Lexical and syntactic features of academic Russian texts: a discriminant analysis

This article presents three mathematical models to differentiate academic texts from three subject discourses written in Russian (i.e., Philological, Mathematical, and Natural Sciences) which further enable design and automated profiling of corresponding typologie

DEGRADATION KINETICS OF ANTHOCYANINS IN ACIDIC AQUEOUS EXTRACTS OF BERRIES

The effect of pH, light and temperature on degradation of anthocyanins in acidic aqueous extracts of chokeberries, elderberries and blackberries was studied. The degradation of anthocyanins in berry extracts under influence of pH, light and temperature followed the first-order reaction kinetics. Anthocyanins of chokeberry extracts had the highest values of rate constants of degradation. Anthocyanins of blackberry extracts had the highest values of half-life time. The temperature dependences of the rate of anthocyanin degradation were described by the Arrhenius equation. Activation energies of anthocyanin degradation were 5.7, 10.1 and 15.0 kJ/mol at pH=2, respectively, for chokeberry, elderberry, and blackberry аnthocyanins

КІНЕТИКА ДЕСТРУКЦІЇ АНТОЦІАНІВ У КИСЛИХ ВОДНИХ ЕКСТРАКТАХ ЯГІД

The effect of pH, light and temperature on degradation of anthocyanins in acidic aqueous extracts of chokeberries, elderberries and blackberries was studied. The degradation of anthocyanins in berry extracts under influence of pH, light and temperature followed the first-order reaction kinetics. Anthocyanins of chokeberry extracts had the highest values of rate constants of degradation. Anthocyanins of blackberry extracts had the highest values of half-life time. The temperature dependences of the rate of anthocyanin degradation were described by the Arrhenius equation. Activation energies of anthocyanin degradation were 5.7, 10.1 and 15.0 kJ/mol at pH=2, respectively, for chokeberry, elderberry, and blackberry аnthocyanins.Вивчено вплив рН, світла і температури на деструкцію антоціанів у кислих водних екстрактах ягід аронії, бузини і ожини. Показано, що процес деструкції антоціанів ягід під впливом рН, світла і температури описується рівнянням кінетики першого порядку. Знайдено, що для антоціанів ягід аронії спостерігаються найвищі значення констант швидкості деструкції, а для антоціанів ягід ожини – найвищі значення часу напіврозпаду. Температурні залежності швидкості деструкції антоціанів ягід описані за допомогою рівняння Арреніуса. Розраховані енергії активації процесу деструкції антоціанів при рН=2, які дорівнюють відповідно для антоціанів аронії, бузини і ожини 5,7, 10,1 і 15,0 кДж/моль

Hereditary colorectal cancer: genetics and screening diagnostics

Aim of review. To present the data on main forms of hereditary colorectal cancer (CRC) and to discuss issues of its diagnostics, genetic testing and patient management. Summary. CRC is one of the most widespread oncologic diseases and takes the leading positions for morbidity and mortality in the pattern of neoplastic diseases in Russia. In 30% of cases disease development is associated to genetic predisposition, however only 5% of all CRC cases are linked to established hereditary syndromes, such as Lynch syndrome (hereditary non-polyposis colorectal cancer), family adenomatous polyposis, MUTYH-associated polyposis, juvenile polyposis, hereditary mixed polyposis syndrome, Peutz-Jeghers syndrome and serrated polyposis syndrome. The current review presents clinical and genetic features of two basic colorectal hereditary syndromes - Lynch syndrome and family adenomatous polyposis. Conclusion. Both clinical and molecular genetic investigations of hereditary CRC forms make possible individual comprehensive approach for diagnosis verification, evaluation of cancer risk, early diagnostics, treatment and prevention for decrease of morbidity and mortality

Improvement of amperometric transducer selectivity using nanosized phenylenediamine films

Abstract In this work, we studied the conditions of deposition of a semipermeable polyphenylenediamine (PPD)-based membrane on amperometric disk platinum electrodes. Restricting an access of interfering substances to the electrode surface, the membrane prevents their impact on the sensor operation. Two methods of membrane deposition by electropolymerization were compared—at varying potential (cyclic voltammetry) and at constant potential. The cyclic voltammetry was shown to be easier in performing and providing better properties of the membrane. The dependence of PPD membrane effectiveness on the number of cyclic voltammograms and phenylenediamine concentration was analyzed. It was shown that the impact of interfering substances (ascorbic acid, dopamine, cysteine, uric acid) on sensor operation could be completely avoided using three cyclic voltammograms in 30 mM phenylenediamine. On the other hand, when working with diluted samples, i.e., at lower concentrations of electroactive substances, it is reasonable to decrease the phenylenediamine concentration to 5 mM, which would result in a higher sensitivity of transducers to hydrogen peroxide due to a thinner PPD layer. The PPD membrane was tested during continuous operation and at 8-day storage and turned out to be efficient in sensor and biosensors

Antiproliferative 4-(1,2,4-oxadiazol-5-yl)piperidine-1-carboxamides, a new tubulin inhibitor chemotype

We discovered a new chemical class of antiproliferative agents, 4-(1,2,4-oxadiazol-5-yl)piperidine-1-carboxamides. SAR-guided optimization of the two distinct terminal fragments yielded a compound with 120 nM potency in an antiproliferative assay. Biological activity profile studies (COMPARE analysis) demonstrated that 4-(1,2,4-oxadiazol-5-yl)piperidine-1-carboxamides act as tubulin inhibitors, and this conclusion was confirmed via biochemical assays with pure tubulin and demonstration of increased numbers of mitotic cells following treatment of a leukemia cell line. © 2014 Elsevier Ltd. All rights reserved

Development of electrochemical biosensors with various types of zeolites

In the work, different types of zeolites were used for the development of enzyme-based electrochemical biosensors. Zeolites were added to the biorecognition elements of the biosensors and served as additional components of the biomembranes or adsorbents for enzymes. Three types of biosensors (conductometric, amperometric and potentiometric) were studied. The developed biosensors were compared with the similar biosensors without zeolites. The biosensors contained the following enzymes: urease, glucose oxidase, glutamate oxidase, and acetylcholinesterase and were intended for the detection of urea, glucose, glutamate, and acetylcholine, respectively. Construction of the biosensors using the adsorption of enzymes on zeolites has several advantages: simplicity, good reproducibility, quickness, absence of toxic compounds. These benefits are particularly important for the standardization and further mass production of the biosensors. Furthermore, a biosensor for the sucrose determination contained a three-enzyme system (invertase/mutatorase/glucose oxidase), immobilized by a combination of adsorption on silicalite and cross-linking via glutaraldehyde; such combined immobilization demonstrated better results as compared with adsorption or cross-linking separately. The analysis of urea and sucrose concentrations in the real samples was carried out. The results, obtained with biosensors, had high correlation with the results of traditional analytical methods, thus the developed biosensors are promising for practical applications

Antiproliferative 4-(1,2,4-oxadiazol-5-yl)piperidine-1-carboxamides, a new tubulin inhibitor chemotype

We discovered a new chemical class of antiproliferative agents, 4-(1,2,4-oxadiazol-5-yl)piperidine-1-carboxamides. SAR-guided optimization of the two distinct terminal fragments yielded a compound with 120 nM potency in an antiproliferative assay. Biological activity profile studies (COMPARE analysis) demonstrated that 4-(1,2,4-oxadiazol-5-yl)piperidine-1-carboxamides act as tubulin inhibitors, and this conclusion was confirmed via biochemical assays with pure tubulin and demonstration of increased numbers of mitotic cells following treatment of a leukemia cell line. © 2014 Elsevier Ltd. All rights reserved