ИСПОЛЬЗОВАНИЕ КРЕМНИЙ-ТИТАНОВЫХ КСЕРОГЕЛЕЙ ДЛЯ ТВЕРДОФАЗНО-СПЕКТРОФОТОМЕТРИЧЕСКОГО ОПРЕДЕЛЕНИЯ ФТОРИД-ИОНОВ В ИСКУССТВЕННОЙ СЛЮНЕ

Silica-titania xerogels modified with the pyrocatechol violet have been proposed as new sensor materials for fluoride determination in the artificial saliva. The determination is based on the ability of fluoride ions to disrupt the colored titanium(IV)-pyrocatechol violet complexes. The complex reactions of matrix embedded titanium(IV) with pyrocatechol violet (resulting in blue colored xerogels) and with fluoride ions (resulting in bleaching of colored xerogels) have been investigated. The selected conditions have been used for developing the procedures of fluoride determination in the artificial saliva and water. Varying the volume of the analyzed solution two analytical ranges (0.05-1 ppm (LOD 2 ppm) and 5-100 ppm (LOD 0.02 ppm)) have been obtained. The procedures’ accuracy has been evaluated using the spiked probes of the artificial saliva achieving the RSD of 5-23%. The developed sensor materials can be used for studying the efficiency of various fluor-containing products for medical diagnostics, scientific research, and also for the construction of new dental materials.Keywords: silica-titania xerogels, solid phase spectrophotometry, fluoride ions, artificial saliva.(Russian)DOI: http://dx.doi.org/10.15826/analitika.2015.19.4.001 M.A. Morosanova, Z.V. Samodelov and E.I. Morosanova Lomonosov Moscow State University, Moscow, Russian FederationДля твердофазно-спектрофотометрического определения фторид-ионов в искусственной слюне были предложены и использованы новые индикаторные материалы – модифицированные пирокатехиновым фиолетовым кремний-титановые ксерогели. Определение основано на разрушении окрашенных комплексов иммобилизованного титана(IV) с пирокатехиновым фиолетовым фторид-ионами. Выбраны условия комплексообразования титана(IV), включенного в матрицу кремний-титановых ксерогелей, с пирокатехиновым фиолетовым и условия разрушения иммобилизованных окрашенных соединений в присутствии фторид-ионов. Разработаны методики твердофазно-спектрофотометрического определения фторид-ионов в искусственной слюне: в зависимости от объема анализируемого раствора диапазоны определяемых содержаний составляют  0.05-1 (предел обнаружения 0.02 мг/л) и 5-100 мг/л (предел обнаружения 2 мг/л).  Правильность методик проверена методом "введено-найдено", относительное стандартное отклонение – 0.05-0.23. Время анализа 10 минут. Ключевые слова: фторид-ионы, определение, искусственная слюна, твердофазная спектрофотометрия, кремний-титановые ксерогели.DOI: http://dx.doi.org/10.15826/analitika.2015.19.4.001

Cognitive and regulatory characteristics and mathematical performance in high school students.

The study examined the links of cognitive and regulatory characteristics with mathematical outcomes in high school students. Participants were 318 14-16 year old students from 7 state schools in Russia. A computerized test battery was used to measure aspects of number sense, spatial ability, spatial memory and processing speed. The battery also included two measures of mathematical performance. Academic grades and final school test scores in mathematics were also collected. In addition, the students completed the Self-Regulation Profile of Learning Activity Questionnaire – SRPLAQ, which measures different aspects of self-regulation related to achieving learning goals, such as goal planning, results evaluation, and responsibility. The results suggest that cognitive and regulatory features are independently associated with mathematical performance, and that the links differ depending on the specific aspect of mathematical performance used

The use of silica-titania xerogels for the solid phase spectrophotometric determination of fluoride ions in the artificial saliva

Для твердофазно-спектрофотометрического определения фторид-ионов в искусственной слюне были предложены и использованы новые индикаторные материалы - модифицированные пирокатехиновым фиолетовым кремний-титановые ксерогели. Определение основано на разрушении окрашенных комплексов иммобилизованного титана(IV) с пирокатехиновым фиолетовым фторид-ионами. Выбраны условия комплексообразования титана(IV), включенного в матрицу кремний-титановых ксерогелей, с пирокатехиновым фиолетовым и условия разрушения иммобилизованных окрашенных соединений в присутствии фторид-ионов. Разработаны методики твердофазно-спектрофотометрического определения фторид-ионов в искусственной слюне: в зависимости от объема анализируемого раствора диапазоны определяемых содержаний составляют 0.05-1 (предел обнаружения 0.02 мг/л) и 5-100 мг/л (предел обнаружения 2 мг/л). Правильность методик проверена методом "введено-найдено", относительное стандартное отклонение - 0.05-0.23. Время анализа 10 минут.Silica-titania xerogels modified with the pyrocatechol violet have been proposed as new sensor materials for fluoride determination in the artificial saliva. The determination is based on the ability of fluoride ions to disrupt the colored titanium(IV)-pyrocatechol violet complexes. The complex reactions of matrix embedded titanium(IV) with pyrocatechol violet (resulting in blue colored xerogels) and with fluoride ions (resulting in bleaching of colored xerogels) have been investigated. The selected conditions have been used for developing the procedures of fluoride determination in the artificial saliva and water. Varying the volume of the analyzed solution two analytical ranges (0.05-1 ppm (LOD 2 ppm) and 5-100 ppm (LOD 0.02 ppm)) have been obtained. The procedures’ accuracy has been evaluated using the spiked probes of the artificial saliva achieving the RSD of 5-23%. The developed sensor materials can be used for studying the efficiency of various fluor-containing products for medical diagnostics, scientific research, and also for the construction of new dental materials

CONSCIOUS SELF-REGULATION: THE EVOLUTION OF SCIENTIFIC APPROACHES

Modern trends in the development of scientific ideas in the field of psychology of self-regulation are considered. It is emphasized that the study of human self-regulation is one of the fundamental problems of modern psychology. The study of integrative processes and phenomena of the psyche, which ensure the self-organization of human activity, the integrity and formation of his individuality and being, is one of the main tasks of the psychology of self-regulation. The relevance of studying the conscious self-regulation of a person as the most important resource for achieving goals and self-development of a person is substantiated.Рассматриваются современные тренды развития научных представлений в области психологии саморегуляции. Подчеркивается, что исследования саморегуляции человека относится к числу фундаментальных проблем современной психологии. Исследование интегративных процессов и явлений психики, обеспечивающих самоорганизацию активности человека, целостность и становление его индивидуальности и бытия относится к числу основных задач психологии саморегуляции. Обосновывается востребованность изучения осознанной саморегуляции человека, как важнейшего ресурса достижения целей и саморазвития человека

Silica and Silica–Titania Xerogels Doped with Iron(III) for Total Antioxidant Capacity Determination

In order to design a sensor material for total antioxidant capacity determination we have prepared silica and silica–titania xerogels doped with iron(III) and modified with 1,10-phenanthroline. Titanium(IV) tetraethoxyde content in the precursors (titanium(IV) tetraethoxyde and tetraethyl orthosilicate) mixtures has been varied from 0 to 12.5% vol. Iron(III) concentrations in sol has been varied from 1 to 100 mM. The increase of titanium(IV) content has led to a decrease in BET surface area and average pore diameter and an increase of micropore surface area and volume, which has resulted in better iron(III) retention in the xerogels. Iron(III), immobilized in the xerogel matrix, retains its ability to form complexes with 1,10-phenanthroline and to be reduced to iron(II). Static capacities for 1,10-phenanthroline have been determined for all the iron(III) doped xerogels (0.207 mmol/g–0.239 mmol/g) and they are not dependent on the iron(III) content. Sensor materials—xerogels doped with iron(III) and modified with 1,10-phenanthroline—have been used for antioxidants (catechol, gallic and ascorbic acids, and sulphite) solid phase spectrophotometric determination. Limits of detection for catechol, gallic and ascorbic acids, and sulphite equal 7.8 × 10−6 M, 5.4 × 10−6 M, 1.2 × 10−5 M, and 3.1 × 10−4 M, respectively. The increase of titanium(IV) content in sensor material has led to an increase of the reaction rate and the sensitivity of determination. Proposed sensor materials have been applied for total antioxidant capacity (in gallic acid equivalents) determination in soft beverages, have demonstrated high stability, and can be stored up to 6 months at room temperature

Determination of Food Oxalates Using Silica–Titania Xerogel Modified with Eriochrome Cyanine R

The interaction of silica–titania xerogel with triphenylmethane dyes (pyrocatechol violet, chrome azurol S, eriochrome cyanine R) has been investigated to create a new sensor material for solid phase spectrophotometric determination of food oxalates. The complex forming reaction between xerogel incorporated titanium(IV) and triphenylmethane dyes has been studied; half-reaction periods, complex composition, equilibrium constants, and xerogel sorption capacity have been calculated for each dye. Eriochrome cyanine R (ECR) is characterized by the shortest half-reaction period, the smallest equilibrium constant, and the greatest capacity; it has been chosen for the sensor material construction because titanium(IV)-ECR complex is formed faster and can be destroyed easier than other studied complexes. The interaction of this sensor material with oxalates has been described: the presence of oxalates causes sensor material discoloration and the absorbance is used as analytical signal. The analytical range is 35–900 mg/L (LOD 10.5 mg/L, n = 7). High concentrations of interfering inorganic anions, organic acids, and sucrose did not affect oxalate determination. Proposed solid phase spectrophotometric procedure has been successfully applied for the determination of oxalates in food samples (sorrel, spinach, parsley, ginger, and black pepper) and the results are in good agreement with HPLC oxalate determination

A study on regulatory bases of psychological students' success at examinations

The article discusses the aspects of psychological students' success at examinations. The author analyses traits of character that are necessary for passing final examinations

Interrelation between consious self-regulation development and sociability of school teachers

The study is devoted to investigation of conscious self-regulation role in pedagogical interaction. Specific connections of regulation processes with sociability components of school teachers are described. It was discovered that development of conscious self-regulation system facilitates communication difficulties negotiation in teacher-student interaction

Осознанная саморегуляция и школьная вовлеченность как ресурсы экзаменационной успешности: лонгитюдное исследование

Introduction. The current direction of modern research in the field of psychology of education is the study of psychological resources that can be considered as long-term predictors of learning success. Self-regulation and school engagement are traditionally considered as such resources. The study objectives included exploring the relationship of these resources among schoolchildren during their studies in the secondary school and clarifying whether the development of conscious self-regulation can predict examination success. Students participated in a 3-year longitudinal study during their schooling since 7th to 9th grade, a total of 81 participants (52 % – boys). Methods. “Self-regulation Profile of Learning Activity Questionnaire” by V. I. Morosanova (SRPLAQ-M); “Multidimensional Scale of School Engagement” adapted to the Russian sample (T. G. Fomina, V. I. Morosanova). The study collected data on the students’ performance (an average of annual grades in the main academic subjects) and results of their major state exams in the 9th grade. Results. Statistical data analysis included the calculation of descriptive statistics, correlation analysis, and structural modeling. On its basis, a structural model was built, its correspondence to empirical data was assessed using the following agreement indices. The model demonstrates the specifics of longitudinal relationships between school engagement, conscious self-regulation, and the final exams results in the secondary school. It shows that the level of conscious self-regulation development, as measured in 7th grade students, is actually a long-term predictor of their academic performance and results of the major state exam in the 9th grade. School engagement turned out to be a less significant factor in the success of passing exams, and its influence is mediated by the level of conscious self-regulation development. Discussion. For the first time, the longitudinal study has revealed the specificity of relationship between conscious self-regulation and school engagement at different stages of education in the secondary school. The stated fact of the existence of long-term prognostic effects of the conscious self-regulation development on examination results is of undoubted scientific significance.Введение. Актуальным направлением современных исследований в области психологии образования является изучение психологических ресурсов, рассматриваемых в качестве долгосрочных предикторов успешности обучения. В качестве ресурсов рассматриваются осознанная саморегуляция достижения учебных целей и школьная вовлеченность обучающихся. Задачи исследования включали изучение взаимосвязи ресурсов у школьников в период их обучения в средней школе, а также поиск ответа на вопрос, является ли развитие осознанной саморегуляции долгосрочным предиктором экзаменационной успешности, что отражает новизну исследования. Обучающиеся приняли участие в 3-летнем лонгитюдном исследовании в период обучения с 7-го по 9-й класс, общее количество – 81 человек (52 % – мальчики). Методы. Опросник В. И. Моросановой «Стиль саморегуляции учебной деятельности (ССУД-М)»; адаптированный на российской выборке опросник «Многомерная шкала школьной вовлеченности» (Т. Г. Фомина, В. И. Моросанова). В исследовании были собраны данные об успеваемости учащихся (среднее значение годовых отметок по основным учебным предметам) и результаты итоговых экзаменов в 9-м классе (ОГЭ). Результаты. Статистический анализ позволил предложить модель, описывающую характер взаимосвязи исследуемых характеристик. Модель дает представление об особенностях лонгитюдных взаимосвязей школьной вовлеченности, осознанной саморегуляции и результатов итоговых экзаменов в основной школе. Она демонстрирует, что уровень развития осознанной саморегуляции, измеренный у обучающихся в 7-м классе, является долгосрочным предиктором академической успеваемости и результатов основного государственного экзамена в 9-м классе. Школьная вовлеченность оказалась менее значимым фактором успешности сдачи экзамена, ее влияние опосредовано уровнем развития осознанной саморегуляции. Обсуждение результатов. Впервые в лонгитюдном исследовании выявлена специфика взаимосвязи осознанной саморегуляции со школьной вовлеченностью на разных этапах обучения в средней школе. Научную значимость имеет факт существования отдаленных прогностических эффектов влияния развития осознанной саморегуляции на экзаменационные результаты в средней школе