3,068 research outputs found

    Redox regulation of type-I inositol trisphosphate receptors in intact mammalian cells.

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    A sensitization of inositol 1,4,5-trisphosphate receptor (IP3R)-mediated Ca2+ release is associated with oxidative stress in multiple cell types. These effects are thought to be mediated by alterations in the redox state of critical thiols in the IP3R, but this has not been directly demonstrated in intact cells. Here, we utilized a combination of gel-shift assays with MPEG-maleimides and LC-MS/MS to monitor the redox state of recombinant IP3R1 expressed in HEK293 cells. We found that under basal conditions, ∼5 of the 60 cysteines are oxidized in IP3R1. Cell treatment with 50 μm thimerosal altered gel shifts, indicating oxidation of ∼20 cysteines. By contrast, the shifts induced by 0.5 mm H2O2 or other oxidants were much smaller. Monitoring of biotin-maleimide attachment to IP3R1 by LC-MS/MS with 71% coverage of the receptor sequence revealed modification of two cytosolic (Cys-292 and Cys-1415) and two intraluminal cysteines (Cys-2496 and Cys-2533) under basal conditions. The thimerosal treatment modified an additional eleven cysteines, but only three (Cys-206, Cys-767, and Cys-1459) were consistently oxidized in multiple experiments. H2O2 also oxidized Cys-206 and additionally oxidized two residues not modified by thimerosal (Cys-214 and Cys-1397). Potentiation of IP3R channel function by oxidants was measured with cysteine variants transfected into a HEK293 IP3R triple-knockout cell line, indicating that the functionally relevant redox-sensitive cysteines are predominantly clustered within the N-terminal suppressor domain of IP3R. To our knowledge, this study is the first that has used proteomic methods to assess the redox state of individual thiols in IP3R in intact cells. © 2018 Joseph et al

    Effects of solute concentrations on kinetic pathways in Ni-Al-Cr alloys

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    The kinetic pathways resulting from the formation of coherent L12-ordered y'-precipitates in the g-matrix (f.c.c.) of Ni-7.5 Al-8.5 Cr at.% and Ni-5.2 Al-14.2 Cr at.% alloys, aged at 873 K, are investigated by atom-probe tomography (APT) over a range of aging times from 1/6 to 1024 hours; these alloys have approximately the same volume fraction of the y'-precipitate phase. Quantification of the phase decomposition within the framework of classical nucleation theory reveals that the y-matrix solid-solution solute supersaturations of both alloys provide the chemical driving force, which acts as the primary determinant of the nucleation behavior. In the coarsening regime, the temporal evolution of the y'-precipitate average radii and the y-matrix supersaturations follow the predictions of classical coarsening models, while the temporal evolution of the y'-precipitate number densities of both alloys do not. APT results are compared to equilibrium calculations of the pertinent solvus lines determined by employing both Thermo-Calc and Grand-Canonical Monte Carlo simulation.Comment: Submitted to Acta Materialia, June, 200

    Supporting Child and Family Wellbeing through Nature during the Pandemic

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    The global pandemic of COVID-19 poses many unprecedented challenges on our way of life. Since the introduction of social distancing measures as one of our biggest weapons in slowing the spread of disease and mitigating the effects on the health services, other challenges have been introduced. One of these is the challenge of supporting and maintaining wellbeing in children and families. A way to achieve this is through maintaining our contact and connection with the non-human natural world. Regular contact with the natural world has been found to have benefits for our mental and physical health. The aim of this paper is to identify how families can gain the benefits of nature engagement, in the instances where the access might be limited or non-existent  Whilst we are able to identify a number of opportunities and mechanisms for nature contact and connection to promoting family wellbeing there are some methodological challenges remaining, given that a significant number of research papers exploring the affective influence of nature contact and connection focuses on adults. We also identify a number of areas where research would be beneficial to better understand the mediating influences on wellbeing from nature contact and connection

    2-De­oxy-2,3-O-isopropyl­idene-2,4-di-C-methyl-β-l-arabinose

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    X-ray crystallography unequivocally confirmed the stereochemistry of the C atom at position 2 in the carbon scaffold of the title mol­ecule, C10H18O4. The pyran­ose ring exists in a chair conformation with the methyl group on the C atom in the 2 position in an equatorial configuration. The absolute stereochemistry was determined from the starting material. The crystal structure consists of O—H⋯O hydrogen-bonded chains of mol­ecules running parallel to the b axis

    2,3-O-(S)-Benzyl­idene-2-C-methyl-d-ribono-1,4-lactone

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    The crystal structure of the title compound, C13H14O5, establishes (i) the (S) – rather than (R) – configuration at the acetal carbon and (ii) that both the acetal and the lactone form five- rather than six-membered rings; the absolute configuration is determined by the use of 2-C-methyl-d-ribono-1,4-lactone as the starting material. The compound consists of hydrogen-bonded chains of mol­ecules running along the a axis; there are no unusual packing features. Only classical hydrogen bonding has been considered

    tert-Butyl 2-de­oxy-4,5-O-isopropyl­idene-d-gluconate

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    The relative configuration of tert-butyl 2-de­oxy-4,5-O-iso­propyl­idene-d-gluconate, C13H24O6, an inter­mediate in the synthesis of 2-de­oxy sugars, was determined by X-ray crystallography, and the crystal structure consists of chains of O—H⋯O hydrogen-bonded mol­ecules running parallel to the a axis. There are two mol­ecules in the asymmetric unit. The absolute configuration was inferred from the use of d-erythrono­lactone as the starting material

    Reviews

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    The following publications have been reviewed by the mentioned authors;Design Assignments for GCSE and Standard Grade by Jeff Nocholls, reviewed by Bob BoothDesign and Communication for Foundation Courses by Peter Gowers, reviewed by Peter ToftThe Celtic Art Source Book by Courtney Davis, reviewed by Rosemary BoothThe World of Plastics by the British Plastics Federation, reviewed by George RaperIllumination: A Source Book for Modern Calligraphers by Christopher Jarman, reviewed by John LancasterCraft, Design and Technology. Materials: Investigation and Choice. A database for pupil use by David Barles, Simon Powell, Sheila Nelmes and Adrienne Jones, reviewed by David BarlexDesign in Context by Penny Sparke, reviewed by John H. CarswellDesignwise 2 by N. McLean, reviewed by H. G. DentonAirbrushing the Human Form by Andy Charlesworth, reviewed by S. W. GarnerDouglas Scott by Johnathan Glancey, reviewed by K. J. McAule

    Fluorescence imaging detection of nanodomain redox signaling events at organellar contacts

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    This protocol describes how to visualize, detect, and analyze redox signals (oxidative bursts) at the ER-mitochondrial interface. It uses drug-inducible crosslinking to target the genetically encoded glutathione redox sensor Grx1roGFP2 to organellar contact sites to measure local redox changes associated with transient depolarizations of the mitochondrial membrane potential (flickers). The strategy allows imaging of the oxidized to reduced glutathione ratio (GSSG:GSH) in subcellular regions below the diffraction limit with good temporal resolution and minimum phototoxicity. Moreover, the strategy also applies to diverse parameters including pH, H2O2, and Ca2+

    Drone-Based Vegetation Assessment in Arid Ecosystems

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    Proof of long-term vegetation change in arid rangelands is often insufficient to influence policy, even when the change is clear to ecologists. Drones provide a way to collect unbiased evidence of plant spatiotemporal distribution at a dramatically reduced cost for the scales needed in these habitats. Assessment of phytomass spatial distribution by drone has become a routine, but further analysis requires advanced skills in data collection and post-flight processing. Accurate assessment of phytomass temporal change will require protocols to be developed for data collection and analysis. Biodiversity assessment by drone is unreliable, but there is potential for assessing phytomass change within and among taxonomic groups in arid rangelands, by repeatedly sampling areas in which perennial plants have been classified manually
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