1,320 research outputs found
Strong excitonâphoton coupling in a low-Q all-metal mirror microcavity
Copyright © 2002 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 81 (2002) and may be found at http://link.aip.org/link/?APPLAB/81/3519/1We report the experimental observation of strong excitonâphoton coupling in a planar microcavity composed of an organic semiconductor positioned between two metallic (silver) mirrors. Via transmission and reflectivity measurements, we observe a very large, room temperature Rabi splitting in excess of 300 meV. We show that the Rabi-splitting is enhanced in all-metal microcavities by a factor of more than 2 compared to an organic film positioned between a silver mirror and a dielectric mirror. This enhancement results from the significantly larger optical fields that are confined within all-metal microcavities
Mechanism of Vanadium Leaching during Surface Weathering of Basic Oxygen Furnace Steel Slag Blocks: A Microfocus X-ray Absorption Spectroscopy and Electron Microscopy Study
© 2017 American Chemical Society. Basic oxygen furnace (BOF) steelmaking slag is enriched in potentially toxic V which may become mobilized in high pH leachate during weathering. BOF slag was weathered under aerated and air-excluded conditions for 6 months prior to SEM/EDS and ΌXANES analysis to determine V host phases and speciation in both primary and secondary phases. Leached blocks show development of an altered region in which free lime and dicalcium silicate phases were absent and Ca-Si-H was precipitated (CaCO 3 was also present under aerated conditions). ΌXANES analyses show that V was released to solution as V(V) during dicalcium silicate dissolution and some V was incorporated into neo-formed Ca-Si-H. Higher V concentrations were observed in leachate under aerated conditions than in the air-excluded leaching experiment. Aqueous V concentrations were controlled by Ca 3 (VO 4 ) 2 solubility, which demonstrate an inverse relationship between Ca and V concentrations. Under air-excluded conditions Ca concentrations were controlled by dicalcium silicate dissolution and Ca-Si-H precipitation, leading to relatively high Ca and correspondingly low V concentrations. Formation of CaCO 3 under aerated conditions provided a sink for aqueous Ca, allowing higher V concentrations limited by kinetic dissolution rates of dicalcium silicate. Thus, V release may be slowed by the precipitation of secondary phases in the altered region, improving the prospects for slag reuse
Structure Function Scaling in the Taurus and Perseus Molecular Cloud Complexes
We compute the structure function scaling of the integrated intensity images
of two J=1-0 13CO maps of Taurus and Perseus. The scaling exponents of the
structure functions follow the velocity scaling of supersonic turbulence,
suggesting that turbulence plays an important role in the fragmentation of cold
interstellar clouds. The data also allows to verify the validity of the two
basic assumptions of the hierarchical symmetry model, originally proposed for
the derivation of the velocity structure function scaling. This shows that the
same hierarchical symmetry holds for the projected density field of cold
interstellar clouds.Comment: submitted to Ap
Mechanism of Vanadium Leaching during Surface Weathering of Basic Oxygen Furnace Steel Slag Blocks: A Microfocus X-ray Absorption Spectroscopy and Electron Microscopy Study
Basic oxygen furnace (BOF) steelmaking slag is enriched in potentially toxic V which may become mobilized in high pH leachate during weathering. BOF slag was weathered under aerated and air-excluded conditions for 6 months prior to SEM/EDS and ÎŒXANES analysis to determine V host phases and speciation in both primary and secondary phases. Leached blocks show development of an altered region in which free lime and dicalcium silicate phases were absent and CaâSiâH was precipitated (CaCOâ was also present under aerated conditions). ÎŒXANES analyses show that V was released to solution as V(V) during dicalcium silicate dissolution and some V was incorporated into neo-formed CaâSiâH. Higher V concentrations were observed in leachate under aerated conditions than in the air-excluded leaching experiment. Aqueous V concentrations were controlled by Caâ(VOâ)â solubility, which demonstrate an inverse relationship between Ca and V concentrations. Under air-excluded conditions Ca concentrations were controlled by dicalcium silicate dissolution and CaâSiâH precipitation, leading to relatively high Ca and correspondingly low V concentrations. Formation of CaCOâ under aerated conditions provided a sink for aqueous Ca, allowing higher V concentrations limited by kinetic dissolution rates of dicalcium silicate. Thus, V release may be slowed by the precipitation of secondary phases in the altered region, improving the prospects for slag reuse
Expanding the genotypic spectrum of TXNL4A variants in BurnâMcKeown syndrome
From Wiley via Jisc Publications RouterHistory: received 2021-09-06, rev-recd 2021-10-21, accepted 2021-10-23, pub-electronic 2021-11-05Article version: VoRPublication status: PublishedFunder: Biotechnology and Biological Sciences Research Council; Id: http://dx.doi.org/10.13039/501100000268; Grant(s): BB/N000358/1Funder: Health Education England Genomics Education ProgrammeFunder: Medical Research Council; Id: http://dx.doi.org/10.13039/501100007155; Grant(s): 1916606Funder: National Institute for Health Manchester Biomedical Research Centre; Grant(s): ISâBRCâ1215â20007Abstract: The developmental disorder BurnâMcKeown Syndrome (BMKS) is characterised by choanal atresia and specific craniofacial features. BMKS is caused by biallelic variants in the preâmessenger RNA splicing factor TXNL4A. Most patients have a lossâofâfunction variant in trans with a 34âbase pair (bp) deletion (type 1 Î34) in the promoter region. Here, we identified two patients with BMKS. One individual has a TXNL4A c.93_94delCC, p.His32Argfs *21 variant combined with a type 1 Î34 promoter deletion. The other has an intronic TXNL4A splice site variant (c.258â3C>G) and a type 1 Î34 promoter deletion. We show the c.258â3C>G variant and a previously reported c.258â2A>G variant, cause skipping of the final exon of TXNL4A in a minigene splicing assay. Furthermore, we identify putative transcription factor binding sites within the 56 bp of the TXNL4A promoter affected by the type 1 and type 2 Î34 and use dual luciferase assays to identify a 22 bp repeated motif essential for TXNL4A expression within this promoter region. We propose that additional variants affecting critical transcription factor binding nucleotides within the 22 bp repeated motif could be relevant to BMKS aetiology. Finally, our data emphasises the need to analyse the nonâcoding sequence in individuals where a single likely pathogenic coding variant is identified in an autosomal recessive disorder consistent with the clinical presentation
Hydration of dicalcium silicate and diffusion through neo-formed calcium-silicate-hydrates at weathered surfaces control the long-term leaching behaviour of basic oxygen furnace (BOF) steelmaking slag
Alkalinity generation and toxic trace metal (such as vanadium) leaching from basic oxygen furnace (BOF) steel slag particles must be properly understood and managed by pre-conditioning if beneficial reuse of slag is to be maximised. Water leaching under aerated conditions was investigated using fresh BOF slag at three different particle sizes (0.5â1.0, 2â5 and 10âĂâ10âĂâ20 mm blocks) and a 6-month pre-weathered block. There were several distinct leaching stages observed over time associated with different phases controlling the solution chemistry: (1) free-lime (CaO) dissolution (days 0â2); (2) dicalcium silicate (CaâSiOâ) dissolution (days 2â14) and (3) CaâSiâH and CaCOâ formation and subsequent dissolution (days 14â73). Experiments with the smallest size fraction resulted in the highest Ca, Si and V concentrations, highlighting the role of surface area in controlling initial leaching. After ~2 weeks, the solution Ca/Si ratio (0.7â0.9) evolved to equal those found within a CaâSiâH phase that replaced dicalcium silicate and free-lime phases in a 30- to 150-ÎŒm altered surface region. V release was a two-stage process; initially, V was released by dicalcium silicate dissolution, but V also isomorphically substituted for Si into the neo-formed CaâSiâH in the alteration zone. Therefore, on longer timescales, the release of V to solution was primarily controlled by considerably slower CaâSiâH dissolution rates, which decreased the rate of V release by an order of magnitude. Overall, the results indicate that the BOF slag leaching mechanism evolves from a situation initially dominated by rapid hydration and dissolution of primary dicalcium silicate/free-lime phases, to a slow diffusion limited process controlled by the solubility of secondary CaâSiâH and CaCOâ phases that replace and cover more reactive primary slag phases at particle surfaces
New hyperekplexia mutations provide insight into glycine receptor assembly, trafficking, and activation mechanisms
Background: Hyperekplexia mutations have provided much information about glycine receptor structure and function. Results: Weidentified and characterized nine new mutations. Dominant mutations resulted in spontaneous activation, whereas recessive mutations precluded surface expression. Conclusion: These data provide insight into glycine receptor activation mechanisms and surface expression determinants. Significance: The results enhance our understanding of hyperekplexia pathology and glycine receptor structure-function. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc. Published in the U.S.A
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