7,435 research outputs found

    Ultrafast spectroscopy of single molecules

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    We present a single-molecule study on femtosecond dynamics in multichromophoric systems, combining fs pump-probe, emission-spectra and fluorescence-lifetime analysis. At the single molecule level a wide range of exciton delocalisation lengths and energy redistribution times is revealed. Next, two color pump-probe experiments are presented as a step to addressing ultrafast energy transfer in individual complexes

    До побудови узагальнених граничних умов конвективного теплообміну тіл із середовищем через тонкі неплоскі покриття

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    Запропоновано підхід до побудови узагальнених граничних умов конвективного теплообміну тіл із середовищем через тонкі неплоскі покриття, який грунтується на розвиненні функції температури за товщиною покриття у ряд Тейлора. Отримано розрахункові варіанти узагальнених граничних умов з різною точністю. Також виведено формули відновлення для розподілу температури за товщиною покриття через граничні значення температури та її похідної.An approach to constructing the generalized boundary conditions of convective heat exchange of bodies with the environment via thin nonplanar coatings, which is based on the use of the expansion of a temperature function in a Taylor series in the coating thickess has been suggested. Computational variants of generalized boundary conditions with different accuracies have been obtained. Restoration formulas for the temperature distribution over the coating thickness in terms of boundary values of the temperature and its derivative have also been derived

    Free initial wave packets and the long-time behavior of the survival and nonescape probabilities

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    The behavior of both the survival S(t) and nonescape P(t) probabilities at long times for the one-dimensional free particle system is shown to be closely connected to that of the initial wave packet at small momentum. We prove that both S(t) and P(t) asymptotically exhibit the same power-law decrease at long times, when the initial wave packet in momentum representation behaves as O(1) or O(k) at small momentum. On the other hand, if the integer m becomes greater than 1, S(t) and P(t) decrease in different power-laws at long times.Comment: 4 pages, 3 figures, Title and organization changed, however the results not changed, To appear in Phys. Rev.

    Inmate emotion coping and psychological and physical well-being: The use of crying over spilled milk

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    The study investigated the relation between coping strategies of inmates and their psychological and physical well-being. General affective states such as optimism were related to both psychological and physical well-being. Moreover, inmates who experienced specific negative emotions such as regret, anxiety, and sadness reported more psychological and physical complaints. The way in which inmates coped with these negative emotions was also important. Inmates who used an active emotion-focused coping strategy were in better health than inmates inclined to keep their negative feelings to themselves. Emotion-focused coping by sharing negative emotions with people in one's social network can help to increase both psychological and physical well-being. Engaging in emotion management in a more cognitive way, by emphasizing positive aspects of the situation, can help to reduce the intensity of negative emotions. Possible research and policy implications of these results are discussed. © 2007 American Association for Correctional and Forensic Psychology

    The effect of malotilate, a derivative of malotilate and a flavenoid on eicosanoid production in inflammatory bowel disease in rats

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    Acetic acid induced colitis in rats was used to investigate the effects of malotilate, a drug which has been shown to inhibit 5-1ipoxygenase in human macrophages, the malotilate derivate ZY16268 and the flavenoid ZY16369 on the eicosanoid production and the colonic morphology in inflammatory bowel disease. Acetic acid produced an acute inflammatory response in the colon, associated with a markedly raised inflammation score (15.8 vs. < 0.5), based on a seven-scaled scoring system which includes observation of haemorrhage, submucosal oedema, cellular infiltration, goblet cell depletion, loss of architecture, crypt abscesses and serosal involvement, of which every item was subdivided as mild, moderate and severe. Incubation of colonic mucosa from rats treated with arachidonic acid and stimulated with A23187 showed an increase of the cyclooxygenase product 12-hydroxy-heptadecatrienoic acid (HHT) and the 12-1ipoxygenase product (12-HETE) and a decrease in the formation of 6-keto-prostaglandin F1α(6kPGF1α) in comparison with normal rat mucosa. Malotilate, ZY16268 and ZY16369 all resulted in a decrease in HHT, leukotriene B4 (LTB4)-like compounds and 12-hydroxyeicosaenoic acid (12-HETE) production. None of the tested compounds significantly reduced the colonic damage by acetic acid although the formation of 12-HETE was proportional to the histologically obtained inflammation score. There were marked differences in eicosanoid formation patterns between rat and human mucosa, both normal and inflamed. In view of the hyperacute nature of the mucosal damage and the marked differences in eicosanoid production, acetic acid induced colitis in rats is probably not a suitable model of ulcerative colitis in humans

    Rhetoric in the language of real estate marketing

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    “Des. Res.”, “rarely available”, “viewing essential” – these are all part of the peculiar parlance of housing advertisements which contain a heady mix of euphemism, hyperbole and superlative. Of interest is whether the selling agent’s penchant for rhetoric is spatially uniform or whether there are variations across the urban system. We are also interested in how the use of superlatives varies over the market cycle and over the selling season. For example, are estate agents more inclined to use hyperbole when the market is buoyant or when it is flat, and does it matter whether a house is marketed in the summer or winter? This paper attempts to answer these questions by applying textual analysis to a unique dataset of 49,926 records of real estate transactions in the Strathclyde conurbation over the period 1999 to 2006. The analysis opens up a new avenue of research into the use of real estate rhetoric and its interaction with agency behaviour and market dynamics

    Sequential release of cytokines, lipid mediators and nitric oxide in experimental colitis

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    The object of this study was to establish whether different pro- and anti-inflammatory mediators were formed in colonic tissue from experimental colitis depending on the course of the disease. Concentrations of mediators of inflammation were examined in colonic tissue in dextran induced colitis in mice. Initial inflammation was produced by 5 days treatment of 10% dextran sodium sulfate (DSS) in drinking water, followed by a further 9 day period of 2% DSS in an attempt to produce a milder chronic inflammation. The degree of inflammation was scored by a standardized macroscopic and histological examination. Initially, a 60% maximum inflammation score was observed at day 4. At this time inflammation was associated with the release of interleukin-lβ (IL-1β) and tumour necrosis factor-α (TNFα), whereas both prostaglandins 6kPGF1α and PGE2 and nitric oxide (NO) markedly decreased. Then a 25% inflammation score was reached which coincided with an increased production of platelet-activating factor (PAF). No significant changes were observed in leukotriene B4 and C4 formation. In conclusion, pro-inflammatory cytokines IL-1β and TNFα are considered to be primary mediators, whereas PAF, eicosanoids and NO may reflect secondary mediators in experimental colitis
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