Delay and distortion of slow light pulses by excitons in ZnO

Light pulses propagating through ZnO undergo distortions caused by both bound and free excitons. Numerous lines of bound excitons dissect the pulse and induce slowing of light around them, to the extend dependent on their nature. Exciton-polariton resonances determine the overall pulse delay and attenuation. The delay time of the higher-energy edge of a strongly curved light stripe approaches 1.6 ns at 3.374 eV with a 0.3 mm propagation length. Modelling the data of cw and time-of-flight spectroscopies has enabled us to determine the excitonic parameters, inherent for bulk ZnO. We reveal the restrictions on these parameters induced by the light attenuation, as well as a discrepancy between the parameters characterizing the surface and internal regions of the crystal.Comment: 4 pages, 4 figure

Mie-resonances, infrared emission and band gap of InN

Mie resonances due to scattering/absorption of light in InN containing clusters of metallic In may have been erroneously interpreted as the infrared band gap absorption in tens of papers. Here we show by direct thermally detected optical absorption measurements that the true band gap of InN is markedly wider than currently accepted 0.7 eV. Micro-cathodoluminescence studies complemented by imaging of metallic In have shown that bright infrared emission at 0.7-0.8 eV arises from In aggregates, and is likely associated with surface states at the metal/InN interfaces.Comment: 4 pages, 5 figures, submitted to PR

INTRAPLEURAL IMMUNOTHERAPY FOR METASTATIC PLEURISIES IN PATIENTS WITH BREAST CANCER

Intrapleural immunotherapy for metastatic pleurisies demonstrates a high efficiency in the treatment of patients with breast cancer (BC). This immunotherapy modality is regarded as one of the stages of complex treatment in patients with disseminated BC and allows its capabilities to be extended for their further management

Metal Hydrides Form Halogen Bonds: Measurement of Energetics of Binding

The formation of halogen bonds from iodopentafluorobenzene and 1-iodoperfluorohexane to a series of bis(η5-cyclopentadienyl)metal hydrides (Cp2TaH3, 1; Cp2MH2, M = Mo, 2, M = W, 3; Cp2ReH, 4; Cp2Ta(H)CO, 5; Cp = η5-cyclopentadienyl) is demonstrated by 1H NMR spectroscopy. Interaction enthalpies and entropies for complex 1 with C6F5I and C6F13I are reported (ΔH° = −10.9 ± 0.4 and −11.8 ± 0.3 kJ/mol; ΔS° = −38 ± 2 and −34 ± 2 J/(mol·K), respectively) and found to be stronger than those for 1 with the hydrogen-bond donor indole (ΔH° = −7.3 ± 0.1 kJ/mol, ΔS° = −24 ± 1 J/(mol·K)). For the more reactive complexes 2–5, measurements are limited to determination of their low-temperature (212 K) association constants with C6F5I as 2.9 ± 0.2, 2.5 ± 0.1, <1.5, and 12.5 ± 0.3 M–1, respectively

Object search by manipulation

We investigate the problem of a robot searching for an object. This requires reasoning about both perception and manipulation: some objects are moved because the target may be hidden behind them, while others are moved because they block the manipulator’s access to other objects. We contribute a formulation of the object search by manipulation problem using visibility and accessibility relations between objects. We also propose a greedy algorithm and show that it is optimal under certain conditions. We propose a second algorithm which takes advantage of the structure of the visibility and accessibility relations between objects to quickly generate plans. Our empirical evaluation strongly suggests that our algorithm is optimal under all conditions. We support this claim with a partial proof. Finally, we demonstrate an implementation of both algorithms on a real robot using a real object detection system

Время реакции в ответ на эмоциональные стимулы (включая фотопортреты с различной мимикой) в ходе фМРТ-исследования лиц с легкой и умеренной депрессией, дистимией

Objective. Estimation of the response time and accuracy of emotional stimuli during the fMRI task fulfillment in participants suffering from mild to moderate depressive disorder or from dysthymic disorder.Materials and methods. 21 subjects with mild to moderate depressive disorder or dysthymic disorder (D) participated, and 21 healthy volunteers (H) matched by age and sex ratio were included in the control group.  In two fMRI paradigms subjects were observing photos of the faces with different emotional expressions. The first task was to guess the gender of the people on the screen, and the second one was to recognize the emotion experienced by the person in the photo. In the third paradigm participants were sorting different images into pleasant and unpleasant. The subjects responded by pressing one of two buttons. The response time and accuracy were the subjects of analysis.Results. On the most of the computed parameters patients with depressive disorder did not differ from controls. However, in the first paradigm these subjects demonstrated slower reaction to neutral (H = (1415 ± 408) ms,  D = (1 878 ± 850) ms; t = 2.25; p &lt; 0,05) and disgusted (H = (1 183 ± 310) ms, D = (1 526 ± 646) ms; t = 2.20; p &lt; 0.05) expressions, and greater standard deviations of the response time to disgusted (H = (219 ± 125) ms,  D = (675 ± 645) ms; t = 3.18; p &lt; 0,01), happy (H = (445 ± 310) ms, D = (836 ± 579) ms; t = 2.73;  p &lt; 0.05), surprised (H = (580 ± 438) ms, D = (1 043 ± 785) ms; t = 2.36; p &lt; 0,05), and neutral  (H = (487 ± 416) ms, D = (895 ± 727) ms; t = 2.23; p &lt; 0.05) faces. On the second stage group of participants with depressive disorder had greater standard deviation of the response time to disgusted portraits (H = (1 506 ± 1 273) ms, D = (2 168 ± 1 355) ms; U =131; p &lt; 0.05). Moreover, subjects diagnosed with a depressive disorder less often chose the answer “happy” (H = (6,8 ± 1,1) ms, D = (6.0 ± 0.8) ms; U = 131; p &lt; 0.05) while guessing the emotion in the photo.Conclusion. Participants diagnosed with mild to moderate depressive disorder or dysthymic disorder perform significantly slower than healthy ones during the “background” processing of the facial expressions and also tend to identify mimic as happy less often than controls while aiming to recognize the feelings of others. However, the role of these features in the progress of depressive disorders and their perspectives as diagnostic markers are subjects for further research.Цель исследования – оценить время и содержание реакций на эмоциональные стимулы в процессе фМРТ-исследования у лиц с легким или умеренным депрессивным эпизодом или дистимией.Материалы и методы. В исследовании приняли участие группа (21 человек) с диагностированным легким или умеренным депрессивным эпизодом или дистимией (Д) и контрольная группа (21 волонтер) (З), идентичных по полу и возрасту. В двух задачах испытуемые, находясь внутри магнитно-резонансного томографа, воспринимали изображения лиц с различной эмоциональной мимикой. В первой пробе от участников требовалось определить пол людей на портретах, во второй – переживаемые ими эмоции. В третьей задаче предъявлялись изображения, которые нужно было разделить на нравящиеся и не нравящиеся. Ответ давался нажатием одной из двух кнопок. Оценивались время реакции и содержание ответов.Результаты. По большинству рассчитанных параметров лица с депрессивным эпизодом не отличались от условно здоровых людей. Тем не менее в первой задаче эти испытуемые характеризовались более медленной реакцией на лица с нейтральной мимикой (З = (1 415 ± 408) мс, Д = (1 878 ± 850) мс; t = 2,25; p &lt; 0,05) и выражением отвращения (З = (1 183 ± 310) мс, Д = (1 526 ± 646) мс; t = 2,20; p &lt; 0,05) и большим стандартным отклонением времени реакции на черты отвращения (З = (219 ± 125) мс, Д = (675 ± 645) мс; t = 3,18; p &lt; 0,01), радости (З = (445 ± 310) мс, Д = (836 ± 579) мс; t = 2,73; p &lt; 0,05), удивления (З = (580 ± 438) мс, Д = (1 043 ± 785) мс; t = 2,36; p &lt; 0,05), а также на нейтральные портреты (З = (487 ± 416) мс, Д = (895 ± 727) мс; t = 2,23; p &lt; 0,05). Во второй задаче в группе лиц с депрессивным эпизодом большим было стандартное отклонение времени реакции для лиц с брезгливой мимикой (З = (1 506 ± 1 273) мс, Д = (2 168 ± 1 355) мс; U = 131; p &lt; 0,05). Кроме того, эти участники несколько реже выбирали ответ «радость» для характеристики мимики лиц (З = (6,8 ± 1,1) мс, Д = (6,0 ± 0,8) мс; U = 131; p &lt; 0,05).Заключение. Показаны достоверное замедление реакций лиц с легким и умеренным депрессивным эпизодом в контексте «фоновой» обработки эмоциональной экспрессии и их тенденция реже определять мимику как радостную при целенаправленном распознавании чувств других людей. Однако изучение роли этих особенностей в развитии депрессивных расстройств и как диагностических маркеров требует дальнейших исследований