Driving photochemistry by clustering: The ICl-Xe case

We present slice imaging data demonstrating the influence of clustering on the photodissociation dynamics of a diatomic molecule: iodine monochloride (ICl) was dissociated at 235 nm in He and Xe seed gasses, probing both Cl and I photofragment energy and angular distributions. We observe that the kinetic energy releases of both Cl and I fragments change from He to Xe seeding. For Cl fragments, the seeding in Xe increases the kinetic energy release of some Cl fragments with a narrow kinetic energy distribution, and leads to some fragments with rather broad statistical distribution falling off exponentially from near-zero energies up to about 2.5 eV. Iodine fragment distribution changes even more dramatically from He to Xe seeding: sharp features essentially disappear and a broad distribution arises reaching to about 2.5 eV. Both these observations are rationalized by a simple qualitative cluster model assuming ICl dissociation inside larger xenon clusters and on surface of smaller Xe species. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4758317

Depressive symptoms, sleep quality, physical fitness, and fatigue among adult women with different obesity status

Purpose: The aim of this cross-sectional study was to examine the association between depressive symptoms, sleep quality, objectively assessed physical fitness, and fatigue, among a sample of adult women with different obesity status. Methods: One hundred and ninety-four volunteer adult women (36.1 ± 11.1 years) participated in the study. Based on body mass index (BMI), the participants were allocated into three groups: normal weight (n = 134), overweight (n = 32), and obese (n = 25). Physical fitness-related parameters such as aerobic fitness, flexibility, lower limb explosive strength, isometric handgrip strength, and sprint performance were assessed with a battery of field tests. Total body fat and trunk fat levels were assessed by bioelectrical impedance analysis. Depressive symptoms were assessed using the Beck depression inventory, sleep quality was assessed using the Pittsburg sleep quality index, and fatigue levels were examined using the fatigue severity scale. Results: Obese women experienced a significantly worse score regarding depressive symptoms (p < 0.05). Similarly, the obese and overweight women were found to exhibit lower levels of aerobic fitness compared to women with normal BMI (p < 0.05). All examined body composition variables were shown to be inversely associated with the score on all physical fitness tests as well as with poor sleep, depressive symptoms, and fatigue levels (p < 0.05). Conclusions: Depressive symptoms and performance on various physical fitness tests were found to be significantly impaired in obese and overweight adult women indicating the negative impact of increased body weight in health and well-being. © 2019, Springer-Verlag Italia S.r.l., part of Springer Nature

Non-Invasive Detection of Early Retinal Neuronal Degeneration by Ultrahigh Resolution Optical Coherence Tomography

Optical coherence tomography (OCT) has revolutionises the diagnosis of retinal disease based on the detection of microscopic rather than subcellular changes in retinal anatomy. However, currently the technique is limited to the detection of microscopic rather than subcellular changes in retinal anatomy. However, coherence based imaging is extremely sensitive to both changes in optical contrast and cellular events at the micrometer scale, and can generate subtle changes in the spectral content of the OCT image. Here we test the hypothesis that OCT image speckle (image texture) contains information regarding otherwise unresolvable features such as organelle changes arising in the early stages of neuronal degeneration. Using ultrahigh resolution (UHR) OCT imaging at 800 nm (spectral width 140 nm) we developed a robust method of OCT image analyses, based on spatial wavelet and texture-based parameterisation of the image speckle pattern. For the first time we show that this approach allows the non-invasive detection and quantification of early apoptotic changes in neurons within 30 min of neuronal trauma sufficient to result in apoptosis. We show a positive correlation between immunofluorescent labelling of mitochondria (a potential source of changes in cellular optical contrast) with changes in the texture of the OCT images of cultured neurons. Moreover, similar changes in optical contrast were also seen in the retinal ganglion cell- inner plexiform layer in retinal explants following optic nerve transection. The optical clarity of the explants was maintained throughout in the absence of histologically detectable change. Our data suggest that UHR OCT can be used for the non-invasive quantitative assessment of neuronal health, with a particular application to the assessment of early retinal disease