598 research outputs found

    Femtosecond laser written scattering chip for high-resolution low-cost reconstructive spectrometry

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    The common challenge for reconstructive spectrometers is achieving high spectral resolution without sacrificing device stability, size and costs. Here a fully integrated scattering chip-based spectrometer build on Raspberry Pi platform is designed and implemented. It exhibits no dependence on temperature and humidity (22.7-23.8 °C and 39.5-41 %), is confined in small space (box 50x35x35 mm) and it can reconstruct spectra with resolution up to 0.05 nm (50 pm). The only instability – gravitational mechanical micromovements were compensated by applying pixel binning and device can still reconstruct spectra from binned pictures as small as 32 x 24 pixels

    The Metallicity and Dust Content of HVC 287.5+22.5+240: Evidence for a Magellanic Clouds Origin

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    We estimate the abundances of S and Fe in the high velocity cloud HVC 287.5+22.5+240, which has a velocity of +240 km/s with respect to the local standard of rest and is in the Galactic direction l~287, b~23. The measurements are based on UV absorption lines of these elements in the Hubble Space Telescope spectrum of NGC 3783, a background Seyfert galaxy, as well as new H I 21-cm interferometric data taken with the Australia Telescope. We find S/H=0.25+/-0.07 and Fe/H=0.033+/-0.006 solar, with S/Fe=7.6+/-2.2 times the solar ratio. The S/H value provides an accurate measure of the chemical enrichment level in the HVC, while the super-solar S/Fe ratio clearly indicates the presence of dust, which depletes the gas-phase abundance of Fe. The metallicity and depletion information obtained here, coupled with the velocity and the position of the HVC in the sky, strongly suggest that the HVC originated from the Magellanic Clouds. It is likely (though not necessary) that the same process(es) that generated the Magellanic Stream is also responsible for HVC 287.5+22.5+240.Comment: AASTEX, 3 postscript figures, AJ, 1998, Jan issu

    Primary Caregivers of Children Affected by Disorders of Sex Development: Mental Health and Caregiver Characteristics in the Context of Genital Ambiguity and Genitoplasty

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    Purpose. To determine the relationship between having a child with a DSD including ambiguous external genitalia, as well as the decision of whether or not to have early genitoplasty for that child, on the mental health and parenting characteristics of caregivers. Materials and Methods. Caregivers were recruited from centers that specialize in DSD medicine and completed the Beck Depression Inventory 2nd Edition (BDI-2), Beck Anxiety Index (BAI), Parent Protection Scale (PPS), Child Vulnerability Scale (CVS) and Parenting Stress Index/Short Form (PSI/SF). Results and Conclusions. Sixty-eight caregivers provided informed consent and completed the study. Among female caregivers whose children never received genitoplasty, greater parenting stress was reported (F(1, 40) = 5.08, p = .03). For male caregivers, those whose children received genitoplasty within the first year of life reported more overprotective parenting and parenting stress than those whose children received genitoplasty later than 12 months of age (F(1, 13) = 6.16, p = 0.28); F(1, 15) = 6.70, p = .021), respectively)

    An interacting spin flip model for one-dimensional proton conduction

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    A discrete asymmetric exclusion process (ASEP) is developed to model proton conduction along one-dimensional water wires. Each lattice site represents a water molecule that can be in only one of three states; protonated, left-pointing, and right-pointing. Only a right(left)-pointing water can accept a proton from its left(right). Results of asymptotic mean field analysis and Monte-Carlo simulations for the three-species, open boundary exclusion model are presented and compared. The mean field results for the steady-state proton current suggest a number of regimes analogous to the low and maximal current phases found in the single species ASEP [B. Derrida, Physics Reports, {\bf 301}, 65-83, (1998)]. We find that the mean field results are accurate (compared with lattice Monte-Carlo simulations) only in the certain regimes. Refinements and extensions including more elaborate forces and pore defects are also discussed.Comment: 13pp, 6 fig

    Human dental pulp stem cells can differentiate into Schwann cells and promote and guide neurite outgrowth in an aligned tissue-engineered collagen construct <i>in vitro</i>

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    In the present study, we evaluated the differentiation potential of human dental pulp stem cells (hDPSCs) toward Schwann cells, together with their functional capacity with regard to myelination and support of neurite outgrowth in vitro. Successful Schwann cell differentiation was confirmed at the morphological and ultrastructural level by transmission electron microscopy. Furthermore, compared to undifferentiated hDPSCs, immunocytochemistry and ELISA tests revealed increased glial marker expression and neurotrophic factor secretion of differentiated hDPSCs (d-hDPSCs), which promoted survival and neurite outgrowth in 2-dimensional dorsal root ganglia cultures. In addition, neurites were myelinated by d-hDPSCs in a 3-dimensional collagen type I hydrogel neural tissue construct. This engineered construct contained aligned columns of d-hDPSCs that supported and guided neurite outgrowth. Taken together, these findings provide the first evidence that hDPSCs are able to undergo Schwann cell differentiation and support neural outgrowth in vitro, proposing them to be good candidates for cell-based therapies as treatment for peripheral nerve injury

    Strokes of serendipity: community co-curation and engagement with digital heritage

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    This article explores the potential that community–led digital engagement with heritage holds for stimulating active citizenship through taking responsibility for shared cultural heritage and for fostering long-lasting relationships between local community heritage groups and national museums. Through the lens of a pilot project titled Science Museum: Community-in- Residence, we discovered that — despite working with community groups that were already loyal to and enjoyed existing working ties with the Science Museum in London, U.K — this undertaking proved challenging owing to a range of structural and logistical issues even before the application of digital devices and tools had been considered. These challenges notwithstanding, the pilot found that the creation of time and space for face-to-face dialogue and interactions between the Science Museum and the participating community heritage groups helped to establish the parameters within which digital co-curation can effectively occur. This, in turn, informed the development of a digital prototype with huge potential to enable remote, virtual connectivity to, and interactivity with, conversations about shared heritage. The ultimate goal was two-fold: (a) to help facilitate collaborative sense-making of our shared past, and (b) to aid the building of sustainable institutional and community/public working ties around emerging affinities, agendas and research questions in relation to public history and heritage

    The combined use of steroids and immune checkpoint inhibitors in brain metastasis patients:a systematic review and meta-analysis

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    BACKGROUND: Immune checkpoint inhibitors (ICI) have been a breakthrough for selected cancer patients, including those with brain metastases (BMs). Likewise, steroids have been an integral component of symptomatic management of BM patients. However, clinical evidence on the interaction between ICI and steroids in BM patients is conflicting and has not adequately been summarized thus far. Hence, the aim of this study was to perform a systematic literature review and meta-analysis on the association between steroid use and overall survival (OS) in BM patients receiving ICI. METHODS: A systematic literature search was performed. Pooled effect estimates were calculated using random-effects models across included studies. RESULTS: After screening 1145 abstracts, 15 observational studies were included. Fourteen studies reported sufficient data for meta-analysis, comprising 1102 BM patients of which 32.1% received steroids. In the steroid group, median OS ranged from 2.9 to 10.2 months. In the nonsteroid group, median OS ranged from 4.9 to 25.1 months. Pooled results demonstrated significantly worse OS (HR = 1.84, 95% CI 1.22-2.77) and systemic progression-free survival (PFS; HR = 2.00, 95% CI 1.37-2.91) in the steroid group. Stratified analysis showed a consistent effect across the melanoma subgroup; not in the lung cancer subgroup. No significant association was shown between steroid use and intracranial PFS (HR = 1.31, 95% CI 0.42-4.07). CONCLUSIONS: Administration of steroids was associated with significantly worse OS and PFS in BM patients receiving ICI. Further research on dose, timing, and duration of steroids is needed to elucidate the cause of this association and optimize outcomes in BM patients receiving ICI
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