Palladium (II) Oxide Nanostructures as Promising Materials for Gas Sensors

One of the most important environment monitoring problems is the detection of oxidizing gases in the ambient air. Negative impact of noxious oxidizing gases (ozone and nitrogen oxides) on human health, sensitive vegetation, and ecosystems is very serious. For this reason, palladium (II) oxide nanostructures have been employed for oxidizing gas detection. Thin and ultrathin films of palladium (II) oxide were prepared by thermal oxidation at dry oxygen of previously formed pure palladium layers on polished poly-Al2O3, SiO2/Si (100), optical quality quartz, and amorphous carbon/KCl substrates. At ozone and nitrogen dioxide detection, PdO films prepared by oxidation at T = 870 K have demonstrated good values of sensitivity, signal stability, operation speed, and reproducibility of sensor response. In comparison with other materials, palladium (II) oxide thin and ultrathin films have some advantages at gas sensor fabrication. Firstly, for oxidizing gas detection, PdO films with p-type conductivity are more perspective than the material with n-type conductivity. Secondly, at ambient conditions, palladium (II) oxide is insoluble in water and does not react with it. These facts are favorable for the fabrication of gas detectors because they make possible to minimize the air humidity influence on PdO sensor response values. Thirdly, the synthesis procedure of PdO films is rather simple and is compatible with planar processes of microelectronic industry

Regulation of Mitochondrial Biogenesis as a Way for Active Longevity: Interaction Between the Nrf2 and PGC-1α Signaling Pathways

Aging is a general degenerative process related to deterioration of cell functions in the entire organism. Mitochondria, which play a key role in energy homeostasis and metabolism of reactive oxygen species (ROS), require lifetime control and constant renewal. This explains recently peaked interest in the processes of mitochondrial biogenesis and mitophagy. The principal event of mitochondrial metabolism is regulation of mitochondrial DNA (mtDNA) transcription and translation, which is a complex coordinated process that involves at least two systems of transcription factors. It is commonly believed that its major regulatory proteins are PGC-1α and PGC-1β, which act as key factors connecting several regulator cascades involved in the control of mitochondrial metabolism. In recent years, the number of publications on the essential role of Nrf2/ARE signaling in the regulation of mitochondrial biogenesis has grown exponentially. Nrf2 is induced by various xenobiotics and oxidants that oxidize some Nrf2 negative regulators. Thus, ROS, in particular H2O2, were found to be strong Nrf2 activators. At present, there are two major concepts of mitochondrial biogenesis. Some authors suggest direct involvement of Nrf2 in the regulation of this process. Others believe that Nrf2 regulates expression of the antioxidant genes, while the major and only regulator of mitochondrial biogenesis is PGC-1α. Several studies have demonstrated the existence of the regulatory loop involving both PGC-1α and Nrf2. In this review, we summarized recent data on the Nrf2 role in mitochondrial biogenesis and its interaction with PGC-1α in the context of extending longevity

Divalent cation chelators citrate and EDTA unmask an intrinsic uncoupling pathway in isolated mitochondria.

We demonstrate a suppression of ROS production and uncoupling of mitochondria by exogenous citrate in Mg2+ free medium. Exogenous citrate suppressed H2O2 emission and depolarized mitochondria. The depolarization was paralleled by the stimulation of respiration of mitochondria. The uncoupling action of citrate was independent of the presence of sodium, potassium, or chlorine ions, and it was not mediated by the changes in permeability of the inner mitochondrial membrane to solutes. The citrate transporter was not involved in the citrate effect. Inhibitory analysis data indicated that several well described mitochondria carriers and channels (ATPase, IMAC, ADP/ATP translocase, mPTP, mKATP) were not involved in citrate's effect. Exogenous MgCl2 strongly inhibited citrate-induced depolarization. The uncoupling effect of citrate was demonstrated in rat brain, mouse brain, mouse liver, and human melanoma cells mitochondria. We interpreted the data as an evidence to the existence of a hitherto undescribed putative inner mitochondrial membrane channel that is regulated by extramitochondrial Mg2+ or other divalent cations

PROGRAM-ORIENTED AND GOAL-ORIENTED APPROACH TO RESEARCH PLANNING

The article analyzes the program-oriented and goal-oriented approach used to enhance Voronezh State University's advanced world-class level research and development and faster growth of human resource capacity and the university facilities. It also reviews the processes of information technologies introduction into the main fields of the university activities. Additionally, it discusses research support mechanisms and the university target programme results

Figure 9 from: Syromyatnikov MY, Golub VB, Kokina AV, Soboleva VA, Popov VN (2017) DNA barcoding and morphological analysis for rapid identification of most economically important crop-infesting Sunn pests belonging to Eurygaster Laporte, 1833 (Hemiptera, Scutelleridae). ZooKeys 706: 51-71. https://doi.org/10.3897/zookeys.706.13888

The genus Eurygaster Laporte, 1833 includes ten species five of which inhabit the European part of Russia. The harmful species of the genus is E. integriceps. Eurygaster species identification based on the morphological traits is very difficult, while that of the species at the egg or larval stages is extremely difficult or impossible. Eurygaster integriceps, E. maura, and E. testudinaria differ only slightly between each other morphologically, E. maura and E. testudinaria being almost indiscernible. DNA barcoding based on COI sequences have shown that E. integriceps differs significantly from these closely related species, which enables its rapid and accurate identification. Based on COI nucleotide sequences, three species of Sunn pests, E. maura, E. testudinarius, E. dilaticollis, could not be differentiated from each other through DNA barcoding. The difference in the DNA sequences between the COI gene of E. integriceps and COI genes of E. maura and E. testudinarius was more than 4%. In the present study DNA barcoding of two Eurygaster species was performed for the first time on E. integriceps, the most dangerous pest in the genus, and E. dilaticollis that only inhabits natural ecosystems. The PCR-RFLP method was developed in this work for the rapid identification of E. integriceps

Succinate dehydrogenase in Arabidopsis thaliana is regulated by light via phytochrome A

AbstractThe effect of light on succinate dehydrogenase (SDH) activity and mRNA content was studied in Arabidopsis thaliana plants. The transition from darkness to light caused a short transient increase in the SDH activity followed by a decrease to a half of the original activity. The white or red light were found to be down-regulating factors for the mRNA content of the sdh1-2 and sdh2-3 genes and SDH catalytic activity both in A. thaliana wild-type plants and in the mutant deficient in the phytochrome B gene, but not in the mutant deficient in the phytochrome A gene, while the far-red light of 730nm reversed the red light effect. It is concluded that phytochrome A participates in the regulation of mitochondrial respiration through effect on SDH expression

Вычисление числа Пуазейля в кольцевой области при неизотермическом течении газа

A slow longitudinal non-isothermal gas flow in the annular region caused by small pressure and temperature drops across a long micro-channel is considered in the paper. A method for calculating the values of the Poiseuille number in the transitional gas flow regime is proposed. The method is based on the solution of the model linearised Bhatnagar-Gross-Krook (BGK) kinetic equation using Cheby- shev polynomials. The calculated values are compared with similar results obtained using analytical solutions of the Navier–Stokes equations with no-slip and slip boundary conditions. The effect of the accommodation coefficient of the tangential momentum of the gas molecules and the gas rarefaction parameter on the change in the Poiseuille number is analysed for small ratios of the temperature and pressure gradients of the gas in the channelВ статье рассматривается медленный продольный неизотермический поток газа в кольцевой области, обусловленный малыми перепадами давления и температуры на концах длинного микроканала. Предложен метод расчета значений числа Пуазейля в промежуточном режиме течения газа, основанный на решении модельного линеаризованного кинетического уравнения Бхатнагара-Гросса-Крука (БГК, BGK) с использованием полиномов Чебышева первого рода. Вычисленные значения сравниваются с аналогичными результатами, полученными с использованием аналитических решений уравнений Навье–Стокса с граничными условиями прилипания и скольжения. Анализируется влияние коэффициента аккомодации тангенциального импульса молекул и параметра разрежения газа на изменение числа Пуазейля при малых отношениях градиентов температуры и давления газа в канал

β-Guanidinopropionic Acid Stimulates Brain Mitochondria Biogenesis and Alters Cognitive Behavior in Nondiseased Mid-Age Mice

β-guanidinopropionic acid (β-GPA) has been used as a nutritional supplement for increasing physical strength and endurance with positive and predictable results. In muscles, it works as a nonadaptive stimulator of mitochondria biogenesis; it also increases lipid metabolism. There are data indicating that β-GPA can be also neuroprotective, but its mechanisms of action in the brain are less understood. We studied the effects of β-GPA on animal behavior and mitochondrial biogenesis in the cortex and midbrain of mid-age healthy mice. We found that even short-term 3-week-long β-GPA treatment increased the mitochondrial DNA (mtDNA) copy number in the cortex and ventral midbrain, as well as the expression of several key antioxidant and metabolic enzymes—indicators of mitochondria proliferation and the activation of Nrf2/ARE signaling cascade. At the same time, β-GPA downregulated the expression of the β-oxidation genes. Administration of β-GPA in mice for 3 weeks improved the animals’ physical strength and endurance health, ie, increased their physical strength and endurance and alleviated anxiety. Thus, β-GPA might be considered an adaptogene affecting both the muscle and brain metabolism in mammals

Вычисление изгиба тонкой ортотропной пластины с использованием многочленов Лежандра и Чебышева первого рода

The problem of bending of a thin orthotropic rectangular plate clamped at the edges is considered in the paper. The solution is obtained using the Legendre and Chebyshev polynomials of the first kind. The function that approximates the solution of the biharmonic equation for an orthotropic plate is presented in the form of a double series expansion in these polynomials. Matrix transformations and properties of the Legendre and Chebyshev polynomials are also used. Roots of these polynomials are used as collocation points, and boundary value problem is reduced to a system of linear algebraic equations with respect to coefficients of the expansion. The problem of bending of a plate caused by the action of a distributed transverse load of constant intensity that corresponds to hydrostatic pressure is considered. This boundary value problem has analytical solution. The results of calculations for various ratios of the lengths of sides of the plate are presented. The values of deviation of solutions constructed using Legendre and Chebyshev polynomials from the analytical solution of the problem are presented in terms of the infinite norm and the finite norm in the space of square-integrable functionsВ работе получено решение задачи об изгибе тонкой ортотропной прямоугольной пластины, защемленной по краям, с использованием многочленов Лежандра и Чебышева первого рода. Функция, аппроксимирующая решение бигармонического уравнения для ортотропной пластины, представлена в виде разложения в двойной ряд по этим многочленам в комбинации с матричными преобразованиями и свойствами многочленов Лежандра и Чебышева. С использованием корней этих многочленов в качестве точек коллокации краевая задача приведена к решению системы линейных алгебраических уравнений относительно коэффициентов в разложении искомой функции по этим многочленам. Представлены результаты вычисления изгиба пластины, обусловленного действием распределенной поперечной нагрузки постоянной интенсивности, нагрузки вида, допускающего аналитическое решение краевой задачи, и с интенсивностью, соответствующей гидростатическому давлению, для различных отношений длин сторон пластины. Полученные значения отклонений построенных решений с использованием многочленов Лежандра и Чебышева от аналитического решения задачи приведены по бесконечной норме и конечной норме в пространстве интегрируемых с квадратом функци