4,350 research outputs found

    Crystal structures of NiSO4·9H2O and NiSO4·8H2O: magnetic properties, stability with respect to morenosite (NiSO4·7H2O), the solid-solution series MgxNi1−x)SO4·9H2O

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    Since being discovered initially in mixed-cation systems, a method of forming end-member NiSO 4 ·9H 2 O and NiSO 4 ·8H 2 O has been found. We have obtained powder diffraction data from protonated analogues (with X-rays) and deuterated analogues (using neutrons) of these compounds over a range of temperatures, allowing us to determine their crystal structures—including all H-atoms—and to characterise the transitions on warming from 220 to 278 K; glass → 9-hydrate → 8-hydrate + ice → 7-hydrate + ice → partial melt (7-hydrate + liquid). NiSO 4 ·8D 2 O is triclinic, space-group (Formula presented.), Z = 2, with unit cell parameters at 150 K, a = 6.12463(8) Å, b = 6.8401(1) Å, c = 12.5339(2) Å, α = 92.846(1)°, β = 97.822(1)°, γ = 96.627(1)° and V = 515.58(1) Å 3 . The structure consists of two symmetry-inequivalent Ni(D 2 O) 6 octahedra on sites of (Formula presented.) symmetry. These are directly joined by a water–water H-bond to form chains of octahedra parallel with the c-axis at x = 0. Two interstitial water molecules serve both to bridge the Ni(D 2 O) 6 octahedral chains in the b–c plane and also to connect with the SO 4 2− tetrahedral oxyanion. These tetrahedra are linked by the two interstitial water molecules in a reticular motif to form sheets perpendicular to c. NiSO 4 ·9D 2 O is monoclinic, space-group P2 1 /c, Z = 4, with unit-cell parameters at 150 K, a = 6.69739(6) Å, b = 11.8628(1) Å, c = 14.5667(1) Å, β = 94.9739(8)° and V = 1152.96(1) Å 3 . The structure is isotypic with the Mg analogue described elsewhere (Fortes et al., Acta Cryst B 73:47‒64, 2017b). It shares the motif of H-bonded octahedral chains with NiSO 4 ·8D 2 O, although in the enneahydrate these run parallel with the b-axis at x = 0. Three interstitial water molecules bridge the Ni(D 2 O) 6 octahedra to the SO 4 2− tetrahedral oxyanion. The tetrahedra sit at x ≈ 0.5 and are linked by two of the three interstitial water molecules in a pentagonal motif to form ribbons parallel with b. A solid-solution series exists between Mg and Ni enneahydrate end-members where we observe preferential partitioning of Ni 2+ into the octahedral sites on the 2c Wyckoff positions rather than the 2a sites. The solution is slightly non-ideal, as indicated by the small positive excess volume of mixing. Measurements of the DC magnetisation of quenched NiSO 4 solutions reveal anomalies in the molar susceptibility on warming through the region from 221 to 225 K, probably due to devitrification of the (assumed) glassy specimen into a mixture of NiSO 4 ·9H 2 O + ice Ih. Further temperature-dependent measurements on repeated warming and cooling provide no evidence of magnetic ordering and indicate a weak ferromagnetic coupling between neighbouring Ni 2+ ions, likely via super-exchange through the H-bond between neighbouring Ni(H 2 O) 6 octahedra

    Histone deacetylase inhibitors induce medulloblastoma cell death independent of HDACs recruited in REST repression complexes

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    Background Repressor element 1‐silencing transcription factor (REST) acts as a transcriptional repressor by recruiting several chromatin modifiers, including histone deacetylase (HDAC). Elevated REST expression in medulloblastoma has been associated with tumor progression nevertheless, the tumor shows high sensitivity to HDAC inhibitors (HDACi). However, the functional implications of REST and its requirement for HDACi‐induced anti‐cancer effects are not well understood. Methods In this study, the expression of REST was evaluated across the medulloblastoma subgroups and subtypes using published gene expression data. Further, the expression of REST was modulated using the CRISPR/Cas9 knockout and shRNA knockdown in the Daoy medulloblastoma cell line. Results The results of this study showed that the expression of REST is elevated in most medulloblastoma subgroups compared to the non‐cancerous cerebellum. Blocking of REST expression resulted in increasing the expression of REST‐regulated genes, a moderate decrease in the fraction of the cells in the S‐phase, and reducing the cells' migration ability. However, REST deficiency did not lead to a marked decrease in the Daoy cell viability and sensitivity to HDACi. Conclusion The findings of this study indicate that REST is not essential for sustaining the proliferation/viability of the Daoy cells. It also revealed that the anti‐proliferative effect of HDACi is independent of REST expression

    3D visualisation tool for improving the resilience to urban and coastal flooding in Torbay, UK

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    This is the final version of the article. Available from Elsevier via the DOI in this record.Torbay, located in South West England, UK, is one of the Case Studies on the EU-funded project EU-CIRCLE, which is aimed at enhancing resilience of Critical Infrastructures (CI) to natural hazards. The region includes three urban centres (Torquay, Paignton and Brixham) and hosts more than 3 million tourists every year that contribute over £450 million to local economy. However, flooding, including coastal, fluvial and pluvial, has been a major threat to the area with more than 15 major incidents occurring since 1999. Rising sea levels, combined with increasing rainfall intensity, linked to climate change, are expected to exacerbate the problem. Better adaptation strategies are needed to safeguard CIs and services while improving resilience to climate hazards. EU-CIRCLE partners are engaged in a review of the existing capacity of flood defenses and the drainage systems in Torbay. To enhance the risk communication with the stakeholders, we adopted a high performance flood model to analyse the flood risk to Cis under a wide range of scenarios. The results are integrated into an innovative 3D visualization tool, showing the progress over time of any flood scenario in the region, via a fully interactive interface allowing stakeholders to better understand flood impacts to CIs.The work presented in this paper was partially funded by the ongoing EC H2020 EU-CIRCLE (GA 653824) and the FP7 PEARL (Preparing for Extreme And Rare events in coastaL regions, GA 603663) projects

    Nanozyme-amplified lateral flow immunoassay for molecular signature detection of cardiovascular diseases

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    Point-of-care (PoC) devices offer the opportunity to decentralize the analysis of biomarkers in biological fluids thus providing patients with more personalized medicine. The golden standard of PoC platforms are lateral flow assays since they are low cost, quick to perform and user-friendly [1]. Here we show the use of a nanozyme-mediated signal readout on a multiplexed PoC lateral flow immunoassay for the diagnosis of cardiovascular diseases. Our aim has been to expand the application of this ultrasensitive detection method towards the development of a multiplexed PoC assay for cardiovascular-related biomarkers to support triage of myocardial injury

    Spatially Resolved On-Chip Picosecond Pulse Detection Using Graphene

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    We present an on-chip time domain terahertz (TD-THz) system in which picosecond pulses are generated in low-temperature-grown gallium arsenide (LT-GaAs) and detected in graphene. The detected pulses were found to vary in amplitude, full width at half maximum (FWHM), and DC offset when sampled optically at different locations along a 50-μm-long graphene photoconductive (PC) detector. The results demonstrate the importance of detection location and switch design in graphene-based on-chip PC detectors

    Measurement of sulfur L2,3 and carbon K edge XANES in a polythiophene film using a high harmonic supercontinuum

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    We use a high harmonic generated supercontinuum in the soft X-ray region to measure X-ray absorption near edge structure (XANES) spectra in polythiophene (poly(3-hexylthiophene)) films at multiple absorption edges. A few-cycle carrier-envelope phase-stable laser pulse centered at 1800 nm was used to generate a stable soft X-ray supercontinuum, with amplitude gating limiting the generated pulse duration to a single optical half-cycle. We report a quantitative transmission measurement of the sulfur L2,3 edge over the range 160-200 eV and the carbon K edge from 280 to 330 eV. These spectra show all the features previously reported in the XANES spectra of polythiophene, but for the first time they are measured with a source that has an approximately 1 fs pulse duration. This study opens the door to measurements that can fully time-resolve the photoexcited electronic dynamics in these systems

    Case study of the cascading effects on critical infrastructure in Torbay coastal/pluvial flooding with climate change and 3D visualisation

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    This is the final version. Available on open access from IWA Publishing via the DOI in this record.Critical infrastructures (CIs) are commonly designed, built and maintained based on rigorous standards in order to withstand the climate and weather-related pressures. However, shifts in climate characteristics may result in increases of the magnitude and frequency of potential risks, or expose specific CI to new or increased risks not previously considered. As vital components of the normal functioning of modern societies, their resilience encompasses the operational elements, their structural integrity and the capacity to maximise business output under climate stressors. In this work, we apply an integrated and participatory methodological approach to assess the risk and enhance the resilience of interconnected CIs to urban flooding under climate change. The proposed methodology has been applied to an extended case study in Torbay to extend previous works (Gibson et al. 2018), which seeks to protect coastal communities from future through using the proposed methodology to justify future investment in coastal defences, as a part of the validation of EU-CIRCLE projects developed methodologies.Natural Environment Research Council (NERC)UK Royal Academy of EngineeringEuropean UnionEngineering and Physical Sciences Research Council (EPSRC

    Solar Wind and its Evolution

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    By using our previous results of magnetohydrodynamical simulations for the solar wind from open flux tubes, I discuss how the solar wind in the past is different from the current solar wind. The simulations are performed in fixed one-dimensional super-radially open magnetic flux tubes by inputing various types of fluctuations from the photosphere, which automatically determines solar wind properties in a forward manner. The three important parameters which determine physical properties of the solar wind are surface fluctuation, magnetic field strengths, and the configuration of magnetic flux tubes. Adjusting these parameters to the sun at earlier times in a qualitative sense, I infer that the quasi-steady-state component of the solar wind in the past was denser and slightly slower if the effect of the magneto-centrifugal force is not significant. I also discuss effects of magneto-centrifugal force and roles of coronal mass ejections.Comment: 6 pages, 1 figure, Earth, Planets, & Space in press (based on 5th Alfven Conference) correction of discussion on a related pape
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