922017 research outputs found
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Perspective - Formate as a key intermediate in CCU
No full textReplacing fossil feedstocks for chemicals and polymers in the chemical industry is a key step towards a future circular society. Making use of CO2 as a starting material in Carbon Capture and Utilization (CCU) or Carbon Capture and Storage (CCS) processes presents a great opportunity. Unfortunately, converting CO2 is not easy - due to its stability and inherently low reactivity either high energy inputs or nifty catalytic systems are required for its conversion. An electrochemical cell using a gas-diffusion electrode to convert CO2 into formate is such a promising system. But making formate alone does not allow us to substitute many fossil carbon-fed processes. Oxalic acid on the other hand is a potential new platform chemical for material production as useful monomers such as glycolic acid can be derived from it. Fortunately, formate can be converted into oxalate (and subsequently oxalic acid) by coupling two formates in a formate to oxalate coupling reaction (FOCR). The FOCR is a reaction that has been studied for more than 175 years and has seen widespread industrial use in the past. In this work, we critically discuss the history of the FOCR, present the most recent advances and draw a perspective for its future. We provide an overview of all (side)products obtained in FOCR and examine the various reaction parameters and their ability to influence the reaction. To understand the reaction better and improve it in the future, we critically discuss the many mechanisms proposed for the various catalytic systems in the FOCR. At last, we explore the potential to introduce new catalytic and solvent systems or co-reactants to the FOCR to improve reaction performance and broaden the range of products from CO2 derived formate
Legitimacy, Power, and Aesthetics, in the International Baccalaureate
No full textThis paper explores the facilitation of the emancipatory in an International Baccalaureate (IB) context of privilege. It aligns with the idea that capitalism, even in welfare state democracies or ‘do good’ corporations, maintains the interests of the owners of capital. It is by nature unjust and exploitative and must conceal this injustice by securing a (spurious) legitimacy for itself (Edgar, 2006, p. 88). This makes a rare methodological contribution as the article provides critical ‘meta-analysis’ (Card, 2015) of IB research literature by prioritising work that affords insight into the lived reality within the IB-Sphere. It then triangulates this analysis through the work of German Social Philosopher Jürgen Habermas (1970; 1981; 1983; 1989; 1991).This work provides a significant and timely contribution to ‘franchised education’ (Apple, 2000; Ball, 2012) in the 21st Century, and will be of essential reading to scholars, policy makers and leadership whether involved in the IB, or active in the Neo Liberal spaces of education more generally: such as Multi Trust Academies, Free Schools, or Charter Schools. This is thanks to the lessons learned over nearly 60 years of educational franchise in a diverse and globalising sphere as presented here from IB research through critical analysis. <br/
Unintended consequences of patient online access to health records: a qualitative study in UK primary care
No full textEndoscopic surveillance alone is feasible and safe in type I gastric neuroendocrine neoplasms less than 10mm in diameter
No full textPurposeType I gastric neuroendocrine neoplasms (g-NENs) have a low risk of metastasis and a generally favourable prognosis. Patients with small type I g-NENs (≤10mm) frequently require no treatment, whereas those with larger polyps usually undergo resection. We evaluated the safety and outcomes of endoscopic surveillance after no initial treatment in selected patients with type I g-NENs.MethodsRetrospective analysis of type I g-NEN patients across two European Neuroendocrine Tumour Society Centers of Excellence 2003-2019.ResultsFollowing initial assessment, 87 of 115 patients with type I g-NEN (75 with polyps ≤10mm) received no initial treatment and underwent endoscopic surveillance. 79/87 (91%) demonstrated no clinically meaningful change in tumour size or grade over a median 62 month follow up. Only two patients developed NEN progression that required a change in management and two other patients developed gastric adenocarcinoma/high grade dysplasia; all four initially had ≥11mm g-NENs.ConclusionsPatients with ≤10mm type I g-NENs were unlikely to develop clinically significant tumour progression and in most cases, resection was not needed. The endoscopic surveillance interval could therefore potentially be safely increased to every 2-3 years in such patients. However, lifelong surveillance is still advocated due to the additional risk of developing gastric adenocarcinoma
The interaction of multiple bubbles in a Hele-Shaw channel
No full textWe study the dynamics of two air bubbles driven by the motion of a suspending viscous fluid in a Hele-Shaw channel with a small elevation along its centreline via physical experiment and numerical simulation of a depth-averagedmodel. For a single-bubble systemwe establish that, in general, bubble propagation speed monotonically increases with bubble volume so that two bubbles of different sizes, in the absence of any hydrodynamic interactions, will either coalesce or separate in a finite time. However our experiments indicate that the bubbles interact and that an unstable two-bubble state is responsible for the eventual dynamical outcome: coalescence or separation. These results motivate us to develop an edge-tracking routine and calculate these weakly unstable two-bubble steady states from the governing equations. The steady states consist of pairs of ‘aligned’ bubbles that appear on the same side of the centreline with the larger bubble leading. We also discover, through time-dependent simulations and physical experiment, another class of two-bubble states that, surprisingly, are stable. In contrast to the ‘aligned’ steady states, these bubbles appear on either side of the centreline and are ‘offset’ from each other. We calculate the bifurcation structures of both classes of steady states as the flow-rate and bubble volume ratio is varied. We find that they exhibit intriguing similarities to the single-bubble bifurcation structure, which has implications for the existence of =-bubble steady states
Synthesis and characterisation of an integratively self-sorted [Fe<sub>4</sub>L<sub>6</sub>]<sup>8+</sup> tetrahedron
No full textIsolating metal-organic cage structures which incorporate more than one distinct ligand has been challenging due to competing pressures from narcissistic and social sorting phenomena. Here we report the first example of exclusive formation of a single tetrahedral product from a reaction mixture containing two different bidentate ligands. Exclusive formation of the tetrahedron, which incorporates one unique metal vertex, relies on a triamine to orientate the heteroditopic ligand. Inclusion of perchlorate counterions during the self-assembly process is also found to be a requirement if social sorting is to be avoided. The C3-symmetric structure is characterised by HR-MS, NMR spectroscopy and X-ray crystallography, and provides proof of principle for use of heteroditopic ligands in classical M4L6 supramolecular structures, opening exciting possibilities for their use in separation, storage and catalysis applications
Filament Formation via Collision-induced Magnetic Reconnection – Formation of a Star Cluster
No full textA collision-induced magnetic reconnection (CMR) mechanism was recently proposed to explain the formation of a filament in the Orion A molecular cloud. In this mechanism, a collision between two clouds with antiparallel magnetic fields produces a dense filament due to the magnetic tension of the reconnected fields. The filament contains fiber-like sub-structures and is confined by a helical magnetic field. To show whether the dense filament is capable of forming stars, we use the Arepo code with sink particles to model star formation following the formation of the CMR-filament. First, the CMR-filament formation is confirmed with Arepo. Second, the filament is able to form a star cluster after it collapses along its main axis. Compared to the control model without magnetic fields, the CMR model shows two distinctive features. First, the CMR-cluster is confined to a factor of ∼ 4 smaller volume. The confinement is due to the combination of the helical field and gravity. Second, the CMR model has a factor of ∼ 2 lower star formation rate. The slower star formation is again due to the surface helical field that hinders gas inflow from larger scales. Mass is only supplied to the accreting cluster through streamers
Characterisation of C101248: a novel selective THIK-1 channel inhibitor for the modulation of microglial NLRP3-inflammasome
No full textNeuroinflammation, specifically the NLRP3 inflammasome cascade, is a common underlying pathological feature of many neurodegenerative diseases. Evidence suggests that NLRP3 activation involves changes in intracellular K+. Nuclear Enriched Transcript Sort Sequencing (NETSseq), which allows for deep sequencing of purified cell types from human post-mortem brain tissue, demonstrated a highly specific expression of the tandem pore domain halothane-inhibited K+ channel 1 (THIK-1) in microglia compared to other glial and neuronal cell types in the human brain. NETSseq also showed a significant increase of THIK-1 in microglia isolated from cortical regions of brains with Alzheimer’s disease (AD) relative to control donors. Herein, we report the discovery and pharmacological characterisation of C101248, the first selective small-molecule inhibitor of THIK-1. C101248 showed a concentration-dependent inhibition of both mouse and human THIK-1 (IC50: ~50 nM) and was inactive against K2P family members TREK-1 and TWIK-2, and Kv2.1. Whole-cell patch-clamp recordings of microglia from mouse hippocampal slices showed that C101248 potently blocked both tonic and ATP-evoked THIK-1 K+ currents. Notably, C101248 had no effect on other constitutively active resting conductance in slices from THIK-1-depleted mice. In isolated microglia, C101248 prevented NLRP3-dependent release of IL-1β, an effect not seen in THIK-1-depleted microglia.In conclusion, we demonstrated that inhibiting THIK-1 (a microglia specific gene that is upregulated in brains from donors with AD) using a novel selective modulator attenuates the NLRP3-dependent release of IL-1β from microglia, which suggests that this channel may be a potential therapeutic target for the modulation of neuroinflammation in AD
Writing and Reading Together from Colonial Legacy to World-making:The case of Algerian bilingual authors
No full textKateb Yacine told Geneviève Serreau in 1956 that one does not use a universal language to humiliate a people in its very soul without consequences: sooner or later, the people seize that language and culture for themselves on their way towards freedom. Following this prophecy, Algerian intellectuals have in effect appropriated the French language, which they deploy with a high level of proficiency to address the colonizer in its own language. However, with decolonization, the French language was probed as a legacy of colonialism and an obstacle to Algerian self-realization and cultural authenticity. Algerian governments implemented a top-down Arabization policy, excluding national differences and subscribing wholly to the group of Arab nations. This process alienated those who did not read or speak Arabic in a country that is essentially comprised of a multiplicity of languages, cultures, and identities. This article delves into this bitter polemic as a painstaking search for national identity. It traces the position of the French language in the Algerian intellectual and literary landscape, from an initial gesture of rejection to a later move toward appropriation and nativization
How Cosmic Rays Mediate the Evolution of the Interstellar Medium
No full textWe explore the impact of diffusive cosmic rays (CRs) on the evolution of the interstellar medium (ISM) under varying assumptions of supernova explosion environment. In practice, we systematically vary the relative fractions of supernovae (SN) occurring in star-forming high-density gas and those occurring in random locations decoupled from star-forming gas to account for SN from run-away stars or explosions in regions that have been cleared by prior SN, stellar winds, or radiation. We explore various mixed models by adjusting these fractions relative to each other. We find that in the simple system of a periodic stratified gas layer the ISM structure will evolve to one of two solutions: a "peak driving" state where warm gas is volume filling or a "thermal runaway" state where hot gas is volume filling. CR pressure and transport are important factors that strongly influence the solution state the ISM reaches and have the ability to flip the ISM between solutions. Observable signatures such as gamma ray emission and HI gas are explored. We find that gamma ray luminosity from pion decay is largely consistent with observations for a range of model parameters. The thickness of the HI gas layer may be too compact, however, this may be due to a large cold neutral fraction of midplane gas. The volume fraction of hot gas evolves to stable states in both solutions, but neither settles to a Milky Way-like configuration, suggesting that additional physics which is omitted here (e.g. a cosmological circum-galactic medium, radiation transport, or spectrally resolved and spatially varying CR transport) may be required