0.9996). The differential pulse voltammetry has been applied for the hydroxycinnamic acid quantification. The calibration graphs linearity is continued in 2-5.5 order of concentrations. The approach developed has been utilized for coffee antioxidant capacity (AC) assay based on oxidation of hydroxycinnamic acids containing in coffee beans. Chlorogenic, caffeic and ferulic acids are the contributors to AC that was confirmed by standard addition method. The AC has been expressed in chlorogenic acid equivalents per 100 mL of coffee. AC of instant coffee is statistically insignificant lower than that for ground coffee (148 ± 103 and 197 ± 50 mg per 100 mL, p > 0.05). Positive correlation has been observed between chlorogenic acid equivalent AC of coffee and ferric reducing power based on coulometric titration with electrogenerated hexacyanoferrate(III) ions (r = 0.9602). © 2013 Springer Science+Business Media New York

Voltammetric evaluation of the antioxidant capacity of tea on electrodes modified with multiwalled carbon nanotubes

The characteristics of the voltammograms of tea polyphenols on a glassy carbon electrode modified with multiwalled carbon nanotubes (MCNT-GCE) were evaluated. With the use of atomic force micros copy, it was found that MCNTs are oriented as rows 0.8-1.0 μm wide with alternating hills to 586 nm in height. Polyphenols other than of tannin are reversibly oxidized at the first step. Corresponding electrode reaction schemes are proposed. A voltammetric procedure for the estimation of the antioxidant capacity (AOC) of tea based on the oxidation of its polyphenol compounds was developed. The voltammograms of tea exhibited clearly defined peaks and oxidation steps whose potentials depend on the type of tea. The area of oxidation peaks was chosen as the parameter that characterizes antioxidant properties. The AOC of tea was expressed in terms of catechin equivalents per 100 mL of a beverage. 27 tea samples were analyzed. It was found that the AOC of green tea is 79% higher than that of black tea (290 ± 40 and 54 ± 22 mg/100 mL, respectively, P 0.05). © Pleiades Publishing, Ltd., 2013

Insulin-like Growth Factor-1 and Myocardial Remodeling in Patients with Chronic Heart Failure of Ischemic Origin

Aim. To study the presence and nature of correlations between the level of Insulin-like growth factor-1 (IGF-1) and structural and functional parameters of the heart in the development of myocardial remodeling and fibrosis in patients with chronic heart failure (CHF) of ischemic origin.Material and methods. The study included 120 men with class II-IV CHF who have history of myocardial infarction, which are divided into 3 groups depending on the CHF class. The control group included 25 healthy men. Assessment of left ventricular (LV) structural-functional state was carried out by echocardiography. Investigation of IGF-1 and N-terminal precursor indices of cerebral natriuretic peptide (NT-pro BNP) was performed by enzyme immunoassay.Results. Patients with class II CHF were hyperexpression of IGF-1, with class III CHF were registered low-normal level, with class IV CHF was established a deficiency of IGF-1. The most significant structural-geometric rearrangement of LV and significant deficit of IGF-1 recorded in patients with class IV CHF (95,6±7,02 ng/ml with class IV CHF versus 178,3±11,36 ng/ml and 124,3±9,14 ng/ml with class II and III CHF; р<0,05). In patients of class III-IV CHF, correlation relationships between IGF-1 level and echocardiographic parameters (LV myocardial mass index are established: r=-0,59, p=0,05; end systolic volume index: r=-0,55, p=0,05; value of LV ejection fraction: r=0,61, p=0,05). Significant negative correlation are established in patients with class III-IV CHF between IGF-1 level and NT-pro BNP levels (r=-0,51; р=0,05).Conclusion. The intensity of myocardial remodeling and fibrosis processes in patients with a progressive course of CHF is related to deficit of IGF-1 and is associated with a high level of activity of natriuretic peptides

Cyclic voltammetry of natural flavonoids on mwnt-modified electrode and their determination in pharmaceuticals

The determination of rutin, quercetin and taxifolin in pharmaceutical dosage forms using cyclic voltammetry on multi-walled carbon nanotube modified glassy carbon electrode (MWNT-GCE) has been developed. The surface of the electrode created has been characterized by atomic force microscopy. Electrode modification with MWNT increases the surface average roughness (190-fold) and structures it. There are two oxidation steps at 0.22 and 0.80, 0.23 and 0.80, 0.26 and 0.86 V on cyclic voltammograms of taxifolin, quercetin and rutin, respectively, in phosphate buffer solution of pH 7.4. The linear dynamic range is 1.4-28 and 28-210, 2.0-220 and 0.52-210 μM with detection limits of 0.71, 1.0 and 0.26 μM for rutin, quercetin and taxifolin, respectively. The relative standard deviation of flavonoids determination in pharmaceuticals does not exceed of 7%. The data obtained are in good agreement with coulometric determination. © 2011 Institute of Organic Chemistry and Biochemistry

Aspects of using accelerated weather testing methods for polymeric materials

© Published under licence by IOP Publishing Ltd. The paper investigates the aspects of using accelerated weather testing methods for polymeric materials. The need has been identified for consistency of polymer ageing and degradation mechanisms in full-scale and laboratory conditions, as well as for equipment that most closely simulates the actual operating conditions

APPLICATION WITH A GRAPHICAL USER INTERFACE FOR SEGMENTATION OF BIOLOGICAL MICROOBJECTS USING MATLAB

In the course of the work, an application with a graphical user interface for the segmen-tation of biological microobjects using Matlab will be created, which will automate the count-ing of microorganisms when working with a microscope

Динамика выживаемости больных раком предстательной железы на популяционном уровне с учетом стадии заболевания и места проживания

Background. Prostate cancer (PCa) is rapidly gaining a leading position in the incidence of malignant tumors among men. With a general decrease in mortality from all oncological diseases, mortality from PCa in the Russian Federation is increasing: in 2005 there were 8192 deaths, in 2015 - 11987.Objective of the study. Calculation and assessment of survival rates for patients with PCa in the Samara region for the period from 2010 to 2016, taking into account the stage of the disease, the place of residence of patients, a comparative analysis of the observed, adjusted and relative 5-year survival for this disease in a number of regions of Russia and in the world.Materials and methods. The object of the study was all registered patients for the period 2010-2016, with the first established PCa.The calculation and analysis of the observed (OS), adjusted (AS) and relative (OS) survival of 7670 patients with PCa taking into account the stage of the disease and place of residence (urban residents — 6408people, rural — 1262), registered in the database of the population cancer registry of Samara Region Clinical Oncology Clinic. The start date of the study is January 1, 2010, the end date is December 31, 2019. The calculation of survival was carried out by the dynamic (actuarial) method.Results. When assessing the survival of patients with PCa, lower rates of observed survival were observed than adjusted, which indicates the presence of intercurrent causes of death.During the study period, an inverse dependence of survival on the prevalence of the tumor process was revealed. The level of observed survival and adjusted survival of all patients is associated in the survival range at stages II—III: 1-year-old observed survival — 89.1 % (adjusted survival — 92.3 %), 5-year-old observed survival — 62.6 % (adjusted survival — 76.6 %).The adjusted and relative survival rate for the urban population is higher than for the rural population, which may indicate an insufficient level of access to cancer care for patients with PCa in rural areas: the indicators of 1-year adjusted survival of urban residents are higher — 3.3 % (relative survival — 2.4 %), 5-year-old adjusted survival—7.4 % (relative survival — 10.3 %) than in patients registered in rural hospitals.Conclusion. A comparative analysis of indicators of 1- and 5-year survival of patients with PCa in the Samara region and a number of regions of the Russian Federation for 2006—2010 revealed that domestic indicators of 1-year and 5-year relative survival are slightly lower than the European average for 2000—2007. The range of indicators of the 5-year relative survivalfor 2010—2013 in the Samara region amounted to 82.2—93.1 %.Введение. Рак предстательной железы (РПЖ) стремительно захватывает лидирующие позиции в структуре заболеваемости злокачественными опухолями среди мужчин. При общем снижении смертности от всех онкологических заболеваний смертность от РПЖв России увеличивается: в 2005 г. было зарегистрировано 8192 летальных исхода, в 2015 г. — 11 987.Цель исследования — расчет и оценка показателей выживаемости больных РПЖв Самарской области за период с 2010 по 2016 г. с учетом стадии заболевания, места проживания; сравнительный анализ наблюдаемой, скорректированной и относительной 5-летней выживаемости при РПЖ в ряде регионов России и мире.Материалы и методы. В исследование включены данные всех зарегистрированных за период 2010—2016 гг. больных с впервые установленным РПЖ. Проведены расчет и анализ наблюдаемой, скорректированной и относительной выживаемости 7670 больных РПЖс учетом стадии заболевания и места жительства (городские жители — 6408 человек, сельские — 1262), зарегистрированных в базе данных популяционного ракового регистра Самарского областного клинического онкологического диспансера. Дата начала исследования — 1 января 2010 г., дата окончания — 31 декабря 2019 г. Расчет показателей выживаемости проводили динамическим (актуариальным) методом.Результаты. При оценке выживаемости больных РПЖ отмечены более низкие показатели наблюдаемой выживаемости, чем скорректированной, что свидетельствует о наличии интеркуррентных причин смерти.За исследуемый период выявлена обратная зависимость выживаемости от распространенности опухолевого процесса. Уровень наблюдаемой и скорректированной выживаемости всех пациентов ассоциирован в диапазоне выживаемости при II и III стадиях РПЖ: 1-летняя наблюдаемая и скорректированная выживаемость — 89,1 и 92,3 %, 5-летняя — 62,6 и 76,6 % соответственно.Показатели 1-летней скорректированной и относительной выживаемости у городского населения соответственно выше на 3,3 и 2,4 %, 5-летней — на 7,4 и 10,3 %, чем у пациентов, состоящих на учете в сельских лечебно-профилактических учреждениях. Это может свидетельствовать о недостаточном уровне доступности онкологической помощи больным РПЖ на территории сельской местности.Заключение. Сравнительный анализ 1- и 5-летней выживаемости больных РПЖ в Самарской области и ряде регионов России за 20062010 гг. выявил, что показатели 1- и 5-летней относительной выживаемости несколько ниже, чем в среднем по Европе за 2000—2007гг. Диапазон показателей 5-летней относительной выживаемости за 2010—2013 гг. в Самарской области составил 82,2—93,1 %