253 research outputs found

    Phase diagram of a solution undergoing inverse melting

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    The phase diagram of α\alpha-cyclodextrin/water/4-methylpyridine solutions, a system undergoing inverse melting, has been studied by differential scanning calorimetry, rheological methods, and X-rays diffraction. Two different fluid phases separated by a solid region have been observed in the high α\alpha-cyclodextrin concentration range (cc≥\geq150 mg/ml). Decreasing cc, the temperature interval where the solid phase exists decreases and eventually disappears, and a first order phase transition is observed between the two different fluid phases.Comment: 4 pages, 5 figures, accepted on Physical Review E (R

    chronic urticaria is usually associated with fibromyalgia syndrome

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    Although the pathophysiology of chronic urticaria is not fully understood, it is possible that dysfunctioning of peripheral cutaneous nerve fibres may be involved. It has also been suggested that fibromyalgia syndrome, a multi-symptomatic chronic pain condition, may be associated with alterations and dysfunctioning of peripheral cutaneous nerve fibres. The aim of this study was to determine whether patients with chronic urticaria are also affected by fibromyalgia syndrome. A total of 126 patients with chronic urticaria were investigated for fibromyalgia syndrome. An unexpectedly high proportion (over 70%) had fibromyalgia syndrome. The corresponding proportion for 50 control dermatological patients was 16%, which is higher than previously published data for the Italian general population (2.2%). It is possible that dysfunctional cutaneous nerve fibres of patients with fibromyalgia syndrome may release neuropeptides, which, in turn, may induce dermal microvessel dilatation and plasma extravasation. Furthermore, some neuropeptides may favour mast cell degranulation, which stimulates nerve endings, thus providing positive feedback. Chronic urticaria may thus be viewed in many patients, as a consequence of fibromyalgia syndrome. Speculatively, skin neuropathy (fibromyalgia syndrome) may trigger neurogenic skin inflammation (chronic urticaria)

    Spatial coherence of light inside three dimensional media

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    Speckle is maybe the most fundamental interference effect of light in disordered media, giving rise to fascinating physical phenomena and enabling applications in imaging, spectroscopy or cryptography, to name a few. While speckle formed outside a sample is easily measured and analysed, true bulk speckle, as formed inside random media, is difficult to investigate directly due to the obvious issue of physical access. Furthermore, its proper theoretical description poses enormous challenges. Here we report on the first direct measurements of intensity correlations of light inside a disordered medium, using embedded DNA strings decorated with emitters separated by a controlled nanometric distance. Our method provides in situ access to fundamental properties of bulk speckles as their size and polarization degrees of freedom, both of which are found to deviate significantly from theoretical predictions. The deviations are explained, by comparison with rigorous numerical calculations, in terms of correlations among polarization components and non-universal near-field contributions at the nanoscale

    Breaking the Contrast Limit in Single-Pass Fabry-PĂ©rot Spectrometers

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    The development of high-resolution Fabry-Pérot interferometers has enabled a wide range of scientific and technological advances—ranging from the characterization of material properties to the more fundamental studies of quasi particles in condensed matter. Spectral contrast is key to measuring weak signals and can reach a 103 peak-to-background ratio in a single-pass assembly.At its heart, this limit is a consequence of an unbalanced field amplitude across multiple interfering paths, with an ensuing reduced fringe visibility. Using a high-resolution, high-throughput virtually imaged phased array spectrometer, we demonstrate an intensity-equalization method to achieve an unprecedented 1000-fold increase in spectral contrast in a single-stage, single-pass configuration. To validate the system, we obtain the Brillouin spectrum of water at high scattering concentrations where, unlike with the standard scheme, the inelastic peaks are highly resolved. Our method brings the interferometer close to its ultimate limits and allows rapid high-resolution spectral analysis in a wide range of fields, including Brillouin spectroscopy, mechanical imaging, and molecular fingerprinting

    Beyond lockdown: The potential side effects of the sars-cov-2 pandemic on public health

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    Lockdowns to contain the spread of the SARS-CoV-2 have disrupted routines and behaviors, which could lead to a worsening of lifestyle and an increase in the burden of non-communicable diseases. This study aimed to describe the changes in physical activity, diet, alcohol drinking, and cigarette smoking during lockdown. A self-administered online survey addressing adults living in a province in northern Italy was advertised through websites and social media. Citizens could access the survey in anonymity from 4 May until 15 June 2020. A total of 1826 adults completed the survey, with a worsening of physical activity (35.1%), diet (17.6%), alcohol drinking (12.5%), and cigarette smoking (7.7%) reported. In contrast, 33.5% reported an improvement in diet, 12.6% in alcohol drinking, 5.3% in physical activity and 4.1% in cigarette smoking. Female sex, young adult age, suspension of work activity, and symptoms of psychological distress were the factors associated with a greater likelihood of change, which was frequently for the worse. Lockdown had an impact on lifestyle, with some net beneficial effects on diet and mostly negative effects on physical activity. Public health measures should be implemented to avoid long-term negative effects of the lockdown, supporting individuals more prone to change for the worse

    The velocity peaks in the cold dark matter spectrum on Earth

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    The cold dark matter spectrum on earth is expected to have peaks in velocity space. We obtain estimates for the sizes and locations of these peaks. To this end we have generalized the secondary infall model of galactic halo formation to include angular momentum of the dark matter particles. This new model is still spherically symmetric and it has self-similar solutions. Our results are relevant to direct dark matter search experiments.Comment: 12 pages including 1 table and 4 figures, LaTeX, REVTEX 3.0 versio

    Investigation of undercooled liquid metals using XAFS, temperature scans and ­diffraction

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    Novel techniques and the experimental station for experiments on condensed matter under extreme conditions that have been developed at the BM29 beamline of the European Synchrotron Radiation Facility (ESRF) are described. The experimental setup includes facilities to collect high-quality extended X-ray absorption fine structure (EXAFS) spectra, to perform controlled temperature scans while monitoring the sample absorption for the direct detection of phase transitions, and to collect high-resolution energy-scanning X-ray diffraction (ESXD) data, with recent enhancements through the installation of a two-channel collimator detector system. Facilities for X-ray absorption temperature scans, introduced five years ago, are now exploited for a wide variety of purposes. A method for the measurement of the nucleation rate in undercooled liquids has been proposed recently. All these advances in the experimental setup and techniques, combined with a simple but rigorous X-ray absorption fine structure (XAFS) data analysis scheme for disordered matter, have contributed to make feasible challenging experiments on undercooled liquid matter that were not even conceivable only a few years ago. An example of the application of these methods to undercooled liquid indium (In) is presented

    The mutant p53-ID4 complex controls VEGFA isoforms by recruiting lncRNA MALAT1

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    The abundant, nuclear-retained, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been associated with a poorly differentiated and aggressive phenotype of mammary carcinomas. This long non-coding RNA (lncRNA) localizes to nuclear speckles, where it interacts with a subset of splicing factors and modulates their activity. In this study, we demonstrate that oncogenic splicing factor SRSF1 bridges MALAT1 to mutant p53 and ID4 proteins in breast cancer cells. Mutant p53 and ID4 delocalize MALAT1 from nuclear speckles and favor its association with chromatin. This enables aberrant recruitment of MALAT1 on VEGFA pre-mRNA and modulation of VEGFA isoforms expression. Interestingly, VEGFA-dependent expression signatures associate with ID4 expression specifically in basal-like breast cancers carrying TP53 mutations. Our results highlight the key role for MALAT1 in control of VEGFA isoforms expression in breast cancer cells expressing gain-of-function mutant p53 and ID4 proteins

    QCD axion and quintessential axion

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    The axion solution of the strong CP problem is reviewed together with the other strong CP solutions. We also point out the quintessential axion(quintaxion) whose potential can be extremely flat due to the tiny ratio of the hidden sector quark mass and the intermediate hidden sector scale. The quintaxion candidates are supposed to be the string theory axions, the model independent or the model dependent axions.Comment: 15 pages. Talk presented at Castle Ringberg, June 9-14, 200
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