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1. Local gate control of Mott metal-insulator transition in a 2D metal-organic framework

Author

Benjamin Lowe, Bernard Field, Jack Hellerstedt, Julian Ceddia, Henry L. Nourse, Ben J. Powell, Nikhil V. Medhekar, and Agustin Schiffrin

Subjects
Science
Abstract

Abstract Electron-electron interactions in materials lead to exotic many-body quantum phenomena, including Mott metal-insulator transitions (MITs), magnetism, quantum spin liquids, and superconductivity. These phases depend on electronic band occupation and can be controlled via the chemical potential. Flat bands in two-dimensional (2D) and layered materials with a kagome lattice enhance electronic correlations. Although theoretically predicted, correlated-electron Mott insulating phases in monolayer 2D metal-organic frameworks (MOFs) with a kagome structure have not yet been realised experimentally. Here, we synthesise a 2D kagome MOF on a 2D insulator. Scanning tunnelling microscopy (STM) and spectroscopy reveal a MOF electronic energy gap of ∼200 meV, consistent with dynamical mean-field theory predictions of a Mott insulator. Combining template-induced (via work function variations of the substrate) and STM probe-induced gating, we locally tune the electron population of the MOF kagome bands and induce Mott MITs. These findings enable technologies based on electrostatic control of many-body quantum phases in 2D MOFs.

Published
2024
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2. Learning Medical Materials From Radiography Images

Author

Carson Molder, Benjamin Lowe, and Justin Zhan

Subjects
computer vision, material analysis, convolutional neural networks, siamese neural networks, image classification, medical imaging, Electronic computers. Computer science, QA75.5-76.95
Abstract

Deep learning models have been shown to be effective for material analysis, a subfield of computer vision, on natural images. In medicine, deep learning systems have been shown to more accurately analyze radiography images than algorithmic approaches and even experts. However, one major roadblock to applying deep learning-based material analysis on radiography images is a lack of material annotations accompanying image sets. To solve this, we first introduce an automated procedure to augment annotated radiography images into a set of material samples. Next, using a novel Siamese neural network that compares material sample pairs, called D-CNN, we demonstrate how to learn a perceptual distance metric between material categories. This system replicates the actions of human annotators by discovering attributes that encode traits that distinguish materials in radiography images. Finally, we update and apply MAC-CNN, a material recognition neural network, to demonstrate this system on a dataset of knee X-rays and brain MRIs with tumors. Experiments show that this system has strong predictive power on these radiography images, achieving 92.8% accuracy at predicting the material present in a local region of an image. Our system also draws interesting parallels between human perception of natural materials and materials in radiography images.

Published
2021
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4. Selective Activation of Aromatic C–H Bonds Catalyzed by Single Gold Atoms at Room Temperature

Author

Benjamin Lowe, Jack Hellerstedt, Adam Matěj, Pingo Mutombo, Dhaneesh Kumar, Martin Ondráček, Pavel Jelinek, and Agustin Schiffrin

Subjects
Colloid and Surface Chemistry, Microscopy, Scanning Tunneling, Temperature, Organometallic Compounds, Gold, General Chemistry, Biochemistry, Catalysis
Abstract

Selective activation and controlled functionalization of C-H bonds in organic molecules is one of the most desirable processes in synthetic chemistry. Despite progress in heterogeneous catalysis using metal surfaces, this goal remains challenging due to the stability of C-H bonds and their ubiquity in precursor molecules, hampering regioselectivity. Here, we examine the interaction between 9,10-dicyanoanthracene (DCA) molecules and Au adatoms on a Ag(111) surface at room temperature (RT). Characterization via low-temperature scanning tunneling microscopy, spectroscopy, and noncontact atomic force microscopy, supported by theoretical calculations, revealed the formation of organometallic DCA-Au-DCA dimers, where C atoms at the ends of the anthracene moieties are bonded covalently to single Au atoms. The formation of this organometallic compound is initiated by a regioselective cleaving of C-H bonds at RT. Hybrid quantum mechanics/molecular mechanics calculations show that this regioselective C-H bond cleaving is enabled by an intermediate metal-organic complex which significantly reduces the dissociation barrier of a specific C-H bond. Harnessing the catalytic activity of single metal atoms, this regioselective on-surface C-H activation reaction at RT offers promising routes for future synthesis of functional organic and organometallic materials.

Published
2022
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5. Direct observation of narrow electronic energy band formation in 2D molecular self-assembly

Author

Jack Hellerstedt, Marina Castelli, Anton Tadich, Antonija Grubišić-Čabo, Dhaneesh Kumar, Benjamin Lowe, Spiro Gicev, Dionysios Potamianos, Maximilian Schnitzenbaumer, Pascal Scigalla, Simiam Ghan, Reinhard Kienberger, Muhammad Usman, Agustin Schiffrin, and Surfaces and Thin Films

Subjects
General Engineering, General Materials Science, Bioengineering, General Chemistry, Atomic and Molecular Physics, and Optics, ddc
Abstract

Surface-supported molecular overlayers have demonstrated versatility as platforms for fundamental research and a broad range of applications, from atomic-scale quantum phenomena to potential for electronic, optoelectronic and catalytic technologies. Here, we report a structural and electronic characterisation of self-assembled magnesium phthalocyanine (MgPc) mono and bilayers on the Ag(100) surface, via low-temperature scanning tunneling microscopy and spectroscopy, angle-resolved photoelectron spectroscopy (ARPES), density functional theory (DFT) and tight-binding (TB) modeling. These crystalline close-packed molecular overlayers consist of a square lattice with a basis composed of a single, flat-adsorbed MgPc molecule. Remarkably, ARPES measurements at room temperature on the monolayer reveal a momentum-resolved, two-dimensional (2D) electronic energy band, 1.27 eV below the Fermi level, with a width of ∼20 meV. This 2D band results from in-plane hybridization of highest occupied molecular orbitals of adjacent, weakly interacting MgPc's, consistent with our TB model and with DFT-derived nearest-neighbor hopping energies. This work opens the door to quantitative characterisation – as well as control and harnessing – of subtle electronic interactions between molecules in functional organic nanofilms.

Published
2022

6. Mesoscopic 2D molecular self-assembly on an insulator

Author

Dhaneesh Kumar, Jack Hellerstedt, Benjamin Lowe, and Agustin Schiffrin

Subjects
Mechanics of Materials, Mechanical Engineering, General Materials Science, Bioengineering, General Chemistry, Electrical and Electronic Engineering
Abstract

Two-dimensional (2D) nanostructures and nanomaterials offer potential for a wide range of technological applications in electronics, optoelectronics, data storage, sensing and catalysis. On-surface molecular self-assembly – where organic molecules act as building blocks and where surfaces play the role of supporting templates – allows for the bottom-up synthesis of such 2D systems with tuneable atomically precise morphologies and tailored electronic properties. These self-assembly protocols are well established on metal surfaces, but remain limited on electronically gapped substrates (insulators, semiconductors). The latter are useful for preventing electronic coupling (that is, hybridization between molecular assembly and underlying surface) and for avoiding quenching of optical processes, necessary for prospective electronic and optoelectronic applications. In particular, molecular self-assembly on surfaces other than weakly interacting metals can be challenging due to substrate reactivity, defects and inhomogeneities, resulting in intricate energy landscapes that limit the growth kinetically and hampers the synthesis of large-area defect-free 2D systems. Here, we demonstrate the self-assembly of a 2D, atomically thin organic molecular film on a model wide bandgap 2D insulator, single-layer hexagonal boron nitride (hBN) on Cu(111). The molecular film consists of flat, aromatic 9,10-di-cyano-anthracene (DCA) molecules. Our low-temperature scanning tunnelling microscopy and spectroscopy measurements revealed mesoscopic (> 100 x 100 nm^2), topographically homogeneous crystalline molecular domains resulting from flat molecular adsorption and noncovalent in-plane cyano-ring bonding, with electronically decoupled molecular orbitals (MOs) lying within the hBN electronic gap. These MOs exhibit an energy level spatial modulation (~300 meV) that follows the moiré work function variation of hBN on Cu(111). This work paves the way for large-area, atomically precise, highly crystalline 2D organic (and metal-organic) nanomaterials on electronically functional wide bandgap insulators.

Published
2023
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7. Estimating the economic value of green water as an approach to foster the virtual green-water trade

Author

Benjamin Lowe, David Oglethorpe, and Yelto Zimmer

Subjects
Rainfall, Atmospheric water, Ecology, Blue water, Economic value of water, General Decision Sciences, Economic water productivity, Water footprint, Global water resources, QH540-549.5, Ecology, Evolution, Behavior and Systematics, Water governance
Abstract

Green water – precipitation that is stored in the soil as moisture and consumed in the production of biomass – provides the main source of water for crop cultivation, pasturelands, forestry, and terrestrial ecosystems. At a local level, green water is land-bound and cannot be easily allocated between uses. However, at the global level, agricultural commodities and their embodied virtual water are traded between countries. This trade typically sees the cultivation of crops in water abundant rainfed locations exported to regions that would otherwise have employed local irrigation resources. The result is a global saving of irrigation water and the negative environmental externalities associated with irrigation. In addition, scarce blue water resources are freed up for other (often higher valued) uses. Here we assess whether there is an economic rationale for the virtual green-water trade and the increased and intentional allocation of crop cultivation to water abundant rainfed locations. We model a realistic case study of maize cultivation on representative farms in 16 major maize producing regions (across four continents) and provide the first spatially variable estimates of the economic value of the green water employed. These economic values are contrasted with the economic value of blue water used for irrigation. We find that the volume of green water employed in the cultivation of maize varies between 409 m3/tonne and 1547 m3/tonne; the estimated economic value of green water varies between $ −0.04 m3 and $0.12 m3. We demonstrate how these economic value estimates can inform crop allocation decisions in favour of green water-based cultivation and inform decisions regarding the intensification and horizontal expansion of rainfed agriculture. In so doing, we aim to provide a further rationale for the green water-based measures that have been identified in the literature as the principal means of providing the additional fresh water needed to address pressing global challenges beyond the case study. Economic and Social Research Council (ESRC): ES/J500215/1. H2020-MSCA-ITN-2018, grant agreement number 814247, Re- TraCE (Realising the Transition to the Circular Economy); H2020- MSCA-RISE-2018, grant agreement number 823967, ProCEedS

Published
2022

8. Manifestation of strongly correlated electrons in a 2D kagome metal-organic framework

Author

Jack Hellerstedt, Bernard Field, Yuefeng Yin, Benjamin Lowe, Dhaneesh Kumar, Nikhil V. Medhekar, and Agustin Schiffrin

Subjects
Condensed Matter - Materials Science, Materials science, Spintronics, Magnetic moment, Strongly Correlated Electrons (cond-mat.str-el), Dirac (software), Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, law.invention, Biomaterials, Condensed Matter - Strongly Correlated Electrons, Chemical physics, law, Electrochemistry, Molecule, Metal-organic framework, Density functional theory, Kondo effect, Scanning tunneling microscope
Abstract

The kagome lattice, whose electronic valence band (VB) structure includes two Dirac bands and one flat band, offers a rich space to realise tuneable topological and strongly correlated electronic phases in two-dimensional (2D) and layered materials. While strong electron correlations have been observed in inorganic kagome crystals, they remain elusive in organic systems. The latter offer versatile synthesis protocols via molecular self-assembly and metal-ligand coordination. Here, we report the synthesis of a 2D metal-organic framework (MOF) where di-cyano-anthracene (DCA) molecules form a kagome arrangement via coordination with copper (Cu) atoms on a silver surface [Ag(111)]. Low-temperature scanning tunnelling spectroscopy revealed Kondo screening--by the Ag(111) conduction electrons--of magnetic moments localised at Cu and DCA sites of the MOF. Density functional theory and mean-field Hubbard modelling show that these local moments emerge from strong interactions between kagome MOF electrons, enabling organic 2D materials as viable platforms for strongly correlated nanoelectronics and spintronics., Main text: 32 pages, 5 figures. Supplementary Information: 51 pages, 20 figures

Published
2021

9. U.S. State-Commissioned Energy Storage Studies: A Case Study of Research and Practice in a Rapidly Evolving Field

Author

Christopher S. Galik, Benjamin Lowe, and Rebecca Widiss

Subjects
Process management, Scope (project management), Renewable Energy, Sustainability and the Environment, Technological change, 020209 energy, Energy (esotericism), Energy Engineering and Power Technology, Timeline, 02 engineering and technology, 021001 nanoscience & nanotechnology, Energy storage, Variety (cybernetics), Transformative learning, 0202 electrical engineering, electronic engineering, information engineering, Business, Electrical and Electronic Engineering, 0210 nano-technology, Pace
Abstract

Energy storage comprises a transformative suite of technologies. Questions remain as to how best to integrate these technologies into existing infrastructure under existing policy and market frameworks. As a result, several U.S. states recently embarked, separately, to investigate the role of energy storage in meeting a variety of objectives. These state studies thus provide a series of natural case studies to assess how energy research is being conducted and incorporated, real-time, into policy. We assess three such state studies—Maryland, Massachusetts, and North Carolina—to compare the origin of each study, the methodological approach used, the findings generated by the study, and the eventual reception by policy-makers and other stakeholders. In each of the three energy storage studies evaluated, we observe the influence of state-commissioned processes in facilitating external information directly into policy deliberations. Though the scope, timeline, output, and ultimate policy implications varied across the three studies reviewed, our findings generally validate the benefits of a collaborative, co-production model of engagement. Given the pace of technological change recently experienced and the continued need to facilitate transformative change in energy systems, we anticipate that co-production models of research-policy engagement will be both increasingly common and relevant in the future.

Published
2021
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10. Validating a minipig model of reversible cerebral demyelination using human diagnostic modalities and electron microscopyResearch in context

Author

Mihai Ancău, Goutam Kumar Tanti, Vicki Marie Butenschoen, Jens Gempt, Igor Yakushev, Stephan Nekolla, Mark Mühlau, Christian Scheunemann, Sebastian Heininger, Benjamin Löwe, Erik Löwe, Silke Baer, Johannes Fischer, Judith Reiser, Sai S. Ayachit, Friederike Liesche-Starnecker, Jürgen Schlegel, Kaspar Matiasek, Martina Schifferer, Jan S. Kirschke, Thomas Misgeld, Tim Lueth, and Bernhard Hemmer

Subjects
In vivo minipig model, Lysophosphatidylcholine, Inflammatory-demyelinating brain disease, PET/MRI, Scanning electron microscopy, Electromagnetic-guided navigation system, Medicine, Medicine (General), R5-920
Abstract

Summary: Background: Inflammatory demyelinating diseases of the central nervous system, such as multiple sclerosis, are significant sources of morbidity in young adults despite therapeutic advances. Current murine models of remyelination have limited applicability due to the low white matter content of their brains, which restricts the spatial resolution of diagnostic imaging. Large animal models might be more suitable but pose significant technological, ethical and logistical challenges. Methods: We induced targeted cerebral demyelinating lesions by serially repeated injections of lysophosphatidylcholine in the minipig brain. Lesions were amenable to follow-up using the same clinical imaging modalities (3T magnetic resonance imaging, 11C-PIB positron emission tomography) and standard histopathology protocols as for human diagnostics (myelin, glia and neuronal cell markers), as well as electron microscopy (EM), to compare against biopsy data from two patients. Findings: We demonstrate controlled, clinically unapparent, reversible and multimodally trackable brain white matter demyelination in a large animal model. De-/remyelination dynamics were slower than reported for rodent models and paralleled by a degree of secondary axonal pathology. Regression modelling of ultrastructural parameters (g-ratio, axon thickness) predicted EM features of cerebral de- and remyelination in human data. Interpretation: We validated our minipig model of demyelinating brain diseases by employing human diagnostic tools and comparing it with biopsy data from patients with cerebral demyelination. Funding: This work was supported by the DFG under Germany's Excellence Strategy within the framework of the Munich Cluster for Systems Neurology (EXC 2145 SyNergy, ID 390857198) and TRR 274/1 2020, 408885537 (projects B03 and Z01).

Published
2024
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11. Photochemical Creation of Covalent Organic 2D Monolayer Objects in Defined Shapes via a Lithographic 2D Polymerization

Author

Miroslav Položij, Tobias Schwarz, Marco Servalli, Thomas Heine, Renato Zenobi, Kerstin Thorwarth, A. Dieter Schlüter, Li-Qing Zheng, Agnieszka Kuc, Andreas Borgschulte, Kemal Celebi, Benjamin Lowe, and Payam Payamyar

Subjects
Anthracene, Materials science, General Engineering, General Physics and Astronomy, Self-assembled monolayer, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Photochemistry, Excimer, 01 natural sciences, Fluorescence spectroscopy, 0104 chemical sciences, chemistry.chemical_compound, Monomer, chemistry, Polymerization, Covalent bond, Monolayer, General Materials Science, 0210 nano-technology
Abstract

In this work we prepare Langmuir-Blodgett monolayers with a trifunctional amphiphilic anthraphane monomer. Upon spreading at the air/water interface, the monomers self-assemble into 1 nm-thin monolayer islands, which are highly fluorescent and can be visualized by the naked eye upon excitation. In situ fluorescence spectroscopy indicates that in the monolayers, all the anthracene units of the monomers are stacked face-to-face forming excimer pairs, whereas at the edges of the monolayers, free anthracenes are present acting as edge groups. Irradiation of the monolayer triggers [4 + 4]-cycloadditions among the excimer pairs, effectively resulting in a two-dimensional (2D) polymerization. The polymerization reaction also completely quenches the fluorescence, allowing to draw patterns on the monomer monolayers. More interestingly, after transferring the monomer monolayer on a solid substrate, by employing masks or the laser of a confocal scanning microscope, it is possible to arbitrarily select the parts of the monolayer that one wants to polymerize. The unpolymerized regions can then be washed away from the substrate, leaving 2D macromolecular monolayer objects of the desired shape. This photolithographic process employs 2D polymerizations and affords 1 nm-thin coatings.

Published
2018

12. Molecular dynamics simulation of potentiometric sensor response: the effect of biomolecules, surface morphology and surface charge

Author

Toshiya Sakata, Benjamin Lowe, Nicolas G. Green, Chris-Kriton Skylaris, and Yasushi Shibuta

Subjects
chemistry.chemical_classification, Materials science, Biomolecule, Potentiometric titration, Nanotechnology, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Molecular dynamics, chemistry, Electric field, Potentiometric sensor, General Materials Science, Electric potential, Surface charge, 0210 nano-technology, Biosensor
Abstract

The silica–water interface is critical to many modern technologies in chemical engineering and biosensing. One technology used commonly in biosensors, the potentiometric sensor, operates by measuring the changes in electric potential due to changes in the interfacial electric field. Predictive modelling of this response caused by surface binding of biomolecules remains highly challenging. In this work, through the most extensive molecular dynamics simulation of the silica–water interfacial potential and electric field to date, we report a novel prediction and explanation of the effects of nano-morphology on sensor response. Amorphous silica demonstrated a larger potentiometric response than an equivalent crystalline silica model due to increased sodium adsorption, in agreement with experiments showing improved sensor response with nano-texturing. We provide proof-of-concept that molecular dynamics can be used as a complementary tool for potentiometric biosensor response prediction. Effects that are conventionally neglected, such as surface morphology, water polarisation, biomolecule dynamics and finite-size effects, are explicitly modelled.

Published
2018

13. Calculation of surface potentials of the silica-water interface using molecular dynamics: challenges and opportunities

Author

Toshiya Sakata, Nicolas G. Green, Yasushi Shibuta, Benjamin Lowe, and Chris-Kriton Skylaris

Subjects
chemistry.chemical_classification, Materials science, Physics and Astronomy (miscellaneous), Biomolecule, Transistor, General Engineering, General Physics and Astronomy, Charge density, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, law.invention, High surface, Molecular dynamics, chemistry, Chemical physics, law, Electric field, Surface charge, 0210 nano-technology
Abstract

Continuum-based methods are important in calculating electrostatic properties of interfacial systems such as the electric field and surface potential but are incapable of providing sufficient insight into a range of fundamentally and technologically important phenomena which occur at atomistic length-scales. In this work a molecular dynamics methodology is presented for interfacial electric field and potential calculations. The silica–water interface was chosen as an example system, which is highly relevant for understanding the response of field-effect transistors sensors (FET sensors). Detailed validation work is presented, followed by the simulated surface charge/surface potential relationship. This showed good agreement with experiment at low surface charge density but at high surface charge density the results highlighted challenges presented by an atomistic definition of the surface potential. This methodology will be used to investigate the effect of surface morphology and biomolecule addition; both factors which are challenging using conventional continuum models.

Published
2018

14. Correction to Photochemical Creation of Covalent Organic 2D Monolayer Objects in Defined Shapes via a Lithographic 2D Polymerization

Author

Li-Qing Zheng, Tobias Schwarz, Renato Zenobi, Payam Payamyar, Marco Servalli, Thomas Heine, A. Dieter Schlüter, Benjamin Lowe, Agnieszka Kuc, Andreas Borgschulte, Kemal Celebi, Miroslav Položij, and Kerstin Thorwarth

Subjects
Materials science, Polymerization, Covalent bond, Monolayer, General Engineering, General Physics and Astronomy, General Materials Science, Photochemistry, Lithography
Published
2019
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16. To be a Red-Blooded American Boy

Author

Mark H. Payne and Benjamin Lowe

Subjects
History, Literature and Literary Theory, Arts and Humanities (miscellaneous), media_common.quotation_subject, Art, media_common
Published
1974
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20. Acid-base dissociation mechanisms and energetics at the silica–water interface: An activationless process

Author

Benjamin Lowe, Chris-Kriton Skylaris, and Nicolas G. Green

Subjects
Proton binding, Grotthuss, Protonation, Photochemistry, DFT, Dissociation (chemistry), Proton transfer, Ion, Biomaterials, chemistry.chemical_compound, Colloid and Surface Chemistry, Deprotonation, ONETEP, Computational chemistry, Molecule, Surface charge, Proton holes, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Surface charging, Silanol, chemistry, AIMD, Surface acidity
Abstract

Hypothesis: Silanol groups at the silica–water interface determine not only the surface charge, but also have an important role in the binding of ions and biomolecules. As the pH is increased above pH 2, the silica surface develops a net negative charge primarily due to deprotonation of the silanol group. An improved understanding of the energetics and mechanisms of this fundamentally important process would further understanding of the relevant dynamics. Simulations: Density Functional Theory ab initio molecular dynamics and geometry optimisations were used to investigate the mechanisms of surface neutralisation and charging in the presence of OH- and H3O+ respectively. This charging mechanism has received little attention in the literature.Findings: The protonation or deprotonation of isolated silanols in the presence of H3O+ or OH-, respectively, was shown to be a highly rapid, exothermic reaction with no significant activation energy. This process occurred via a concerted motion of the protons through ‘water wires’. Geometry optimisations of large water clusters at the silica surface demonstrated proton transfer to the surface occurring via the rarely discussed ‘proton holes’ mechanism. This indicates that surface protonation is possible even when the hydronium ion is distant (at least 4 water molecules separation) from the surface.

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21. Four-dimensional positron age-momentum correlation

Author

Ulrich Ackermann, Benjamin Löwe, Marcel Dickmann, Johannes Mitteneder, Peter Sperr, Werner Egger, Markus Reiner, and Günther Dollinger

Subjects
4D-AMOC, positron annihilation, CDBS, 2D-ACAR, PALS, AMOC, Science, Physics, QC1-999
Abstract

We have performed first four-dimensional age-momentum correlation (4D-AMOC) measurements at a pulsed high intensity positron micro beam and determined the absolute value of the three-dimensional momentum of the electrons annihilating with the positrons in coincidence with the positron age in the sample material. We operated two position sensitive detectors in coincidence to measure the annihilation radiation: a pixelated HPGe-detector and a microchannel plate image intensifier with a CeBr _3 scintillator pixel array. The transversal momentum resolution of the 4D-AMOC setup was measured to be about 17 × 10 ^−3 ${m}_{0}c$ (FWHM) and was circa 3.5 times larger than the longitudinal momentum resolution. The total time resolution was 540 ps (FWHM). We measured two samples: a gold foil and a carbon tape at a positron implantation energy of 2 keV. For each sample discrete electron momentum states and their respective positron lifetimes were extracted.

Published
2016
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23. Effect of hydrocortisone on mortality and organ support in patients with severe COVID-19

Author

Angus, Derek, Derde, Lennie, Al-Beidh, Farah, Annane, Djillali, Arabi, Yaseen, Beane, Abigail, van Bentum-Puijk, Wilma, Berry, Lindsay, Bhimani, Zahra, Bonten, Marc, Bradbury, Charlotte, Brunkhorst, Frank, Buxton, Meredith, Buzgau, Adrian, Cheng, Allen, de Jong, Menno, Detry, Michelle, Estcourt, Lise, Fitzgerald, Mark, Goossens, Herman, Green, Cameron, Haniffa, Rashan, Higgins, Alisa, Horvat, Christopher, Hullegie, Sebastiaan, Kruger, Peter, Lamontagne, Francois, Lawler, Patrick, Linstrum, Kelsey, Litton, Edward, Lorenzi, Elizabeth, Marshall, John, Mcauley, Daniel, Mcglothin, Anna, Mcguinness, Shay, Mcverry, Bryan, Montgomery, Stephanie, Mouncey, Paul, Murthy, Srinivas, Nichol, Alistair, Parke, Rachael, Parker, Jane, Rowan, Kathryn, Sanil, Ashish, Santos, Marlene, Saunders, Christina, Seymour, Christopher, Turner, Anne, van de Veerdonk, Frank, Venkatesh, Balasubramanian, Zarychanski, Ryan, Berry, Scott, Lewis, Roger, Mcarthur, Colin, Webb, Steven, Gordon, Anthony, NIHR, Hôpital Raymond Poincaré [AP-HP], Writing Committee for the REMAP-CAP Investigators, Farah Al-Beidh, Derek Angus, Djillali Annane, Yaseen Arabi, Wilma van Bentum-Puijk, Scott Berry, Abigail Beane, Zahra Bhimani, Marc Bonten, Charlotte Bradbury, Frank Brunkhorst, Meredith Buxton, Allen Cheng, Menno De Jong, Lennie Derde, Lise Estcourt, Herman Goossens, Anthony Gordon, Cameron Green, Rashan Haniffa, Francois Lamontagne, Patrick Lawler, Edward Litton, John Marshall, Colin McArthur, Daniel McAuley, Shay McGuinness, Bryan McVerry, Stephanie Montgomery, Paul Mouncey, Srinivas Murthy, Alistair Nichol, Rachael Parke, Kathryn Rowan, Christopher Seymour, Anne Turner, Frank van de Veerdonk, Steve Webb, Ryan Zarychanski, Lewis Campbell, Andrew Forbes, David Gattas, Stephane Heritier, Lisa Higgins, Peter Kruger, Sandra Peake, Jeffrey Presneill, Ian Seppelt, Tony Trapani, Paul Young, Sean Bagshaw, Nick Daneman, Niall Ferguson, Cheryl Misak, Marlene Santos, Sebastiaan Hullegie, Mathias Pletz, Gernot Rohde, Kathy Rowan, Brian Alexander, Kim Basile, Timothy Girard, Christopher Horvat, David Huang, Kelsey Linstrum, Jennifer Vates, Richard Beasley, Robert Fowler, Steve McGloughlin, Susan Morpeth, David Paterson, Bala Venkatesh, Tim Uyeki, Kenneth Baillie, Eamon Duffy, Rob Fowler, Thomas Hills, Katrina Orr, Asad Patanwala, Steve Tong, Mihai Netea, Shilesh Bihari, Marc Carrier, Dean Fergusson, Ewan Goligher, Ghady Haidar, Beverley Hunt, Anand Kumar, Mike Laffan, Patrick Lawless, Sylvain Lother, Peter McCallum, Saskia Middeldopr, Zoe McQuilten, Matthew Neal, John Pasi, Roger Schutgens, Simon Stanworth, Alexis Turgeon, Alexandra Weissman, Neill Adhikari, Matthew Anstey, Emily Brant, Angelique de Man, Francois Lamonagne, Marie-Helene Masse, Andrew Udy, Donald Arnold, Phillipe Begin, Richard Charlewood, Michael Chasse, Mark Coyne, Jamie Cooper, James Daly, Iain Gosbell, Heli Harvala-Simmonds, Tom Hills, Sheila MacLennan, David Menon, John McDyer, Nicole Pridee, David Roberts, Manu Shankar-Hari, Helen Thomas, Alan Tinmouth, Darrell Triulzi, Tim Walsh, Erica Wood, Carolyn Calfee, Cecilia O’Kane, Murali Shyamsundar, Pratik Sinha, Taylor Thompson, Ian Young, Shailesh Bihari, Carol Hodgson, John Laffey, Danny McAuley, Neil Orford, Ary Neto, Michelle Detry, Mark Fitzgerald, Roger Lewis, Anna McGlothlin, Ashish Sanil, Christina Saunders, Lindsay Berry, Elizabeth Lorenzi, Eliza Miller, Vanessa Singh, Claire Zammit, Wilma van Bentum Puijk, Wietske Bouwman, Yara Mangindaan, Lorraine Parker, Svenja Peters, Ilse Rietveld, Kik Raymakers, Radhika Ganpat, Nicole Brillinger, Rene Markgraf, Kate Ainscough, Kathy Brickell, Aisha Anjum, Janis-Best Lane, Alvin Richards-Belle, Michelle Saull, Daisy Wiley, Julian Bion, Jason Connor, Simon Gates, Victoria Manax, Tom van der Poll, John Reynolds, Marloes van Beurden, Evelien Effelaar, Joost Schotsman, Craig Boyd, Cain Harland, Audrey Shearer, Jess Wren, Giles Clermont, William Garrard, Kyle Kalchthaler, Andrew King, Daniel Ricketts, Salim Malakoutis, Oscar Marroquin, Edvin Music, Kevin Quinn, Heidi Cate, Karen Pearson, Joanne Collins, Jane Hanson, Penny Williams, Shane Jackson, Adeeba Asghar, Sarah Dyas, Mihaela Sutu, Sheenagh Murphy, Dawn Williamson, Nhlanhla Mguni, Alison Potter, David Porter, Jayne Goodwin, Clare Rook, Susie Harrison, Hannah Williams, Hilary Campbell, Kaatje Lomme, James Williamson, Jonathan Sheffield, Willian van’t Hoff, Phobe McCracken, Meredith Young, Jasmin Board, Emma Mart, Cameron Knott, Julie Smith, Catherine Boschert, Julia Affleck, Mahesh Ramanan, Ramsy D’Souza, Kelsey Pateman, Arif Shakih, Winston Cheung, Mark Kol, Helen Wong, Asim Shah, Atul Wagh, Joanne Simpson, Graeme Duke, Peter Chan, Brittney Cartner, Stephanie Hunter, Russell Laver, Tapaswi Shrestha, Adrian Regli, Annamaria Pellicano, James McCullough, Mandy Tallott, Nikhil Kumar, Rakshit Panwar, Gail Brinkerhoff, Cassandra Koppen, Federica Cazzola, Matthew Brain, Sarah Mineall, Roy Fischer, Vishwanath Biradar, Natalie Soar, Hayden White, Kristen 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Ferguson, Katharine Sellers, Joanne Bradley-Potts, David Yates, Isobel Birkinshaw, Kay Kell, Nicola Marshall, Lisa Carr-Knott, Charlotte Summers, and Mégarbane, Bruno

Subjects
[SDV.MHEP.ME] Life Sciences [q-bio]/Human health and pathology/Emerging diseases, [SDV.MHEP.ME]Life Sciences [q-bio]/Human health and pathology/Emerging diseases, General Medicine, [SDV.MHEP.PSR]Life Sciences [q-bio]/Human health and pathology/Pulmonology and respiratory tract, Writing Committee for the REMAP-CAP Investigators, [SDV.MHEP.CSC] Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, [SDV.TOX] Life Sciences [q-bio]/Toxicology, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, [SDV.TOX]Life Sciences [q-bio]/Toxicology, General & Internal Medicine, [SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases, [SDV.MHEP.PSR] Life Sciences [q-bio]/Human health and pathology/Pulmonology and respiratory tract, 11 Medical and Health Sciences
Abstract

Importance Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures The primary end point was organ support–free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned –1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support–free days were 0 (IQR, –1 to 15), 0 (IQR, –1 to 13), and 0 (–1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support–free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support–free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions.

Published
2020
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