The Influence of Temperature on Coumarin 153 Fluorescence Kinetics

The influence of temperature varied in the range 183 K–323 K on the fluorescence quantum yield, fluorescence lifetime, absorption and emission transition moments and non-radiative deactivation rate was determined for the well known and largely used dye Coumarin 153, dissolved in 1-chloropropane. The Kennard-Stepanov relation connecting the absorption and emission spectra was used to check for the presence of more than one absorbing/emitting species and to investigate whether intramolecular vibrational redistribution completes in the C153 excited S1 state before the emission takes place. The emission spectrum corresponding to S1→S0 transition, was fitted at each temperature to the model function including the information on the dye vibrational modes coupling. In this way the displacement in equilibrium distance for the most active vibrational mode was determined for C153 in S1 and in S0. Using the temperature dependence of the fluorescence decay time and quantum yield, the non-radiative deactivation rate was determined. Its temperature dependence was compared to that calculated using the theoretical model with the most active vibrational mode displacement values taken from steady-state spectra analysis. The somewhat surprising dependence of the fluorescence decay time and quantum yield on temperature was related to non-trivial coupling between low-frequency vibrational modes of C153 in the excited and ground states

High-performance shape-engineerable thermoelectric painting

Output power of thermoelectric generators depends on device engineering minimizing heat loss as well as inherent material properties. However, the device engineering has been largely neglected due to the limited flat or angular shape of devices. Considering that the surface of most heat sources where these planar devices are attached is curved, a considerable amount of heat loss is inevitable. To address this issue, here, we present the shape-engineerable thermoelectric painting, geometrically compatible to surfaces of any shape. We prepared Bi2Te3-based inorganic paints using the molecular Sb2Te3 chalcogenidometalate as a sintering aid for thermoelectric particles, with ZT values of 0.67 for n-type and 1.21 for p-type painted materials that compete the bulk values. Devices directly brush-painted onto curved surfaces produced the high output power of 4.0 mW cm(-2). This approach paves the way to designing materials and devices that can be easily transferred to other applications.ope

Effects of Correct and Wrong Answers on ERPs Recorded under Conditions of the Continuous Performance Test in ADHD/Normal Participants

Parameters of event-related potentials (ERPs) regarding correct and wrong answers under conditions of the continuous performance test (CPT) were measured in 50 adult subjects with the absence/presence of attention deficit/hyperactivity disorders (ADHD) and characterized by different levels of sustained attention. For ERP extraction, the average for each group of signals, which were time-locked to the onset of stimuli, was calculated; two ERP groups were considered separately for correct and wrong answers. In both groups, the P300 wave was clearly observed. The time dynamics of ERP components were investigated in six defined time blocks. At the peak of P300, a prominent component of brain activity could be observed. Some ERP morphological features (704 items) were extracted from these potentials. The results indicated that 11 of the obtained features had a significant (P<0.01) relation to the level of sustained attention. When comparing correct and wrong answers, 10 features in the normal group and 3 features in the ADHD group demonstrated significant differences (P < 0.05), which means that the participant’s response is reflected in the features of EEG signal. The results reveal a promising relation between CPT results and some parameters of brain signals, which can be used for further evaluations of the sustained attention level.Параметри пов’язаних з подією ЕЕГ-потенціалів (ППП) вимірювали у 50 дорослих тестованих з відсутністю (норма) та наявністю синдрому дефіциту уваги й гіперактивності (АDНD), котрі демонстрували різні градації рівня підтримуваної уваги. Враховували правильність і помилковість відповідей в умовах тесту безперервного виконання (continuous performance test, CPT). Щоб описати ППП, розраховували середні значення для кожної групи сигналів, «прив’язаних» до моменту пред’явлення стимулу. Було виділено дві окремі групи ППП, відповідно до вірних та помилкових відповідей. Хвиля Р300 була чітко представлена в обох групах ППП. Часова динаміка компонентів ППП була досліджена в межах шести ізольованих часових блоків. Пік Р300 віддзеркалював чітко виражений компонент церебральної активності. У складі ППП було виділено низку морфологічних особливостей (усього 704 риси). Виявилося, що 11 з таких рис вірогідно (P < 0.01) корелювали з рівнем постійної уваги. При порівнянні ППП, пов’язаних з вірними та хибними відповідями, істотні відмінності демонстрували 10 рис у групі норми та три риси в групі АDНD (P < 0.05). Це свідчить про те, що характер відповіді тестованого певним чином віддзеркалюється в патерні ЕЕГ-сигналу. Отримані дані вказують на наявність зв’язку між результатами СРТ і деякими параметрами ЕЕГ-сигналів. Це може бути використано для об’єктивної оцінки рівня підтримуваної уваги

Climate change and zoonotic infections in the Russian Arctic

Climate change in the Russian Arctic is more pronounced than in any other part of the country. Between 1955 and 2000, the annual average air temperature in the Russian North increased by 1.2&#x00B0;C. During the same period, the mean temperature of upper layer of permafrost increased by 3&#x00B0;C. Climate change in Russian Arctic increases the risks of the emergence of zoonotic infectious diseases. This review presents data on morbidity rates among people, domestic animals and wildlife in the Russian Arctic, focusing on the potential climate related emergence of such diseases as tick-borne encephalitis, tularemia, brucellosis, leptospirosis, rabies, and anthrax